Table of contents

The 6th International Conference on Hydraulic and Civil Engineering (ICHCE 2020) is hosted by Shaanxi Society of Geometics and Engineering, Xi'an University of Architecture and Technology, xijing university, Shaanxi Key Laboratory of geotechnical and underground space engineering and Youth Working Committee of shaanxi Institute of Geometics and Engineering, co-organized Xi'an University of Technology, Xi'an Jiaotong University, Hehai University, Chongqing Jiaotong University, Northwest A & F University, Chang'an University, Xi'an University of science and technology, Anhui Jianzhu University, Xi'an University of Technology, Education Committee of the Society of Geomethrology and Engineering of Shaanxi Province, Yulin College, Northern University of Technology, Xi'an Petroleum University, China First Highway Survey and Design Research Institute Co., Ltd, China Power Engineering Consultants Northwest Power Design Institute, Xi'an Research Institute, China Coal Science and Technology Group, China Railway First Survey and Design Institute, Northwest Survey and Design Research Institute of China Hydropower Consulting Group. The conference was successfully held during December 11th to 13th, 2020 at Xi'an China. It mainly focused on the research fields of water conservancy and civil engineering, and is dedicated to provide the experts, scholars, engineers, etc. from different colleges and universities, research institutes, enterprises and institutions from home and abroad, with an academic platform for sharing of academic research findings, exploration of the cutting-edge engineering issues and discussion on the current opportunities and challenges, in a concerted effort to promote international cooperation and communication and the industrialization of scientific research results.

The conference model was divided into two sessions, including oral presentations and keynote speeches. In the first part, some scholars, whose submissions were selected as the excellent papers, were given 15 minutes to perform their oral presentations one by one. Then in the second part, keynote speakers were each allocated 30-45 minutes to hold their speeches.

There were over 130 experts and scholars in the area of Hydraulic and Civil Engineering representing different famous universities and institutes around the globe to attend the conference. During the conference, we were pleased to invite six distinguished experts to present their insightful speeches. Jianping Zhou, Chief engineer of China Power Construction Group Co., Ltd. His report title: Current situation and future development trend of hydropower in the world. Hongwei Wu, Associate vice president, Hong Kong University of science and technology, held a speech: Theory and technology of vegetation slope protection based on unsaturated soil mechanics. Chongshi Gu, Dean of School of water conservancy and hydropower, Hohai University, shared a speech on his specialty related to Theory and method of disease mechanism and health diagnosis of major water projects. Shengshui Chen, President of Nanjing Institute of water resources, talked about Key technical problems and Countermeasures of Dashixia extra high concrete face sand gravel dam. The others keynote speakers, Prof. Deyi Wu from Anhui Jianzhu University and Prof. Liaojun Zhang from Hohai University also presented a wonderful speech.

The participants of the conference were from most part of the world, with background of either academia or industry, even well-known enterprise. The success and prosperity of the conference is reflected high level of the papers received. The proceedings are a compilation of the accepted papers and represent an interesting outcome of the conference. (ICHCE 2020) for exchange of research findings, analysis, information, and knowledge in areas which include but are not limited to: Water Project, Civil Engineering, Geotechnical Engineering, Traffic and Bridge Engineering, Disaster Prevention and Mitigation and Protection Engineering and other related topics.

We would like to acknowledge all of those who supported ICHCE 2020. Each individual and institutional help were very important for the success of this conference. Especially we would like to thank the organizing committee for their valuable advices in the organization and helpful peer review of the papers. We sincerely hope that ICHCE 2020 will be a forum for excellent discussions that will put forward new ideas and promote collaborative researches. We are sure that the proceedings will serve as an important research source of references and the knowledge, which will lead to not only scientific and engineering progress but also other new products and processes.

The Organizing Committee of ICHCE 2020

List of Committee member are avalible in the pdf.

All papers published in this volume of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

• Type of peer review: Double-blind

• Conference submission management system: AI Scholar Submission System

• Number of submissions received: 292

• Number of submissions sent for review: 275

• Number of submissions accepted: 190

• Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100): 65.1%

• Average number of reviews per paper: 2

• Total number of reviewers involved: 130

• Any additional info on review process:

• Step 1. Each of the selected papers should be reviewed by two or three experts who are professional in the related area. A report of the reviewing result will come out by each expert.

• Step 2. After collecting the reviewing reports from the experts, one of the editors will review the reports and decide whether the reports are approved.

• Step 3. After that, the editors inform the authors of the reviewing results along with the three reviewing reports.

• Step 4. Authors are required to revise their paper according to the requirements, then hand in the revised version to the editors. The editors send the revised version to reviewers and will decide whether the paper is approved to be published according to the reviewers' final reports. And at last the editors inform the decision with every details of the publication requirements if the paper is accepted.

• Contact person for queries: Yongkang Xing, Chongqing University, ykxing@cqu.edu.cn

In view of the influence of temperature on the construction of PC slab stiffened beam suspension bridge, combined with the Moon Bay Bridge, the finite element software Midas Civil is used to conduct a static analysis of the Moon Bay Bridge under temperature. The calculation results can be similar to the bridge construction Provide reference, there is a certain reference significance.

Sponge city is a new urban stormwater management concept proposed by China to solve the urban water environment and security problems. The stormwater management model (SWMM) is one of the most commonly used urban stormwater and sponge city simulation models. SWMM is coupled with a two-dimensional hydrodynamic model based on the finite volume method to establish a coupled 1D and 2D hydrodynamic model in this research. The coupled model can simulate the drainage pipe network, sponge measures and flood inundation at the same time. A predictor-corrector method with good stability was used in the coupled model to ensure the non-negativity of the water volume of the 2D model cell. The sponge city construction scheme for a community in Beijing was simulated and analyzed using several design rainstorm processes with different return periods based on the proposed model. It is proved that the coupling model can be applied to sponge city construction problems and sponge measures can reduce the flood inundation and the load of drainage network system by simulating the drainage conditions and ground waterlogging before and after the reconstruction of the drainage community.

An improved borehole shear test (BST) instrument was utilized to obtain the shear strength index of the soil layer in-situ. The results show that the shear strength index of the saturated silty clay measured by the improved borehole shear apparatus has a good linear correlation with the normal pressure, and the correlation coefficient can be greater than 0.98. The testing results were also compared with those obtained by the direct shear test (DST) in the laboratory. It was found that when the soil layer has a depth of less than 8.75m, the difference in the internal friction angle by the BST and DST is small. The former is 8%–33% larger than the latter. The deviation in the cohesion is obvious, which ranges from 20% to 61%. For the soil layer deeper than 8.75m, the situation is different. The difference in the cohesion measured by the two methods is small, which ranges from 8% to 9%, while the difference in the internal friction angle is distinct, and reaches 62%–85%.

As the research base damage and water inrush problem, this article obtains from the body micro units, on the basis of seepage of rock mass and rock mechanics theory, considering the heterogeneity of rock, and established the heterogeneity of rock containing random defects of mesoscopic scale on the seepage flow in heterogeneous model by means of FLAC3D simulation software built-in fish language from the model unit randomly in the unit ID number, total group as defects in the model group, while the rest of the unit as a complete set, the different group gives different mechanics parameter values, implement different defect degrees of homogenization model established The results show that the overall bearing capacity of rocks with high defect degree decreases obviously, and the failure of rocks precedes that of intact rocks.

Based on the concept of "building houses on cable-stayed bridges", a 4-storey bridge is set up in the first and second phase of the project, which makes the structural design interpret the architectural concept in a unique structural form. This paper focuses on the selection concept, structural layout, and the analysis of the rigidity, displacement, internal force and bearing capacity of the bridge structure. The experience can be used for reference in similar projects.

Subgrade collapse is a frequent geological hazard all over the world, which seriously threatens safety of human life and economic development. Compared with conventional methods of collapse, employing geotextile basal reinforcement with the features of reinforcement and filtration can achieve better treatment. In this paper, four symmetrical semi-section model tests with different width of collapse treated by geotextile and one full-section model test were carried out. Data acquisition instruments and particle image velocimetry (PIV) equipment were applied to research soil pressure, vertical displacement of filling and tensile force of geotextile. The following results were achieved: the results obtained from symmetric semi-section and full-section model test was proximal so that the symmetrical semi-section model test had certain feasibility; the laying of geotextile basal reinforcement had good effect on collapse treatment; the width of collapse area was an crucial factor affecting the collapse treatment using geotextile and the geotextile with high tensile strength and enough buried depth should be employed when dealing with large scale collapse problems.

The problem of soil hydrothermal balance in farmland system is an important issue to study the formation and change mechanism of farmland climate and microclimate. As an important part of terrestrial ecosystem, the farmland ecosystem has dynamic changes in soil moisture and heat. Due to its particularity, the farmland ecosystem is also a land type directly affected by human activities. This paper systematically summarized the importance of soil hydrothermal interactions in farmland systems, the law of water and heat balance in farmland system and the recent research on the coupling model of hydrothermal balance in farmland system at home and abroad. In addition, this paper also elaborated the research progress of the response of farmland water and heat balance to farmland irrigation, film mulching and other human activities, so as to provide a theoretical basis for the effective use of farmland water resources and the cultivation of high-quality crops in the future.

The effects of basalt fiber volume fraction and fiber length on the tensile properties of concrete are studied by experiments. The mechanism of fiber improving the tensile failure mode of concrete is analyzed. The results show that the tensile properties of BFRC are significantly improved compared with the matrix concrete. The initial crack strength and yield strength increase significantly with the increase of fiber volume fraction, while the initial crack strain and yield strain increase significantly with the increase of fiber length. The roughness coefficient of BFRC fracture surface can be used as the index of fiber improving concrete tensile properties.

In this study, by referring to the existing test data and numerical simulation parameters of Bos, using the compression constitutive relationship of concrete proposed by Thorenfeldt and the tensile constitutive model proposed by Petersson, the numerical simulation of the flexural toughness of steel fiber notched beam by pouring and 3D printing is carried out by using the finite element software ABAQUS, and the load deflection curve is obtained, which is compared with the test curve of BOS to verify The rationality of the research model. Based on the verified model parameters, ABAQUS is used to simulate the four point bending test of steel fiber reinforced 3D printing concrete and plain concrete, focusing on the influence of steel fiber content and notch depth on the load deflection curve.

There are a large number of deep and thick soft soil foundations along the river and coastal areas. PHC pipe piles have become one of the foundation treatment methods widely used in soft soil foundations. Taking the construction of a pile foundation project in Wenzhou as an example, the thickness of the dredger fill and silt at the site is 27.20∼33.60m, and the impact of large-area pile group construction on the surrounding environment is discussed. The results show that: (1) The load imposed on the pile top and the pile sinking depth during the construction of the foundation pile increase according to an exponential function. (2) The direction of horizontal soil squeezing deformation around the field is related to the position of the measuring point. The corner range is small and the middle range is larger, but the direction of maximum displacement is basically along the shortest line between the pile position and the measuring point. (3) The vertical direction of the measuring point varies greatly with the construction time and pile position, and the uplift and settlement appear repeatedly. The monitoring results can provide a reference for the construction of similar projects.

Aggregate property directly affects concrete property. When natural aggregate sources are lacking, artificial aggregates should be considered. The strata in Cambodia are dominated by sedimentary rocks with weaker lithology, which are not suitable for artificial aggregate. The quality of gneiss and limestone is good, but the distribution area is small, so it is not suitable for mass mining. Basalt is widely distributed, and the rock strength is generally high. There are problems such as scattered distribution, poor uniformity, and large property changes. Suitability of basalt artificial aggregate is studied in combination with specific projects. Research works are from outside to inside, from shallower to deeper. Through general survey and primary selection of quarry, surveying and sampling, rock mineral identification and chemical composition analysis, rock physical mechanics test, alkali activity test and aggregate processing property and other analysis tests, its quality indicators and reserves are found out. Studies have shown that quality and reserves of aggregates in the survey yard can meet the needs of the project, mining and transportation are convenient, making it an ideal choice for concrete artificial aggregates. Research methods and results can be used as the reference for similar projects.

Tectonic stress is an important factor influencing the development of joints. The tectonic stress in Jijicao is preliminary analyzed based on joints measurement, structural features tracing and stereographic projection. It is considered that the NW and NE trending tectonic systems in the study area belong to the products of different tectonic processes in different times. After intrusion, Jijicao granite rock mass has been forced in normal fault type stress, and the NW steeply dipping joints under vertical maximum principal stress and horizontal minimum principal stress squeezing on NE generated. Thereafter, the in-plate action is adjusted, and the minimum principal stress is deflected from NE to NW, resulting in a steep inclined joint system with the maximum principal stress nearly perpendicular and the minimum principal stress being subjected to NW horizontal extrusion.

In order to study the stress and deformation characteristics of the high concrete face rockfill dam over 100 meters, in this paper, Duncan-Zhang E-B nonlinear elastic hyperbolic model is adopted, the finite element software COMSOL Multiphysics is used to establish the model and the MATLAB function is used for secondary development to analyze the stress and deformation of the concrete face rockfill dam of the Panshitou reservoir. The stress and deformation characteristics of the concrete face rockfill dam at the completion period, normal water storage condition, designed flood level condition and checked flood level condition are obtained through analysis, which provide theoretical guidance for the construction and operation of the high concrete face rockfill dam of more than 100 meters.

Using the constitutive model of a square CFST column with binding bars, the constrained mechanism of the stiffened square CFST columns is analyzed in great detail. The equivalent constitutive model under uniaxial compression is established for square CFST columns. The model is then used to describe the stress-strain curve process for concrete and to calculate the bearing capacity. Models of ten concrete-filled square steel tubular columns under axial compression specimens are created with constitutive relation. The results are compared with the axial compression test of an ordinary square CFST specimen column and stiffened square CFST specimens. Our results show that the bearing capacity and stress-strain curves under axial compression are consistent with the actual test measurements. Analysis can be applied to the square stiffened CFST columns, the square CFST columns with binding bars, and the ordinary square CFST columns.

Land Use and Cover Change (LUCC) survey is an important content to understand and study regional ecological environment change. The production and construction of coal mine will have an impact on the local ecological environment. The application of remote sensing technology to select high-resolution images, man-machine interactive interpretation method combined with field investigation verification was used to carry out LUCC in the study area. The current situation investigation can quickly and accurately grasp the land use types and distribution characteristics of the study area, and provide a reference for the rational land development and ecological environment protection in the process of coal mine production and construction in the future.

The main inducement for collapse disaster of gentle incline rock slope is differential weathering, and for rock breakage of it is rock cell. On the study of gentle incline rock slope in this paper, we established the mechanics mode of arbitrary rock in gentle incline rock slope, analyzed the failure mechanism of gentle incline rock slope during the process of rock cell retreat, and established the distinguish method of its stability based on fracture mechanics. Then, taking the rock mass slope of JIMINGSHAN in CHENGKOU as an example, analyzed the stability change law of each rock block during the process of rock cell retreated. The study result of this essay can provide certain theoretical foundation for the prevention of disaster of gentle incline rock slope.

The dynamic monitoring for the scene of the engineering vehicle dynamic load of the vibration was performed. By developing a subroutine of ABAQUS DLOAD to simulate the process of vehicle traffic, the characteristics of vehicle vibration transmission in soil was analyzed. Based on three different indicators: displacement, acceleration and vibration level, the influence of different speeds and different weights of the vehicle vibration on the surrounding soil and reasonable control distance was analyzed. This paper provides reference and guidance to avoid the influence of traffic dynamic load when designing and constructing.

The structural safety calibration is an essential problem of Roller Compacted Concrete (RCC) dams. Due to the simulation complexity of RCC dams and shortcomings of conventional methods, usually, the actual mechanics state cannot be obtained easily by the numerical methods. In this paper, a RCC gravity arch dam in Laos is taken for an example, the simulation program has been developed, and three-dimensional simulation analysis of the temperature field and stress-strain field of the whole process of RCC dam during construction and operation is carried out. The composite contact crack element is proposed to simulate the complicated mechanical behaviors of various kinds of joints and cracks. The research results show that the simulation results of the temperature field, the stress-strain field and cracking are close to the monitoring data, the space-time evolution of the temperature field and the stress-strain field of the RCC dam are obtained. The whole working state of the RCC dam is evaluated, and the causes of the dam cracks are revealed. The research results are adopted by the design institute, which is of great importance to ensure the engineering safety of design, construction, impoundment and operation.

My country's economic pillar industry is the civil construction industry. With the rapid development of our country, modern buildings have greatly increased the difficulty of construction project management due to complex construction techniques and long construction periods. Therefore, we must improve the traditional. In this way, the management model can better improve engineering efficiency. This article is based on the BIM technology of the civil construction management engineering efficiency path to study, the experiment uses the analytic hierarchy process to determine the weights, in order to evaluate the BIM technology of construction engineering safety management. Three local survey units were selected for the experiment, and the survey form was distributed to each unit according to the experimental procedures and requirements. When handing over the BIM model, it could give the acceptance conclusion of the model. Experimental data shows that the incidence of accidents at the entrance of the cave and the border is the highest, which is the most difficult point in construction safety management. Effective measures should be taken to reduce the occurrence of accidents. The experimental results show that the following problems in BIM application have led to a reduction in the efficiency of civil construction management engineering: 85% of BIM standards are unfamiliar, 79% of BIM technology costs are overused, BIM technology is poorly applied 82%, and BIM-related software is not applied. Mature accounted for 78%, and BIM related management methods accounted for 80%. The use of BIM technology can provide an effective way to improve the efficiency of construction project management. This article conducts in-depth research on BIM technology, hoping to make a meager effort in related fields.

This research analyzes the strength and deformation characteristics of rock samples under varying pore pressures during the unloading process. By using fine-grained granite from Western China as the research exemplar, laboratory tests of triaxial unloading under pore pressure are conducted by utilizing the unloading confining pressures method without changing the axial pressure. Pore pressure is tested with a design value of 5 MPa. When the confining pressures are released at 35, 25, 15, and 5 MPa, the pore pressures drainage valve are opened, and the mechanical properties of fine-grained granite under pore pressures are analyzed. The following results are obtained. After unloading at different confining pressures, pore pressure has an evident influence on the stress–strain curve of the rock sample. The bearing capacity of the rock sample decreases. The hole pressure has a significant effect on the ring and volume deformation in the unloading process. Consequently, the evident deformation and damage are generated immediately after unloading to 25 MPa. Under the condition of constant pore pressure for a long time, numerous tension fractures are distributed around the main shear fracture owing to the promotion of pore pressure on the fracture opening. Hence, an evident swelling phenomenon occurs in the rock sample.

