Table of contents

Proceedings of the 4th International Conference on Transportation Infrastructure and Sustainable Development

TISDIC 2023

Editors

Rafat Siddique, Phan H. Nam,

Nguyen M. Hai, Nguyen P. Q. Duy, Pham N. Phuong

Hoang P. Tung, Nguyen V. Te Ron

The 4th International Conference on Transportation Infrastructure and Sustainable Development (TISDIC 2023) is scheduled to take place from 26th to 28th August 2023 at the Da Nang Administrative Centre in the captivating city of Da Nang, Vietnam.

Renowned as one of the most distinguished international conferences in the field of transportation infrastructures within Vietnam, TISDIC has garnered widespread acclaim. It stands as a pivotal platform where leading academics, government entities, civil society representatives, and the private sector converge to exchange research insights and innovative solutions, propelling sustainable development goals in transportation infrastructures.

TISDIC 2023 includes five primary topics, offering a comprehensive exploration of Advanced Structural and Bridge Engineering, Road and Transport Engineering, AI, IoT and Automation in Transportation Systems, Construction and Building Materials for Sustainable Development, and Geotechnical and Geoenvironmental Engineering. By focusing on these areas, the conference aims to highlight the latest advancements and address the pressing challenges facing the field.

The overwhelming response to TISDIC 2023 is a testament to its significance, with a remarkable total of 142 papers submitted for consideration. Through a rigorous evaluation process, 106 exceptional papers were selected for publication in this proceeding, boasting an impressive acceptance rate of 74.6%.

We extend our heartfelt appreciation to the authors for their invaluable contributions, which have enriched the conference proceeding. We also express our deepest gratitude to the dedicated reviewers, whose expertise and meticulous evaluation ensured the inclusion of high–quality papers. Their contributions are instrumental in fostering intellectual growth and pushing the boundaries of knowledge in transportation infrastructures.

Finally, we would like to express our gratitude for the support provided by the Vingroup Innovation Foundation (VINIF – VINBIGDATA) towards the publication of this proceedings.

The Editors

List of Reviewers, Scientific Committee and Organizing Committees are available in this pdf.

All papers included in this volume have undergone a rigorous review process supervised by the Editors. Each paper was evaluated by a minimum of two expert referees, adhering to the high professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Type of peer review: Double anonymous

Conference submission management system: Morressier

Number of submissions received: 142

Number of submissions sent for review: 142

Number of submissions accepted: 106

Acceptance Rate (Submissions Accepted / Submissions Received × 100): 74.6 %

Average number of reviews per paper: 2

Total number of reviewers involved: 85

Contact person for queries:

Name: Phan Hoang Nam

Affiliation: The University of Danang - University of Science and Technology

Email: phnam@dut.udn.vn

* means value has been edited

In many studies, the dynamic response of bridges is influenced by various factors. Multiple factors, such as vehicle loads, road roughness, vehicle-bridge interactions, and travel speed, impact the dynamics of a three-span bridge on highways. Because the mass of the vehicle, including the cargo, fluctuates randomly, a probabilistic methodology based on the Monte Carlo method is utilized to produce random anomalies for dynamic analysis. To examine the Song Gieng bridge, data from the Road Administration Department IV on heavy vehicle loads and overloaded vehicles are utilized to produce random vehicle loads. The analytical results indicate that there is a discrepancy in the probability distribution rules between the vehicle load (input random variable) and the dynamic impact factor (output random variable). This implies that their mapping connection is not monotone. Compared with the threshold values specified in the bridge design standards of Vietnam and the United States, the dynamic impact factor obtained in this study is significantly different. These findings can provide additional guidance for practicing engineers.

Vibration analysis of functionally graded (FG) microbeams carrying a moving mass is carried out in the framework of Timoshenko beam theory. The beam material properties are considered to be graded in the thickness by a power-law function, and they are estimated by Mori-Tanaka scheme. The influence of the microsize effect is captured with the aid of the modified couple stress theory (MCST). A finite beam element is formulated and used to establish the discretized equation of motion for the beams. Vibration characteristics, including the natural frequencies, the time histories for mid-span deflection, the dynamic magnification factor and the stress distribution, are computed for a simply supported beam. The obtained result reveals that both the dynamic deflection and dynamic magnification factor are overestimated by ignoring the microsize effect. The effects of the material distribution, the moving mass velocity and the length scale parameter are studied in detail and highlighted.

An extended meshfree method is employed in this paper for investigating the dynamic behaviour of cracked plates based on the first-order shear deformation theory (FSDT). The FSDT is a straightforward formulation with the assumption of first-order shear deformation as its name implies, which is appropriate for relatively thick plates. In this study, the meshfree method is chosen as an alternative to the conventional mesh-based methods to model plate structures. Among various meshfree formulations, Moving Kriging (MK) is a method that satisfies the Kronecker delta property, allowing for the easy imposition of essential boundary conditions. An extended MK formulation is proposed in this paper to model cracked plates without explicitly pre-defining the crack in the geometry domain. In the extended concept, the extrinsic enriched functions are employed to model the discontinuity due to the crack. Particularly, the Heaviside step function is employed to describe the discontinuity of the displacement fields on two sides of the crack surface. And the asymptotic enriched functions are used for stress singularity around the crack tip. In the dynamic analysis of cracked plates, one of the important factors that must be evaluated is the dynamic stress resultant intensity factor (DSRIF). In this paper, the DSRIFs are shown through many numerical examples and compared with analytical solutions and other numerical methods, showing the accuracy and efficiency of the present extended MK approach.

The dynamic effects of moving vehicle on bridge are generally treated as withstand static loads that are recommended an increment by dynamic impact factors (IMs) (or dynamic amplification factors) in many design codes, that are a function of either the span or the first flexural natural frequency of the bridge. The value of the IM will relate to safe and economical in new bridge designs, evaluate recommendation and operation of bridges. Due to the bridge-vehicle interaction model, previous studies have shown that the calculated IM from field measurements could be higher than the values specified in design codes. Currently, studies on IM often focus on using interaction models with multi mass vehicles move on bridge that are increasingly similar to real models. This study develops a 2D three-axle vehicle–bridge model to analysis the dynamic response of the girder bridge subjected to moving loads consider to some vehicle parameters with the each axle is modelled in two masses, each mass is connected to a spring and a damping corresponding to the suspension and tire. In addition, depending on the stiffness parameters of the suspension and tires of the analyzed vehicle model, the IM results of this study are different from those of some authors and the bridge design rules. Based on the dynamic analysis of the bridge under the vehicle loading consider the stiffness of tire and suspensions, the calculation of the IM needs to be considered more carefully in the process of designing new bridges or existing bridges.

In this study, strand looseness in a multi-strand anchorage is identified using measured impedance features of the PZT (Lead zirconate titanate) interface array under temperature effects. Firstly, a PZT-interface method for impedance monitoring in prestressed structures is briefly described. Secondly, a finite element model of multi-strand anchorage equipped with a PZT array is established to analyze the effects of prestress loss and temperature changes in impedance features. Thirdly, variations in simulated impedance signals are quantified using statistical damage metrics for damage detection in the analyzed structure. Last, a test on real-scale multi-strand anchorage is conducted to measure impedance signatures of the PZT interface under temperature fluctuation and prestress loss. The measured signals are then quantified using damage metrics for prestress looseness monitoring. The result reveals that environmental changes cause significant changes in PZT interfaces' impedance features and affect strand looseness monitoring results.

Vibrational characteristics of a sandwich beam in thermal environments subjected to blast pressure are investigated in this paper. The sandwich beam is composed of two isotropic skins and an open-cell metal foam core with either uniform or symmetric distribution of internal pores. The pressure of blast loading is modelled by Friedlander's equation. A two-unknown higher-order beam theory combined with Hamilton's principle is used to establish the governing equations. Navier-type solution and Newmark-beta method are applied to deal with the governing equation and obtain the dynamic responses. The efficiency and accuracy of the present study are examined through numerical examples. Effects of temperature-dependent material properties, porosity coefficient, core-to-skin thickness ratio, length-to-height ratio, and structural damping on the natural frequencies and dynamic deflection of the sandwich beam are investigated in detail.

The key to improve the accuracy of behavior analysis of the steel composite girder lies in the reasonable modelling the intergration between the reinforced concrete slab and the steel girder. Based on design requirements and construction methods, the type and layout of the shear connectors between the concrete slab and the steel girder are different, significantly affecting the behavior of the composite girder. This study is conducted to (i) investigate the applicability of a truss element available in the popular simulation software Abaqus in modelling the shear connectors of composite girders, (ii) compare the flexural behavior of composite girders with different types and layouts of shear connectors. Two types of shear connectors considered in the study are headed studs and perfobond strips, and their layout corresponds to the construction methods using the cast-in-place and precast concrete slabs. The study results show that a truss element can be used to simulate the shear connector behavior through reasonable assignment of its shear force-slip relationship. With the design principle that the total shear capacity of the shear connector per unit length remains constant, the nonlinear behavior of the composite girder is significantly affected by the type and layout of the shear connectors.

As bridge spans stretch, the structure becomes more flexible and susceptible to dynamic wind effects causing harmful wind-induced vibration. The biggest issue with the design of long-span bridges is the possibility of vibration caused by vortices. This study examines the mechanism of the decrease in the amplitude of vortex-induced vibration for the box girder using a flap countermeasure. Aerodynamic countermeasures such as a flap have successfully increased bridge deck aerodynamic stability. However, their stabilizing mechanism has yet to be fully understood. Based on the proposed approach, a wind tunnel experiment and a CFD technique are used to investigate the aerodynamic instability of the bridge girder in the presence of aerodynamic countermeasures. The flow fields surrounding the bridge deck, both with and without the flap, are examined, and the experiment outcomes are compared. Flow imagery is utilized to explain and understand the modified flow properties surrounding the bridge girder in the presence of aerodynamic countermeasures that minimize vibration amplitude. Indeed, installing flaps on a girder leads to increased turbulence over the surface and at the leeward side, which disrupts vortex formation and decreases lift forces on the structure. In addition, the results revealed that the efficiency of the flap is related to the installed location of the flap and the flap length. This research provides a reliable framework for designing the flap countermeasure and significantly improves the aerodynamic stability of a deck-flap system.

Damping materials are popular applications for almost vibration structures; however, they have rarely been investigated in different practical experiments. That is why new approaches would be necessary to assess these problems. In this study, the mathematical model of cable is remarkable in assessing the cable tension of the cable-stayed bridge. A differential vibration equation is used to derive the cable tension considering material damping as the hysteresis phenomenon. The experimental measurements of cable vibration at Phu My Bridge are calculated to find approximate damping ratio and tension values. The selected damping model with experimental data has been collected to derive an efficient method for evaluating structure status. These values are used to assess damping efficiently in the cable-stayed bridge structures. The results presented in this paper shall help elucidate experimental procedures for characterizing damping materials. The proposed procedures are used not only for the cable-stayed bridge but also for generally cable-stayed structures.

This study aims to improve the recovery of bridge columns after being damaged subjected to an earthquake and also proposes a PC column that reduces residual displacement by prestressing. The proposed column has a repairability of the damaged part of the column by arranging a concrete-filled steel tube at the column core. The seismic performance and post-earthquake recovery of the proposed columns were verified by conducting cyclic loading tests. Test results showed that the residual displacement was not reduced enough to improve the post-earthquake recovery. However, after investigating the column core at the end of the test, almost no visible damage, such as fracture or buckling, was found in the steel tube at the core, which means that the concrete-filled steel tube core itself can support the structure above. Therefore, the proposed system can be repaired quickly after being damaged if the residual displacement can be reduced.

In material, the pre-stress state caused by temperature variation of the working environment is one of the main reasons which cause buckling in structures. This paper aims to analyse the critical temperature rise to cause buckling in functionally graded material (FGM) under different boundary conditions. Reissner-Mindlin plate theory is employed in this paper with the radial point interpolation method (RPIM). The RPIM has the advantage compared to other meshfree methods in the satisfaction of the Kronecker delta property which allows directly imposing boundary conditions on scattered nodes. Factors affecting to thermal buckling phenomenon are investigated. The accuracy of solutions will be shown by comparing them to reliable results in previous studies

Working in an environment with many influencing factors can lead to the deterioration of construction. For bridges, the harshness and unpredictability of the environment can come from temperature, air humidity, wind, soil, and vehicle loads. Over time, these factors cause the quality of the bridge to degrade. Because there are too many factors acting simultaneously with varying degrees of influence, this paper only focuses on the parameter that represents the degradation over time, regardless of which factor the degradation is due to. The proposed parameter has a one-way variation with time, and its change is a sensitive indicator to operation process of the bridge. This parameter is calculated using measurement data of the bridge's vibration over time and in response to actual traffic loads. This demonstrates the viability of this idea in the experiment.

