Table of contents

It is our great pleasure to welcome all of you to 2020 7th International Conference on Coastal and Ocean Engineering (ICCOE 2020) April 22-24, 2020, Singapore. ICCOE 2020 is dedicated to issues related to Coastal and Ocean Engineering.

Due to the COVID-19 pandemic, the conference committees made a decision to hold an online conference instead to ensure every participant's personal safety.

CCOE 2020 is highlighted with four keynote speakers: Prof. Gordon Huang (University of Regina, Canada); Prof. Chou Loke Ming (National University of Singapore, Singapore); Prof. Koh Hock Lye (Sunway University, Malaysia); Associate Professor Edmond Yat-Man Lo (Nanyang Technological University, Singapore).

The Conference had one poster session and four oral sub-sessions on different topics: Environmental Science and Engineering, Innovation and Economic Development, Ocean Engineering, Marine Science and Ship Engineering.

It was a great opportunity for students, researchers and engineers to interact with the experts and specialists to get advice or consultation on technical matters, dissemination and marketing strategies.

This volume of the proceedings presents a selection of papers submitted to the conference. They are organised in nine chapters under the topics of: Utilization of Ocean Space, Marine Resource Exploitation, Utilization of Ocean Energy, Ship Engineering, Marine Dynamics, Architectural Design, Fire Safety Engineering, Environmental Science and Technology, and Economic Innovation. All papers were subjected to peer-review by conference committee members and international reviewers. The papers were selected based on high quality and relevance to the conference theme.

We express our sincere appreciation to the organizing committee and the volunteers who had dedicated their time, effort and help in planning, promoting, and organizing the conference.

Prof. Chou Loke Ming

National University of Singapore, Singapore

2020-04-29

List of Conference General Co-Chairs, Program Co-Chairs and Technical Committee are available in this pdf.

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

In this paper, we analyzed the safety assessment getting from the opinions of captains, pilots and navigators in Ganh Rai Bay. The results showed that the highest risk was caused by unsafe fishing ships and the most unsafe situation was generated by the crossing ships, wind and currents. The influence of human psychology factors was one of the most important factors, which caused the risk of collision. Based on fuzzy logic theory, we proposed risk assessment model which was tested in simulation and compared with the evaluation results of the Experts in Vietnam. The results showed the effectiveness of the novel maritime risk assessment model.

To apply the scour protection device with the flexible material developed by the author to engineering practice, orthogonal optimization design of the device for a fixed offshore platform in Chengdao Oilfield as a case study was presented. The influences of main design parameters, such as pile diameter, thickness of flexible material and elastic modulus of flexible material on the protective effect of the device were studied by two-way fluid-solid interaction numerical simulation based on ANSYS workbench platform. Then, the optimal design plan of the scour protection device with flexible material was determined. Furthermore, by comparing and contrasting the results of the flow field calculation for the pile legs with versus without protective devices were compared and analysed, the device's good effective protection effect functionality was demonstrated. The research results will shed light on the practical engineering design of the flexible energy dissipation guiding antiscour device.

This paper introduces the design and implementation of the realtime scour monitoring system for piers of Hangzhou Bay Sea-Crossing Bridge, including the construction of the monitoring system for the scour of the piers and the key technologies of the monitoring system. Through integration of dual axis scanning sonar technology and monitoring software, real-time seabed topography observation, data processing, analysis and data release based on the Internet is realized, qualitative, quantitative and locational decision support for management departments is provided.

A Seawall requires reflecting and dissipating entire wave energy with zero transmission. The permeability would significantly affect its hydraulic stability under wave loads. Thus, the permeability of a structure changes with the material and consequently a variation in the composite structure may give a different perspective on the hydraulic performance of a seawall altogether. As a first step towards establishing the composite seawall, a comprehensive permeability test is performed as a preliminary assessment of hydraulic conductivity. In the current research, a bag made of non-woven geotextile polymer filled with sand and a roll of non-woven needle punched coir geotextile is investigated. A total number of 20 model tests were performed by varying the orientation and positions of the material composites and thereby the gaps in the structure. The results are noted and future research possibilities into the design and development of a composite seawall as an alternative to traditional seawall are thus presented.