The application of distributed optical fiber sensing technology to stress test of bored pile is a kind of line measurement method developed in recent years. It has the advantages of more measuring points and stronger anti-interference, but its test effect is rarely compared with other methods in practical engineering. In order to evaluate the test effect of distributed optical fiber sensing technology, the optical fiber and sliding micrometer tube were embedded at the same time during the construction of test pile, and then the static load test of pile was carried out to compare the test results of the two. The test results show that the strain distribution of the pile obtained by the distributed optical fiber sensing technology and the sliding micrometer method are the same, and the maximum strain difference between them is about 100 με. The distributed optical fiber sensing technology can better reflect the detailed deformation of the pile.

This paper takes the filling roadbed of the Lipu-Yulin Expressway (Liyu Expressway) project in the Guangxi Zhuang Autonomous Region as the backup project. Numerical simulation research is conducted by employing the general finite-element analysis software ABAQUS. The three-dimensional numerical models of the unreinforced soil embankment and reinforced embankment are formulated and the subgrade's ultimate bearing capacity is calculated and solved by the elastoplastic finite element method. Effects of planar and three-dimensional reinforcement, i.e., geotextile and geocell, on the ultimate bearing capacity of the foundation are calculated and analysed. Simultaneously, the strength and deformation characteristics of geocells and geotextiles under embankment loads are studied. Research results show that the enhanced bearing capacity of geocell-reinforced foundation in this paper is increased by about 30%, which is greater than that of the planar reinforced material. This research results in this paper provide reference and theoretical basis for designing and analysing geocell-reinforced embankment in actual engineering practices.

The article relies on the Guang-Xing section of the southern section of the third phase of Chengdu Metro Line 1 to cross the Cheng-Hua Railway. The change of the stress with the approaching is analyzed. Study the stress change law of the intercalated rock under the change of the distance and angle: when the distance decreases, the maximum principal stress increases more obviously, which shows that the smaller distance, the easier the damage of intercalated rock. The stress state of the rock at different angles is that it is safer to overpassing and undercrossing, the horizontal approach is the most dangerous, and the other angles tend to be between the two. Through three-dimensional numerical simulation, the influence of the excavation process and construction method is analyzed, and it is found that the change of the secondary stress on the sandwiched rock by the mining method is relatively larger than that of the shield method. This makes the surrounding rock disturbance relatively large, resulting in the weakening of the sandwiched rock, which is directly manifested as the increase of the subgrade displacement.

The influence of vibration molding method and manual poking molding method on strength and water permeability of polymer pervious cement concrete with water cement ratio of 0.27, 0.30 and 0.33 is studied. It is found that the compressive strength of vibration molding increases with the increasing of vibration time and the water permeability coefficient decreases. The strength of concrete with vibration molding is higher than that of manual poking molding, and the water permeability coefficient is lower. However, the water permeability coefficient with both molding methods is more than 0.5mm/s.

In order to study the impact of the blasting construction of lately excavated tunnel of the large-section tunnel with small spacing on the early excavated tunnel, the propagation law of vibration velocity of initial support of early excavated tunnel under blasting load is analyzed by combining field test and numerical simulation based on the Mongol Road Tunnel of the Zamalong-Daotanghe Highway Reconstruction and Expansion Project in Qinghai Province; The results show that the radial vibration velocity in the initial support of early excavated tunnel is obviously greater than the vertical vibration velocity and tangential vibration velocity in the blasting construction of lately excavated tunnel with large section and small spacing. The radial vibration velocity of the blasting side of the tunnel is obviously greater than that of the back side, and the maximum is found at the arch waist of the blasting side. The peak value of the radial vibration velocity of the initial support of early excavated tunnel is the maximum at the same section position as the blasting excavation face, and gradually decreases with the increase of the blasting center distance. Compared with the vibration velocity of the initial support before and after the excavation face, the peak attenuation rate of the vibration velocity in front of the blasting excavation face is slightly less than that behind the excavation face.

In order to study the influence of stirrup corrosion level on the peak stress, peak strain, ultimate strain and shape of stress-strain curve of the confined concrete, 15 reinforced concrete prism specimens were subjected to acid rain erosion by artificial climate simulation technique followed by axial pressure tests. Based on Mander's model and the existing research results, the calculation formulas of the peak stress f'_cco, peak strain £_cco, ultimate strain ε_cco, ultimate strain ε_cu0 and shape factor r of the uncorroded specimens are determined. The factor calculation formulas for peak stress, peak strain, ultimate strain and shape factor of corroded specimens is developed by regression analysis of test data, respectively, and then the constitutive model of confined concrete by acid rain erosion is established. By comparing the simulation results with the experimental data, it can be found that all the peak stress, peak strain, ultimate strain and stress-strain curves shape of the specimens obtained by the proposed method are in good agreement with the experimental data. Thus the constitutive mode for confined concrete established in this paper can accurately reflect the mechanical performance of RC prism specimen by acid rain erosion, indicating its adaptiveness for estimating the residual bearing capacity and the seismic performance of RC structure under the acid rain environment.

For evaluating the structure and strength of loess effectively, a series of laboratory tests were performed to investigate and compare the pore meso-structural characteristics, the shear strength and the resistivity of natural loess and loess treated with alkali solutions under 4 different concentrations. Scanning electron microscope(SEM) method, direct shear tests, electrical resistivity tests, and X-ray diffraction analysis were used to detect the changing process in strength parameters, micro-structure, and mineral composition. The evolution result of shear strength index and stress-strain characteristics of loess were analyzed. Combined the SEM micro-structure analysis and X-ray diffraction technology, the microscopic mechanism of alkali solutions and loess interaction was revealed. The results of tests show that the curves of shear stress- displacement featured as strain-hardening, and the increasing of shear strength indexes with the increasing of alkali solutions concentration. Then the relationship between the shear strength index and resistivity was established. The SEM images of LTA specimens were used to quantify the structural parameters by Image Processing Techniques. The changes of multiple structural indicators of LTA such as directionality, abundance, circularity, fractal dimension, and the orientation probability entropy were revealed. The potential mechanism of LTA was revealed by the XRD and EDS tests from the perspectives of mineral composition and chemical element composition. The results of this study show that alkali-loess interaction was the main influence factor for the changes in the shear strength and meso-structure s. The results provide a valuable implication for the construction in the loess deposits.

Based on the MIDAS-GTS numerical analysis platform, the construction characteristics of the left and right holes of the newly-built twin tunnel with a large section and a small distance were systematically analyzed, and the evolution laws of the displacement changes of the tunnel and the mid-rock pillar under the left and right full-section tunnel method were studied. The results show that: (1) with the increase of the lag distance, the surface settlement decreases gradually. When the lag distance is greater than 2.0D, increasing the lag distance has little effect on the maximum settlement value. (2) The maximum value of the surface settlement trough occurs between the left and right tunnels, which is the superposition area affected by the two tunnels. (3) The increase of lag distance has little effect on the final horizontal displacement of arch waist and mid-rock pillar. Considering that the influence range of face excavation on the surrounding rock of the tunnel is within 15m, the lag distance should not be too large and should not be less than 15m. (4) With the decrease of the lag distance, the superposition effect of the twin tunnel becomes more and more obvious. With the increase of lag distance, this phenomenon begins to weaken obviously, and obvious separation phenomenon appears.

As we all know, high-speed rail is a very important business card in China, and the rapid development of high-speed rail is inseparable from the rapid development of tunnel construction, so tunnel construction has become very important. The quality of the tunnel lining directly affects the construction quality of the entire tunnel construction. This paper first introduces the use of IES, one of the most advanced testing methods for non-destructive testing, to achieve non-destructive testing the quality of tunnel lining. The signal is more or less affected by the surrounding environment and human factors, so In this paper, wavelet analysis is used to eliminate the signal noise in order to extract characteristic signals that better reflect the defects of tunnel lining and realize the intelligent diagnosis of the defects of tunnel lining.

As a new green material, basalt fiber has the advantages of high strength and corrosion resistance, and is an ideal material for ecological protection technology. The rapid change of the hydraulic gradient within the slope caused by the sudden drop of river water level is an important factor inducing bank slope instability. Studying the stability of gabion slope protection under this condition is the key to evaluating the effect of gabion support. Taking a basalt fiber gabion slope protection project as an example, this paper carried out the stability study of the gabion slope protection under the condition of sudden drop in water level and compared it with the original slope. The stability was analyzed from the perspectives of deformation and stress, and revealed The deformation mechanism and the beneficial effects of the gabion structure during the instability failure process of the original slope. The results show that under the condition of a sudden drop in river water level, the use of gabion support from the left side of the slope to the slope surface can improve the stability of the slope, and there will be no continuous sliding surface in the slope, and the failure of gabion appears as partial dislocation and separation phenomenon. The research results provide important reference value for river gabion slope protection design and stability evaluation.

Thermal load is an important cause of structural fracture. A model based on the Scaled boundary finite element method (SBFEM) is presented for the fracture modeling due to thermal load. The SBFEM is a semi-analytical method, which has the advantages of both the Finite element method (FEM) and the Boundary element method (BEM) while possessing its own special features. The structure is discretized only at the boundary, thus reducing the dimension of solution. In addition, the stress field and displacement field are obtained analytically in the radial direction, so the stress intensity factors can be obtained directly from its definition and this works for homogeneous material, bi-material and orthotropic material. In the presented model, the temperature load is transformed from the temperature field of the structure, which is included in the structural analysis to get the displacement field, stress field and therefore the stress intensity factors. By introducing the polygon technique, the remeshing process due to crack propagation can be modeled conveniently. Two numerical examples including a rectangular plate and a cross plate are employed for verification of the model.

In order to further study the mechanical properties and development distribution of shear connectors of steel-composite beam under the influence of concrete shrinkage and creep. In this paper, on the basis of the existing experimental research, ABAQUS software is used to establish the steel-composite beam model. The structural forms of the model include simply supported beam and continuous beam, and the shear connectors of steel-composite beam include three types: stud connectors, PBL connectors and composite connectors. The time development and spatial distribution of vertical displacement, connector shear force and slip at interface of each composite beam with concrete creep are calculated by finite element software, and some calculated results are in good agreement with the existing test results. By comprehensively comparing the calculation results of the key sections of each composite beam at some time points, the mechanical properties and their respective applications of the shear connectors of the steel-composite beam are analyzed and summarized, and the research results can guide the design and engineering application of the shear connectors of the steel-composite beam.

By adding ribs and bars to form the double steel-concrete shear wall constrained with ribs and bars, the steel plate of the whole steel-concrete shear wall can be strengthened of the constraint. The research on Eccentric compressive behavior of double steel-concrete shear wall constrained with rib and bar is less, this paper analyzes double steel plate concrete shear wall by using larger length-width rectangular CFST column research methods. Based on the constitutive relation of the rectangular CFST column with ribs and bars, the relative parameters are changed, and a program is written to compare and analyze eccentric compressive behavior of double steel-concrete shear wall constrained with ribs and bars compared with that double steel plate concrete shear wall only constrained with bars.

In order to study the frame structure energy dissipation mechanism on the ground, a 3x3 span 5-story frame structure was used as the research background, and a shaking table test with a scale ratio of 1:15 was designed. Based on the prototype structure, a finite element model based on ABAQUS is established. The correctness of the finite element model is verified by experimental comparison. On this basis, the plastic energy dissipation and damping energy consumption of the structural beam and the plastic energy dissipation law of the column are analyzed. The weak part of the structure of the trans-ground fissure structure under energy conversion is found. This study provides a reference for the arrangement of energy-consuming devices in seismic design and disaster prevention and mitigation design for similar structural engineering.

In order to transform a large amount of dredged sludge into sustainable development of land resources, this paper takes the submarine dredged sludge in Dalian Bay as the research object, and uses the composite solidified material composed of cement, fly ash and phosphogypsum to carry out flow solidification treatment. Through laboratory experiments, the influence of curing temperature, dry-wet cycle and freeze-thaw cycle on the sludge flow solidified soil was studied. The results showed that:(1) When the fly ash-cement mass ratio RFC=0.65 and the cement-sludge mass ratio RCS=0.09-0.16, the unconfined compressive strength of the 35°C sludge flow-solidified soil is the mud-solidified soil in the outdoor curing environment 1.04 times.(2) When RCS=0.11∼0.14 and RFC=0.65, the strength loss rate of silt-solidified soil after the first dry-wet cycle is the highest, respectively 43% and 50%.(3) When RCS=0.09∼0.16 and RFC=0.65, after the third freeze-thaw cycle, the strength loss rate of the sludge solidified soil is the smallest of the first five times.

There are 5∼8 m thick non self weight collapsible loess in the project site of a power plant. In order to study the bearing relationship between compressive and uplift piles in loess site, static load tests were carried out on PHC pipe piles with diameter of 400 mm and 500 mm and pile length of 12 m. Under the same pile top load, the displacement of uplift pile top is greater than that of compression pile top. Based on the measured load displacement curve, the uplift bearing capacity of PHC pipe pile with pile diameter of 500 mm is 32.5% higher than that of pile diameter of 400 mm. When the pile diameter is 400 mm and 500 mm respectively, the ultimate bearing capacity of PHC uplift pile is 26.24% and 27.70% of compression pile respectively. GM (1,1) model of grey system can fit and predict the load displacement curve of PHC pipe pile under compression and pull-out. Compared with the measured results,the relative error of GM (1,1) model of grey system is larger in the previous stages of load, and decreases gradually with the increase of load.

Soil stratification is the basic problem of soil development and utilization in the farmland, which can be used as a reference for later development and planting. Traditional soil stratification method is inefficient and needs to introduce new methods and techniques. In this paper, time domain spectral induced polarization method was introduced to carry out electric sounding exploration for the certain soil, and the observed data were processed and interpreted by using half-life time and deviation degree. The results show that the application of time domain spectral induced polarization method in soil stratification is feasible, and the half-life time and deviation degree are effective as interpretation parameters. The measured results and conclusions of this work can provide a basis for related research and the reference for relevant work.

The surrounding rock is the construction environment and main load source of the tunnel, and its physical parameters have an important influence on the stability of the tunnel face. Based on orthogonal test method, with the Georgia E60 highway 3.0.04 - TA tunnel under construction as the engineering background, numerical test method is used to compare and analyze the influence of different surrounding rock parameters ( elastic modulus E, cohesion C, internal friction Angle φ) on the stability of tunnel face. The multiple linear regression fitting equations of three factors and extrusion deformation are given and verified. The results showed that the elastic modulus and cohesion of surrounding rocks had a significant influence on extrusion deformation of the tunnel face, while the internal friction Angle had no significant influence. The extrusion deformation of the tunnel face is negatively correlated with the elastic modulus, cohesion and internal friction Angle of surrounding rocks. The fitting equation can provide a means for predicting the stability of surrounding rock and guide the construction of the tunnel.

The influence of stone powder content, fly ash and other factors on mechanical properties, pore structure and fractal dimension of machine-made sand mortar were studied, and the relationship between fractal dimension and mechanical properties of mortar was explored. The research shows that with the increase of the content of stone powder, the mechanical properties of mortar and the fractal dimension of pore structure of different sizes increase; the porosity and average pore size of the mortar decrease, and the ternary of cement-fly ash-stone powder The micro-particle system can effectively optimize the pore structure distribution of the mortar; the fractal dimension of the mortar using ordinary river sand is significantly smaller than that of machine-made sand under the same conditions; with the increase of the fractal dimension of the pore structure, the compressive strength and flexural strength of the mortar continue to increase Large, the fractal dimension and the macroscopic mechanical properties of the mortar show a good correlation.

In this paper, different types of basalt fiber concrete (BFRC) were been researched on the tensile properties. Moreover, analyzed the influence of fiber length and fiber volume fraction on the tensile properties of concrete. The results showed that the tensile strength of BFRC increased significantly with the increase of fiber volume fraction, and the strain increased significantly with the increase of fiber length. The BFRC tensile stress-strain curve shows obvious staged failure, and the function of stress-strain relationship based on the regression method has burning relevance with the test results.

The left bank of the cushion pond of Baihetan hydropower station is a slant and dip slope. The gently inclined intra-layer fault zones, the steep-dip faults and the unloading fissures cutting the slope to form several potentially unstable blocks. The computational results show that the stabilities of the blocks are controlled by inclined intra-layer fault zones. A method of treatment applying deep replacement caverns and load-reduction excavation was proposed to reinforce the unstable blocks. In order to study the reinforcement mechanism of the deep replacement caverns for the giant slope blocks controlled by inclined intra-layer fault zones, the 3D simulation analysis of the slope treatment construction was carried out by use of FLAC^3D software, and a 3D geo-mechanical model was developed to carry out experimental research. The results of the calculation and experiment show that the deep concrete replacement caverns effectively control the shear and sliding deformation of the bottom slide surface and improve the stability of the blocks combined by structural surfaces. In the process of slope strength reduction and overloading, the slope deformation and cracking are gradually extended from the surface to the inner part, and shear stresses of the front deep replacement cavern are the largest of all the caverns. Therefore, it is more beneficial to control the deformation of the slope and improve the stability of the giant blocks by increasing the size of the front deep replacement cavern. The research results have important guiding significance for the reinforcement treatment of the giant blocks in the left bank of Baihetan cushion pond and similar projects.

Based on the Dongxiu tunnel project of Liyu highway under construction in Guangxi province of China, this paper attempts to study the supporting time of the secondary lining of the highway tunnel with weak surrounding rocks. Firstly, the measurement data of typical section of the tunnel is fitted and used to reveal the evolution law of the settlement of the tunnel vault and peripheral convergence of the sidewall. Then the three-dimensional simulation is carried out to verify the rationality of the evolution law. After that, the supporting time of the secondary lining is determined relying on the results of field monitoring and numerical simulation. The results show that, both the settlement of the tunnel vault and the peripheral convergence for the Dongxiu tunnel can be characterized by exponential function, and it is reasonable to construct the secondary lining at 24th-25th day after excavation. The results can not only guide the subsequent construction on site but also provide reference for the determination of supporting time of the secondary lining of similar tunnel projects.