This paper discusses the implementation of the incremental launching method in the construction of prestressed reinforced concrete bridges in Vietnam. Since the 1990s, technology transfer has been initiated to develop and rapidly expand the country's road and rail transport network system to support industrialization and modernization. Although the method was successfully applied in several bridge projects, the high construction cost has led to a controversial issue, and the government stopped its application in the country. The paper aims to analyze the limitations and unreasonableness in the project formulation, design survey, and procurement of technological equipment that led to the policy of stopping the application of the incremental launching method. The author provides an in-depth analysis to clarify the suitability of the policy and shed light on the issue's root causes.

The use of ultra-high-performance concrete (UHPC) jackets as a seismic strengthening method for reinforced concrete structures has become increasingly prevalent. Specifically, these jackets are applied to plastic hinge regions of the structures to improve overall earthquake resistance. This study evaluates the effectiveness of UHPC jackets in strengthening reinforced concrete columns through fragility curves. The columns are modeled numerically, accounting for material nonlinearity, and various strengthening scenarios, including those without UHPC jackets and with UHPC jackets of different heights, are modeled and validated with cyclic loading tests. Subsequently, a case study of a two-column reinforced concrete bridge pier is examined. Time-history dynamics analyses are conducted on 140 ground motion records to develop probabilistic seismic demand models of the column with different strengthening designs. Fragility curves obtained using the cloud method indicate a significant impact of the strengthening method on the failure probability of the column. The research findings presented in this paper provide engineers with a basis for selecting appropriate UHPC jacket parameters, including thickness, height, and material strength in a rational manner.

Wire rope is an element often used in transportation infrastructure and systems such as bridges, elevators, ropeways, funiculars and so on. Generally, wire ropes require a high level of safety because they suspend heavy and important components such as roadways in bridges, cages and cabins in elevators, ropeways and funiculars. In addition to dead loads like roadways, wire ropes are subjected to dynamic loads caused by earthquakes, wind and moving cars, etc. Therefore, it is important to accurately simulate the dynamic response of wire ropes to dynamic loads to ensure safety of wire ropes. This paper deals with techniques for vibration response analyses of wire ropes. Techniques in this paper specially focused on a transverse vibration of wire ropes for elevators because their response is complicated by the moving cage and tension distribution. Vibration response analysis techniques using the difference method and a simplified mass point model will be introduced in this paper.

Seismic behavior analysis of the long-span cable-stayed bridge is a complex process involving different uncertainties. This paper performs a sensitivity analysis of cable-stayed bridges using the finite element method on Midas/Civil. They include different types of ground motions scaled to different peak ground acceleration (PGA) levels, the effect of the multi-support excitations due to time-lag propagation or nonsynchronous excitations, and the effect of the angle of the incidence of the earthquake is determined. To evaluate the optimum initial cable prestress forces in cables unknown load factors method is used. The response quantities of interest include the displacement of the tower and deck, variation in prestress force in cables, torsional in the deck, shear force, and bending moment at the supports. Results show that the effect of the PGA variation and angle of incidence of the earthquake is moderate. In contrast, the synchronous and nonsynchronous seismic excitation effect on the response quantities is significant.

Flood-induced scours near the pier foundation are an adverse phenomenon that may cause the collapse of bridges. However, in the seismic design of bridges, the scour impact is commonly ignored when evaluating the seismic response. This study aims to quantify the effect of flood-induced scours on nonlinear static and dynamic behaviors of typical reinforced concrete bridges. For this regard, three-dimensional finite element models of two- and three-span bridges with a multi-cell box girder, circular column bent, and extended pile-shaft foundation are first developed, where the column bent is modeled considering the material and geometry nonlinearity. The interaction between the soil and structure is also accounted for by using soil spring models. By considering different scour depths, the modal, static pushover, and dynamic time-history analyses of the bridges in both directions are investigated. It is observed from the modal analysis that the fundamental periods of the bridges increase with the increase of scour depth. In addition, the results in terms of the column drift ratio show that scour may increase the seismic damage to the bridges, which transfers damage from the column bent to the pile-shaft foundation. The findings of this study exhibit the significant effect of the scour on the seismic damage of reinforced concrete bridges; therefore, it is recommended that this phenomenon should be considered in the bridge seismic design.

The conventional method for calculating averaged tracer concentration in three-dimensional tracer transport equation relies on classical averaging, which averages tracer concentration data obtained from the tracer transport equation in turbulent flow. However, the averaging tracer concentration quantity calculated by this method is not precisely the same as the one obtained by the dual approach. To address this issue, the author proposes a more intricate dual approach for averaging the three-dimensional tracer transport equation in turbulent flow. This paper describes how the author performs two integrations: one from time t to t + r (where r < T, T being the repeated period of fluctuating concentration), and another from time t to time t + T. The fluctuating concentration quantity in turbulent flow is modeled using the trigonometric Fourier series. The resulting three-dimensional mathematical model of tracer transport obtained by this dual approach is more comprehensive than the one obtained by the classical method.

In this research, the main objective is to model and map flood susceptibility in Que Son district, Quang Nam province, Vietnam using one of the effective machine learning model namely CatBoost. With this purpose, a total of 96 flood and non-flood locations and a set of 10 conditioning factors were collected to construct the geospatial database. Thereafter, Shap feature importance method was used to validate and select the most important conditioning factors used for modeling of flood susceptibility, and the results showed that only 8 conditioning factors including aspect, slope, curvature, elevation, land cover, rainfall, distance to rivers, and Topographic Wetness Index (TWI) were selected for final modelling of flood susceptibility at the study area. Validation of the model was also done using various statistical indexes including area under the ROC curve (AUC). Validation results showed that the performance of CatBoost model (AUC = 0.96 for training and AUC = 0.94 for testing) is good for prediction of flood susceptibility of the study area. Thus, it can be concluded that CatBoost is valuable tool for flood susceptibility modeling which can be used to assess flood susceptibility in other flood prone areas of the world. In addition, flood susceptibility map generated from CatBoost model in this study might be helpful in development of better flood mitigation strategies at the study area.

In this article, the main aim is to build landslide susceptibility map at the Dien Bien province (Vietnam) using a hybrid machine learning model including BG-MLP which is a hybridization of Bagging and Multilayer Perceptron (MLP) neural networks. For this purpose, 665 past landslide events together with 665 non-landslide locations and 10 landslide influencing parameters including geology, normalized difference vegetation index (NDVI), distance to roads, distance to rivers, topographic wetness index (TWI), slope, curvature, aspect, distance to faults and elevation were collected and used for generation of datasets for model's development and validation. To validate the predictive capability of the model, area under the ROC curve and other popular statistical indices were used. Results presented that BG-MLP (AUC = 0.81) has a good performance in modeling and mapping landslide susceptibility at the study area, especially its performance is better than single MLP model (AUC = 0.78). Thus, it can be concluded that BG-MLP is powerful tool that can be employed for assessment of susceptibility of landslides in other landslide prone regions of the world. Map of landslide susceptibility created from this study would be useful for decision making and land use planning in reducing the harmful impacts of landslides.

Nearly 10 years have passed since the 2011 Kii Peninsula flood, and assessing the disaster response at that time is crucial for developing a future disaster response system. This study is based on questionnaire and interview surveys of construction managers, i.e., heads of local construction administrations in charge of disaster recovery for public civil engineering facilities in Wakayama Prefecture. We clarify the situational judgments and decisions that are made in the field response of disaster recovery, check whether they were undertaken to extract issues, examine the characteristics, and consider issues for future disaster response.

Transportation infrastructure assets are particularly vulnerable to natural hazards, which are becoming more frequent and severe due to climate change and extreme weather conditions. Floods and flash floods are among the deadliest natural hazards, accounting for 50% of vehicle-related fatalities. This underscores the need for timely transportation flood detection systems adoption. However, current flood detection technologies are inadequate in terms of coverage, speed, geographical specificity, and interoperability, making it difficult for emergency managers to respond effectively to flood events. To address this issue, we propose a high-resolution network of low-cost Industrial Internet of Things (IIoT) sensing devices deployed at flood-prone transportation assets. These sensors collect location-specific data, which is then published in standardized formats, interfaces, and protocols, enabling other systems to generate flood forecasts, nowcasts, and warnings. A framework for Incident Management Systems (IMS) was also discussed to highlight the need for system interoperability during disaster management operations. Our solution employs standards-based interoperability, using the OIIE™ OpenO&M ecosystem architecture, to enable seamless interaction between interdependent systems and manages the risk to critical transportation infrastructure. The technology was tested at a microscale level to evaluate its performance. The model architecture supports scalable systems of systems interoperability for standardized use cases and common asset classes used in transportation, energy, facilities, and other critical infrastructure.

Research highlights in study area, there are various small-scale landslide points occurred and located surround from major landslide point with already 42 field-investigated points. The core zone of study area has the gravity displacement coefficient (Kg) by 0.0006, the buffer zone has Kg by 0.0033, all of them are weak and relative stable. The core zone of the National Park has more than 60 landslide points with total area of 81.19 hectares, and total landslide soil volume is over 2.6 mil m³. The largest landslide volume in study area is about 2.4 mil m³, with added 14 large-scale lanslide volume from 1,000 to 65,000 m³. In particular, a number of slopes occurred consecutively during flood seasons in years of 2020 - 2021. Landslide activities strongly affecting the integrity and aesthetic value of Phong Nha – Ke Bang (PNKB) National Park with calculation results, for the largest landside point during rainny season in October, 2020, show that the sliding soil blocks have displaced more than 130 m, with low factor of safety (FS) by 0.32 and the total sliding soil volume is 2.1 million m³, also consistent with field monitoring data and analysis of remote sensing images (2.4 mil m³).

One of the primary causes that can reduce the lifespan of concrete structures is chloride-induced corrosion of reinforcing steel. Recent research has shown that material properties, exposure conditions and climatic conditions have a significant influence on the structural deterioration of reinforced concrete (RC) structures, especially in marine environments. The objective of this paper is to predict the durability of RC structures damaged by chloride-induced corrosion in near-shore environments in Vietnam, considering regular repair activities. A two-dimensional model of chloride penetration in square cross-section RC columns repaired by cover replacement techniques is studied. Two repair methods with different shapes (orthogonal and circular) are considered. The effects of the different repair methods on the life span of structures are investigated in case studies in Vietnam that consider the variations of annual temperature and humidity in three coastal areas such as Danang, Haiphong, and Ho Chi Minh City. Finally, maintenance and repair costs during the lifetime of structures are calculated for each case. The study suggests that for RC structures exposed to two-dimensional chloride ingress, the most critical areas for assessing chloride concentration, predicting corrosion initiation, and planning repair schedules are the corners of the columns. In addition, the chloride-induced corrosion process is strongly influenced by the local weather conditions, especially in areas with high humidity. The repair method with circular concrete replacement seems to be more efficient in terms of maintenance schedule and cost than the repair method with orthogonal concrete replacement.

Delaminations are generally developed in construction works due to numerous factors, including cyclic loading, water flow, and weather conditions. A conventional non-destructive method, such as tapping or chain dragging, is commonly used to predict subsurface delaminations. However, tapping tests may require more precision, especially for minor subsurface defects. Passive Infrared Thermal Imaging or Passive Infrared Thermography (PIRT) effectively detects sizable delaminated areas of a structure quickly. However, the inspected structural components are recommended to be exposed to direct sunlight. In this study, PIRT was used to investigate an operating ancient rock-cut tunnel and to detect potentially dangerous locations where delamination and spalling have occurred. The results prove that PIRT can effectively detect delaminated areas, even when there is only a 1-2°C atmospheric temperature difference nine hours before testing.

This paper focuses on the establishment of repair or strengthening method of steel structures by externally bonded patch plates. The bending static tests and bending fatigue tests of adhesively bonded joints were conducted and the fatigue life is evaluated. The Konishi E258R is used as an adhesive, and the bending fatigue tests were conducted, varying the applied stress ranges and the stress ratio, the ratio of minimum and maximum stress of fatigue test. The result indicates that the fatigue life of adhesively bonded joints can be evaluated in the function of principal stress ratio, the ratio of principal stress range against principal stress at debonding by the bending test, with constant linearity regardless of the stress ratio.

This study aims to evaluate the effect of the cross-section modification on the performance of square reinforced concrete (SRC) columns discontinuously strengthened with CFRP bands. In line with this research aim, the performance of SRC columns under eccentric and concentric compression was compared with that of circularized square RC (CSRC) columns. Six RC columns with 800 mm height including three SRC columns with 150 mm side length and three CSRC columns with 212 mm diameter were prepared and tested. The test results revealed that SRC columns achieved a substantial enhancement of strength and deformation by applying cross-section modification before strengthening with discontinuous CFRP bands. It was also found that SRC columns received a substantial improvement of deformation and considerable improvement of strength by strengthening with discontinuous CFRP bands.