The sealing between subsea trees and high pressure wellhead is achieved by the metal seal inside the subsea wellhead connector. In this paper, the sealing performance of the metal seal under the dual role of load and temperature is analyzed. The theoretical analysis of the heat conduction in the sealing part of the subsea wellhead connector is carried out, and the basic equation of heat transfer for transient heat conduction is established, finite element simulation calculations were carried out to obtain the thermal stress of subsea wellhead sealing parts in the process of preload and operating. The results show that as the internal pressure of the subsea wellhead increases, the equivalent contact stress inside the metal seal gradually decreases, and the equivalent stress on the sealing surface is still greater than the initial sealing pressure, ensuring the sealing effect. As the internal pressure of the wellhead increases, the contact stress on the sealing surface of the metal seal increases gradually, with the increases of the temperature, the contact stress increases continuously, when the temperature is too high, the negative impact on the seal is relatively large, resulting in excessive stress inside the seal, which is prone to seal crushing accidents. The temperature effects can be reduced by appropriately reducing the amount of axial preload compression to avoid the metal seal failure.

This paper describes the design and fabrication process of a solvent deasphalter unit which included 5 PAUs (Pre-Assembled Process Module Units) and 5 PARs (Pre-Assembled Piperacks) at a refinery in Rotterdam. This paper summarizes the method and experience successfully applied to the shop design and construction process of PAUs and PARs, illustrates the prefabrication and the assembly process of PAU and PAR modules. Many challenges were encountered during the one and a half years' fabrication, such as mass drawing sheets, fabricate in line with DEP specification and Eurocodes, assembly sequence optimization, the integrate construction method, dimension control and quarantine etc. Design and fabrication processes such as relevant code and standards, shop design softwares, work process of shop design, the application of management system, module arrangement, the process of prefabrication and assembly sequence, the integrate construction method and loadout are highlighted. In the shop design process, 3D Model played a key role. The application of management systems such as PCMS and WIMS significantly improved the efficiency of construction management. Reasonable construction sequence and schedule ensure good performance of fabrication activities. The integrate construction significantly reduced the workload of high altitude work and minimized the project period with efficient construction. It is hoped that the construction experience of this project can give some reference and benefit to similar project in the future.

Large monopile is widely used in offshore wind farm due to their relatively simple installation. Monopiles are customarily designed by applying the p-y method. That being said, there is no detailed and uniform interpretation on the reasons for limitations in the current p-y method. An elaborate study is performed to determine the main reasons of such limitations. In this study, a FLAC3D model is presented to evaluate the current p-y method for piles in sand of three different relative densities under a static load, in which the non-linear modulus is taken into account. The results show that the initial stiffness of the p-y method is overestimated and even more magnified in the large depth. The diameter effect should be taken into account under diameters exceeding 3m in loose and medium sand, as well as diameters more than 5m in dense sand.

Nowadays the global demand for energy is growing rapidly, it is highly urgent to conduct the research and develop the efficient renewable wave energy equipment, wave energy converter (WEC). This paper introduces the PTO (Power Take-Off) system and theory of wave energy generators, which shows that the hydraulic system can transfer energy well. We found the relationship between the pendulum length and the wavelength of the floating pendulum wave energy generator and the relationship between the pendulum height and the wavelength. Through the influence of PTO on the power of different wave periods, the power increases first a then decreases with the increase of PTO and we also found the optimal PTO of different wave periods.

The paper presents a theoretical foundation of the effects of free surface and propeller rotation on the flow surrounding the rudder of a vessel. This is the scientific ground to evaluate the instability of the rudder force, thence building a research model and applying CFD in simulated to calculate the phenomenon. On the other hand, this paper also issues the idea of designing and creating a test system for carrying out practical experiments on related problems by using ship models similar to M/V TAN CANG FOUNDATION. The input data merely including ship's lines, ship's speed, rudder angle... are observed in the period of manoeuvering the vessel in the Haiphong fairway, Vietnam. The results are shown in this article distinctly figure out pulsating air bubbles caused by the synchronous effects of the free surface, the propeller rotation and indicate that the oscillating period of the rudder force at the time cavitation at the leading edge of the rudder which has not been formed is compatible with the revolutions of the propeller.