The web cracking of continuous rigid frame bridge is still a common phenomenon. A part of the reason is that the vertical prestress does not work well. At present, the mechanical research of vertical prestressed reinforcement is not comprehensive, the mechanical effect between two adjacent vertical prestressed tendons is not thorough, theoretical analysis cannot be carried out through formula derivation, and finite element modeling is relatively dependent on, so the work is cumbersome and the application is not convenient. In view of this problem, this paper uses elastic mechanics theory to deduce the stress effect formula of two adjacent vertical prestressed tendons, and verifies the correctness of the formula through finite element modeling. In addition, this paper also uses the finite element theory to carry on the modeling calculation, obtains the distribution law of the web stress caused by the vertical prestress along the height of the web and the longitudinal direction of the box girder, providing guidance for the vertical prestressed design of rigid frame bridge.

Based on the 3D finite element method, considering the plastic damage model of concrete, the uncoordinated deformation relationship between steel foundation ring and concrete, and the coordinated displacement relationship between steel bars and concrete, this paper conducts a simulation analysis on onshore wind power generation foundation, and studies the stress characteristics of the foundation under ultimate load condition. The results show that the lower part of the steel foundation embedded plate is a weak part, which not only needs to pay attention to the tensile failure, but also needs to prevent the compression failure. Perforated steel bars arranged on the top of steel plates have a obvious stress effect, which obviously strengthens the connection between steel plates and concrete. With the weakening of the connection between steel foundation and concrete, the top displacement and relative displacement of the contact surface between steel plate and concrete gradually increase. With the increase of friction coefficient between steel foundation and concrete, the stress of perforated steel bars and the displacement of foundation ring top surface also decrease. The research results of this paper can provide an important reference for the design and reinforcement of infrastructure.

At present, the level of bridge crack detection is not high. In order to solve the problems of weak robustness of traditional image processing methods and time-consuming and laborious manual detection, a pixel level detection algorithm of bridge cracks based on adding residual block is proposed, which provides more intuitive and accurate detection results for bridge health assessment. Firstly, the concrete beam slab crack data set with a certain amount of data is built to train and test the model. After comparing and analyzing the four learning rates, 2×10⁻⁴ is chosen as the initial learning rate. Finally, in the aspect of fracture segmentation, the model proposed in this paper has good performance and good crack identification effect. It can accurately and efficiently locate, classify and identify fractures, which has certain practical application value.

At present, fiber-reinforced solidified soil is a research hotspot in the civil engineering field, but there are few related researches. Researches mainly focus on solidified soil and fiber-reinforced soil. Based on this, the research status of solidified soil and fiber reinforced soil is comprehensively analyzed in this paper. It is found that there is still a great lack of research on the strengthening mechanism of solidified soil. The research on the mechanism is still in the stage of qualitative description, and the related technical problems need to be further studied. Similarly, there are still great limitations in the research of fiber reinforced soil. These are reflected in the limited types of soil studied, more laboratory mechanical properties tests, but less research on fiber toughening mechanism.

The initial geostress field is an important basis for the design and stability analysis of geotechnical engineering. The geostress field of the whole engineering area must be calculated by inversion analysis with the limited geostress data, because there are few measured geostress points. Based on the geological background of a tunnel in northern Hebei province and considering the influence of regional highly weathered, moderately weathered and slightly weathered stratum on the stress field, the 3D finite difference method and multiple linear regression method were used to calculate the three-dimensional geological model of the study region to get the optimal regression coefficient. It is found by comparing the regression value with the field measured value that the two values are equal in magnitude and close in direction, indicating that the geostress field calculated by regression is reasonable, then the distribution law of the geostress field in the study area is further analyzed on this basis. The results show that there is a stress concentration in the tunnel center, z peaking at 50m below the center, and decreasing in the left and right direction with a large stress gradient then getting out of the area of stress concentration and tending to be stable. The study area is a medium geostress area, based on gravity stress, the control effect of gravity stress field is gradually enhanced with the increase of buried depth. The research results have important value in the design and construction of tunnel in special geological conditions.

To investigate the ageing characteristics of dam concrete, concrete core samples were obtained from an existing dam. The compressive strength and carbonation depth were determined. The relationship between compressive strength, carbonation depth and operation time were analyzed. The results show that the compressive strength of dam concrete increases with operational time, the increasing rate of compressive strength was gradually decreased, and the compressive strength gradually increases with depth carbonation growth. There was a certain correlation between compressive strength, operational time and depth carbonation. The research results will provide a reference for the safety evaluation of hydraulic concrete structures in service.

In order to extend the service life of the bridge and reduce the occurrence of catastrophic accidents, it is necessary to monitor and identify the damaged parts of the bridge in time. In this paper, the author firstly proposes a basic theory of deflection influence line, then analyzes the calculation basis and proposes a method of deflection influence line of simple supported structure. Finally, according to displacement-time curve of simply-supported beam structure under different load-moving speed can be obtained by using MIDAS, the mid span, damage degree and load-moving speed of structure model can be set to carry out the simulation calculation. The results show that: when the load moving speed is 10km/h, 30km/h, 60km/h and 100km/h, the influence line of deflection difference has no obvious change pattern, and there are different peak values, which cannot be used for damage identification. Under the static load condition, the influence lines of deflection difference at 1/2L position, 3/4L position and end part at 10% and 25% damage degree basically show linear change, while the deflection difference value at 1/2L position appears peak value, and the maximum deflection difference value at different damage positions shows nonlinear change. It indicates that the damage degree can be judged according to the deflection differences at the damage positions identified above.

In order to investigate the influence of materials parameters on chloride diffusion coefficient in concrete, experiments were conducted by orthogonal design and factorial design, and 15 sets of concrete specimens with different mix proportion were prepared. RCM test for each concrete specimen was performed to determine the chloride diffusion coefficient. Results show that water-to-binder ratio, replacement of mineral admixtures and the ratio of replacement of fly ash to replacement of granulated blast furnace slag have a significant influence on chloride diffusion coefficient, but the water-to-binder ratio is the most important one.

To solve the problem of difficulty in controlling the construction quality of fresh concrete due to the low applicability and accuracy for the existed referencing vibration time when using internal vibrator, an innovative parameter of vibration energy density is created based on concept of energy and a hardened porosity prediction model is constructed considering the parameter and mix characteristics. The model is used to obtain the minimum porosity value of concrete and corresponding energy density threshold under certain ratio conditions. Finally, the accuracy and effectiveness of method are verified by field tests. The results show the method can realize precise quantitative quality control of concrete vibration and guide the construction work.

Tailings pond is used to store the tailings discharged from the mine after separation and mining. As a potential hazard source with high potential energy, the tailings mortar with high potential energy after dam break is transformed into high-speed dynamic energy sand flow to impact the downstream area through energy conversion. In this paper, through the establishment of a three-dimensional model of a tailings pond, the FLOW-3D software is used for numerical simulation, and the influence of correlation coefficient on the discharge speed of tailings mortar after dam break is analyzed, and the relevant migration law is obtained. The test in this paper can provide a reference for the corresponding disaster and protection engineering research.

In view of the mechanical characteristics of the support structure under the mechanized construction conditions of the shallow buried section of the tunnel entrance, numerical simulation methods are used to compare and analyze the different cycle footage and the different tunnel face depth before and after the tunnel face reinforcement been carried out when the shallow buried section of the tunnel entrance is constructed by the micro-step method. The results of the study show that the primary support and pipe shed force increases with the increase in the depth of the tunnel face (buried depth), and decreases with the increase of the cyclic footage; When the fiberglass bolt is used to reinforce the face, the axial tensile stress of the fiberglass bolt can reach 18kN; Without reinforcement of the tunnel face, the primary support of the arch at the entrance of the tunnel is vulnerable to cause tensile damage; After the tunnel face is reinforced, the tensile stress of the primary support is significantly reduced.

In order to determine the color modified emulsified asphalt and its preparation process in cold areas represented by Hulunbuir, Inner Mongolia, a variety of materials such as saturated hydrocarbon A, petroleum resin B, copolymer C, copolymer D, and plasticizer E were selected to simulate four components of asphalt are used to prepare colored asphalt, and a colored modified emulsified asphalt suitable for cold regions is developed by the preparation process of emulsified asphalt emulsifying and modifying. The performance of the prepared colored modified emulsified asphalt was analyzed, and the optimal dosage range of modifier, emulsifier, stabilizer, and pH adjuster was determined, and the high and low temperature performance of colored modified emulsified asphalt was improved to adapt to environment of cold areas. Through the colored micro-surfacing mix design to determined the optimal emulsified asphalt dosage, and the test compares the surface performance and durability of the ordinary micro-surfacing mixture and the colored micro-surfacing mixture, which proves that the CMS-3 type mixture has good water sealing effect, anti-slip performance and ability of water damage resistance.

Aiming at the problem of the value of the stability and limit displacement of the surrounding rock of highway tunnel with high pressure, the method of numerical limit analysis is adopted, and one of the working conditions is analyzed in detail. Firstly, this paper adopts the formation structure method to calculate and establish a plane model for calculation and analysis with the help of FLAC3D software, so as to study the influence of reduction coefficient on surrounding rock deformation and its law. Secondly, by holding other variables unchanged, two different working conditions with and without high water pressure are compared and analyzed, and it is obtained that the ultimate safety factor of the integrity instability of surrounding rock of the formation tunnel with high water pressure is 1.30, and that of the integrity instability of surrounding rock of the formation tunnel without high water pressure is 1.80. Finally, the results are compared and analyzed and it is found that the stability of tunnel surrounding rocks with high pressure is lower than that without high pressure, and the limit displacement is greater than that without high pressure.

After a large-scale construction period, there are a large number of old high piled wharfs in China's ports. The pile cap piles and beam members of some wharfs close to the earth retaining structure appear obvious dislocation, and some of them are increasing year by year. In this paper, the typical section of Tianjin Port 16 ∼ 18 wharf is taken as the research object, and a three-dimensional mathematical model is established to simulate the deformation trend of wharf structure with bank slope soil under unbalanced load condition. The results show that the pile cap plays a positive role in the stability of the wharf slope. Partial load can cause the deformation of soil along the bank. The horizontal earth pressure acting on several rows of piles behind the pile cap is large, which leads to large deformation and internal force of the pile body. When the force between the pile top and the beam exceeds the lap strength between them, the pile top and beam will be staggered. The fundamental method to avoid or improve the seaward movement of high piled wharf and bank slope is to block or reduce the horizontal earth pressure from the rear storage area to the front. The scheme of sheet pile wall or bored pile can be selected according to the actual situation.

In view of deep water and soft soil foundation, a new type of breakwater with cylindrical jacket and pile foundations is proposed. According to the hydrological and geological conditions of Tianjin Port, the stability and bearing capacity of breakwater are numerically simulated by ABAQUS software. The results show that when the pile is an elastic model, the failure of soil is the main cause of structural instability. In the limit state, the structure is unstable in rotation in addition to arc sliding, and its turning point is below the bottom of the cylindrical jacket and deviates from the structural axis near the front-pile side. When the pile is a damage plastic model, the loss of bearing capacity is the cause of structural instability. The safety coefficient is greater than 1, but it is obviously smaller than the one of elastic model. The research results provide a reference for structural design and stability study of the breakwater with cylindrical jacket and pile foundations.

Subgrade collapse is widespread in karst areas of south China, which is easily causing economic losses and casualties. Compared with the traditional treatment methods, using geotextile has obvious advantages in treating the subgrade after karst collapse. In this paper, two scale model tests with different laying depth of geotextile used to treat karst collapse were performed. Instrumentations and particle image velocimetry system (PIV) were applied to investigate soil pressure, vertical displacement of filling and tension distribution of geotextile. Following results were found: from the point of view of soil pressure, compared with deep buried, there had not enough stable soil under the shallow buried geotextile to improve the collapse treatment effect effectively; Compared with using deep buried geotextile, shallow buried geotextile would cause a larger overall settlement with the surrounding fill, which reduced the reinforced effect and had unsatisfactory treatment effect. Therefore, the geotextile with deep layout should be used in the collapse control and the soil beneath it should be compacted to achieve a good treatment effect.

In order to study the feasibility of replacing part of longitudinal reinforcement with layered steel fibers, four-point bending tests were carried out on a group of ordinary recycled concrete beam and three groups of layered steel fibers recycled concrete beams. The cracking moment and ultimate moment, ductility and energy dissipation, deformation and deflection of the experimental groups with lower contents of steel fibers and higher reinforcement ratio and the experimental groups with lower reinforcement ratio and higher contents of steel fibers were compared and analyzed. The results show that it is feasible to replace some longitudinal bars with layered steel fibers when considering cracking moment, ultimate moment, elastic stage and working stage with cracks of load-deflection curve, while it is not feasible when considering ductility, energy dissipation and post-yield stage of load-deflection curve.

Low pylon cable-stayed bridge is a new type of composite bridge between girder bridge and traditional cable-stayed bridge. Because of its good mechanical properties, economic benefits and beautiful shape, low pylon cable-stayed bridge is widely used in highway and urban landscape bridges. In this paper, a wide and low pylon cable-stayed bridge under construction is taken as the research background, and the numerical simulation model is established by using the finite element analysis software MIDAS CIVIL. The influence of the length of the cable-free zone is studied. By changing the length of cable-free zone at the tower root and the length of cable-free zone in the middle of span, the influence of the length of non-cable zone on the deformation, bending moment, internal force and cable force of low pylon cable-stayed bridge at the completion stage is studied. The reasonable value range of non-cable zone length is obtained. The research results will provide theoretical guidance for the design and construction of similar projects.

With the rapid development of my country's construction industry, people's requirements for construction quality and safety control are becoming more and more stringent. However, the results are often unsatisfactory, and the cost risk in civil engineering construction still cannot be effectively controlled. This article aims to study the risk control analysis of civil engineering costs based on BIM technology. This article analyzes the experiment from the perspective of quantification. The Experimental Integration Facility Engineering Center has conducted research on multiple BIM projects and learned about the actual operation status of these projects. Then summarize the actual effect of BIM technology. Experimental data shows that the use of BIM technology can improve the quality of design, quickly determine project cost, control design changes, avoid rework, and reduce costs. The experimental results show that the use of BIM can reduce the time used to estimate the cost to 35%, the accuracy of the estimate is controlled to <5%; the extra-budgetary changes are reduced to 70%; through the discovery and resolution of conflicts, the contract price is reduced by 13%; The project time has been reduced by 10%, and investment income can be obtained relatively quickly. Therefore, the research on construction hazard management and control based on BIM technology can not only promote the development of BIM information technology, but also make up for the inefficient and imperfect defects of hazard management and control, and greatly improve the cost risk of civil engineering.

Aimed at the construction stability of the shallow-buried and biased exit section of the Georgia No.3 tunnel under construction. Using numerical simulation analysis method, the displacement and deformation of the unsymmetrical rock wall and the construction dynamic characteristics of the supporting structure are studied. It points out the weak links that should be paid more attention to in the construction. Numerical analysis results show that the side of the unbiased rock wall is most affected by the excavation, and the maximum tunnel displacement on both sides appears at the arch waist. The protection of this part should be strengthened during construction. The smooth implementation of this project can provide reference for similar highway tunnel construction.

In recent years, China has made great efforts to promote prefabricated concrete bridge technology. However, due to the construction quality problems, the application of prefabricated concrete bridge technology is limited. BIM technology can be applied to the whole life cycle of a construction project, which is a new way to solve the problem. This paper uses questionnaires to investigate the quality problems of prefabricated concrete structures, the necessity of BIM application at various stages and the application effects are analyzed. The results show that the application of BIM Technology in each stage of the project can improve some quality problems.

In order to overcome the problem of extraction and deformation information analysis of tunnel cross-section by 3D laser scanning technology in tunnel engineering application, a method of extraction and fitting of tunnel cross-section based on cubic B-spline curve was proposed. First, obtain the initial cross-sectional point cloud by using the cross-sectional intercept method based on the spatial point cloud subset;Then, the cross-section was fitted with a cubic B-spline curve, and the missing part of the point cloud was repaired automatically.In the end, specific points are extracted from the fitted cross-section point cloud to realize cross-section deformation analysis.And cross-section analysis of point cloud data of a section of subway tunnel shows that this method can quickly and accurately analyze the deformation information of the tunnel cross-section.

The method and application situation of neural network is universal application. Datum of project and monitoring from a project of soft foundation by vacuum preloading was filtrated and summarized. After analysis and comparison, establishment of optimization neural network model was used to evaluate the consolidation effect. By the sensitivity of impact factors, it was analyzed that the main parameter of soft foundation consolidation process.

According to the reinforcement principle of hybrid fiber, steel fiber and PVA fiber were used to prepare hybrid fiber reinforced concrete (HyFRC) with compression strength of 120 MPa (SPHFC120). The tensile properties of SPHFC120 were studied by uniaxial tensile test, and the uniaxial tensile constitutive equation was established according to the stress-strain curve. An efficient and applicable three-dimensional mesoscale model to simulate HyFRC was developed. It consists of two components involving concrete matrix and fibers, and the bond between concrete matrix and fibers was considered indirectly by defining the fiber constitutive model. The model was validated with uniaxial tensile test. Then parametric studies were conducted to investigate the effect of fibers content on the tensile performance of HyFRC. The results show that PVA fibers obviously improve the tensile strength, peak tensile strain and tensile toughness of steel fiber reinforced concrete.

The double steel-concrete shear wall combines the advantages of steel and concrete effectively, with high bearing capacity, good plasticity, superior seismic and fire resistance performance, saving materials and simple construction, and has obvious advantages in the application of high-rise buildings, especially super high-rise buildings. Research on axial compressive behavior of double steel-concrete shear wall constrained with ribs and bars is less. In this paper, the constitutive relation of double steel-concrete column with ribs and bars is used to change the relevant parameters and program to analyze the influence of ribs and bars on the axial compression performance of double steel-concrete shear wall.

The basic mechanical properties of steel slag concrete with waste thermal steel slag instead of the coarse and fine aggregates in concrete are studied and compared with the mechanical properties of ordinary concrete. The test results show that the addition of steel slag as coarse aggregate will enhance the compressive strength and flexural strength of concrete, and it will improve with the increase in the steel slag content. When steel slag is used as fine aggregate, the compressive strength of the steel slag concrete subjected to first increases and then decreases with increase in the steel slag sand content. To obtain better performance for the steel slag concrete, the suggested optimum content of steel slag sand as fine aggregate is 50%. Within. The addition of steel slag as fine aggregate can improve the flexural strength of concrete, and the flexural strength increases with the increase of the addition of steel slag sand. The steel slag concrete with the highest strength can be obtained when 100% of steel slag replaces the concrete aggregate, and the steel slag has good basic mechanical properties for the application of road engineering.