The size dependent static pull-in instability of functionally graded (FG) microbeams in micro-electromechanical systems (MEMS) is studied, considering the influence of the axial force. The material properties of the microbeams are varied in the beam thickness by a power-law function, and they are calculated by the rule of mixture. To account for the microsize effect, the classical Euler-Bernoulli beam theory is employed in combination with the modified couple stress theory to describe the microbeams deformation. Based on Von Kármán nonlinear relationship, a beam element is derived and employed to establish the discretized governing equation for the microbeams. Newton-Raphson iterative procedure is adopted to compute frequencies and pull-in voltages for the microbeam with clamped ends. Numerical result reveals that the pull-in voltage is increased by the increase of the power-law exponent and the microscale parameter. The effects of the material distribution, the axial force as well as the microstructural parameter on the pull-in instability of the FG microbeams are investigated in detail.

The present study investigates the shear behavior of the Ultra High Performance Concrete girder strengthened by steel bars and stirrups by simulation approach. Utilizing the Concrete Damage Plasticity model that involves strength reduction and nonlinear behavior of the material, 3D simulation models are established and analyzed by the commercial software Abaqus. The numerical simulation model is verified by comparing the test data to ensure reliability. Numerical simulation models were then developed to investigate the relationship of shear force with parametric studies of shear span to depth ratio, steel bar ratio and stirrups spacing. Based on the obtained results, the simulation model and test results show a good agreement. The relation between the shear capacity of UHPC girder and parametric studies was also enlightened.

Recently, many flyover steel bridges have been built due to high demand of transportation development mega cities in Vietnam, especially in Ho Chi Minh City and Ha Noi City. The steel bridges are selected as effective solutions in urban area because of their advantages such as rapid construction, aesthetic design, high performance. For the construction method of concrete deck slab, wood panels, plastic panels, and precast concrete panels are often used to reduce construction costs. From actual construction projects, these form solutions may not be suitable for large span over 2.0 meters and take more time to install and to dismantle. This study aims to develop an improved solution with reusable steel deck forms for bridge slabs which has been used as permanent deck forms in buildings. Experimental studies are conducted to investigate the frequency of reusability and to verify the bending capacity of the steel deck after many times of reuse. The experiments are separated into two phases including concrete casting stage and strength tests in laboratory. Bending strengths of reused forms are compared with that of new one. Results shows that steel deck forms are still in good condition and provide sufficient bending capacity after 10 times of concrete casting comparing. Therefore, reusable steel deck forms can be effectively applied in the construction of bridge slabs to optimize the construction time and cost.

Vietnam's mountainous highways are increasingly affected by landslides each year, with climate change being a major cause. The government has allocated significant funds to repair, rehabilitate, and maintain these highways, but conventional methods like excavation and embankment are not always effective for roads that pass through unstable, large-angle slopes that have a high risk of landslides. This results in additional rehabilitation costs following natural disasters. To address this issue, JFE Civil Engineering & Construction Corporation has developed a new solution for constructing mountainous highways in Vietnam - a viaduct that functions as a space steel frame supported by steel pipe columns and beams. Prefabricated in a factory and transported to the construction site, the steel beams are then assembled, and steel piles are driven deep into the ground for a rigid pile-to-ground connection. These proposed structures offer sustainable and cost-effective solutions for mountainous highways with minimal impact on the surrounding environment. Two case studies in Quang Ngai Province and Lam Dong Province are presented as preliminary designs to demonstrate the feasibility of this solution.

In this study, we introduce a new rotating uniform eddy current (RUEC) probe designed to identify artificial cracks in conductive materials. The RUEC probe comprises four rectangular coils, divided into two sets of diagonally positioned coils. By providing two alternating current sources with a 90° phase difference to the two sets of coils, a RUEC distribution with uniform amplitude in all directions can be produced on the surface of the test specimen. Furthermore, ferrite cores are integrated into the four coils to enhance the crack detection ability. To confirm that the RUEC probe model produces RUECs with uniform amplitude in all directions on the test specimen surface, we conducted finite element method (FEM) simulations. We then conducted experiments with the RUEC probe to identify artificial cracks of varying sizes on the test specimen. The experimental results demonstrate that the RUEC distribution on the test specimen surface enabled successful detection of cracks in all directions with the probe.

Self-sensing concrete (SSC) is a smart material created by dispersing a conductive filler into the concrete. This helps to increase the resistivity variation of concrete when the microstructure of the material changes under the effect of load. Thus, the stress, strain or damage of the concrete can be sensed by resistivity measurements of the concrete itself. This study aims to clarify the effects of parameters related to the measurement method on the self-sensibility of SSC. SSC specimens were prepared using carbon black with 7% volumetric content. A series of compression tests were conducted to investigate the relationship between the resistivity variation and the applied load of different test specimens in terms of excitation voltage, electrode distance and specimen size. The results show that the excitation voltage need to be large enough to generate a current of suitable stability when measuring the self-sensibility of SSC. The resistivity of all specimens decreased with increasing compressive load on the SSC specimen. The larger the specimen size and the smaller the electrode distance, the more pronounced the resistivity variation.

Analysis and identifying the displacement characteristics play a key role in timely monitoring and detecting the physical responses of the bridge to ensure the safety of the human and structure. Many previous kinds of research used GNSS data to identify displacement and oscillation modelling of the bridge with different algorithms. This study uses GNSS time-series data to determine linear displacement and model oscillation of the bridge using a procedure including filtering outliers, linear regression, and sin function to identify amplitude in three directions, the plane displacement velocity, spatial displacement velocity, and vibration model of the bridge. The data in the research in the GNSS time-series data from three P5 GNSS receivers of the CHC brand on the Dachongyong bridge in Nanning, China with 1646 observations, at one-hour sample intervals in 68 consecutive days. The plane and spatial velocity of the three points DCQ01, DCQ02, and DCQ03 is 0.0181 mm/h, 0.0185 mm/h; 0.0114 mm/h, 0.0173 mm/h; and 0.0071 mm/h, 0.0082 mm/h respectively. The study results are significant in analyzing and identifying the bridge's displacement characteristics.

Global Navigation Satellite System (GNSS) plays an important role in the real-time monitoring of superstructures, especially for long-span cable-stayed bridges. Currently, GNSS has been applied to integrate a Structural Health Monitoring system (SHMs) of many long-span cable-stayed bridges worldwide through its advantages in observing a large displacement of structures and monitoring the global deformation of bridges. However, some studies of actual GNSS monitoring data of a cable-stayed bridge showed that there are a lot of abnormal data occurrences such as missing data or several abnormal data. This paper investigates the application of some methods for processing the GNSS abnormal data acquired from an actual cable-stayed bridge in Vietnam. Firstly, a long-term monitoring dataset of an actual bridge was acquired for the study experiment. A clean-short dataset was used to investigate the accuracy and applicability of some methods in the interpolation of abnormal data, for example, linear formula, Moving Average, Artificial Neural Network, and Hampel Identifier. Some criteria are used to assess the difference between the interpolated data and actual data such as Root Mean Square Error (RMSE) or correlated coefficients with temperature data. Otherwise, the applied methods were then assessed their abilities and effectiveness in real applications, for instance, creating an automatic interpolated program of abnormal data.

Failure-induced vibrations are a common phenomenon in many civil structures, and the characterization of their vibration frequencies is crucial for monitoring their structural health. This paper presents a new optics-based mechanical system that can monitor the vibrations of civil structures through the fluctuation of laser spot size using advanced image sensors. The principle behind this vibrometer combines mechanical oscillation and laser optics, and it provides information on vibration through the precise variation of spot size in a low-cost, low-risk, and high-speed manner. The system comprises simple components that are easily integrated into various civil structures. Therefore, this novel approach offers a promising method for effectively monitoring the health of civil structures.

This study explores an automated method for identifying cracks on a concrete bridge structure using an unmanned aerial vehicle (UAV) equipped with a high-resolution camera. First, images are captured from the bridge, then a novel automated algorithm are used to isolate the region of interest. The deep learning algorithm then detects cracks on the structure using a pre-trained Convolutional Neural Network (CNN) model. The proposed method was tested on Tran Phu bridge, and the results confirmed the effectiveness of the UAV-based inspections for identifying cracks on structures.

This study presents a diagnostic technique for identifying the loss of stiffness of homogeneous beams using only the deformed shape in an effort to develop more effective building health monitoring instruments. Method based on a correlation between beam deformation at two damaged and undamaged selection states. Diagnostic indicators such as the correlation coefficient (CC) and the absolute value of the mean deviation ratio (MAPD) are extensively used to determine the presence of decreased stiffness. Using an approach based on finite element analysis, the deformation line data is computed. Various failure scenarios are proposed to evaluate the beam damage detection sensitivity of the indicators. In the case of beam damage, the CC index value is less than 1, and in the absence of damage, it is equal to 1. Similarly, for the MAPD index, the value is greater than 0 in the case of damage to the beam and 0 in the case of no assumed failure. The result demonstrates that the deformed line data can be used to calculate the assessment indicators for determining the onset of damage in homogeneous beams. Indicators that have not yet determined the location of the local stiffness decline on the beam when using input data are the deformed shape corresponding to the survey examples in this study.

In this paper, a method for damage monitoring of bridges using modal parameters is presented. At first, fundamentals of frequency-based damage occurrence alarming are introduced. Second, building information modeling (BIM) software is used to construct a 3D geometric model of a bridge. A custom tool add-in based on Microsoft Excel is linked and analyzed related data for damage detection of the bridge using modal parameters. A finite element model of a bridge girder is established to investigate vibration characteristics under prestressing loss and structural damage. Frequency-based damage detection is implemented to alarm the damage occurrence of an inspected bridge girder. Last, the structural information of the bridge is updated to the BIM model to provide the structural performance of the inspected structure. The result reveals that BIM integrated with the damage detection algorithm can efficiently facilitate structural health bridges.

Building facade is an integral piece to the overall design of a building, which not only ensures adequate interior thermal comfort, minimizing cooling load rate but also lowering overall building energy consumption. In recent years, aluminum composite material wall (ACM) is a new decorative material that is increasingly being used by developers, designers, and architects, which led to many innovative building facade designs. It is a straightforward and versatile product that provides a weather-resistant, sound-insulation, heat-insulation, earthquake-resistant, and shock-resistant façade that is simple to install. As a result, this study proposes a perfomance of energy simulation with ACM material applied in building design using Building Energy Modeling (BEM). Energy simulation in buildings using a Building Information Modeling (BIM) system is proposed to reduce the Energy Use Intensity (EUI) and energy cost of building in its construction process. The results of this study are expected to assist architects and building managers in improving and enhancing the energy efficiency of buildings. These significant findings demonstrate the potential of using ACM wall to improve building energy efficiency.

In the Fourth Industrial Revolution, innovative approaches that are emerging to solve traditional problems are regularly updated and improved. Prominent among them is the gamification application in the infrastructure construction industry. This is an intuitive simulation tool that brings a high level of experience and efficiency. The article presented an overview of the gamification application in infrastructure. It can be seen that with the development of modern game engine and new technologies such as Building Information Modelling (BIM), Virtual Reality (VR), Mixed Reality (MR), Augmented Reality (AR), digital twin, gamification is used in different phases of a project such as design, construction and operation. Furthermore, the article also provides an assessment of opportunities and challenges when applying gamification to the infrastructure construction in Vietnam. Furthermore, some preliminary suggestions to improve the application efficiency are also made.

Since the beginning of the last decade, Algeria has given notable importance to sustainable transportation systems. The objective of this paper is to show the importance of two modern transportation means and to assess their operation. The methodology used in this work is based on the data recorded by the National Office of Statistics (ONS). The data analysis consists of two parts, the first part aims to show the importance of the subway and tram through an analysis of the passengers' number who traveled by this two means in all cities. Then, the second part focuses on the Algiers subway and trams' assessment by comparing the offered capacity and the passengers' demand per year between 2017 and 2020. On the one hand, the results show that the number of users increased for the subway and trams except in 2020, due to the COVID-19 pandemic. On the other hand, the results show that the capacity offered for these two modes is high compared to the real passengers' demand. This last finding can influence the sustainability criteria, especially for energy consumption. This contribution presents several recommendations for improving the subway and trams performance in Algeria.

Predictions of traffic volumes on road networks must be precise for transportation planning, and equilibrium trip assignment models based on the Volume Delay Function (VDF) are typically employed. In 1964, the U.S. Bureau of Public Roads (BPR) created a VDF widely used in many countries, including Indonesia. However, using capacity manuals from Western nations in Indonesia did not produce the desired results due to differences in traffic composition and driver behaviour. Using the Indonesian Highway Capacity Manual's macroscopic fundamental diagram, this paper aims to derive a more accurate VDF for Indonesia. This method enables the development of a VDF tailored to the unique traffic conditions in Indonesia. It can enhance the precision of traffic volume forecasts in the region. The BPR function parameters tends to overestimate travel time delay, making the road network model flow misestimated. This is presumably caused by traffic count survey inability to record the build-up of traffic flow in the urban network during peak traffic periods.

Given ever-increasing private transportation ownership, a rising population, and unceasing mobility, it is crucial to ensure the usage and improvement of public transportation services. Therefore, it is important to review and understand relationships between variables affecting ridership to boost them. This paper acts as a preliminary data analysis in which correlation and multiple linear regression (MLR) analyses were constructed to examine bus transit ridership. The main goal of this study is to identify the variables that influence transit ridership and the degree to which they do so during a) peak hours and b) off-peak hours. Independent variables such as bus commercial speed, service frequency, in-vehicle travel time, bus stop distance, and rainfall were employed in this study. Results show that all the independent variables are significant and correlated with ridership. However, the regression models show that distance and travel time are not statistically significant during peak and off-peak hours, respectively. The findings of this study recommend the creation of relevant policy initiatives that can assist transit agencies in increasing ridership by analysing significant predictive factors. Additionally, the output from this study can be used in future works on designing efficient bus routes, stop locations, and even bus schedules.

Microscopic traffic simulation packages, which were invented for car-based environments, have also been used for motorcycle-based environments. Because the interactions between several transport modes (e.g., buses, cars, and motorcycles) are different in these two environments, default parameters relating to these modes (e.g., acceleration, deceleration, speed) should be modified in the simulation of motorcycle-dominated networks. However, there seems to be very little evidence on the modification of these parameters in microscopic traffic simulation for these networks. To fill this gap in the literature, this research develops a VISSIM model (as one of the most appropriate microscopic simulation packages) for motorcycle-dominated mixed transport, which includes data collection, creation of a VISSIM model, and calibration and validation processes. For parameters which cannot be observed on-site, some values for each parameter are chosen based on the default values in VISSIM or local conditions. These values are then run in VISSIM models and tested in the calibration and validation processes to choose the values that best describe vehicle movements. By contrast, parameters that might be collected on-site are statistically analysed and inserted directly in to VISSIM. Acceleration and deceleration of motorcycles, the desired speed of car and bus, the desired speed of motorcycle, minimum lateral distance driving when overtaking vehicles on the same lane, and average standstill distance were applied for developing VISSIM models for a motorcycle-dominated mixed traffic corridor in Hanoi, Vietnam. Acceleration and deceleration surveys were carried out on-site by using the speed gun Stalker ATS. The results of statistical tests prove that the VISSIM models are sufficiently reliable to represent real traffic. Transport modellers can draw on the findings of this study. Desired acceleration and deceleration default values in VISSIM, which are for typical motorcycles used in Europe, should be replaced by local acceleration and deceleration rates. The methodology for developing a VISSIM model can be modified to suit other local motorcycle-dominated mixed traffic conditions.

The development of electric motorcycles depends on the motorcycle usage rate in each country, which is crucial in forming sustainable urban development. In this study, we investigated determinants of using e-motorcycles among students in Hanoi, Vietnam. Students are the research subject due to their critical role in shaping future travel patterns. The used data were collected by surveying 290 students from three universities. We found that the prevalence of adopting electric motorcycles among students is 11%. The results of binary logit regression show that female students in Hanoi living within distances between home and school from 3 to 5 km are more inclined to utilize electric motorcycles. The perception of usefulness and environmental concern are facilitators of the adoption. However, perceived ease of use is not a significant predictor. This study plays a role as an exploratory analysis of the actual use of electric motorcycles. However, in order to have a better understanding of the motives behind the choice of electric vehicles for students and other population segments, more research in different settings is needed.

This work aims to examine the factors that influence users' satisfaction and reuse intention in respect of the monorail system in Kuala Lumpur, Malaysia. The hypotheses were tested with 417 survey data collected among monorail users. The newly developed model of users' satisfaction and reuse intention was evaluated through structural equation modelling, the basis of which was a parameter estimation of partial least squares (PLS-SEM). Findings reported that the proposed model led to 70.4% and 59.5% of the variances explained by user satisfaction and reuse intention towards the service provided. The findings demonstrated convincingly that overall satisfaction and reuse intention are affected by two key factors from the users' perspectives: perceived quality and perceived value. The results are useful for service providers and related bodies in their effort to enhance user satisfaction as well as increase the monorail service ridership.

Customer's satisfaction plays the most important role in shaping continuance usage intention (i.e. loyalty). Therefore, much scientific effort has been invested in exploring the factors contributing to the satisfaction of passengers using the bus, air, intercity rail, and metro services. Notwithstanding, little is known about the determinants of customers' satisfaction with the services offered by long-distance bus stations. Aiming at filling this research gap, the current study analyzed the passengers' satisfaction in the case of Mien Dong station in Ho Chi Minh City, Vietnam. The used data from 300 passengers were collected in August 2022 through face-to-face interviews. As regards the analytical methods, the Exploratory Factor Analysis was applied to the responses to the attitudinal items in order to extract underlying constructs, which were then used together with demographical variables to fit an ordinal logit model. The findings show that most demographics were irrelevant, but habit was a significant predictor. Specifically, the higher usage frequency was involved in the lower level of satisfaction. All constructs derived from EFA (Information availability, Customer services, Reliability, Comfort, Safety and Security) were positively associated with the satisfaction level. Among latent constructs, security & safety and comfort were the strongest while information availability was the weakest. Based on the results of influential factors, some practical implications were suggested. Since Ho Chi Minh City is a typical megacity in developing countries, our findings are expected to be useful for other research in settings beyond Vietnamese cities/provinces.

Young motorcyclists have been considered a high-risk population contributing to a high number of traffic crashes. Since rider risky behaviours have a serious impact on traffic safety, identifying the rider's mindset can help clarify the nature of accidents. The data of the study were collected from students in some universities located in Da Nang city, Vietnam using a self-report questionnaire. Based on the combined framework of the theory of planned behaviour (TPB) and deterrence theory (DT), psychological factors affecting risky riding behaviour are explored. The research results show that the factors in the TPB model have a positive and significant influence on the intention to involve in risky riding behaviours among university students. In contrast, certainty has a negative impact on the behavioural intention. Additionally, in this study, a multi-group analysis is performed to further explore the differences between male and female riders. The results of this study are useful for developing strategies which aim to reduce risky riding behaviours among young riders, particularly in the context of a motorcycle-dependent country.

The horizontal curve segment is where traffic crashes often occur in rural areas of Vietnam. Although many safety countermeasures have been implemented, their effectiveness still needs to improve. The main reason is that the implemented countermeasures are unfit for the crash causes. More specifically, determining crash causes and contributory factors to the severity of crashes needs to be more accurate because of the need for more critical data and specialized analytical tools. This study applies the crash reconstruction technique to simulate, reconstruct, and analyze crashes that occurred at horizontal curve segments to address the abovementioned issues. The study results have reproduced the sequence of events, crash causes, and contributory factors to the severity of roadway departure crashes of four-wheeled vehicles in rural areas. This research is a scientific foundation to help researchers choose the suitable technique to reconstruct traffic crashes and identify the appropriate solutions for enhancing traffic safety at horizontal curve segments in Vietnam.

Transportation Demand Management (TDM) has been introduced in Vietnam to keep the balance between the limited supply of road network, and the increase of private vehicles and Park & Ride (P&R) is one of TDM's measures focused on the transition from private to public transport at stations. This research investigated the current situation of parking areas and bus users' behavior in 4 main stations in Hanoi, Vietnam. Furthermore, bus users were asked in the assumption case that if they cannot use the bus, how much they will pay for the travel cost and time in that case compared to the actual case when they use the bus. The results have found that many people have accepted to travel in a longer time to save travel costs. This research also identified the factors which influence on using P&R services in station of bus users. Based on the Binary logistic regression model, the "Income" factor is one of the significant characteristics of bus users on selection use or not use of P&R services at the bus station. Finally, bus users' expectations on the current situation of the parking services at stations gave some suggestions to improve the P&R services in bus stations in Hanoi.

Road traffic accidents are a significant contributor to the global disease burden and a major cause of fatalities worldwide. In order to enhance traffic safety and minimize accidents, this study investigated the effect of driver safety attitudes and risk perception on driving behavior. To gather responses on risk perception and safety attitudes, surveys were conducted both online and on paper in three Vietnamese cities: Hanoi, Yenbai, and Laocai, and data was collected from 500 drivers. Exploratory factor analysis was performed on the 48 items in the questionnaire, resulting in eight factors that were subsequently analyzed using confirmatory factor analysis to generate risk perceptions on road systems and usage, safety attitude, and driving behavior. The four driving behavior factors identified were aggressive driving, careless driving, adherence to traffic rules, and multitasking. A structural equation model was used to explore the effects of driver risk perception and safety attitude on driving behavior. The results showed a significant positive correlation between drivers' risk perception and safety attitude, with both factors significantly impacting driving behavior. This study provides a comprehensive analysis of traffic safety, with a specific focus on human factors.

Motorcycles with internal combustion engines using fossil fuels account for the majority of traffic flow in major Asian cities. The increase in the number of conventional motorcycles using a gas engine is one of the main causes leading to air and noise pollution in comparison with other lower-emitting transport modes (e.g., walking, cycling, and public transport). Thus, many Asian countries have promoted the adoption of electric motorcycles to significantly reduce air pollution and non-renewable energy consumption as a solution for motorcycles using internal combustion engines. However, the application of electric motorcycles still faces many limitations and challenges. This study explores factors influencing the adoption of electric motorcycles in Vietnam based on the extention of TAM model. Based on 751 valid responses in Ho Chi Minh and Da Nang cities, Vietnam, a structural equation model (SEM) with first-order and second-order latent variables is proposed to analyse the collected data. The results indicate that perceived of usefulness is the most significant positive effect on the adoption of electric motorcycles. In contrast, perceived risk is found to be a barrier of the adoption intention. In addition, the results of multigroup analysis show that age moderates the correlation between prceived easy to use and the adoption intention. Similarly, the correlation between perceived risk and the adoption of electric motorcycles is influenced by the difference in monthly income. Several policies and governance implications are also discussed in this study.

The elderly are a potential segment of electric bicycles (EBs); however, so far the understanding of the factors contributing to the choice of this mode for older persons in developing countries has been rather limited – particularly compared to that in developed countries. The current study aims at exploring people's intention to accept EB in later life in Hanoi, Vietnam using the data from 360 older persons (at least 55 years old) to empirically analyse a conceptual framework formulated based on the Model of Goal-Directed Behaviour (MGDB) and the Theory of Planned Behaviour (TPB). Desire is found to be the major contributor to intention, which is found to be significantly higher for younger and employed respondents. Desire is facilitated by subjective norms and attitude but is deterred by perceived crash risk. Perceived behavioural control and descriptive norms are irrelevant predictors. This study is one of the first research on the elderly's intention to ride an EB in low- and middle-income countries.

By the end of June 2022, Hanoi has 2,835 schools, nearly 70,200 classes, and more than 2.2 million students. More than one million children ride the bus to school, and 100% of these school buses run on diesel. Diesel exhaust has proven links to serious physical health issues as well as cognitive development impacts. Transitioning to electric school buses from traditional diesel-powered school buses can reduce students' exposure to harmful pollutants that contribute to respiratory disease, heart disease, cancer and physical problems - and which can harm students' cognitive development. However, the adoption of electric school buses concerns significant issues relating to the purchasing and operating costs, driving distance and charging systems. Therefore, the possibility of electric school buses remains unknown. The study used documents and semi-structured interviews with students, parents, school vehicle organizers, and bus service providers who involving in the decision-making of electric school bus adoption. The results show that the purchasing and operating cost, the driving distance and charging systems are major concerns and experiences by involved stakeholders are highly context-dependent. Financial and regulatory support from the national government, along with student demand and route characteristics had a significant influence on electric school bus adoption.

This study aims to examine service quality factors and the extent of their influence on passenger satisfaction with public bus transport service. The study will describe the steps of creating a SEM (Structural Equation Modeling) model to demonstrate the service quality - satisfaction relations. Survey data conducted by the Ho Chi Minh Public Transport Management Centre in collaboration with the World Bank consultants from December 2019 to January 2020 includes 3,913 questionnaires on 25 subsidized bus routes. The analysis results from the SEM model indicate that the factors with the strongest impact on satisfaction are availability possibility, service information, fare, service attitude and friendliness with the environment. This result suggests that public transport should focus on improving these service quality factors to ensure a high level of passengers' satisfaction.