3D printing technology can provide an effective method for specimen preparation of rock mass, but the mechanical properties of 3D printed rock mass still need to be further studied. In this paper, uniaxial compression tests are carried out on the intact and jointed rock mass models which are printed by laser rapid prototyping printer with photosensitive resin materials, stress-strain curve and fracture propagation are obtained, and the mechanical properties of 3D printed rock mass are studied. The results show that the intact model of the photosensitive resin material has greater plasticity and stress hardening after the peak strength, while the jointed models have obvious brittle mechanical characteristics, but in general, plastic deformation occurs before brittle failure; that the joint dip angle has an important influence on the physical parameters such as the peak strength of the model, strain at brittle fracture, elastic modulus, and the crack propagation; and that photosensitive resin material can simulate rock fracture, but it is not as good as natural rock or rock-like material. The research results can be used for reference in the study of mechanical properties of photosensitive resin and its application in 3D printing for rock mass.

The concrete face rockfill dam (CFRD) generally encounters structural health problems during long-term operation. Therefore, it is necessary to study the safety evaluation of CFRDs. This paper proposes a comprehensive evaluation method for the safety behavior of CFRDs on the basis of regression relationship method and fuzzy recognition model. The method of sub-index safety evaluation is established by using regression relationship method. The multiplication scale method was adopted to determine the sub-indexes weight. In combineing of sub-index safety evaluation value and sub-indexes comprehensive weight, the fuzzy recognition model is used to determine the comprehensive evaluation grade of dam safety. Safety evaluation of several CFRDs were evaluated by the method proposed in this paper and exisiting safety evaluated method to verify reasonable and rationality of the method.

Deformation assessment and control are essential issues in the construction of concrete face rockfill dams (CFRDs). The design and construction of CFRDs require deformation behavior that can be estimated rapidly to support engineering optimization and safety assessment. Based on 87 case histories of in-service CFRDs, a new ensemble learning model has been developed to predict maximum crest settlement (CS) of CFRDs. The model is based on the support vector machine regression algorithm (SVR) combined with multiple variables, and then the foundation model is integrated by the weighted average integration method. It is demonstrated here that the new ensemble learning model weakens the nonlinear characteristics of case data, makes up for the instability of single regression algorithm, improves the generalization ability, and provides a new idea for predicting the CS of CFRDs.

Collapsible loess has the poor characteristics of obvious strength reduction after being soaked by water. The construction of towering structure in western China is threatened by the unfavourable geological conditions of collapsible loess. This paper analyses the foundation treatment, pile foundation optimization design of the towering structure in collapsible loess areas, provide technical support for the construction of towering structure in collapsible loess areas.

A super high-rise civil building was originally designed with a relatively large area of shear wall section steel configuration, coupled with the configuration of steel bars, resulting in the construction of the project more difficult. To solve this problem, PKPM was used to build the model to extract and calculate the tensile stress of inflexible wall limbs under moderate earthquakes, and the configuration of the section steel in the original design was analyzed. An in-depth interpretation of the "Technical Points for Special Examination of Seismic Fortification of High-rise Buildings Exceeding Limits" (Jianzhi [2015] No. 67), Chapter 4, Article 12, Paragraph 4, on the provision of shear wall section steel configuration was conducted. Finally, based on the original design, an optimization criterion for the configuration of the section steel in the wall was proposed.

Rheology often occurs in the dam rockfill deformation. In this paper, we carried out a large-scale triaxial rheological test for the tuff rockfill materials of a concrete faced rockfill dam in China, and then obtained the parameters of the seven parameter rheology model. Finally, we analyzed the dam rheology using the three-dimensional finite element model. The results show that the dam settlement, horizontal displacement, face deflection and the displacement of the joints around the face slab are all obviously increased when considering the rheological behavior of the rockfill. We find that the calculated settlement of the dam body is in good agreement with the filed measured value when the dam is completed, and the maximum settlement during the impoundment period is within the normal range.

In order to explore the viscoelastic properties of waste engine oil (WEO) on mixed asphalt, mixed asphalt was prepared by fusing base asphalt and aged asphalt. The effect of waste engine oil content on the physical and viscoelastic properties of asphalt mixtures was studied through experiments. The test results show that the viscosity and softening point of asphalt mixture is reduced by adding waste engine oil. The complex modulus (G*) of asphalt binder decreases with the addition of waste oil at different test frequencies. With the increase of waste oil content, the phase angle (ä) of asphalt mixtures increases at specific frequencies. When the content of waste oil exceeds 6%, G* and δ will not change significantly. The stiffness increase caused by ageing asphalt in mixed asphalt will be offset by adding 2-4% waste oil. This indicates that waste oil can be used as regenerant to provide elasticity and flexibility for asphalt binder.

In alkaline and near-neutral soil environments, the mechanical and seismic performance of buried steel pipes degrades with deepening corrosion over time. To study the seismic fragility of buried steel pipes of different service ages in these environments, an incremental dynamic time history analysis of typical pipes was carried out with the time-varying constitutive model of steel. A probabilistic seismic demand model for buried steel pipes of different service ages in alkaline and near-neutral soil environments was then established, which can characterize the probability relationship between the ground motion intensity and structural response. Furthermore, on the basis of the tristate criteria, the limits of each ultimate failure state were determined. Time-varying seismic analytical fragility models of the pipes, including pipe units in two different soil environments and four service ages, were then established, which can characterize the probability of different failure states of structures under different earthquakes. The corresponding seismic fragility curves were then drawn. Seismic fragility curves were also obtained under three different diameter ranges based on seismic damage statistics. Results showed that, under the same ground motion, with increasing service time and decreasing pipe diameter, the probabilities of three failure states, namely, basically intact, moderately damaged, and severely damaged, all increased.

In order to study the advantages and disadvantages of dry mixed mortar and traditional shotcreting in underground shotcreting operation, and improve the mechanization level of underground shotcreting operation. This paper makes a statistical analysis on the use of dry mixed mortar shotcreting machines in 10 pairs of mines, such as Fucun and Tianchen of Zaokuang group. It is found that the dust content in the feeding point and the shotcreting point is higher, and the rebound is also higher. Six pairs of coal mines, such as Fucun and Tianchen, were selected to compare and analyze the shotcreting efficiency, rebound rate, dust rate and economic and technical indicators between dry mixed mortar and traditional mortar. The results showed that compared with traditional mortar, the shotcreting efficiency of dry mixed mortar was increased by 55.1%, the work efficiency was increased by 97.9%, and the rebound rate was reduced by 4.8%. Based on the above problems existing in dry mixed mortar shotcreting operation, the joint scientific research institute of Zao mining group put forward the schemes of bag feeding of finished dry mixed mortar and centralized feeding of finished dry mixed mortar, as well as the new shotcreting machine JSPB-8LX which can automatically adjust the water cement ratio, laying a foundation for the comprehensive promotion and application of dry mixed mortar under the mine.

In this study, a series of glacial lake dam overflow experiments are conducted. In those experiments, the influence of surge scale on dam outburst was studied. According to the results of the experiment, the surge overflow is the direct trigger factor of the natural lake outburst, and the periodic return of the small amplitude surge is favorable to the formation of the dam outburst. The scale of the surge will affect the time required to form the break, and the shape of the outburst flood curve. The scour movement of the water in the dam back side will make the dam form a gully. The scour movement of the water in the back side will make the dam form a gully, when the gully developed to a certain extent, the interaction between the water flow and the bottom bed changed from shear action (friction resistance) to impact action, which greatly increased the erosion and destruction capacity of the water flow and formed a "headcut". The water flow constantly brushes the bottom of the "headcut" and produced retrospective erosion, make the break constantly expanded, eventually result in dam break.

Water transfer is an effective approach to improve water quality in reservoir area. However, the research focusing on optimum efficiency of water transfer is limited, especially the dissolved oxygen (DO) in reservoir area. As a case study of Guangting reservoir (GTR) in Beijing City, the three-dimensional DO model was built based on environment fluid dynamic code (EFDC). And the spatial and temporal distributions of DO concentration with and without ecological regulation were analysed. The results show that both water transfer and ecological discharge will disturb the "oxycline" of the water body, while the effect on the surface DO is not obvious, ranging from -4.65% to 7.28%, but it has a significant impact on increasing oxygen in the bottom layer. The DO concentration in the bottom water increased by 1.85-8.52 mg/L when the output ecological discharge was used in the reservoir, and the oxygen enrichment effect of bottom water was more obvious when considering water transfer and ecological discharge simultaneously, with an increase of 2.71-12.83 mg/L. this study has the guiding significance to improve the dissolved oxygen in the bottom water of GTR area, and can also provide a method reference in evaluating the DO variation driven by the upstream water transfer or ecological discharge similar reservoirs.

Due to the construction of irrigation districts always aims at maximizing project benefits, coupling with the impact of climate change and human activities, the ecological environment of the irrigation areas has faced severe challenges, so, the construction of ecological irrigation areas and the formation of a systemic ecological production view are essential for realizing the modernization of irrigation areas and sustainable agricultural development. This paper briefly introduced the connotation, characteristics, main contents and evaluation research system of ecological irrigation districts by consulting literatures, summarized the current research and construction of ecological irrigation districts facing problems, and the inevitability of ecological transformation of irrigation districts. Integrating the overall development of irrigation areas and the harmonious coexistence concept of human and nature, the construction of ecological irrigation areas in the future will continue to move forward, and the research on relevant theories and technical systems has broad prospects.

The hydrological response of rivers to upstream reservoir regulation is one of the increasingly important research issues of watershed management. In this study, a hydrodynamic coupling model was used to simulate water level and flow processes of the Jing river and diversion flow of three outlets before and after the operation of TGP (Three Gorges Projects). The results indicated that water level and flow of three diversion channels both decreased in flood and dry seasons: the compensation regulation of the TGP was significant to maintain the water level and flow of three diversion outlets in the Jing river, but it also increased zero-flow days in the diversion channels of the Yangtze River. The riverbed erosion of channels in the upper reaches as well as lower reaches caused hydraulic gradient varying so much that it can't be ignored in the water exchange process between the Yangtze and Jing river. This mechanism cooperates with the operation of TGP to change the natural process of the Yangtze-Jing river's hydrologic process. This work provides essential information for future water resources and environmental management of the river-lake system and facilitates the effective flow regulation of dams, which has significant implications not only for the Dongting river-lake system but also the similar lakes and rivers elsewhere.

River chief system is an innovative river and lake management system and model with Chinese characteristics. At present, the river chief system has achieved remarkable results in the management and protection of rivers and lakes in various regions. To promote the green development of small hydropower stations under the river chief system is not only the internal requirement of protecting water ecological environment, but also the urgent need of small hydropower stations to adapt to the green development in the new era. Based on the current situation of small hydropower development, this study establishes the evaluation system of small hydropower cleaning and rectification, evaluates the main problems existing in the green development and ecological transformation of small hydropower, and puts forward a practical development path, in order to promote the small hydropower ecological problems rectification and gradually embarking on the road of green development.

The soft soil stratum has low carrying capacity, poor permeability and is hard to be drained, which affects the excavation speed of foundation pit. This paper introduces the application of a new type of dewatering technology in deep soft soil foundation pit dewatering. This technology adopts air compressor and vacuum pump to improve the water collection efficiency and pumping efficiency effectively and gains good economic and environmental benefits.

The monthly precipitation data of 56 stations during 47 years (1973-2019) in South Korea are comprehensively analysed using the EOF technique and CSEOF technique respectively. The main motivation for employing this technique in the present study is to investigate the physical processes associated with the evolution of the precipitation from observation data. The first mode account for 77.07% of the total variance and exhibits annual cycle of corresponding PC time series with traditional spatial pattern, and the second mode spatial patterns account for 8.13% of the total variance and show strong north to south gradient. In CSEOF analysis, two leading modes temporal pattern of PC time series reveals the annual cycle on a monthly time scale and long-term fluctuation, the first mode temporal pattern of PC time series account for 73.55% of the total variance and shows an increasing linear trend which represents that temporal variability of first mode pattern has been strengthened. The spatial distribution corresponding to two leading modes show monthly spatial variation. Compared with the EOF analysis, the CSEOF analysis preferably exhibits the spatial distribution and temporal evolution characteristics and variability of South Korea historical precipitation.

Based on the large-scale shaking table model test of aqueduct, the interaction and influence of large-scale aqueduct structure-water-damping bearing were studied. Through the dynamic detection of white noise, the free vibration characteristics of aqueduct model under different working conditions were obtained. Based on the comparison of seismic responses of aqueduct under three conditions of water, half water and normal water level and two states of locking and releasing damping bearing, the influence of water quality and damping bearing on natural frequency, dynamic water pressure and dynamic strain of aqueduct structure was studied. By inputting Ricker waves with different frequencies, the correlation among the input wave frequency, the fundamental frequency of aqueduct structure and the frequency of water sloshing and the influence on the aqueduct response were studied. The experimental results show that with the increase of water quality, the interaction between water and aqueduct structure enhanced, which had a great influence on the fundamental frequency of aqueduct structure, and the influence of water level presented an obvious nonlinear. The hydrodynamic pressure decreased along the middle section elevation of the aqueduct, and the acceleration increased with the increase of the tank elevation, which reflected the complexity of the interaction between water and aqueduct structure. The results provide support for the seismic design of aqueduct and the application of shock absorption bearing.

As an agricultural country, the shortage and waste of water resources seriously restrict the rapid development of agriculture in China, so how to realize water-saving agriculture is imminent. This paper expounds the current situation and existing problems of water-saving agriculture in China, studies and discusses the development trend of water-saving agriculture in the future, which provides a certain theoretical basis for the rapid development of China's agriculture.

In order to find out the optimal scheme of irrigation quota for seed corn in Zhangye, field experiments were carried out to study the effects of different irrigation quotas on the growth and yield of seed corn. Seed corn was used as test crop, drip irrigation under plastic film was used as water supply mode different irrigation quota treatment T1(4200m³/ha), T2(4650m³/ha), T3(5250m³/ha), T4(5400m³/ha), CK(5850m³/ha) were set up.The results showed that the plant height of T2 was the highest, reaching 154.6 cm,and the ear height of T4 was the highest, reaching 74.8cm.There was a significant difference in the double ear rate among different treatments, among which the double ear rate of T4 was the highest, reaching 19.12%, followed by T3(17.86%) and CK(15.12%), and the double ear rate of T1 was the lowest, reaching 12.98%. The empty stalk rate of T2 was the largest(7.72%), followed by T3 and T4, and the empty stalk rate of T5 was the smallest. The ear of T3 was the longest(14.74cm), and the invalid ear length of T4 was the largest(1.64cm). The grain number per ear of T4 was the largest, followed by T2, CK and T3, and CK was the smallest. Compared with T2 and T3, T4 increased by 0.23% and 4.32%(P>0.05), respectively, and significantly increased by 16.56% compared with T1.Different treatments have different responses to the yield of seed production. Among them, the T4 treatment has the largest yield, reaching 6655.8kg/hm², followed by T2 and T3, which are 5853.6 and 5661.9kg/hm², respectively.The T1 yield is the smallest, only 5362.2kg/hm²,T4,T2 increased by 24.12% and 9.15% respectively compared with CK, significant difference. Comprehensive consideration of agronomic traits, ear economic traits, crop yield and yield increase rate and other indicators show that the optimal irrigation quota for corn planting areas in the Hexi Corridor is 5400m³/ha The irrigation quotas for each growth period are 825m³/ha at the jointing stage, 825 m³/ha at the big bell mouth stage, 975m³/ha at the tasseling stage, 975 m³/ha at the flowering stage, 975m³/ha at the filling stage, and 825 m³ at the milking stage/ha. This research can provide theoretical and technical reference for realizing high-efficiency water-saving cultivation and industrialization development of maize seed production in the oasis irrigation area of the Hexi Corridor.

In this paper, two methods of finite element and structural mechanics are used to study the design of the lining structure of the spillway tunnel, so that the design of each part of the spillway tunnel is economical, reasonable and safe. The finite element method is used to analyze the influence of the surrounding rock consolidation grouting, drainage holes, system bolts and the new and old concrete combination on the bearing capacity of the building. The results show that it is very necessary for the lining structure to be consolidated and grouted, to install system anchor rods and drainage holes. Inserting reinforcement for the old concrete lining is beneficial to improve the stability of the lining structure. Structural mechanics reinforcement can meet the safety and stability requirements of the lining structure.

According to the equation of discrete solid particles' motion in arbitrary flow field, the dynamic characteristics and trajectories of sediment particles are discussed. The small disturbance method is used to analyze the stability of sediment particles at the equilibrium point, it is shown that the change of turbulence frequency will lead to the sudden change of sediment particles, under the condition of a certain periodic excitation amplitude; and under the condition of certain periodic excitation amplitude, the change of sediment particle size will also lead to the sudden change of sediment particle movement, All of the above prove that the movement of sediment particles near the river bed surface has a catastrophe.

By taking bending shoal-cutting of Water Conservancy park in Lingjiang as a case, the change of flow pattern in the curved channel before and after the shoal-cutting project is analyzed by numerical simulation, and application effect is analyzed. By analyzing the tidal level data of the engineering reach, the appropriate barrier clearance elevation is determined. The relationship between water level variation and different range of shoal-cutting is established, and the suitable range of shoal-cutting is recommended. It has an important reference for the management of bend in tidal river.

Under the marine environment, the durability of the reinforced concrete (RC) infrastructures is greatly influenced by the chloride-induced corrosion of the ordinary reinforcing bars. In order to prolong the service life of the RC infrastructures, stainless steel rebars (SSRs) are gradually used in marine infrastructures due to their better corrosion resistance. However, research on the corrosion and mechanical properties of the SSR under marine environmental attack is quite limited. In this paper, tensile tests at room temperature were carried out on corroded SSR samples with different types and diameters. Results show that, no obvious yielding plateaus can be observed in the stress-strain relation curves of the SSRs when compared with those of the ordinary carbon steel bars; the yielding strength and ultimate strength of the corroded ordinary carbon steel bars and SSRs decrease with the increased average cross-sectional loss while the elongation change of the corroded SSRs with the average cross-sectional loss is variable. Basing on the constitutive model of uncorroded SSR proposed by Ramberg and Osgood and considering the influence of the average and maximum cross-sectional loss on the strengths of corroded SSRs, stress-strain constitutive models of the corroded SSRs were proposed.