Cracking is one of the essential indicators to evaluate pavement surface conditions; however, it is challenging to rate pavement cracking automatically from 3D digital images. Recently, a two-level automated crack rating system was proposed for pavement management in Singapore where Level 1 provides detailed crack information including cracking extent, types, and severity. Level 2 is a macro-indicator ranging from 0 to 5 based on crack extent over a 10-m length pavement section, with 0 being excellent condition and 5 being very bad condition. On the other hand, the new ASTM E3303-21 standard has introduced the Pavement Surface Cracking Metric which is a dimensionless measure equivalent to crack density and the Pavement Surface Cracking Index which provides ratings of pavement cracking ranging from 0 to 100, with 0 being the worst possible condition and 100 being the best possible condition. This study was conducted to compare and potentially bridge the gaps between the two mentioned cracking rating methods. Cracking data were collected from the Singapore road network using the Laser Crack Measurement System-2 (LCMS-2). Based on the study findings, three severity ranks (low, medium, and high) were proposed to facilitate the inclusion of the ASTM E3303-21 cracking protocol into Pavement Condition Index calculations.

Superelevation is known as a transverse slope made available to mitigate the impact of centrifugal force and minimize the vehicle's tendency to overturn and skid. However, in an intersection or interchange that has horizontal curves with small radius consecutively, it is difficult to design superelevation. If the superelevation arrangement is not good enough, the alignment is not smooth, causing unfavourable and unsafe conditions. Moreover, for expressway interchange, it become more complicated to design by manual method because the expressway requirements in term of safety and aesthetics is higher than that of conventional intersection. On the other hand, ADSCivil Road, a software in the ADSCivil solution suite for infrastructure design developed by Baezeni Soft Co, Ltd. is a useful tool for geometric road design. This paper presents the results of ADSCivil Road software application in designing the superelevation at the expressway. ADSCivil Road has arranged superelevation for an interchange ramp (with a design speed of 60 km/h) that includes the small radius circular curves connecting together (R=125 m and R=100 m). The results show that using the superelevation diagram and corridor model in ADSCivil Road makes the superelevation design process more intuitive, make it easier to adjust the slope at each point, and controls the rate of superelevation difference. In addition, ADSCivil Road automatically updates the superelevation change for profile, cross-section and plan. Also, 3D simulation results show that the superelevation layout for this interchange meets technical, economic, and aesthetic requirements. Obviously, it can be seen that can become an effective tool to help engineers solve complex problems in road design.

Semi-flexible pavement has a more notable advantage over asphalt concrete pavement in terms of rutting performance. Cement grouting and open-graded asphalt concrete are components of the semi-flexible pavement. In cement grouting, two commercial modifiers from Sika Vietnam were used, Sika Latex and Sika TH Latex, with different contents from 4.5% to 7.5% for Sika Latex and 7.5% to 9.5% for Sika TH Latex. 72 samples of cement mortar were fabricated in laboratory conditions from PCB40. All cement grouts were cured at the age of 7 days. The paper results focus on the flexural strength and the compressive strength of both mortars, the suggestion of Sika content to produce the stable strength of cement grout, and the viscosity of cement mortar based on the Sika contents.

The performance of a cement-treated base in semi-rigid pavements is greatly influenced by temperature change. Therefore, the thickness of asphalt concrete (AC) layer is one of the biggest concerns when designing semi-rigid pavement structures. The article evaluated the effect of AC layer thickness on the temperature distribution in semi-rigid pavement. First, a large-scale model for a semi-rigid pavement structure with a 13-cm AC surface layer placed on a 15-cm CTB layer was constructed to monitor temperature fluctuation in the pavement. This temperature monitoring result was then used for proposing and verifying a numeric prediction model developed in the ANSYS program to estimate the temperature distribution in the pavement structure. The model was then applied to cases of changing AC thicknesses to analyze the effect on CTB temperature. The results showed that the thickness of the AC layer significantly influenced the temperature distribution in the semi-rigid pavement; the thicker AC layer resulted in a low-temperature distribution in CTB.

A Falling Weight Deflectometer is popular equipment to measure surface deflections under imposed loadings, providing the necessary parameters for back-calculating the elastic moduli of road pavements. There are several back-calculation programs available that accurately back-calculate pavement layer moduli. The Gravitational Search Algorithm (GSA), a metaheuristic optimization algorithm inspired by Newton's law of universal gravitation, is one such algorithm. The Binary Gravitational Search Algorithm (BGSA) is an enhancement algorithm based on GSA that can be used as an efficient search algorithm for back-calculating pavement moduli based on matching measured and calculated surface deflection of road pavements. Choosing the best BGSA parameters is critical for accurate back-calculation of road pavement moduli. Nevertheless, there has not been much study on selecting the best BGSA parameters for back-calculating road pavement moduli in the literature. Therefore, this study proposes strategies for selecting BGSA parameters based on the least computational effort and the least root mean square error between measured and calculated road pavement surface deflections. In this study, the Burmister theory is discussed and the Richardson extrapolation is adopted to improve the accuracy of the calculated points near the pavement surface; the best parameter of BGSA including the agent size A of 50 and an iteration step T of 300 are suggested to back-calculating the road pavement moduli.

Ultra-thin whitetopping (UTW) is a thin (5-10 cm) layer of concrete overlaying over an existing asphalt pavement. This concrete layer is bonded on the asphalt surface. Although UTW has been successful in strengthening asphalt pavement, in some cases, the composite pavement may debond at the interface under the concrete slab due to high shear stress. This paper aims to determine the interface shear strength required for UTW pavement systems using theoretical methods and calibrated numerical models (FEMs). The study analysed 432 pavement scenarios with different slab sizes, thicknesses, and material properties. The results show that higher shear stress occurs when the asphalt modulus is stiffer. The size of the slab, the modulus of the supporting layer, and the asphalt thickness have only a minor effect on the shear stress value. However, the thickness of the concrete slab significantly affects the maximum shear stress in the UTW, with an increase of up to 36.6% when reducing the slab thickness from 100mm to 50 mm. The FEM calculations can be used to determine the required interface horizontal shear strength for UTW.

Subsidence of embankment foundation at the approach roadway is quite common in South Vietnam because natural soil layers are high water content and low bearing capacity. Soil-cement columns could be a potential method to deal with foundation subsidence. A critical issue is to determine proper soil-cement mixtures, mainly depending on maintenance conditions. In this study, materials characteristics of soil-cement samples are experimentally tested under various maintenance conditions. To achieve the objective, first, we drill to get natural soil samples at various depths for different boreholes located in southern Vietnam. Second, soil samples are used to fabricate soil-cement cylinder samples. Third, a set of fabricated samples are maintained under various environmental conditions for 7, 14, and 28 days. Last, experimental tests are conducted to test axial compressive strength to evaluate the effects of environmental parameters on strength development. The result reveals that the proportion of soil cement should be properly designed for soil layers to maximize the performance of the soil-cement column.

Deterioration of concrete structures is an issue that affects the entire world and is brought on by various causes like climatic conditions, aging, attack of aggressive media, etc. Periodic inspections and proper maintenance are crucial to prevent the degradation of structures. Conventionally, the condition of the structures is monitored visually but over a while, non-destructive evaluation (NDE) technologies have gained significance and are expected to be successfully used for the inspection and management of civil structures. Infrared imaging is an effective NDT tool to monitor the health of civil structures. In this study, Infrared Thermography (IRT), an image-based method, is introduced and implemented for the assessment of concrete structures. Experiments on cement concrete cubes were conducted to investigate and enhance the applicability of the infrared thermography technique. The results are quite promising and helps to detect defects like delamination, voids, and cracks, etc. as the IR camera can pick-up the difference in temperature between sound and defective regions. However, the utilization of IRT for inspection poses many challenges but they can be overcome by combining it with other techniques like finite element method, acoustic emission and ultrasonic guided waves. Hence, the infra-red thermography technique is an excellent technology for practically evaluating concrete structures.

Gas condensate diesel fuels, being an excellent resource base, often do not meet modern standards of the cetane number value and the content of sulfur compounds (SC). Currently, Euro 5 and Euro 6 (<10 ppm sulfur content) diesel motor fuels are produced worldwide. High-quality diesel fuels are produced using hydro desulfurization process. Analysis of scientific publications has shown that the adsorption is effective method of desulphurization, which can serve as a method of removing SC from fuels or refining oil and its fractions, which allows removing residual sulfur. The advantages of the adsorption method are: low level of capital costs; simplicity of equipment; carrying out the process under much milder conditions compared to hydro desulfurization. In this paper, an original adsorption-catalytic method of reducing the concentration of SC to <10 ppm using a nanoporous adsorbent-catalyst is proposed. The structure and content of complex sulfur compounds in gas condensate fuels obtained from the raw materials of two deposits – Yamburgsky and Zapolyarny – were determined by gas chromatography–mass spectrometry. The next SC substances were found: tert-hexadecanethiol (C₁₆H₃₄S); 4,4,6-trimethyl-5-phenyl-1,3-oxazinane-2-thione (C₁₃H₁₇NOS); 1,2-bis(2-methylundecan-2-yl)-disulfane (C₂₄H₅₀S₂); 3-methyl-2,4a,9,9a-tetrahydro-1H-2λ⁴-indeno [2,1-c]thiopyran-2-carbonitrile (C₁₄H₁₅NS) and 2,3,4,5-pentamethylbenzene-sulfoneamide (C₁₁H₁₇NO₂S). Three-dimensional images of SC molecules and their adsorption complexes with Al-Ni-Mo-O component of a complex adsorbent-catalyst were obtained by molecular modeling. The adsorption energies of SC on the Al-Ni-Mo-O catalyst are calculated. The obtained values of the adsorption energies are in the range of −99.17 ÷−231.66 kJ/mol. As a result of the conducted research, a cartridge with selected adsorbent catalysts has been developed, which must be activated by heating in an inert medium up to 350 ° C. The average life of the cartridge is 1.5 years, after which it needs restoration.

This research aims to evaluate the strength development and microstructure of a green mortar produced from waste red brick powder (WRP) as a partial cement replacement. The mortar samples were prepared with various WRP content of 0%, 10%, 20%, 30%, and 40% of total binder weight, and the w/b was fixed at 0.4. The fresh properties were checked by flowability and fresh unit weight. While the compressive strength was conducted up to 28 days. The mortar samples exhibited a reduction in flowability and unit weight with increasing WRP content. The incorporation of 10%-20% WRP improved the compressive strength of mortar samples at 28-day, while the compressive strength reduced with higher WRP content (30%-40%). The C-S-H/CaCO3 gel, Ca(OH)2 and ettringite were hydration products of WRP mortar samples. The incorporation with WRP significantly reduced the Ca(OH)2 content

The principles of the energy variation method are commonly utilized in mechanics. Energy is a scalar variable, so these are more convenient and simple to establish the equilibrium equations compared to vector-based approaches (i.e. using forces and displacements). The present article applied the theorem of the energy variation method in order to set the equilibrium equations for various complicated problems. Four examples of applying the energy variation method include the differential equation of the Euler – Bernoulli beam based on the energy method, the system of Equilibrium Equations of the Euler–Bernoulli beam with the theorem of Least Work, the principle of maximum work to establish the equation of motions for the Euler–Bernoulli beam and the equation of motion for the Euler–Bernoulli beam by the virtual work theorem, have been implemented. The results obtained from this study open up further research directions on the application of the energy variation method in mechanics as well as in the analysis theory of beam bridges.

The article studies the punching shear capacity of reinforced concrete slabs by simulation method. Based on the Concrete Damage Plasticity (CDP) constitute model, the simulation model is established in the Abaqus software. The simulation model was verified by the comparison of punching shear tests. The parametric studies were implemented to investigate the effect of concrete and steel strength on the punching shear resistance capacity of the reinforced concrete slab. The punching shear resistance capacity of reinforced concrete slab was also calculated by the formulas proposed by available standards. Obtained results show that increasing concrete strength leads to a significant increment in the punching shear resistance capacity of slabs while the influence of steel strength is slight.

The valorisation of waste glass is part of a sustainable development plan. It presents several challenges, starting with the elimination of the various types of waste sent to landfill and the related costs, the reduction of the inconveniences associated with glass (shards, landfill fires), the development of new economic sectors and raw material saving (aggregate quarries). Several research works have previously been carried out to highlight the interest of using waste glass as a partial replacement for unbound granular aggregate in pavement structure. Nevertheless, industrialists remain reluctant to apply such a technique, which encourages researchers to extend their studies in order to properly control the behaviour of granular materials containing glass grains and consequently give more confidence to companies to enforce this technical solution. The present work consists in studying the influence of the shape of glass grains less than 5 mm (rounded and sub-rounded) on the mechanical behaviour of granular pavement materials. The study consists in making a comparison, from a behaviour point of view, between the two forms of glass grains obtained from two different grinding processes. As a result, the Proctor test clearly shows that there is no significant difference between rounded and sub-rounded shape in terms of compactabiliy. It was noted that the addition of particles of recycled glass makes the mixture more insensitive to water. It has been also found that the limiting percentage of addition of glass particles is situated between 20% and 30% reported to the total mass of the mixture.

With economic and social development, the total amount of domestic and industrial solid waste discharged is considerable. In 2020, Vietnam generated about 2.2 million tons of plastic waste and 2 million tons of industrial solid waste. And most of them are landfilled and take a long time to decompose. This has dramatically affected the environment, costly land resources, and considerable transportation, burial, and management costs of those landfills. Therefore, many scientists have studied to recycle these wastes. There are two approaches to using recycled waste in hot mix asphalt (HMA). Waste plastic changes the properties of the asphalt binder, and solid waste replaces coarse particles in an asphalt mixture. During the research on using recycled waste for asphalt concrete, PET (Poly Ethylene Terephthalate) and RFCC (Residue Fluid Catalytic Cracking) were chosen for the study. This paper presents a study on the influence of PET (with 0.2% content in HMA) and RFCC (with 5% content in HMA) on the viscoelastic property of asphalt concrete based on dynamic modulus, phase angle, and complex viscosity values. At high temperatures, HMA using PET and RFCC exhibit complete elastic behavior (φ ≈ 50) in contrast to the viscous elastic behavior of the control sample (φ ≈ 150). Compared control sample, RFCC significantly increased the stiffness of HMA at low and high temperatures; with the dynamic modulus of HMA using RFCC increased 1.1 times at low and 1.6 times at high temperatures; the viscosity of HMA using RFCC and PET decreased 10 times and 7 times at low temperatures.

Ferrochrome and Steel slags are by-products of the stainless steel and steel production, respectively. The utilization of slag as an aggregate replacement to provide a sustainable solution has gained attention from the construction industry in recent years. By reducing the demand for natural aggregate and providing an alternative use for industrial waste products, the use of slag is an environmentally conscious and economically viable option. This paper focuses on the potential application of using slag as road base/subbase layers. The paper examines the physical and chemical properties of the slag and reports on the strength and toxic metal analysis results. Slag can be processed into a coarse and fine aggregate that satisfies the necessary standards for road base/subbase layers. The testing results highlight the successfulness of using slag as an aggregate replacement for base/subbase layers, making it a promising and sustainable solution for the construction industry.

Steel slag aggregates can be utilized as unbound materials for road bases or as fine/coarse aggregates in asphalt/cement paving concrete. However, the availability of free lime (f-CaO) in the materials is detrimental to volumetric stability, affecting the strength or durability of resulting paving products incorporating steel slag aggregates. This paper investigates the potential expansion of fine and coarse steel slag aggregates compacted at different compaction densities. The experimental results exhibited a higher stability of the coarse granular mixture exposed to water than the fine one. Also, more compaction increased expansibility in the fine mix, especially at high compaction density. Furthermore, the graded steel slag aggregate exhibited higher strength than the other aggregates. The findings provide reference information on the useability of steel slag in cement-based materials, like the replacement of coarse aggregate is better than the fine ones in volume stability of steel slag concrete.

The application of the bus rapid transport (BRT) system has developed in many metropolitan cities owing to its cost-effective transportation which separates the bus routes from the private car route. However, the channelized bus load caused by narrow space operation in this road type leads to very fast pavement deterioration, especially, potholes and rutting issues have been a major concern in BRT pavement. Therefore, the main goal of this research is to develop a polymer-modified stone matrix asphalt (PSMA) with the aim of enhancing the permanent deformation resistance of pavement in this BRT section. PSMA mix designs were developed from different styrene-butadiene-styrene admixture contents and gradation types. Afterward, laboratory tests were conducted to evaluate the performance of the proposed mixture involving the dynamic modulus test and Hamburg wheel tracking test. The Falling Weight Deflectometer test was subsequently performed to verify the behavior of the best mixture in the severely damaged bus stop location in Seoul. The findings suggest that gradations impose a major impact on the performance of PSMA specimens, especially at high temperatures or low-frequency zone associated with congestion areas. In general, the test results confirmed the potential use of PSMA mixture to reinforce the bearing capacity of bus stop stations for sustainable infrastructure development.

As a basic component of the city's structure and, particularly, an integral part of the transportation infrastructure, pavements fundamentally contribute to the city's achievement of sustainability goals. This paper examines the environmental, societal, and economic impacts of using natural stone for the pavement to pursue an ideal image of Green-Clean-Beautiful city by the government in the burgeoning city of Hanoi, Vietnam. It addresses the urgent question of whether natural stone is a sustainable paving material in a tropical climate under the impacts of climate change. By analysing the published contents of the official press, supported by data and information gathered from interviews with key experts, stakeholders, and urban residents, this paper argues that the actual impacts of natural stone use for pavements on the environment, economy, and society are strongly negative, compared to the positivity initially perceived in Hanoi's scheme of changing the pavement facelift. It shows that by overemphasising appearance and imagined nationalism values when selecting natural stone, Hanoi government shows a slow progress in improving and balancing functional, social, environmental, and economic dimensions. The paper is significant in contributing to knowledge on pavement sustainability and sustainable materials while shedding light on the challenges of applying these theoretical perspectives into real-life practice.

Nowadays, the development of infrastructure is in full swing, which exploits natural resources and causes environmental pollution. Furthermore, cement is the most essential commodity for construction material mainly concrete, and its production is rapidly increasing to fulfil the demand for construction. The cement production is regarded as the one of the key causes of CO₂ emissions, which adversely affect the atmosphere by causing global warming. In addition to this, the ecosystem may suffer from marble quarrying and construction material processing. Nonetheless, waste marble can be used as a by-product if managed in accordance with regional, national, and international environmental laws. On the other hand, Currently, LD slag is disposed of in landfills, which exacerbates the scarcity of available land and contaminates groundwater through the leaching of heavy metals. The waste materials have the potential to be used in the development of infrastructure materials. The infrastructure development has aggravated the issue of rainwater runoff and flash flooding in rainy seasons because of inappropriate drainage. The elimination of sand in pervious concrete reduces its strength performance its practical applications are still limited. This study is aimed toward the permeability improvement of conventional pavement concrete by the implementation of pervious concrete and also to improve its strength characteristics. In this study, an attempt has to be made to replace the cement with marble dust up to a replacement level of 0% to 20% with an interval of 5%. Also, natural aggregate is replaced with Linz-Donawitz (LD) slag by 5%, 15%, 25%, and 35%. From the study, it is found that the use of marble dust and LD slag improves the strength properties, but reduces the permeation properties.

Cement-treated bases are commonly used in high-classified road pavements due to their stable strength and improved durability. However, this type of pavement base is sensitive to shrinkage caused by early water loss or temperature change after construction, resulting in shrinkage cracks and subsequent reflective cracking in semi-rigid pavements. To address this issue, various waste or by-products, such as oil, steel slag, end-of-life tires etc., have been investigated for use as an additive or a replacement for aggregates in cement-treated base. This review focuses specifically on the impact of rubber aggregates on the properties of rubberized cement-stabilized aggregates. In general, rubber aggregates are detrimental to the mechanical properties of cement-treated aggregates. However, the rubberized cement-stabilized aggregates exhibited reduced shrinkage and improved shrinkage cracking resistance, as confirmed through actual field applications. Furthermore, internal microstructure analyses indicate that rubberized cement-stabilized aggregates possess excellent anti-cracking capacity, particularly when subjected to compressive loadings. The review ends with recommendations and future studies to promote the applicability of rubberised cement-stabilized bases in semi-rigid pavements.

Pervious concrete, also known as porous concrete, contains interconnected pores that allow water from various sources to pass through. This type of concrete is generally used for pavement construction to protect the environment. Pervious concrete contains only coarse aggregate and sometime very small amount of fine aggregate. Many researches were conducted to develop an efficient type of pervious concrete with different types and combination of aggregates. In many studies, along with natural stone aggregate, other types of waste materials were also tried to use as a coarse aggregate in the mix design of pervious concrete. Some of waste materials showed very promising characteristics which can be effectively used in the mix design of pervious concrete with double environmental benefits. This review article provides an overview of some of the earlier investigations on pervious concrete made from waste and industrial by-product materials. The relationships between crushing strength, porosity and water permeability of the pervious concrete with different types of aggregate are presented in this paper. Steel slag, recycled aggregate, and palm oil clicker were among the waste materials utilized as aggregate in pervious concrete, showed comparable performance; even in some instances, better performance was achieved than pervious concrete made with conventional natural aggregate. The shape of waste aggregate, described by the elongation and flakiness indices, greatly affects the strength properties and water infiltration rate of pervious concrete. If these indices are high, the strength properties of the pervious concrete are significantly reduced, but the water permeability is significantly increased.

Coal bottom ash (CBA) is a significant waste produced by the coal manufacturing power plant, harming the environment. CBA has been used in many studies to replace sand in cementitious materials. However, few studies have investigated the use of CBA in concrete as a sand replacement with densified silica fume (DSF) as a cement replacement. DSF is a potential supplementary cementitious material (SCM) to combat the engineering properties of concrete that are typically decreased when CBA is used as a replacement for natural aggregate. Therefore, the present study aimed to evaluate the influence of DSF on the engineering properties of concrete containing different content of CBA as a partial replacement for natural sand. The mix design of the ordinary Portland cement (OPC) and binary blended concrete comprised 90% OPC and 10% DSF by total binder's weight. The CBA as the fine aggregate replacement was used at 25%, 50%, 75%, and 100% by total aggregate volume. The mechanical, porosity, absorption performance of DSF and CBA (DSF+CBA) concrete containing CBA as partial aggregate replacement material were investigated. DSF+CBA with 50% CBA replacement showed improved mechanical strength performance than control by 15% at 28d and 5.6% at 56d of curing. However, the total porosity performance for DSF+CBA concrete decrease as CBA content increases. In conclusion, the DSF as SCM in binary blended concrete with CBA content up to 50% achieved a better performance in terms of mechanical properties even though the porosity was marginally increased.

Currently, there is no report on the combined use of ground coal bottom ash (GCBA) and ground granulated blast furnace slag (GGBS) as supplementary cementitious material (SCM) with lime kiln dust (LKD) as an additive in mortar. Hence, the current work aimed to investigate the impact of the addition of LKD on the properties of ternary blended cement mortar consisting of a large volume of GCBA and GGBS as SCM. The total substitution level of cement was up to 80%, where 50% of GGBS was combined with 0 to 30% of ground CBA. LKD was used with a content of 0%, 4% and 8%. A polycarboxylate-ether-based superplasticiser was used to achieve the mortar's flow diameter of 200 ± 10 mm. Also, the fine aggregate-to-binder and water-to-binder ratios were fixed at 3.0 and 0.4, respectively. The result revealed that the setting time of the mortar increased by increasing the cement replacement level by GCBA. Besides, the setting time was reduced with increased LKD content. All the mortar mixtures are considered good quality according to the ultrasonic pulse velocity (UPV) results. The UPV values decrease with the increased GCBA replacement ratio but increase with extended curing ages. The mortar incorporating up to 15% GCBA achieved comparable or greater strength than the control mortar (50% OPC and 50% GGBS) at a curing age beyond 28 days. Moreover, increased strength performance was noticed with increased LKD content from 0% to 8%.

In present day scenario the human activities have led to environmental degradation with increased urbanization contributing to many fold increase in constructing activities, which uses limited natural resources. Therefore, prevention of resource over-utilization and recycling of the waste is of utmost priority in construction sector. Waste tires rubber is one such potential material which can be used in concrete as replacement for fine aggregates replacement. This study represents the effect of addition of crumb rubber in concrete as sand replacement ranging from 5-20% on volume basis. The study evaluated the workability, compressive strength, ultrasonic pulse velocity (UPV), electrical resistivity and water permeability at 28 days. Tire rubber was also pre-treated with NaOH and KMnO₄ as an effort to enhance its bonding characteristics. The contact angle was measure to test the efficacy of the treatment in reducing water hydrophobicity of crumb rubber. The treatment of tire rubber with NaOH and KMnO₄ proved to be promising in regaining some of lost compressive strength and improved water permeability. However, both treatment processes didn't have any significant effect on the workability. The NaOH treatment proved to be an overall better treatment than KMnO₄ which was due to the reduced hydrophobicity as depicted by lower contact angle.