Focusing on the aquatic ecological and environmental problems of waterway regulation structure, the research progress of waterway regulation structure on the physical and chemical properties of river water bodies, river benthic community structure and distribution and fish habitat was summarized, and the existing problems in current scientific research and engineering application were analyzed. Key researches were also put forward that should be carried out in the future for the protection of water ecological environment of waterway regulation structure including constructing and protecting the regional river ecological health index system in the waterway regulation building area and improving the construction of ecological waterway.

Aiming at the problem of the integrity of the regional flood control planning with the division of administrative boundaries in the coordinated development of the region, the typical inter-provincial basin of Beijing, Tianjin and Hebei is selected as the research object, and the numerical coupling model of flood control and drainage based on MIKE11, MIKEurban and MIKE21 is constructed to identify the regional problems of river flood control, to reveal the systemicity, linkage and synergy of flood control and drainage planning under the background of regional coordinated governance, and to explore the planning ideas for linkage planning of regional flood control and drainage projects.

For the purpose of safe and efficient construction of multi-row pipe jacking in water-rich sand layer, a case study was carried out, taking the three-row pipe jacking project of the water-rich sand layer in Haikou city as an example. Firstly, based on the analysis of the disturbance mechanism of surrounding rock in multi-row pipe jacking construction, the principle that multi-row pipe jacking construction should give priority to excavate two pipe jacking tunnels which are far apart in turn was established. Secondly, taking the maximum ground settlement at the center of pipe jacking as the judgment index, the optimal scheme of the construction sequence of multi-row pipe jacking was determined. Finally, based on the field measured data, the relationship between the jacking force, the pressure of the palm surface, the average frictional resistance and the jacking process during the jacking process was analyzed, and summarized the experience of the site construction. The results show that: (1)it is better to give priority to construct two pipe jacking tunnels which are far apart in the construction order multi-row pipe jacking; (2)Based on the empirical method of surface subsidence, the maximum surface subsidence at the center of pipe jacking group can be used as the judgment index to determine the optimal jacking sequence; (3)Under the condition of "from the two sides to the middle", the surrounding rock around the middle jacking pipe is greatly disturbed by the construction of the first jacking pipe, its jacking rate should be reduced on the basis of the first building jacking pipe, and the cutting rate of the cutter and the grouting pressure should be increased, so as to realize the continuous jacking construction. The results of this paper are of great reference value to the determination of the jacking parameters of multi-row pipes in the future.

The response relationship between pollutant and flow rate is very important and is one of the key factors for the reasonable simulation of the model for a basin. The basin land use type, soil types, weather, vegetation distribution, soil and water loss situation are taken as the influence factors to explore its concentration change in migration of pollutants in relation with the response of the flow in Xiangxi River watershed. Emphasis was put on the effects of nitrogen pollutants based on the mass conservation equation combined with the total nitrogen concentration of pollutants. Relationship between total nitrogen pollutants and flow of three types of response relation is preliminary established. Measured data of total nitrogen from 2014 to 2017 are used for verification and error analysis. Results show that the power function is the best relationship, while the logarithm function is the second one, and the exponential function is the third one through trend coincidence, fluctuation range and error analysis. This study is helpful to understand the response relationship between pollutant concentration and discharge in small watershed, so it can also be used for pollutant prediction in small watershed without measured data.

In order to investigate the influence of the yield and water use efficiency of onions in the Hexi Corridor, this paper tested the yield and water use efficiency of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the dry matter accumulation process of onion was measured in each reproductive period, and the results showed that: The black mulch full irrigation treatment T1 yielded 120393.45 kg⋅ha⁻¹ with an output value of 72236.07 yuan⋅ha⁻¹, while the black mulch moderate loss adjustment irrigation treatment T3 yielded only 61697.39 kg⋅ha⁻¹and 37018.43 yuan⋅ha⁻¹. The yield per square meter, irrigation water use efficiency and water use efficiency decreased with the increase of regulated deficit irrigation degree, and there was no significant difference between black film mulching and transparent plastic film mulching, but they were significantly higher than that of fine sand mulching. The onion yield and water use efficiency indexes were combined, so that the best control of yield could be achieved by covering the onion with black mulch and irrigation throughout the growing season, which is of theoretical guidance and significance for onion cultivation in the Hexi Corridor.

Wenzhou city is Located in the southeast of Zhejiang Province, it belongs to subtropical climate. The main factors that affect the climate in Wenzhou include strong solar radiation and the regulation of marine water body. The annual variation of rainfall in Wenzhou City is very large. The disastrous weather in Wenzhou mainly includes typhoon, rain and drought. The ways of Typhoon Affecting Wenzhou include direct landing and adjacent area landing. Direct landing is more harmful. Rainfall is the most important factor affecting flood and drought disasters in Wenzhou City, so the analysis of rainfall can provide a reference for flood control and drought relief work in Wenzhou City. In this paper, BP neural network method is used to analyze and forecast the rainfall of Xishan station in the main urban area of Wenzhou City. The results show that the precipitation in Wenzhou City will change greatly in the next ten years. Flood disaster may occur in 2022 and 2028, and drought may occur in 2023.

The selection of the layout scheme is the key content of the pre-feasibility study of large and medium-sized hydropower stations. Based on the topographical and geological conditions, and considering the construction conditions, reservoir flooding, project investment and other factors, this paper makes an in-depth analysis of the layout comparison and design of the pre-feasibility stage of Shitouzhai Hydropower station, in order to provide beneficial inspiration for similar project design.

It is one of the effective methods to increase the reliability of flood discharge buildings with high water head and reduce the project cost to transform the diversion tunnel of temporary buildings into permanent spillway by using the horizontal swirl flood discharge system. Based on Gongboxia hydropower station and combined with prototype monitoring, this paper studies and analyzes the key points of shape layout, structural characteristics and operation effect of horizontal swirl flood discharge system, the results show that the horizontal swirl flood discharge system has strong adaptability to topographic and geological conditions, good energy dissipation effect and hydraulic characteristics, stable inlet and outlet flow pattern, stable cyclone cavity, no obvious signs of adverse negative pressure and cavitation erosion, no adverse structural vibration and dynamic response, and safe operation of the spillway tunnel.

In order to study the corrosion resistance of the stainless steel bars under marine environmental attack, simulated seawater drying and wetting test on the two types of the stainless steel bars (SSRs), 304 and 316L austenitic SSRs as well as S32304 and S32205 duplex SSRs, was carried out in the laboratory. Electrochemical monitoring of open-circuit potential, linear polarization and electrochemical impedance spectroscopy (EIS) was carried out via CS310H electrochemical potentiostat. Zview software was used to discuss the measured data. Results show that the Stern-Genry coefficient B of the ordinary carbon steel bar is about 20mV, while those values of the duplex SSRs and austenitic SSRs are in the range of 14∼16mV and 15∼17mV, respectively. For the above-listed reinforcement, better corrosion resistance is shown in the duplex SSRs with the best behaviour observed in S32304 duplex SSRs; the corrosion resistance of the austenitic SSRs 304 and 316L is good and similar, while poor corrosion resistance is shown in the ordinary carbon steel bar as expected.

The water-stop curtain can effectively isolate or weaken the hydraulic connection between the inside and outside of the foundation pit, which has a significant impact on the safety of foundation pit excavation and the surrounding environment. In the event of the failure of the water-stop curtain, the measures of laying groundwater recharge wells outside the pit can be used to maintain the water level outside the pit and avoid excessive settlement of buildings outside the pit. Through the practice of a certain foundation pit in Shanghai, this paper proves the feasibility of groundwater recharge measures in dealing with the failure of the water-stop curtain and provides a reference for similar projects. Groundwater recharge measures have certain advantages over other treatment measures in terms of cost and construction period, and have good economic and social benefits.

In the new era of rapid development of information technology, intelligent water conservancy has become the inevitable trend of the development of water conservancy industry. This paper describes the development and status quo of smart water conservancy in China in recent years, analyzes and discusses the existing problems, and puts forward some suggestions for the corresponding problems, so as to provide a certain reference for the follow-up development of smart water conservancy in China.

Based on Tianjin Xihe control sluice, this paper uses the improved resistance coefficient method and ABAQUS finite element software to calculate the seepage at the bottom of sluice. By comparing the calculation results, the advantages and disadvantages of two methods to calculate the seepage at the bottom of sluice are analyzed, which provides a new idea for the calculation of sluice bottom seepage.

In this paper, a two-dimensional physical model was established in a laboratory sink, the stability of a breakwater structure at a LNG terminal in Pakistan was studied, and the wave propagation simulation of two designed cross-sections was studied. And make conclusions to evaluate the layout scheme and provide a reference for other similar structures.

Urban sewage sludge is rich in a large amount of organic matter, which has a significant impact on the compression characteristics of sludge, and ultimately affects the landfill disposal and resource utilization of sludge. Quartz sand was mixed into the sewage sludge to prepare sludge samples with an organic content of 8%, 16% and 26% (raw sludge) respectively, and then a standard consolidation test was carried out to explore the influence of the organic content on the compression properties of the sludge and mechanism of action. The results show that the compressibility of urban sludge increases with the increase of organic content. The compression coefficient and index of sewage sludge both increase exponentially with the increase of organic content. The ln(1+e)∼lgp curve of urban sludge has a significant "inflection point" and a certain consolidation yield stress. With the increase of organic content, the consolidation yield stress decays exponentially. Organic matter in the sludge has a flocculent structure and a large specific surface area. It is easily adsorbed on the surface of the clay particles, hindering the cementation of the clay particles and reducing the permeability of the sludge. At the same time, organic matter has water-retaining property, hinders the consolidation and drainage of sludge, and ultimately affects the compression properties of sludge.

Water-saving reform in irrigated districts is of great significance to agricultural water-saving and production increase, and to promote economic development. Hence, a reasonable evaluation of the comprehensive benefits of irrigation district water-saving reform is conducive to the planning and management of the water, and to the modernization of irrigation districts. Through the collation of relevant literature, the necessity and feasibility of water-saving reform in irrigation districts were briefly described, and the application progress of different evaluation models in the benefit evaluation of water-saving reform in irrigation districts was clarified. The problems and development trends of benefit evaluation of water-saving reform in irrigation districts are put forward, and the benefit evaluation model widely used at present is described. Benefit evaluation has involved all aspects of human life, and its application fields have become wider and wider, and more and more methods have been adopted. Therefore, it is of great importance to summarize the evaluation methods and theories.

In order to investigate the influence of the soil temperature of onions in the West Hebei Oasis, this paper tested the soil temperature of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the soil temperature of onion was measured in each reproductive period, and the results showed that: The most significant changes in soil temperature were found in the 5 cm soil layer, where the soil temperature was more affected by external influences, and in the 10 and 20 cm soil layers, where the soil temperature was less affected by external influences. The difference in soil temperature was not significant between full irrigation and regulated deficit irrigation. The soil temperature in the black mulch layer was higher than that in the transparent mulch layer and fine sand mulch layer at the seedling and leaf development stages, while the soil temperature in the black mulch layer was higher than that in the transparent mulch layer and fine sand layer at the bulb expansion and maturity stages.The soil temperature of the onion can be best controlled by irrigation while covering the onion with black mulch throughout the growing season, which is of great significance for onion cultivation in the Hexi Irrigation Zone.

The treatment effect of dam foundation fracture zone is related to dam safety, A case is provided base on the fault-fracture zone with large permeability in a core dam foundation in Xinjiang province, The dam foundation seepage model is established with the seepage finite element method base on The test results of post-grouting in the fault-fracture zone, simulation working conditions of different curtain depth and permeability indicate that significant impervious effects of compound grouting and depth-curtain at fault zone, leakage is less in the dam foundation and seepage stability meet the requirement on the riverbed overburden in the downstream, The results are high reference value for similar projects.

Under the action of an earthquake, the interaction between water bodies and solids is an important part of analyzing the stability of water retaining structures. This paper proposes the use of shell elements to simulate two-way water retaining thin plates, and the correctness of the method is verified by ANSYS fluid-solid coupling plate; then the new method is used to simulate the impact of the water on the thin plate under the action of earthquakes. Earthquake water pressure is used to analyze the seismic response law of the two-way water retaining plate. The research results show that: the hydrodynamic pressure of the two-way water-retaining sheet is greater than that of the one-way water-retaining, and is approximately equal to the sum of the dynamic pressures of the two-way water-retaining.

This experiment was conducted in order to study the effects of commodity functional organic fertilizers on maize yield, soil fertility and economic benefits, and to provide a feasibility basis for the application of functional organic fertilizers instead of chemical fertilizers in maize production. Using seed-producing maize as experimental crop, drip irrigation under the mulch as water supply mode, and different fertilization treatments CK (no fertilization treatment), T1 (3000kg⋅hm⁻²), T2 (2250kg⋅hm⁻²), T3 (local method), T4 (Local conventional reduction) in a total of 5 treatments. Research shows that maize yields have different responses under different organic fertilizer conditions. Compared with T3, the plant yield of CK is reduced by 26.4%. The remaining CK, T1, and T3 are increased by 7.8%, 3.4%, and -5.6% respectively compared with T2. Compared with CK, T1, T2, T3 and T4 significantly increased by 31.7%, 28.8%, 26.4%, 22.0%. The difference was significant. The economic shape of fruit spike was also different in response to different modes of functional organic fertilizer application. T1 treatment plants were the highest, reaching 139.8 cm, followed by T3, T4, T2 and CK, which were 11.2%, 4.5%, 8.3%, 6.4% higher than CK compared with T1, T2, T3 and T4, and the difference was significant. T1, T2, T3 and T4 increased by 11.2%, 4.5%, 8.3%, 6.4% compared with the spike length of CK, the difference was significant. ear diameter increased respectively by 20.5%, 21.6%, 20.6%, 14.0%. the difference is significant; compared with CK, the ear rows of T1, T2, T3 and T4 are increased by 5.5% overall. The number of ear rows in the remaining treatments remains between 0.7% and 3.4%. The difference is not significant; the bald tip after each treatment was generally shortened, compared with CK, T1, T2, T3 and T4 are shortened by 44.6%, 28.6%, 12.5%, and 60.4%, respectively. the difference was significant; the number of rows after treatment Compared with CK, T1, T2, T3, and T4 increased by 18.1% overall. The number of ear rows in the remaining treatments remained between 0.3% and 4.7%, with no significant difference. The Spike grain after each treatment increased significantly. Compared with CK, T1, T2, T3, and T4 are increased by 30.1%, 29.5%, 27.6%, and 26.4% respectively. The difference is significant; the 100-seed weight of T1 was the largest, compared with CK, the 100-seed weight of T1, T2, T3 and T4 are increased by 27.7%, 15.6%, 11.1% and 6.1% respectively. the difference was significant. After two years of experiments, the soil fertility of T1 was improved, in which alkaline-hydrolysis nitrogen Basically remain unchanged, the content of rapidly-available potassium and alkaline-hydrolysis nitrogen was slightly increased. The content of available phosphorus was nearly four times higher than before the experiment. The soil is more weakly-alkaline. The comprehensive soil evaluation index is 40% before the test. The comprehensive evaluation was index increased by 54 after the test. The evaluation index was medium. Applying functional organic fertilizer 3000kg⋅hm⁻², additional fertilizer is based on the total nutrients of soil nutrients and chemical fertilizers. It can significantly increase the cluster length, panicle diameter, kernel number per row, and grain number per spike of seed-producing maize. while effectively reducing the invalid spike length, providing a guarantee for increasing production at the late stage. The application of functional organic fertilizer is 3000kg⋅hm⁻² has a significant increase in yield, which is 7.5% higher than the habitual fertilization of local farmers (average of two-year data).

The participation of gas hydrate constitutionally affects the mechanical properties of gas hydrate-bearing sediments. The hydrates contribute to the mechanical properties of hydrate-bearing sediments by pore-filling, bearing and bonding effects. A discrete element model of hydrate-bearing silt was established randomly filled by the hydrate particles into silt-sized granular skeleton reservoir. The cluster & bonding hydrate is generated in the pores of the numerical silt reservoir to study hydrate's mechanical effects. One-dimensional loading was applied to the numerical sample to investigate its volume change, bond degradation and stress transmission. The main conclusions are as follows. The structural yield stress corresponds with the abrupt bond breakage. Particles and contacts will be redistributed after the widespread bond breakage. The breakage of hydrate-hydrate bonded contacts is more quickly than that of silt-hydrate contacts ascribe to a crushing process of hydrate clusters (especially for SMH=45%).

The impact of habitat changes on fish has become increasingly prominent, leading to the decline of fish population in varying degrees. Therefore, the study of fish habitat is an important means to protect fish resources. This article introduces the current status of fish habitat research at home and abroad. Overseas fish habitats are more comprehensive. Domestic fish habitat research mainly focuses on fish reproduction hydrology research, fish reproduction hydrodynamics research, and fish habitat suitability. The purpose of this study is to provide a systematic scientific basis for the protection of fish key habitats, and to protect the sustainable utilization of fish germplasm resources and the sustainable development of fisheries.

In view of the overlapping project between the double track bridge of Ningbo-Taizhou-Wenzhou expressway and seawall, the large-scale three-dimensional finite element calculation is carried out by using the finite element software ABAQUS, the displacement limit of bridge pier top is studied, the internal force deformation of bridge pile foundation and its variation law in the process of seawall filling and later consolidation settlement are analyzed, and the influence of sea seawall filling on the stress and deformation of bridge pile foundation is studied. The calculation results show that: the main pier in the enclosure side of the two main piers in the design scheme is most affected by the construction of seawall. At the end of seawall construction, the longitudinal displacement along the bridge is 25.56cm, the transverse displacement is -10.68cm, and the settlement is 3.49cm. From the beginning of seawall construction to 15 years after the completion of seawall, the maximum longitudinal displacement along the bridge is -80.87cm, the maximum transverse displacement is -38.94cm, and the maximum settlement is 382.2cm, in which the settlement during the construction period is 346.0cm, accounting for 90.5%. The calculation results of design scheme show that the displacement of bridge pier top is too large, and the tensile stress of bridge pile is also large, therefore, it is necessary to optimize the design scheme to reduce the displacement of the bridge.