In this paper, the influence of different thermal activation methods, namely the hot water curing method and steam curing method on the properties of cement mortar blended with low-volume non-ferrous slag (NFS) (15% cement replacement) is investigated. Therefore, mortar specimens are intrinsically prepared and cured at a controlled temperature of 60 °C in the different curing methods for a short period of 6 hours. Results showed that the steam curing method can significantly improve the compressive strength, reduce the water absorption level and densify the morphology of NFS blended cement mortar. The findings may contribute to accelerating the strength gain of NFS in cement-based material and reduce the amount of cement used.

The Australian government aims to achieve net-zero carbon emissions by 2050. Therefore, introducing a market-oriented carbon emissions trading scheme to offer a financial reward (or penalty) to those who emit below (or beyond) the allowed limits is expected. Under such a scheme, the cement industry is forced to reduce its energy consumption and carbon emissions. Limestone calcined clay (LC3) cement has been extensively studied and regarded as a promising solution to substitute ordinary cement clinker up to 50% without compromising the performance of concrete. In this paper, a comparative life cycle assessment (LCA) of the LC3 mortar considering cradle-to-gate system boundaries is conducted for the scenario in Australia. The LCA is undertaken on 122 collected LC3 mortar mix designs, and it includes the modification of traditional cement production to incorporate the calcined clay manufacture and evaluation of the environmental impact of different substitution levels. Results show that CO2 emissions associated with LC3 system production were reduced by up to 38% compared to Ordinary Portland cement mixtures.

This research focuses on analyzing the behavior of reinforced concrete (RC) columns under axial compression, both in their uncorroded and corroded states, through a combination of experimental and numerical investigations. For the experiment, seven specimens were prepared and manufactured subjecting to centric compression. The cross-sectional side length of the square columns was 200 mm. The column height was selected as 800 mm based on the dimensions of the testing machine. The specimens were divided into three groups: (i) the control columns, (ii) the corroded columns without strengthening, and (iii) the corroded columns strengthened with an external carbon textile reinforced concrete (TRC) layer. The experimental results showed that when the corroded columns had approximately 10% mass loss in longitudinal reinforcement and stirrups, the ultimate load was reduced by 5.7%. Meanwhile, the axial compression capacity of corroded columns strengthened by TRC layer was approximately 28% higher than the corroded unstrengthened ones. All tested specimens failed due to the buckling of the longitudinal reinforcement. The strengthened columns failed at the corners due to the rupture of the textile reinforcement. To validate the experimental results, a finite element (FE) modeling was presented.

This work studies the mechanical and chemical effects of utilizing baghouse dust (BHD) from secondary aluminum processing waste as a cement additive for potential use in concrete materials. The baghouse dust was added to cement pastes at replacements of 4 % and 8 % by cement mass. In addition, a combination of BHD and silica fume at different blended ratios were added to the cement mixture as a combined additive. Some reference proportions were also prepared for a comprehensive comparison. Unconfined compressive strength and the chemical composition of the extracted pore solution of the abovementioned hardened cement pastes were investigated. In addition, the effect of BHD on the hydration characteristics of the cement paste was also observed through isothermal calorimetry. It was found that an 8 % substitution of cement by BHD resulted in increased compressive strength after 1 day and 3 days of curing and a reduction of less than 2 % at 7 days of curing. Comparatively, samples with 8 % silica fume resulted in a strength increase of 17 %. As such, it was concluded that BHD addition of up to 8 % was not detrimental to concrete strength but did not improve performance either. This finding was supported by isothermal calorimetry data, which showed that the addition of BHD and the addition of silica fume both increased the initial peak of hydration and accelerated the hydration process but did not significantly impact the total energy of hydration over a period of 7 days. Finally, the high chloride content in BHD may promote corrosion in steel bars and increase concrete scaling potential.

Fly ash (FA) is pozzolanic, while blast furnace slag (GGBS) is latent hydraulic. These two materials react slowly in the presence of water to harden. Adding an alkali activator such as strong hydroxide could boost the hardening process, but the safe handling of highly corrosive materials is the primary concern. Therefore, the present work prescribed various types of gypsum to activate FA and GGBS as a binder phase for making mortar. It aimed to investigate the influence of different types and contents of gypsum on the mechanical properties and porosity of sulphate-activated binder. Gypsum is a less corrosive material to provide calcium and sulphate ions for activating GGBS and FA. The main component of gypsum was calcium sulphate. Gypsum provides calcium sources that promote more C-S-H to be formed. A few types of gypsum were studied with their effect on FA/GGBS blended mortar. Furthermore, the mechanical strength and porosity of gypsum-activated GGBS/FA blended mortar were assessed. The mortar containing white gypsum exhibited the best mechanical performance among all types of gypsum. On the other hand, red gypsum and dental gypsum were established to be more effective in pore refinements, lowering the mortar's total porosity. In conclusion, white gypsum is the most suitable material for activating the FA/GGBS blend among the various types of gypsum examined.

This study presents recycled aggregate concrete (RAC) properties considering coarse recycled aggregate (CRA) composition. The CRA is prepared by a French company with a fraction of 5-20 mm. The composition variability is created using a replacement coarse natural aggregate (CNA) ratio with CRA at 40%, 60%, and 80%. The composition CRA is determined by using convolutional neural networks (CNNs). The mix proportion for RAC used water to cement ratio (W/C) is 0.6, and the slump was 18-20 cm after one hour. The performance of RAC is assessed using compressive strength, porosity, and chloride diffusion coefficient. The results were compared to those for the original concrete. This paper shows the main results of evaluating the critical composition of recycled aggregate (RA), such as coarse recycled concrete aggregate, natural aggregate (NA), recycled brick, and tiles, on the properties of RAC.

Road and railway embankments are earth structures that lose stability under rainfall, and accumulation of rainfall causes an elevation of the phreatic surface within an embankment. For these reasons, drainage systems are needed when constructing an earth structure. Drain pipes are one type of drainage system applicable even for an existing earth structure. However, it is difficult to estimate the effects of the drain pipe quantitatively, and design and construction of drain pipes proceed according to past experience. In this study, the authors succeeded in expressing the drainage effects of drain pipes using an existing soil/water/air coupled analysis framework. This study specifically focused on the cross-sectional shape of drain pipes. Five kinds of cross-sectional drain pipe shapes were created, and rainfall infiltration series was simulated using the same procedure for each case. Consequently, the simulations determined that seepage behavior is dependent on the cross-sectional shape of the drain pipe. Furthermore, this analysis found that infiltrated rainwater does not drain when the phreatic surface is located below the drain pipe.

The present study calculated the maximum bearing capacity of a strip footing against eccentrically inclined coupled loading on c-ϕ soil, by means of the plane strain rigid plastic finite element method (RPFEM). The influence of soil strengths and footing width on the V-H and H-M failure envelopes (presenting the vertical load V, horizontal load H, and moment M) was thoroughly surveyed to assess the uniqueness of the V-H-M failure envelope. Based on the obtained results, the V-H-M failure envelope was found to be distinct for each value of normalized cohesion c/γB and internal friction angle ϕ. A novel equation, which is a function of c/γB and ϕ, was achieved to predict the failure envelope of the V-H-M limit load space.

The dual character of expansive subgrade soil, which includes swelling and shrinkage, causes a premature collapse on the pavement surfaces. The scopes of the current study include comparison of the field performance of cement and alkali activated binder (AAB) stabilized expansive subgrade soil. To assess the strength properties, a 12 m long semi-field test section with expansive soil that has been treated with AAB, cement, and untreated expansive soil is built. Steel slag and fly ash are used as dry pozzolanic precursors in AAB, while sodium silicate and sodium hydroxide are used as an activator solution in a 0.4 water:solids ratio. AAB provides twin benefits of reducing the need for traditional binders and lowering the cost of fly ash/slag disposal in landfills. It also has a less carbon footprint than a PC-based binder, stronger mechanical strength and longer durability. By embedding a number of stress metres and strain gauges in the subgrade layer and applying a load through a dual-wheel truck load (12-tonne rear axle load) on the field track, the in-situ subgrade strength behaviour is assessed. On samples taken from the field section, the effects of AAB, curing duration, and the proportion of steel slag/fly ash in the alkaline soil mixture on the geomechanical properties of soil are examined. Additionally, using KGP-BACK software, falling weight deflectometer investigations were conducted to assess the elastic moduli of each layer. It has been noted that subgrade layers treated with AAB had larger elastic moduli than those treated with cement or left untreated. In comparison to cement-treated soil, the AAB mixture's subgrade strength is increased by 23-26% by the combined addition of slag and fly ash. Based on the semi-field test section studies, recommendations for the effective application of AAB stabilisation for expansive soils as subgrade are given.

The research quantitatively explores the linking properties between the circular plate anchor and the granular assembly during the failure process under the subject of a specified pullout force given to the anchor using three-dimensional discrete particle simulations. This circular anchor is created as a hard cluster of spherical grains and is initially buried at a depth in the granular assembly. The numerical method is constructed based on the frictional interaction force law. The linking dynamic is characterized by the variation of the drag force acting on such anchor due to interaction with grains at the bottom of the frustum which is formed during the uplifting movement of the anchor. The results show that the drag force acting on the anchor first reaches a nearly constant value corresponding to the loading phenomenon at small anchor movement, reflecting the plastic deformation of granular bed as a result of particle rearrangement, and then fluctuates in a wide range, this range increases with increasing the anchor movement as a result of the unloading/reloading events. These loading/unloading/reloading events provide evidence for the linking properties between the anchor movement and granular assembly, which are highlighted by the density and intensity of force network within the frustum.

Bidirectional static load tests to evaluate the axial load-bearing capacity of large cross-sectional bored piles are indispensable. Nonetheless, this test is complicated, costly, and easy to fail. A case history of a bidirectional static load test conducted in HoChiMinh City is reported and analyzed. In particular, a bored pile with 1.8m in diameter and ∼60m in embedment length, located in Tan Binh district, HoChiMinh City, is tested using the bidirectional static load test. The testing load is close to 48MN. The state-of-the-art methods to analyze the data of bidirectional load tests such as back-calculation, constructing equivalent load-displacement curve as head-down static load test, will be adopted then the lessons learned from the case history are elucidated. A guideline to carry out a bidirectional load test is presented. In essence, this study could facilitate the success of bidirectional load tests conducted on large cross-section bored piles.

To resume trains operation as soon as possible after disasters, it is necessary to quickly find out locations of ballasted railway with insufficient lateral ballast resistance. In this study, a new method was proposed to evaluate the lateral ballast resistance using dynamic lateral excitation. The dynamic method was performed on 1/9-scale ballasted railway models with ballast densities of 1.5 and 1.6 g/cm³. The simple harmonic excitation was generated from a pair of 20g flywheels, and the accelerations of the vibrator and the central sleeper were recorded by sensors attached on the central sleeper and the vibrator, respectively. Based on the obtained data sets, maximum accelerations as well as the maximum amplitudes of the lateral displacements of the vibrator and the central sleeper were analysed. It was found that the maximum accelerations of the vibrator were higher than those of the central sleepers. This was also true for the maximum amplitude of the lateral displacements. The ratio of the maximum amplitude of the lateral displacement of the central sleeper to that of the vibrator was evaluated. It was found that the amplitude ratio of the track model with the ballast density of 1.5 g/cm³ was higher than that with the ballast density of 1.6 g/cm³. This implies that the difference in the lateral ballast resistance owing to the difference in the ballast density may be detected based on the evaluation of the amplitude ratio.

Landslide hazards are one of the most common geological disasters due to the impacts of natural factors, mainly rainfall, and human activities, such as the construction of transport infrastructure and mining projects. In Vietnam, most of the landslides and slippage frequently occur in mountainous areas, especially in Lao Cai province during the rainy season. In 2021, a slope failure happened near the Mong Hoa valley, on Road No. 152, sections Km 2+728.26–Km 2+827.04 in Cau May ward, Sapa town, Lao Cai province. In this study, topographical features, geomorphological features, hydrological features, geological investigation, and laboratory tests were performed to analyse the slope stability. This study used the Limit Equilibrium Method (LEM) and the Finite Element Method (FEM) to analyse the slope stability, and several countermeasures were proposed for this slope such as the retaining wall, ground anchors, and soil nails. This numerical result showed that the ground anchors and soil nails are the suitable method to prevent the instability of the slope. This study shows that compared with the traditional LEM method and advanced FEM method is that it can capture more results not only safety factor but also horizontal displacement and load anchor result. As a result, this analysis showed that the safety factor value in the finite element method was greater than that in the limit equilibrium method.