In order to investigate the influence of the physiological characteristics of onions in the Hexi Corridor, this paper tested the physiological characteristics of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the physiological characteristics of onion was measured in each reproductive period, and the results showed that: The net photosynthetic rate, stomatal conductance, and intercellular CO₂ concentration all decreased with increasing amplitude of the transfer loss. Although the net photosynthetic rate, stomatal conductance, and intercellular CO₂ concentration of black mulch T1 were higher than those of transparent mulch T4, there was no significant difference between the two treatments, and the net photosynthetic rate, stomatal conductance, and intercellular CO₂ concentration of T1 and T4 were significantly higher than those of sand mulch T5. The physiological characteristics of the onion can be best controlled by irrigation while covering the onion with black mulch throughout the growing season, which is of great significance for onion cultivation in the Hexi Corridor.

A ship maneuvering mathematical model was established considering the influence of river bank effect based on the depth integrated 2-D flow mathematical model. Tanking the section of the Suoluo beach reach of Lancang River in Yunnan Province as an example, the numerical simulation of ship maneuvering motion under bank effect was carried out. Results show that the typical ship can not ascend rapids when considering the bank effect, so it is necessary to implement channel regulation. The study reveals that the model can simulate the ship maneuvering motion and navigation status under bank effect, which can provide some useful references for the ship's navigation and maneuvering in mountainous rivers.

In order to know the water quality of rural water supply projects, the water samples are collected from finished water and tap water of administrative villages in some counties and districts of the Pearl River Basin for sampling inspection in 2019. The water quality indexes and limits in Table 1 and Table 4 are taken from Standards for Drinking Water Quality for evaluation. The detection results showed that the water quality of finished water and the water source area was completely up to the standard. For 71 water samples collected from the finished water of the water treatment factory detected, except for some parameters that slightly exceeded the limits, the rate of reaching the standard is up to 97.2%. It can thus be seen that the water quality safety of the rural water supply projects in the Pearl River Basin area is highly reliable.

Tidal levels designed for coastal levee in Pearl River estuary have been provided by Department of water resources of Guangdong Province in 2002 and played important role in ensuring the security of coastal cities in recent decades. However, big changes have taken place in the hydrological regime of the estuary as the sea water level rise and Frequent storm surges in recent years. The proportions of the coastal levee lengths in Guangzhou and Zhuhai city occupied a large part of the portion in the Bay Area, about 30% and 23% respectively, while the shortest in Shenzhen city, accounting for only 5%. The designed tidal levels used for coastal levees in the past were compared with those proposed by PRWRC in the year 2011, showing lower about 0.2∼0.5m totally in the mouths and open waters including Shiziyang of the estuary. It would reach to about 0.6∼0.7m lower in the waters around Nansha district after considering the influence of the typhoon Mangkhut and Hato, while there was little variation in the net river area upstream in any case. The controlled tidal levels designed for coastal levees were analyzed for its applicability and it showed that those used in Guangzhou, Shenzhen and Jiangmen city meet the requirements and were somewhat lower in Dongguan, Zhuhai and Zhongshan city under variation of hydrological regime recently.

Since the 20^th century, national investment in agricultural irrigation has been increasing, indicating that the state is paying more and more attention to the "Three Rural Issues". Along with the national emphasis on the "Three Rural Issues" and the background of increasing economic investment in agricultural irrigation, irrigation technology has been developing rapidly in Gansu Province, which is reflected in the year-on-year expansion of efficient water-saving irrigation area. The goal of water-efficient irrigation technology is to improve the water utilisation coefficient, thus optimising the planting structure of crops and increasing crop yields. Therefore, a variety of high-efficiency water-saving irrigation technologies such as pipe irrigation, sprinkler irrigation and micro-irrigation have been vigorously promoted and applied. The article analyses the current status and benefits of high-efficiency water-saving irrigation infrastructure in Gansu Province, and aims to provide data support and theoretical guidance for the development and improvement of high-efficiency water-saving irrigation in the province.

In the reach from Jieshou to Ducheng of the Xijiang River, the flow and sediment conditions are complex, the shallows are linked together and the rocks are densely covered. With the promotion of waterway classification, the navigation-obstructing phenomenon appears in some shoal reaches due to insufficient depth. There are some safety hazards for ship navigation due to the distribution of rocks in channel or on both sides of channel. Based on the navigation-obstructing characteristic, the channel regulation principles mainly in dredging and rock blasting and secondly by damming were put forward. And according to the concrete condition of different shallow reaches, different channel regulation methods were proposed. By fixed and movable bed physical model test, the variations of the water level along the reach and the velocity in channel before and after different engineering plans were studied. The results show that the dredged channel will be stable and the water depth in channel will meet the demands of design depth after the recommended plan implementation.

Taking Fortran language as the platform, a depth-integrated two-dimensional non-uniform flow mathematical model and a ship maneuvering mathematical model were developed from the bottom layer. By further coupling the influence of wind, the mathematical model of ship maneuvering motion based on wind and current effects was constructed. Taking a typical river section in the Three Gorges Reservoir area as an example, the numerical simulation of ship maneuvering motion under still wind and non-uniform wind effect was carried out. Results show that the ships are obviously affected by wind in this river section. With the increasing change frequency of wind speed and direction, the difficulty of ship control increases correspondingly. In order to avoid the average accident, the ship must change its steer in time accordingly. This model can simulate the ship maneuvering motion and navigation status under wind effect quite well, which can provide some references for the ship's navigation and maneuvering in inland rivers.

Zhejiang Datang Wushashan power plant is composed of farmland and aquaculture ponds in the Xizhou seawall, which are backfilled with artificial riprap. In order to block the seepage path in the rock fill layer, the vertical curtain cement paste grouting anti-seepage reinforcement measures are adopted to block the connection between the underground water and the surrounding surface water in the plant area, so as to achieve the purpose of gas closure. This paper mainly analyzes and evaluates the technical indexes, such as grout diffusion range and impermeability, of the cement paste grouting curtain, via field tests and two dimensional numerical simulation based on the platform of PFC2D or Geostudio.

By calculating the vegetation water requirements(ET_C) of the typical plantations of Robinia pseudoacacia and Robinia pseudoacacia-Platycladus orientalis mixed plantation in the Loess Gully Region and analysing the coupling relationship between rainfall(P) and water requirements of each plantation, thereby scientifically guides local tree planting and afforestation, and better vegetation restoration.The Penman-Monteith formula is used to calculate the reference crop evapotranspiration in the study region, and then the double crop coefficient method is used to calculate the daily ET_C of Robinia pseudoacacia and its mixed plantation in different hydrological years. The result shows that from dry year to normal year, the ET_C-RP-CO is less than ET_C-RP by 48.8 mm and 52.2 mm respectively, and the growth season accounts for the largest proportion. The ET_C-RP-PO and ET_C-RP are not satisfied in most months of the growth season. Among them, the initial period and the development period of the growth season are the largest, with the largest water requirements deficits(D) reaching 58.65mm, 51.32mm (dry year) and 106.21mm, 93.18mm (normal years).The ET_C of two plantation increases from dry year to normal year.And the D also increases when vegetation water requirements satisfaction(S) increases, but the increase rate is expressed ET_C > S > D.

In the bidding process of wetland planning and design scheme, in order to obtain the optimal solution through comprehensive trade-off from multiple bidding schemes, this paper proposes a comprehensive evaluation and decision-making method of wetland planning and design scheme based on the wetland planning and construction objectives and the commonly used evaluation index system of wetland planning and design scheme. The fuzzy correlation coefficient from the bidding scheme to the optimal and inferior wetland planning and design scheme is used to determine the relative advantage fuzzy correlation degree of each bidding scheme, and the priority degree of each bidding scheme is ranked according to the relative fuzzy correlation degree, so as to realize the evaluation and decision-making of wetland planning and design scheme. The application shows that the method can effectively solve the uncertainty problem in the comprehensive evaluation and decision-making process of wetland planning and design scheme, and has strong operability. It can provide a reference for similar problems in the process of engineering practice.

In order to investigate the influence of the water consumption characteristics of onions in the Hexi Corridor, this paper tested the water consumption of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the water consumption of onion was measured in each reproductive period, and the results showed that: (1) the soil water storage decreased with the increase of water loss, i.e. the soil water storage size was T1>T2>T3. The difference in soil water storage between black mulch and transparent mulch was smaller, but significantly larger than that of fine sand mulch. (2) The water consumption and water intensity of onion showed a decreasing trend with the increase of the adjustment loss, and the water consumption of fine sand cover > transparent mulch cover > black mulch cover. (2) The water consumption and water intensity of onions decreased with the increase of the regulation deficit, and the water consumption of fine sand mulch was more than that of transparent mulch and black mulch.

The VOF (volume of fluid) method was applied to track free water surface, and the Realizable turbulent model was used to close the two-phase flow time-averaged equation to numerically simulate the hydraulic characteristics of surface jet on horizontal base plate with shallow depth. The result showed that a big vortex exists in the flow field, and the greater the inlet flow velocity, the longer the length of vortex. The distribution laws of horizontal velocity and longitudinal velocity of a cross section are different in the backflow region and open channel flow region. The gradient decaying of the maximum velocity on cross-section was mainly affected by the inlet velocity.

With the construction of reservoirs in China, inland waterway conditions have been greatly improved. The number of ships and tankers navigated in the inland waterways significantly increased which may lead to an increased risk of oil spill accidents. Oil pollution is one of the major threats to economy and ecosystem. To date research on oil spill is mainly focus on marine environment, however it is very limited on inland river. The purpose of this study is to combine our previous liner experimental study of characteristic of spread and transport of oil spill to develop a coupled two-dimensional oil spill model. An oil trajectory model has been conducted and applied for water surface spread simulation in the Luoqi reach of Yangtze River. The results can provide a reference for the prediction of spread and transport of oil spill in inland waterway.

When ships sail on the inland river in mountainous areas, the limited water depth can frequently lead to shallow water effect. To some extent, safety and maneuverability of shipping will be impacted. Consequently, it's necessary to consider the shallow water effect when studying the ship ascending rapids in mountainous rivers. By considering the impact of shallow water effect, a three freedoms maneuvering mathematical model based on shallow water effect was established in this paper on the basis of two-dimensional water flow mathematical model. Application of the model was implemented on the regulation of the waterway in Suoluo rapids section of the Lancang River to obtain ship navigating parameters (helm angle, drift angle, heading angle, ship's speed and speed against the water) for comparative analysis. Results show that the ship can reduce the impact of shallow water effect by adjusting the rudder angle and reducing the ship speed when navigating in shallow and narrow channel. The obtainment of the voyage line diagram by the simulation of ship's maneuverability test validates that the ship can ascending rapids through self-propulsion after the river regulation.

Pneumatic lifting pump, as one of the ideal new methods for mining and upgrading, has obvious advantages such as simple structure, safety and reliability. The research of it has important scientific value and engineering significance. Based on Fluent simulation software, using Euler model and SST k-ω turbulence model, with the help of UDF self-programming, the influence of variable air volumes-linear opening, linearly closing on the hydraulic characteristics of the air-water lifting pump is discussed. The results are shown as follows. 1) In the slow linear opening mode of the gas flow, the liquid lifting flow increases, the change trend of it is slower than that of fast linear closing mode. 2) In the slow linear closing mode of the gas flow, the liquid lifting flow reduces, the change trend of it is slower than that of fast linear closing mode. These research results will lay the theoretical foundation for the application of pneumatic lifting technology in river dredging, sewage treatment, oil extraction and other fields.

The influence of slag powder, cement and bentonite on the permeability coefficient of granite residual soil at different incorporation ratios was analyzed by means of seepage test with variable head. Meanwhile, the permeability coefficient was compared with that of the original granite residual soil. It is found that the effect of slag powder on reducing the permeability coefficient of granite residual soil under non-alkaline environment is limited. The effect of cement on decreasing permeability coefficient of granite residual soil is obvious. Bentonite has the best effect on reducing permeability coefficient of granite residual soil.

This paper systematically analyzes the quality supervision data system of water conservancy projects. Then, according to the characteristics of water conservancy project quality supervision text, the Word2vec algorithm and TFIDF algorithm are combined to construct a feature extraction system of water conservancy project quality supervision text suitable for short length and few samples. Finally, a semi-supervisory model system consisting of logical regression, simple Bayes, and SVM is introduced to solve the problem of incomplete quality supervision risk data for water conservancy projects. To sum up, on the basis of the three parts, i.e. data system, feature extraction, and semi-supervisory text classification, we build a water conservancy project quality risk assessment framework and provide a data processing tool for machine learning of hydraulic engineering quality risks.

This paper takes Yuhuan City as the research object, based on the single factor evaluation method, Nemero index method and gray relevance analysis method, selects three indexes of ammonia nitrogen, total phosphorus and permanganate index. By analyzing the main pollutants, the reduction of each pollutant and the differences between different evaluation methods, the effectiveness of water environment governance is evaluated, and then targeted regulatory measures are proposed to further improve water environment. The results show that the main pollutants in Lupu Town, Yuhuan City are NH₃-N and TP. The single factor evaluation method and the Nemero pollution index method showed that the water quality categories are mostly type III and type IV. The evaluation results of the gray correlation analysis method are mostly Class II water, and all three methods indicate that most of the sites before the construction meet the Class IV water standard. During the construction process, the single factor evaluation method and the Nemero pollution index method show improvement in water quality, while the grey correlation analysis method showed little change in water quality categories. According to the various indicators and water quality changes, it can be seen that the effect of the zero-drainage project is significant for the improvement of river water quality.

This paper introduces the bridge design and the basic situation of the river channel. Through the calculation of the design flood, backwater, scouring and silting at the bridge site, the paper analyzes and demonstrates the rationality of the construction project from the aspects of the relationship and influence with the relevant planning, the adaptability with the existing flood control standards and management requirements, the impact on the flood safety and appropriate stability, the impact on the existing flood control projects and the flood control and emergency rescue.

In order to study the overall status of the research on water conservancy talent development in China, 6135 articles on the water conservancy talent development published in the past 30 years were downloaded from CNKI. Taking these articles as the sample, the time distribution, hot topic, topic cluster and research frontier of the water conservancy talent development research were quantitatively analysed with CiteSpace software. The results indicate that the scale of water conservancy talent development research has increased significantly in the past 30 years, but it has not become a popular school in the field of water conservancy research. Moreover, the research on the development of water conservancy talent involves a wide range of topics, including water conservancy reform, talent management in enterprises, talent education, rural water conservancy talent development, but the research appears extensive on the whole, so the future research can develop in a more refined way.

Since the Three Gorges Dam (TGD) was operated, the sediment characteristics in the downstream river have changed significantly. The characteristics of sediments can be partly reflected by the critical diameter to distinguish wash load and bed material load (WAB) and the ratio of wash load to suspended sediment (WTS). However, the WAB and WTS of the Yangtze River(YR) have not been fully investigated. In this study, data of sized suspended sediment and bed material at four stations in the middle and lower YR were collected to calculate the WAB and WTS, using the most-curvature method. The variations were then analyzed. The results suggest that the WAB and WTS of Yichang station varied greatly before the impoundment, while that of other stations were in small fluctuations. After the impoundment, the WAB of Yichang station increased dramatically to 1.856 mm, and the growth rate of the WAB at Jianli and Hankou stations were 1.0% and 4.1%, respectively (compared with WAB in 2002), while that of Datong station was -8.4%. Comparing with the rising WAB, the WTS of Yichang station continued to rise until it was close to 100%. However, the WTS of other stations decreased overall (30%-40% in Jianli and Hankou, and 8% in Datong).

The dynamic environment of lingdingyang estuary is very complex due to the confluence of runoff and tide as well as the different characteristics of each entrance. Meanwhile, human activities are intensive. Taking the large bridge project of the Pearl River Estuary--Shenzhen-Zhongshan Bridge Project as an example, this paper divides the waters of Lingdingyang estuary where the project is located into tidal channel area, shoal area and two west flood discharge areas based on the differences of hydrodynamic and environmental characteristics. Combined with the one and two-dimensional tidal current model of estuary and delta, the paper discusses the dynamic response of different dynamic characteristic areas to the engineering construction, and carries out the construction scheme optimization and hydrodynamic influence demonstration. The project impact analysis based on dynamic zoning proposed in this paper not only rationally evaluates the hydrodynamic environmental impact of large water-related projects of Lingdingyang, but also is of great significance to the balance of protection and development of Lingdingyang Estuary.

The steel gate based on the principle of hydraulic lifting mechanism has been widely used in urban water ecological construction, but the retaining height of this kind of gate is mostly l-5m at present. With the development of water conservancy engineering and the deepening of the application research of steel gate, the retaining height gradually grows to 6-8m. However, at present, there are few researches on hydraulic lifting mechanism in the case of large retaining height. In this paper, Inventor is used to firstly establish three-dimensional visual entity models of the direct push type, Booster type and Maleli type hydraulic lifting mechanism. Then, the changing rules and relations among hydraulic cylinder diameter, stroke and stability safety factor of the three hydraulic lifting mechanisms are calculated and analyzed by changing the constraint conditions in the case of large retaining height (4m, 5m, 6m, 7m, 8m) and different opening and closing angles. It is aimed at providing a scientific basis for the optimization of hydraulic lifting mechanism of steel gate under the condition of large retaining height.

Being influenced by fluctuating precipitation, long-term rainfall-induced landslide displacement prediction could be unstable. To solve this problem, a rainfall-induced landslide displacement prediction model based on Attention Mechanism Neural Network(AMNN) is proposed in this paper. Firstly, accumulative landslide displacement is decomposed into the trend term and the periodic term. Secondly, multivariate linear regression is adopted to fit the trend term and AMNN is used to predict the periodic term. Finally, the accumulative predicted displacement is given by summing the trend and the periodic displacement components. In this paper, one rainfall-induced landslide in Chongqing province, China was taken as an example to evaluate the designed model. Compared with some existing methods, the model proposed in this paper can captured the correlation between each feature sequence and the predicted term with higher prediction accuracy of 0.97 Goodness of Fit. The results of this paper are believed to be contributive to further rainfall-induced landslide forecast and early warning research.

The basin of Nansihu lake is dominated by alluvial plain landform in Shandong Province, China. The region is rich in coal resources and coal mining has formed a large number of subsidence areas. In view of the difficulty of surface water regulation and storage in plain area and the fact that coal mining subsidence area can provide effective storage capacity. The mode of combination of flood, waterlogging control and water resources regulation by using coal mining subsidence area in the basin is put forward. The advantages and disadvantages compared constructing plain reservoirs with using coal mining subsidence area as reservoirs is recognized. The effects of flood control and waterlogging control in coal mining subsidence areas from the scale of watershed and specific cases are analysed. From the perspective of flood and waterlogging control effect, in 2025 and 2035, coal mining subsidence area can reduce the flood of 5% frequency by 12.43% and 34.22% respectively. By 2025, urban waterlogging at 20% frequency will be reduced by 56.19%. In 2035, the ability of coal mining subsidence area to resist urban waterlogging at the same frequency can reach 100%. The coal subsidence area in Longguhu can reduce the flooding at 10%, 5% and 2% frequencies by 15.8%, 12.1% and 9.2%, respectively. It can completely resist the one-day waterlogging in the city at 20% frequency and reduce the waterlogging in the city for three-days by 70.8%. The reconstruction of plain reservoir using the coal mining subsidence area is feasible in technology and engineering construction. But it is still faced with the problem to be solved of the guarantee rate of water supply, water quality etc...

In order to investigate the influence of the growth characteristics of onions in the Hexi Corridor, this paper tested the growth characteristics of onions in the Oasis by using the early golden dragon onion as a test material and randomly grouped it into different irrigation modes and cover methods. There were five treatments in the experiment, and the growth characteristics of onion was measured in each reproductive period, and the results showed that: The transverse diameter and longitudinal diameter of bulb showed a decreasing trend with the increase of regulation deficit range. The transverse diameter and longitudinal diameter of bulb in T3 treatment were significantly lower than those in T1 and T2 due to the large amplitude of regulation deficit in the whole growth. There was no significant difference between T1 and T4, but it was significantly larger than T5. Moderate deficit and fine sand mulching were not conducive to the growth of bulb transverse diameter and longitudinal diameter.According to the growth characteristics of onion, the best regulation of onion growth can be achieved by covering the whole growth period with black plastic film and sufficient irrigation, which has theoretical guidance and reference significance for onion planting in Hexi irrigation area.

In this paper, we used typical riverbed topography and hydrodynamic conditions, combined with the arrangement of the Babao ship lock exit guiding wall and three tidal gate construction schemes, to calculate the planar flow regime for the exit channel area. In addition, the variation of the planar flow field at typical moments in local outside the entrance area, the size of the recirculation region, the lateral flow velocity, and the longitudinal flow velocity in the outlet channel are used to analyze and compare the navigational flow conditions of different schemes. The calculation shows that the magnitude and direction of the mainstream flow outside the guiding wall are basically unchanged after the construction of tidal gates. Out-of-port flow patterns are not related to whether or not tide gates are built, and the impact of building gates is primarily in the waters inside the head of the guiding wall. Compared with and without a tidal gate, the time required for transverse velocity to meet navigational requirements is less for each scheme.

There are complex and diverse engineering structures in the Middle Route Project of South to North Water Transfer. In order to ensure the normal operation of the project during the operation period. By analysing and summarizing the possible dangerous situations, it can effectively improve the emergency response ability of relevant management departments. In this paper, typical structures and risk databases are built based on the method of entity relationship graph. Using the related factors in the history risk databases, the engineering factors, environmental factors and human factors are sorted out to subdivide the entities. The relationship between risk factors and typical structures is carried out by risk codes, so as to build a complete engineering risk database.

The South-to-North Water Diversion Project will pose a great threat to the lives and property safety of people along the route once a dangerous situation occurs. Therefore, this paper analyzes the historical risk data of the South-to-North Water Transfer Project to identify risk sources, combs the actual risk occurrence process with the basic structure of "Risk Factor→Destruction Link→Destruction Mode", and builds a main canal system risk interpretation model. At the same time, taking the typical high-fill section of the main canal of the South-to-North Water Transfer Project as an example, a typical failure evolution process is selected to construct a dynamic simulation model based on system dynamics to simulate the failure process of the canal embankment under three kinds of manual intervention, as the channel operation under risk input scheduling decisions provides new ideas.

With the current social and economic development and the acceleration of urbanization, garden construction has begun to attract more and more attention from the society. In the process of garden construction, landscape design is a very important section, especially under today's green ecological concept, garden ecological landscape design is even more important. Based on this, this article analyzes the integration of ecological concepts in the process of garden landscape design, so as to provide corresponding references for garden design and its development.

Nowadays, with the reduction of energy sources and deterioration of the natural environment, people pay more and more attention to infrastructure sustainability. It is because a large part of the pollution comes from the construction industry. There are lots of construction and demolition (C&D) waste produced every year. This paper analyzes the recycle of aggregates, asphalt, plastic, glass, ferrous metal, and wood and discusses and compares the future of recycling these materials.

Aiming at the problem of the effect on damage identification caused by noise and modal incompleteness, a two-stage damage identification method based on cross-model modal strain energy and simultaneous optimization was proposed. This paper proposed an improved damage index (Modified Index of Cross-model Modal Strain Energy, MICMSE) based on cross-model modal strain energy. This method first locates the damaged elements by MICMSE, and introduces simultaneous optimization to quantify the damage ratios of damaged elements. The two-step method avoids the calculation of the sensitivity of the modal parameters and the reanalysis of the characteristic equation, speeds up the convergence speed, and guarantees the recognition accuracy. The results of the numerical example show that the method proposed in this paper can effectively locate the damage elements and identify the damage ratios under different damage cases and noise levels.

Traditional airport location work mainly relies on 2D CAD drawing to draw and express the intersection relationship of multiple three-dimensional planes in space. In this way, the mapping speed and update are slow. And it involves more professional knowledge. It is difficult for non site professionals such as the planning department and the government to understand. They still use the method of manual on-site measurement points to calculate the excavation and filling volume, which makes the site selection work and earthwork volume calculation in the site selection stage time-consuming and laborious. In this paper, the airport model based on CAD design drawing and the three-dimensional real scene model of the site to be selected based on photogrammetry technology are established. The two-dimensional GIS analysis function and three-dimensional GIS visualization function of SuperMap are used to realize the high integration of two-dimensional data and three-dimensional GIS, and the three-dimensional real scene model of airport with superimposed design drawings is established, which is used for the evaluation and display of airport site selection.

By using exhaust gas concentration tester, the degradation efficiency and mechanism of asphalt pavement coated with nano-TiO2 composite photocatalyst (TCP) has been analyzed. The results showed that the addition of dispersant greatly reduced the amount of TCP under the condition of similar degradation efficiency. When the optimum coating amount of TCP is 500g/m2, the degradation efficiency reaches 76.39%. As shown by scanning electron microscope, the TCP without dispersant will aggregate and exhibit uneven dispersion, while the TCP containing dispersant does not have this phenomenon, which indicates that TCP have a better exhaust gas degradation effect after being mixed with dispersant.

Displacement of fracture formation for highway tunnel surrounding rock stability and limit the problem of value, of deep buried tunnel by FLAC3D and the plane model is established, through strength subtraction, get tunnel vault subsidence and peripheral convergence value, secondly, based on the presence of fault cases surrounding rock ultimate shear strain analysis, it is concluded that with the loss of the reduction factor, tunnel inverted arch and arch foot site first achieve ultimate strain value and the limits of tunnel surrounding rock integrity buckling safety factor is 1.40, the fracture formation of tunnel surrounding rock stability safety factor than under the condition of no fault, lower limit displacement value than under the condition of no fault.

Rural building fires, especially catastrophic ones that destroy a large number of houses even total village in southern regions of China, are becoming a growing concern from common people to local governments. There is a few literature on research progress of large scale rural building fires in China. In this paper, several typical massively rural building fire cases are described firstly. Mechanism of external fire spread among rural wooden buildings is qualitatively analyzed secondly. Some important preventive measures, such as sandwich panels with inner galvanized sheet, are suggested thirdly. The authors hope this paper may provide valuable information and enlightenment for people who hope to learn about the current situation, research progresses and preventive measures of external fire spread in southwest Chinese traditional villages.

In this paper, the Geo-studio finite element analysis software is used to establish a variety of dam models to analyze the seepage of permeable dam and the slope stability, the results of seepage data are compared by hydraulic physical model experiment. The results show that the single width seepage flow of the permeable dam is 0.0017398m²/s, which meets the design permeability; the XY rate of seepage of the dam meets the law of permeability coefficient mutation. The minimum safety factor is 1.0388, the most likely slip surface appears in the middle and lower part of the dam body facing the water surface, and the leakage point is above the reservoir in the dam, reinforce this area in advance to prevent seepage damage; the simulation process also showed that dams with similar permeability coefficients are safer and more reliable. These research results have certain reference value for the design and research of permeable dams in the future.

On the background of airfield engineering of Chengdu Tianfu International Airport, firstly, the paper introduces the construction method of vibrated stone column piles and explains its importance in foundation treatment. Secondly, it describes the basic concept of vibrated stone column piles and the digital monitoring system, and mainly describes the system function of the digital monitoring system. Thirdly, it shows that the system is fully installed and used in the construction of the airport. Finally, we analyzed the collected real data to testify our opinion that the system can optimize management level, ensure and improve the quality of the airport construction.

With the construction of urban subway lines, the network characteristics of subways have begun to appear. Under certain objective conditions such as capital, manpower, and material resources, the construction sequence of subway lines ought to be different, so that priority construction of lines can maximize network benefits. In order to study the time sequence of urban subway line construction and the network effect of the line, the evaluation index of urban rail transit construction time sequence based on the complex network theory is constructed. The catastrophe progression theory is applied to avoid the subjectivity of the weighting of the primary indicators. The existing lines of Xi'an Metro are transformed into the L-space topology, and the relevant network indicators are calculated to judge the network characteristics of the subway. Through the calculation of the membership degree, the construction priority of each line is finally determined. The route planned for the third phase of the Xi'an Metro is taken as an example, the calculation results show that the small-world characteristics of the Xi'an Metro network are emerging and the network is in its infancy. The calculation results of the priority of the planned line construction sequence indicate that large-scale sports meeting and events have a decisive influence on the construction sequence of the subway line.

In order to solve contact problems, ANSYS provides a variety of contact algorithms. However, there is no basis for how to select the contact algorithm when solving the contact problem in hydraulic structure engineering. Therefore, this paper introduces the basic concepts of contact algorithms briefly, such as penalty method, lagrange method, augmented lagrange method and L&P method, which are commonly used in ANSYS. Then, different examples are used to compare the four contact algorithms in terms of accuracy, convergence and efficiency. Finally, considering the accuracy, convergence and efficiency, it is suggested to adopt L&P method in hydraulic structure contact analysis.

There has to date been no quantitative analysis of the anti-sliding effects of protective measures implemented in high steep rockfill slope engineering under conditions of instability, despite the importance of this analysis for engineering design, improvement to engineering measures, and promotion of hazard warning and management. This study established a discrete element model (DEM) of a high steep rockfill slope based on an engineering project. Numerical simulation was used to investigate the anti-sliding effect of concrete retaining wall height on the high rockfill slope under conditions of instability, with a focus on the distributions of rock before and after slope instability, rock displacement, the quantity of rock crossing the concrete retaining wall, and the quantity of rock reaching the riverbed. The trajectory of rolling rock changes in velocity under different concrete retaining wall heights, and the resistance to rolling rock by the retaining wall were analyzed. Movement trajectories and velocity time-history curves of rolling rock suggested that a higher concrete retaining wall could enhance slope stability under long-term operation. Quantitative analyses determined the optimum height of the concrete retaining wall. The method proposed in this study could provide guidance for effective protective measures in high steep rockfill slope engineering.

With the development of tunnel construction technology and mechanical equipment, the mechanized drilling and blasting construction of mountain tunnels has gradually developed, but there are still certain problems in the mechanized tunnel entry. Relying on a tunnel project in Yunnan, this article uses FLAC3D software to study the stability of surrounding rock under the condition of mechanized large-section construction of shallow buried section of the tunnel entrance. When the shallow buried section of the cave entrance is constructed by the micro-step method, the surrounding rock displacement and plastic zone changes of the surrounding rock before and after the use of different cyclic footage and the tunnel face reinforcement when the tunnel face is used are compared and analyzed. The results of the study show that when the tunnel face is not reinforced, in order to ensure the safety of construction, the mechanized excavation cycle footage of the tunnel entrance section should be controlled within 1.2m, and the overlap length of the leading pipe shed should be greater than 5m; if the circulation is to be increased for footage, the tunnel face must be reinforced. Under the condition that the tunnel face is reinforced with glass fiber anchors with a length of 10m and a pitch of 1.5m, the cycle footage can be increased to 1.8m at most.

Taking Georgia's E60 Highway No. 3008 tunnel as the engineering background, a finite element calculation model was established for the construction stability of the shallow buried and unsymmetrical section of the tunnel exit, and the slope displacement and deformation and the construction dynamic characteristics of the supporting structure were analyzed. Finally, through analysis, the dangerous parts in the construction process are obtained. The analysis results show that: it is safe and feasible to simultaneously excavate the entrance section of the tunnel with unsymmetrical pressure and small spacing using the full-section method. The slope settlement process roughly goes through three stages: rapid change stage, slow change stage, stable stage, and the position stability of the slope toe is more sensitive to the overall construction of the tunnel. The maximum vertical settlement occurs at the position of the vault at the end of the tunnel, and more attention should be paid to this position during the construction. The research results can provide a certain theoretical reference for the construction of similar road tunnels in Europe.

Due to the construction of large hydropower stations and the impoundment of reservoirs, the earthquakes occurred in or around the reservoir area are called reservoir-induced earthquakes, which have the characteristics of low magnitude, shallow source and high intensity. The construction of large reservoirs plays an important role in promoting the local economic development, improving the water conditions of the people and affecting people's life and property. Therefore, the identification, prediction and judgment of reservoir induced earthquake is an important technical support to ensure the construction and operation safety of hydropower stations. Over the years, many scientific and technological personnel have carried out active and large amount of research. This paper reviews and sorts out the macroscopic identification of reservoir induced earthquakes, including the mechanism of reservoir induced earthquakes, the cases of reservoir induced earthquakes, and the identification of reservoir induced earthquakes. Some problems and future research directions of reservoir induced earthquakes are discussed.

The flood disaster is one of the most common natural disasters in China, and the indoor property loss of residents is huge every year due to the flood. Therefore, it is of great significance to study the evaluation of the indoor property flood loss of residential buildings. Based on HAZUS flood loss assessment method, this paper reclassifies the residential buildings in China according to the number of households. The post-disaster loss data and household income level were used to establish the depth-loss percentage function. It provides an important method for the rapid evaluation of the loss after disaster in this area. In order to transfer the risk of flood loss of indoor property of residents in Mayangxi River Basin, an insurance scheme is designed, which provides an important idea for disaster prevention and mitigation in similar areas.

As urban land use is relatively tight, the rational use of sludge landfills has become a problem that must be solved. Because the sludge has the characteristics of high water content, poor permeability, strong flocculation, high combined water content, and high organic matter content, the traditional vacuum preloading method, stacking preloading method and other curing methods are too inefficient and can not meet engineering requirements. In this paper, an indoor electroosmosis drainage consolidation test was designed for sludge in a sludge landfill area in Shenzhen. The test results show that the reasonable drainage method, stacking method and shortening the electrode spacing increase the strength of solidified sludge by 1.1 times, 1.6 times and 2.8 times. The water content is reduced by 19.8%, 25.5% and 55.6%.The drainage rate is linear with the current.

The management of civil construction safety must start from understanding the causes of construction safety accidents. For this reason, experts and scholars at home and abroad have conducted a lot of investigation and research, and have come up with a series of good analysis theories of the causes of construction safety accidents. This article aims to study the statistical analysis and risk control of civil construction safety management accidents. This paper is based on the safety risk assessment model of construction projects, and uses it to discover potential construction risk factors. The experiment in this paper mainly USES statistical analysis method to estimate the probability of each possible event by observing the occurrence times of each potential construction safety risk. Experimental data shows that construction safety risks are mainly caused by certain uncertain reasons during the construction process, and then the future state of the construction of the project can be accurately judged based on historical data or statistical data. The results show that after the classification of 400 accidents occurred in the investigation area, 150 of them fell from high places and 140 people died. 87 electric shocks, 75 deaths; 73 collapses, 65 deaths; Objects struck 38 times, killing 22 people; 43 mechanical injuries, 36 persons. It is the government's responsibility to reduce construction safety and quality accidents, and it is also the minimum requirement of construction enterprises. The safety issues of civil construction must be strictly managed.

Because the stability of the slope is affected by many factors, in order to be able to collect as much information as possible about the stability of the slope, a multi-parameter, multi-device composite system integration based on the Internet of Things technology is proposed. Monitoring systems and slope monitoring projects require low real-time data because most monitoring cycles are long. However, due to the particularity of the monitoring process environment, there are higher requirements for energy saving, scalability, and robustness of wireless transmission networks. RF433MHz technology can meet the problem of wireless transmission in slope monitoring in many aspects such as power consumption, network scalability, network networking capabilities, and operating costs, so it is very suitable for slope monitoring and early warning systems with multiple parameters and multiple measurement points. Through engineering tests, the system works stably and the validity and accuracy of the monitoring data. The researched road slope composite monitoring system based on the Internet of Things technology has certain engineering application value.

Combined with the construction of the No. 6 tunnel of the Khevi-Ubisa-Shorapani- Argveta section of Georgia's E60 highway, the Midas GTSNX software was used to simulate the stability of the tunnel portal section during full-face construction. This paper analyzes the characteristics of displacement and stress variation of the tunnel portal slope during the whole section construction, the deformation law of surrounding rock during the whole section excavation, the deformation law of the initial support and final lining structure of the tunnel. The results based on the numerical simulation analysis show that when the entrance section of Georgia Tunnel No. 6 adopts full-face construction, the displacement of the supporting structure and the rock mass at the 5 m in front of the tunnel entrance changes greatly. Therefore, it is recommended to complete the invert construction of the tunnel before construction to ensure the safety of the tunnel entrance section; As for the entrance section as a whole, during the full-section construction process, the side slope of the entrance, the surrounding rock of the tunnel, and the supporting structure are all in a relatively stable state. Therefore, the full-section excavation of the No. 6 tunnel entrance section is safe and feasible.