This paper presents a novel solution for predicting the bearing capacity of a strip footing on a c-ϕ (cohesive-frictional) slope under rainfall conditions. The commercial finite element PLAXIS code was adopted for numerical modelling purposes. The bearing capacity of the strip footing is expressed through a dimensionless bearing capacity factor. The bearing capacity was examined considering the rainfall conditions and variation of design parameters, e.g., soil strength parameters, slope angle, and setback ratio. The results show that the bearing capacity of strip footing on the slope decrease under rainfall compares to its normal condition and the effects of each parameter on the UBC. The paper's results can be a helpful reference for practical engineering in predicting the bearing capacity of strip footing on the c-ϕ slope under rainfall conditions.

Water supply pipes in urban areas are always buried underground. There are many causes of pipe breakage and leakage of high-pressure water from the pipe to the outside, the flow of water has a pressure higher than the soil erosion limit, causing the soil structure to be broken, eroding the surrounding clayey sandy soil. The development of the eroded clayey sandy soil area, which expands over time, is the cause of the formation of a sinkhole under the road, which is dangerous for vehicles and people. In this study, the authors apply finite element software (Plaxis 3D) to model water supply pipelines in sandy soil in case the pipeline leaks water with different pressures. Analytical models indicate that sinkhole formation is dependent on the extent of the erosive clayey sandy soil, which is related to the extent and direction of the pressurized water jet, and the depth of the pipe.

A method of reinforcing breakwaters with piles has been proposed. In this structure, designing piles as passive piles is important. Although most previous studies on horizontal subgrade reactions have been limited to the deformation mode of walls, the subgrade reaction to the wall is known to depend on the deformation mode of the wall. Herein, we investigated the changes in the subgrade reaction due to different deformation modes of the wall using model loading experiments and finite element analysis. The model ground was simulated using an aluminum rod mass, and an aluminum plate was used for the wall model. The model ground height was set to the horizontal ground condition with a 200 mm step at the front and rear of the wall. Lateral loads were applied simultaneously to the wall at two different depths. By controlling the ratio of the two levels of the lateral load applied to the wall, the deformation mode of the wall was altered. The experimental results indicated that the magnitude of the subgrade reaction at the same deflection depended on the deformation mode of the wall. The elastoplastic finite element analysis results of the lateral pile-head loading experiment in the horizontal ground condition exhibited good agreement with the experimental results. Under the two-point loading condition, the behavior of the wall was significantly different for cases in which the deformation mode differed from that of the lateral pile-head loading condition. By comparing the behavior of the ground around the wall, we discovered that the shear deformation of the ground differed depending on the deformation mode.

Curing temperature is widely known for its effects on the strength of various cementitious-based civil engineering materials, including in stabilized soils. Curing materials at different temperatures can cause negative or positive impacts on the mechanical properties of these materials due to the effect of temperature on hydration behavior, hydration rate, and ion exchange. This paper aims to better understand these factors in geoengineering applications. In particular, the discussion focuses on the effects of curing temperatures ranging from below freezing to 50 °C on the hydration process of cement paste (i.e., hydration rate, mineral dissolution, compressive strength) and the hydration process and strengthening mechanism of cement-stabilized soils. Finally, an informative table listing the advantages and disadvantages of the influences of each temperature level on these materials is provided as a summary of the findings from the literature.

The advancement of the latest techniques allows surveyors to have various approaches to solving survey tasks. The paper is an experimental study on collecting terrain data using different techniques including Lidar on a UAV, normal UAV, and GNSS-RTK. The study uses the point clouds extracted from Agisoft for data from Phantom 4 RTK, and Copre for data from Lidar. The lidar method uses AA450, the first lidar product line of the CHC brand in Vietnam with a Livox Avia scanner. UAV phantom4 RTK uses a 1" CMOS camera, with 20M effective pixels. Both Lidar and UAV methods use the PPK processing technique, and flight altitude is 80m and 100m respectively while GNSS-RTK uses the single-base method at around 7km distance between base and rover. The study results show the deviations in coordinates are very small, and the differences in elevation of Lidar and Phantom4 RTK compare to GNSS-RTK range from 3-5cm at open positions. The differences in elevation between Lidar - GNSS-RTK and Phantom 4RTK-GNSS RTK are 5-8cm and 10-15 cm respectively at the low vegetation and sparse density positions. The differences in elevation between Lidar and GNSS-RTK method range from 8-15cm while Phantom 4RTK cannot reach the ground point at the high and dense vegetation. However, the deviations in elevation between Lidar and GNSS-RTK are 15-25cm at the low, dense positions.

The Red river and Thai Binh river's dyke system includes 56 dikes classified from grade III to special grade with a total length of 2.207,75km which 37.709km of special grade, 553.70km of grade I, 502,43km of grade II and grade III. At the present, on the Red River and Thai Binh River systems, there are 230 existing weak locations, which have not been completely reinforced yet. It might cause unsafety situations of large flood flush and high water levels of rivers for a long time. Therefore, studying the solutions to support the response under unsafety situations of the dike system is a significant meaning topic. The present paper aims to evaluate the effectiveness of solutions using reservoirs at the Red river upstream in order to store and reduce floods in downstream. This also supports the effort to respond the urgent situations upstream such as huge floods, dyke failures in downstream and dyke failure at Lien Mac. In the scope of this paper, one and two-dimensional hydraulic simulation method was utilized, which describes the scenarios to regulate the upstream reservoir of the Red River and hydraulic calculation of the downstream river network. Then, the effectiveness of flood reduction in each scenario can be estimated. Simulation results show that depending on the calculation scenarios, the capacity of reservoirs can be 5.553 million m³ to cut and reduce flood for downstream. The flooded area might be decreased by 47.528 ha in case using a part of the capacity of the construction. The time when the reservoirs completely close the floodgates and do not discharge the flood into downstream is from 27 to 30 hours, this is an important time for the Lien Mac dike to be completely sealed within 24 hours. The time when the reservoirs completely close the floodgates and do not discharge the flood into downstream is from 27 to 30 hours, this is an important time for the Lien Mac dike to be completely closed within 24 hours.

Roadbed materials of base and subbase layers are frequently unsaturated caused by rainfall, drainage, and evaporation. However, the movement of water in these layers is still poorly understood because of lacking data on unsaturated properties such as the water retention curve (WRC) and unsaturated hydraulic conductivity (K). This study, therefore, recycled concrete aggregates (RCA) blended with autoclaved aerated concrete (AAC) grains (% of substitution on the mass basis from 0 to 50%) were used to examine the WRC and K for unbound roadbed materials in Vietnam using the evaporation method. Natural aggregates (NA) and Toyoura sand were used as control and reference material. Results showed that compared to NA100% and RCA100%, the water capacity of RCA mixed samples was much improved by blending AAC grains. Toyoura sand showed higher water capacity at saturation compared to RCA100% and NA100%, but quickly became lowest when matric potential exceeds 10 kPa. Toyoura sand showed the highest saturated hydraulic conductivity, but decreased dramatically around 10 kPa, while other tested samples remained higher K. The original van Genuchten – Mualem model was well fitted for Toyoura sand and underestimated for other tested samples, but showed an agreement with estimated conductivity parameter ranging from – 3.0 to -4.4.

Shipping plays an important role in Japan surrounded by the sea and navigation channel must be dredged to accommodate the increasing size of vessels. Most of the dredged soil is usually discharged into a disposal pond. Since it is not easy to secure a new disposal pond, it is necessary to make effective use of the pond currently in use. Therefore, measures to accurately predict the amount of consolidation settlement of dredged soil discharged into the disposal pond are being studied. In this paper, regarding the Shinmoji-Oki disposal pond (S-3 area), which currently accepts dredged soil from the Kanmon waterway, we reported the way to discharge the dredged soil to the pond and the annual accumulated soil volume in it. Then, through the distribution chart of mud surface elevation in S-3 area and elapsed time, we clarified the effects of different way to discharge the dredged soil. Furthermore, to accurately estimate the future acceptable capacity of the pond, the prediction model identified by back analysis is also proposed.

The study aims to develop proposed predictive formulas for determining the unconfined compression strength (UCS) of fly ash and cement stabilised clayey soil based on Multi-Gene Genetic Programming (MGGP) and Artificial Neural Network (ANN) techniques. Thirteen parameters, including the soil characteristics, the binder types, the binder contents, the curing period, the mixing method, and the fly ash characteristics, such as calcium oxide (CaO) content, CaO/SiO₂ ratio, loss of ignition, were considered as the independent variables in the model. The results show that the selected optimal ANN and MGGP models can predict the target values with high correlation coefficients (R-value approximately 0.994 and 0.973, respectively), and low errors. The performances of the MGGP and ANN models were compared based on statistical parameters and several external criteria. The study finds that both models show their generalisation capabilities with robust, powerful, and accurate prediction ability; however, the ANN model slightly outperforms the MGGP model. The proposed predictive equations formulated from the selected optimal MGGP and ANN models could help engineers and consultants to choose the suitable binder and a reasonable amount of fly ash in the pre-planning and pre-design period.

Bio-cementation through bacterial mineralization can be considered an "eco-friendly" solution for soft or loose sandy soils, particularly in ground slopes and high rainfall zones, to achieve sustainable development goals. Using urelytical bacteria with the ability to decompose urea for calcium carbonate precipitation can be selected as the primary agent for the bio-cementation process. This study clarifies the effects of adding nano calcite as nucleation sites for enhancing the bio-cementation with Vietnam-isolated bacteria. Both microstructure of the precipitation and MICP capacity were studied. Microscopic, SEM/EDS, and X-ray diffraction data were used to characterize and identify the mineral compositions. Also, a simulated rainfall model and wind flow were set up to evaluate the erosion resistance of sand samples.

In the literature, there are a few analytical methods for evaluating stress induced on the CDM column heads and most of them involve the use of geosynthetics embedded layers, except the method of ALiCC. However, the ALiCC method still has some limitations in actual designs. This paper presents numerical analysis (by using Plaxis software) and analytical analysis (by using the ALiCC method) on the influence of thickness and stiffness of the SM layer (without the use of geosynthetics embedded layers) on stress induced on column heads and settlement of the improved ground. A typical parametric case and actual project case were taken into analyses. Analysis results from the examined cases indicate that, as expected, when the thickness or stiffness of the SM layer increases, the settlement of the ground decreases and the stress induced on the column head increases. An important finding from this study is that the maximum stress induced in the CDM column is typically not on the head of the columns but at the middle depths where soil layers are softer than the SM layer and the bearing layer at the column toes.

When building Soil Geosynthetic Composite (SGC) walls, fill compaction is normally carried out by operating a compactor in a general direction parallel to the wall face. In other words, a moving point or area load is often used to apply a compaction load on a newly installed soil lift. Pham (2009) and Wu and Pham (2010) demonstrated that the compaction-induced stress (CIS) caused by multiple passes of a compactor moving toward or away from a section can be calculated by taking into account the compaction load applied directly above the section under consideration using a simplified stress path proposed by Duncan and Seed (1986). Additionally, by simulating the compaction, the CIS due to fill compaction may be correctly assessed. The CIS resulting from fill compaction can also be accurately assessed by simulating the compaction load, such as by applying a distribution load on top of each backfill layer or a distribution load at the top and bottom of each soil layer, or by applying various widths of strip load to the top of each backfill layer. The objective of this study was to validate the numerical simulation of the compaction load to stress deformation behavior of SGC mass under operating stress conditions. In order to conduct the numerical analysis, data from both a full-scale instrumented SGC mass based on large-scale soil geosynthetic composite (SGC) experiments and a 6 m-high SGC (Pham, 2009) were employed. This study will examine a few SGC behavior parameters, including reinforcement strains, lateral displacements, and reinforcement strains. The objective of the FE modeling is to demonstrate the effect, emphasize the significance of the compaction conditions to the stress-deformation behavior of SGC mass, and validate the findings from the field-scale experiments and proposed model by Pham (2009) and Wu and Pham (2010).

Every year, many typhoons make landfall in Japan causing disasters on mountain slopes across the country. Rainfall induced landslides in Japan mostly occur at shallow depths. Developing simple models of rainfall-induced landslides provides a practical alternative to finite element methods in large-scale landslide modelling and prediction. Therefore, authors previously developed a simple method to calculate the advance of the wetting front into fine sand slopes subjected rainfall. However, during intense rainfall, the excess rainfall that cannot be absorbed into the soil will generate runoff on the slope surface, which has not been included in the previous model. Thus, this study integrated the model with a surface water modeling module to simulate the disasters more comprehensively. The surface water is controlled by 2D shallow water equations and the digital elevation model depression removal process. The combined model is able to provide the maps of the wetting front, surface water depth, and factor of safety of slope during rainstorms. The newly integrated model was used to simulate rainfall-induced disasters in the Gogoshima Island during the July 2018 typhoon. The simulation results disclosed that both moving of the wetting front and surface water flows contributed to shallow landslides along catchments in this island.