Due to the uncertainty of the position of the failure column in the building structure, the surrounding constraints of the beam-column substructure are different after the local failure. Three-column and two-beam substructures with two different boundary conditions are taken as the research object (overall constrained and partially constrained), the failure mode, mechanical form and anti-collapse mechanism of the beam-column substructures are investigated by static loading tests. Tests show that the deformed forms of the two specimens are similar, the development process of the resistance mechanism follows the beam mechanism stage, the mixing stage of beam mechanism and catenary mechanism, and the catenary mechanism stage, however, boundary conditions have a significant influence on the development of catenary mechanism of beam-column substructure, the catenary mechanism of overall constraint specimens accounts for 30% of the total resistance, while the ultimate deformation capacity of partial constraint specimens is weak, and the catenary mechanism resistance only accounts for 15%.

Recently, SHM is applied not only in civil infrastructure aspect, but it is also applied in buildings and aircraft maintenance and many other aspects, which is fundamentally used in our daily life. But, as it is becoming more and more significant in structural health, we are on an urge to apply it in more different fields, and a valuable attempt is found to bear in archeological field. In the process of providing existing applications of SHM, the subsequent articles in this theme are cited in an effort to show how SHM is used in many kinds of circumstances. In conclusion, technical challenges that must be addressed if SHM is to gain wider application are discussed in a general manner.

Taking airport transportation system as the main research object, this paper studies the potential danger and direct economic loss of earthquake. Based on the structural response and damage characteristics of airport transportation system under earthquake action, the framework and theoretical model of HAZUS disaster assessment and direct economic loss developed by FMEA are introduced. This paper focuses on the application of vulnerability curve and capacity curve in airport transportation system risk assessment and economic loss assessment. Taking an airport terminal suffering from a magnitude 8 earthquake as an example, the potential damage degree, probability and direct economic loss of the earthquake are quantitatively calculated, and the property loss is given, thus explaining the importance of the seismic risk assessment framework and method to the safety assessment of China.

Modern Yellow River Delta has become one of the areas with serious land subsidence disaster in the plain area of Shandong Province. In this paper, Small Baseline Subsets - Interferometry Synthetic Aperture Radar (SBAS-InSAR) technology was used to process the Sentinel-1A data from August 2018 to October 2019 in the modern Yellow River Delta, in order to obtain the range and rate of land subsidence in the study area. At the same time, use the Leveling results of the same period to verify the accuracy. By selecting four larger land subsidence rate as feature points to analyze the characteristics of surface time series deformation, the influencing factors of land subsidence in this area are found out. The results show that during the past 2018-2019 years, the land subsidence in the the Yellow River Delta area was mainly distributed in Xianhe Town, southern the Huanghekou Town, Hubin Town, Guangrao County and its surrounding areas, DaWang Town, Yingli Town, Yangkou Town and the western part of Binhai Township, the most serious subsidence area is located in Xianhe Town, with an annual settlement rate of -204.7 mm/a. The land subsidence in the Yellow River Delta is mainly affected by groundwater overdraft, and the distribution characteristics of land subsidence funnel and deep groundwater depression funnel are basically consistent. In addition, natural factors such as consolidation of Quaternary loose sediments and regional tectonic movement also exacerbate the occurrence of land subsidence.

In view of the traditional vacuum preloading method to reinforce soft soil foundation, puts forward a new method of foundation reinforcement: flocculation - vacuum - electroosmosis method, and indoor test, the test shows that flocculation - the vacuum - electroosmosis method can greatly reduce the moisture content of reinforced soil, enhance the vane shear strength, and the reinforcement effect was homogeneous.

The construction project provides a large number of employment opportunities for the construction workers, and the health of the construction workers is closely related to the safety management of the construction site. This paper first designs construction workers' health and construction site safety management measurement scale by using literature analysis and group interview. After that, through the structural equation model(SEM), the author reveals the path between the construction workers' health and construction site safety management of the labors and contractors. According to the results of the discussion, the construction workers' physical health and the safety technology management are the core of construction site safety management.

Urbanization is taking place rapidly in developing countries. There are many problems of urbanization, and flood hazard is one of the serious problems. Flooding events and hydrologic process are complex in urbanized watershed. Current methods for urbanized watershed flood hazard risk assessment exist shortage. With the advance of observation technology and geographic information system technology, the multi-source spatial-temporal data have been collected increasingly. The data driven methods have provided a potential solution for the complex urbanized watershed flood hazard risk assessment. The paper has discussed the complexity of urbanized watershed flood hazard. The framework of observation based modeling of urbanized watershed flood hazard risk assessment has been given. Multi-source spatial-temporal information fusion approach for watershed flood hazard risk assessment has been discussed. A case of Hanyang urbanized watershed has been developed based on the multi-source information fusion method of local weighted linear combination.

Gas pipeline is occupied by high-filled soil and a large amount of soil has caused long-lasting additional stress on the pipeline. Under the action of the additional stress of the high fill soil, the pipeline may undergo relatively large displacement and deformation, which will cause harm to the safe operation of the pipeline. In order to clarify the stress and deformation state of gas pipeline body and weld in the high fill area, this paper preliminarily calculated the radial stability of gas pipeline under the action of the high-fill soil and the stress state of the weld under the ovality deformation. According to the actual parameters, boundary conditions and deformation of pipeline, a finite element model is established to calculate and check the stress state of the pipeline in the high fill area. Analyzed the serviceability of the pipeline according to the requirements of gas pipeline integrity management specification. Finally, according to the analysis results, a comprehensive assessment of the high fill area of the pipeline is carried out, and recommendations for the next treatment measures are put forward.

The evaluation of the seismic stability of electrical equipment is very important in substation. In this paper, the influence of support on seismic response and vulnerability of voltage transformer is studied., First, the support-voltage transformer finite element models(FEM) is established by Abaqus. Natural frequency, dynamic amplification factor of support-voltage transformer with different PGA are investigated. Afterwards, the seismic response parameters obtained by FEM simulation are applied to the vulnerability analysis of voltage transformers. Finally, the vulnerability result indicated that support height and ceramic material have significant effects on the probability of equipment failure.

Industry Foundation Classes(IFC) defines the standard exchange data format of building information model. For making it possible to serve the whole life cycle of structure, it is necessary to parse and save BIM information based on IFC Standard into database. The research is implemented by Java language and MySQL database. The whole project is called IFCParser and consists of three modules: IFC Entity Module, IFCFile Parser Module and Persistence Module. IFCFile Parser Module uses lexical analyzer and syntax analyzer to decompose IFC files based on EXPRESS language into entity classes, which is called the IFC entity. Persistence Module establishes the mapping relationship between Java class and MySQL database, and uses MyBatis framework to save information into relational database.

Taking the demolition blasting of complex structure of continuous multi-span aqueduct as the research object and combining with the importance analysis of safety factors in safety evaluation, the blasting scheme, reliability of electric blasting network, pretreatment quality, protection of buildings around the blasting area and safety protection are emphatically studied. The numerical model of aqueduct is established by LS-DYNA. Through the simulation analysis of the whole process of aqueduct blasting demolition and collapse, the blasting breakpoint and the design of pretreatment notch are reasonably determined. Carry out the equivalent electric blasting network test and field blasting test to check the reliability of the blasting network and determine the single hole charge. By the analysis and verification of safety parameters such as blasting shock wave, collapse vibration and safety distance, the active protective measures are taken to protect the important structures and public facilities within the blasting area. The blasting effect and monitoring data show that the safety technical measures can effectively control the safety risk of aqueduct blasting demolition.

Based on the environmental functional area allocation, point and non-point sources, hydrology and water quality data of Hun River, SWAT model is built and used to calculate the hydrological, water quality and environmental capacity processes in the river channel. The results showed: (1) When the upstream water quality concentration was limited to the grade III of the national surface water quality standard, the environmental capacity of total phosphorus (TP) in Hun River is about 582.01 t/a. (2) According to the results of water environmental capacity in different water periods, the environmental capacity of Hun River is seriously overloaded in the flood season, although annual value is satisfied the standard. For the strong driving effect on the pollutants transport in the river by the intense rainfall in flood season, the concentration in flood season exceeds the water quality standard of grade III. (3) To strengthen the environmental management of Hun River, it is necessary to monitor non-point sources in the cultivated land, standardize the fertilization measures, and improve the rural sewage pipe networks and related facilities.

Building industrialization, promote the industrialization of the world architecture development, promoted the pace of urbanization construction, in the aspect of building industrialization in China started late, so under the background of industrialization, in the course of the construction of construction engineering quality management experience a slight lack of current industrial construction project quality management of construction was still in the stage of research and practice, this article mainly through to the building industrialization construction quality has carried on the detailed analysis of existing problems, and combined with the traditional construction project quality management method, analyses the construction quality control factors of industrialization, It will provide some research data for future research on engineering quality control methods.

the entrance portal of No.8 tunnel of F3 bid section of E60 highway in Georgia is shallow buried and under unsymmetrical pressure, which leads to high risk and difficulty in tunnel construction. Tunnel 8 is designed based on ADECO-RS (analysis of controlled deformation in rock and soil). In order to understand the stability characteristics of tunnel portal in the whole section construction process and determine reasonable and feasible engineering countermeasures, the numerical simulation analysis of tunnel construction process is carried out. We not only studied the relationship between the stability of the slope at the entrance and the stability of the whole tunnel body under the actual stratum conditions, but also studied the mechanical and deformation characteristics of the surrounding rock and supporting structure of the tunnel.The numerical analysis results show that the stability characteristics of the portal slope directly affect the overall stability of the tunnel portal section; due to the disturbance of tunnel excavation, a large range of plastic zone appears at the interface of rock and soil at the portal section, resulting in large settlement deformation of vault. The collapse and deformation of the upper soil layer with poor engineering properties will cause excessive additional load on the supporting structure of the tunnel.Therefore, advance support measures should be taken to control the excessive deformation of vault. At the same time, due to the influence of asymmetric pressure, the supporting structure of the shallow buried side and the deep buried side of the tunnel appears obvious asymmetric pressure state. It is suggested to strengthen the stiffness of the shallow buried side support structure and adopt the asymmetric support structure to ensure the safety of the support structure.

More than 400 friction piles of a highway bridge in northern China were detected by both acoustic transmission method and low strain reflection method,while the integrity levels of the piles were judged different by the two methods, they were finally identified by means of drilling core-taking or drilling television. The misjudgment of the acoustic transmission method and the low strain reflection method are counted, and classified statistics were conducted according to the location and type of defects, while the reasons of misjudgment are analyzed. Some suggestions for the comprehensive application of the acoustic transmission method and the low strain reflection method are put forward, which can be for the reference of the testing technician.

With the continuous development of society, as a transitional level between rural and urban areas in urban system, towns are facing a series of problems such as ignoring ecological environment, unreasonable planning content and lack of public space. In this paper, from the perspective of "urban catalyst", taking Jingfu town of Santai County as the research object, the concept of catalyst is introduced by investigating the existing problems of the site and respecting the local natural and cultural environment. It has a certain reference value for the activation and development of urban and rural towns to integrate and update the site resources, select the appropriate space of catalyst to promote the activation of surrounding areas, and promote the sustainable renewal of small towns through the framework of catalyst space system.

This paper firstly judges the change of credit level of the credit subject from the dynamic perspective of "state-behavior". Then, according to the conditional random field theory, the data of credit behavior and credit status are taken as random variables in the conditional random field to construct multiple characteristic functions representing the relationship between the credit behavior and the credit status. And finally, the credit evaluation system based on the conditional random field is constructed. In summary, this paper constructs a credit evaluation framework of market entities from the credit evaluation system and conditional random field credit labeling, which can be used in the construction of market credit dynamic supervision for reference.

In this paper, a numerical calculation method based on CFD is proposed to calculate the force and analyze the flow field of the cable car in static state. When the wind attack angle and the wind deflection angle are both 0°and the wind speed is 10m/s, the drag coefficient of the cable car is calculated by numerical simulation to be 0.77, which is consistent with the experimental results. Vortices with different sizes and intensities were observed on the lateral, upper and lower sides, and behind the cable car. The positions of the vortices correspond to the positions of the negative pressure zone.

Aiming at the current application status of digital construction in various industries in China, this paper analyzes the GIS and BIM technology used in the existing digital construction, and summarizes the application of GIS and BIM technology in the digital construction in the airport construction industry, which also analyzes the application value and development prospect of digital construction in the area of airport construction.

With the popularization of space grid structure, the health detection of structure is an urgent problem to be solved. According to the distribution law of members and the characteristics of clear force transmission, a grid model with 29 nodes and 76 members is designed. For the model, the response time history curves of nodes are collected when the model is in good condition and some members are damaged, and the curve time history information is taken as the input vector to construct the damage information matrix. The deep learning network is established step by step by using the deep learning algorithm and trained. Through the establishment of a simplified network, the damage location and damage degree of single bar are identified. The results show that the established network can identify the health state of the structure well, and it has reference value for application.

In this paper, the weight distribution characteristics of overloaded vehicles and the influence of overloaded vehicles on pavement service life are studied based on WIM data. Based on the vehicle weight data collected from weight in motion station, the vehicle weight distribution function of different axle type trucks and the weight overload ratio distribution function of different axle types are obtained by fitting. Equivalent single axle loads of the pavement under different weight limits are calculated based on the vehicle weight distribution function, and finally the pavement life growth factors under different weight limits are determined. The calculation results show that: the maximum overload ratio of two-axle vehicle can reach 340%; the number of six-axle overloaded vehicle accounts for more than 50% of the total number of overloaded vehicles, which is the largest proportion. Pavement life can be improved effectively by limiting load, and the road life growth factor shows a quadratic parabolic trend to increase with the decrease of load limit value. For two axle trucks with serious overload, the pavement life can be increased by more than 15 times with a strict load limit value.

Considering the particularity of the station house withstanding dynamic load as well as the characteristics of frame structure, the discrete analysis was used to study the finite element structure of the station house. By comparative analysis on various element simulation approaches, this paper studied the rational approach to simplify the model so as to achieve a more realistic stress status for computation results.

Green and development have important guiding significance for campus planning and design. The article analyzes the campus planning and design project of the Hai'an campus of Nantong Institute of Technology as an example, and explains that campus planning and design are the basis and norms for the construction of universities and the guarantee for the sustainable development of the school. Taking the green concept as the center, reasonable campus planning and design can comprehensively reflect the characteristic concept of the school, interpret the cultural vision of the campus, and meet the diverse functional needs of teachers and students' research-practice-humanistic spirit. It can enhance the centripetal force of students, play an imperceptibly important role in enhancing the sense of identity and belonging of the campus image, and can promote the overall, coordinated and ecological development of university campus construction, and thus better exert the ability and role of applied universities. It is the source of the intention to create planning and design, and the core idea of campus design.

Nano-porous silica aerogels are synthesized by two steps by the supercritical condition. By synthesized process, tetra-ethyoxysilane is used as raw material, isopropanol and H₂O which is distilled after ion exchange was used as solvent, HCl and NH4OH are used as hydrolysis and condensation catalysts, glycerol is used as drying control chemical agent. Silica aerogels are obtained by supercritical drying condition after aging, surface modification and exchanging solvent. The effect of water, PH, temperature, and so on, are analysed at supercritical drying condition. The resulting aerogels are characterized by means of X-ray diffraction and scanning electron microscopy. It is found that the aerogels made by this method have high porosity, specific surface area and the structure is sponge with narrow particle and pore size distribution.

The safety review calculation of the gate is an important job in the safety evaluation of metal structures. In accordance with the requirements of the specification, this paper has developed an intelligent software for metal structures safety review calculation, which can automate the calculation process and generate a review evaluation report. In order to simplify the labor of the manual input of a large number of gate review calculation parameters, this paper used a deep-learning-based image recognition technology to partially realize the collection of the information relevant to the calculation from the drawings of metal structures, laying the foundation for later realization of the fully intelligent gate safety review.

Under the condition of high altitude and complicated geological environment, lots of risks existing in the process of highway construction, how to control effectively safety risk has become the serious problem. Taking the construction project of Sichuan-Tibet highway as an example, combining with regional environment, safety risk indicators of construction project for plateau mountain highway is constructed. Method of construction safety risk assessment for plateau mountain highway is established. The feasibility of the evaluation method is verified by a case, and corresponding risk control measures are put forward.

Quantitative assessment of the highway settlement hazard in permafrost regions is urgently needed for maintaining the performance of highway service. This study firstly conducted a field monitoring of an embankment located in the permafrost region by performing the distributed fiber optic monitoring. Subsequently, a novel indicator named embankment disease indicator(EDI_ε) was developed based on strain gradient calculated through the monitoring results to build a permafrost embankment settlement hazard quantitative assessment framework. The results indicate that, (1) the distributed fiber optic monitoring can reflect the uneven settlement distribution of permafrost embankment over a wide range and long distance; (2) 0.152% is suggested as the strain gradient criterion to calculate EDI_ε, EDI_ε can quantitatively indicate differential settlement disease rate in permafrost embankment; (3) the model implementation results have a dynamic quantity consistent with the actual situation, the assessment framework is particularly useful for large regional uneven settlement assessment of permafrost embankment.

The construction and management of airport asphalt pavement project has the characteristics of large construction scale, high technology, many professionals involved, and high quality requirements. The traditional monitoring and management method that relies on manual on-site inspections and records is vulnerable to many factors such as environmental conditions and the ability of the implementer. It is difficult to ensure real-time monitoring of construction quality and data backtracking. With the rapid development of various advanced technologies such as global navigation satellite system(GNSS), geographic information system(GIS) and internet of things(IoT), digital construction monitoring and management technology for airport asphalt pavement has emerged as the times require. Digital construction technology is implemented through professional testing equipment, data collection, data integration, and system installation. It covers the entire construction process of airport asphalt pavement from the background management of the mixing plant, the transportation management of vehicles to the field management of paving and compaction. The technology monitors the construction quality, guarantees the construction progress, improves management efficiency, and saves costs, which has great social and economic benefits.