This paper took the product tanker at sea and its mooring positioning system as the research object and used the time-frequency domain method to calculate the movement of the product tanker. In the three-dimensional potential flow theory, a single-point mooring system was established as a numerical model in the ANSYS Workbench. The frequency-domain computing module was to analyze the hydrodynamic response of the tanker under the unit regular waves, the dynamic response amplitude operators (RAOs) of the tanker, and the motion conditions under different frequency distributions. The time-domain computing module was to analyze the response of a single-point mooring system under the actions of wind, wave, and current. Setting the mooring point, pretension, layout, mooring radius, and other parameters, of the mooring product tanker was calculated lasted 1 hour for the time-domain coupling analysis under the extreme offshore environment. The tension of each cable was compared with the minimum breaking strength of the mooring cable to determine its safety.

When a generated solitary wave starts to propagate, it needs an establishment distance to create fully developed velocity profiles. We consider that the solitary wave moving in a viscous fluid under laminar flow. An important detail to state is the proper location to measure the solitary wave velocity profile due to its finite extent. This article discusses the establishment distance and the reattachment point on the bottom in the wave's deceleration phase.

Storm surge has posed a great threat to the safe development of marine ranch in Dongji Islands. Research on the tidal dynamics and storm surge of Dongji Islands is more and more urgent. For this reason, based on measured data of tidal level in 2012, this paper conducts research on the variations of tidal level and storm surge in Dongji Islands. Main conclusions are: Affected by the topography and tidal waves in the East China Sea, temporal and spatial distribution of tidal level and storm surge is asymmetric. Tidal intensity is strong in the eastern sea and weak in the western. The amplitudes of main semi-diurnal tides (M2, S2, N2) in the western sea have a significant attenuation, with the average tidal range decreased by about 16%. Cycle of the practical storm surge is consistent with the tidal constituents, for the cycle at Daishan station was close to 24 h, while Miaozihu station was about 12 h.

Bangladesh has a unique geophysical location at the northern apex of the Bay of Bengal. Waves originating in the Indian Ocean, are constantly travelling up the bay area and interacting with the Bangladesh coastlands. In order to estimate the major wave properties required for coastal engineering purposes, a 2D coupled Wave-Hydrodynamic model of the greater bay area was developed in this study, using the Delft3D modeling suite. The model was simulated for a year and from the model outputs, significant wave height was primarily assessed at multiple locations along the Bangladesh coastline. Considerable spatial variation was observed in the wave parameters, along the whole coast at different locations, with the south-eastern coastal region showing high trends of wave height; whereas in the deltaic south-western, and south-central zones, wave heights were rather moderate. Strong seasonal variation was also observed for the different parameters, as both wave heights and depth-average current velocity were very high during the wet monsoon season, compared to the lean winter period. The results of this study is expected to provide a reasonably sound characterization of the wave spectrum along the coastline of Bangladesh.

Natural ventilation is an effective measure to reduce energy consumption and improve indoor environment. The enlargement of the depth of high-rise residential buildings allows only single-sided natural ventilation, which makes the problem of poor natural ventilation itself more serious. In this study, CFD numerical analysis was used to verify the optimal design strategy of one-sided ventilation residence in a practical case, and the results showed that the design strategy could improve the ventilation effect of one-sided ventilation houses [1].

Nowadays, LINE is one of the widely used communication software in Taiwan and fire protection work is also deeply affected through applying LINE. In this study, the Integrated Technology Acceptance Model (UTAUT) is applied to explore the behavior usage of LINE in assistance of fire safety works. A questionnaire survey is designed to explore the three aspects that affect the "behavioral intension", such as "performance expectation", "effort expectation" and "social influence"; and whether "usage behavior" is subject to "behavioral intension" and "facilitating conditions". Moderator variables such as gender, age, experience and voluntary interference with each aspect are also explored. Through the statistical analysis, it is concluded that LINE's assistance to fire safety works is definitely positive. "Performance expectation", "effort expectation" and "social influence" can affect "behavioral intention" to be very significant; "behavioral intension" and "facilitating conditions" can also affect "usage behavior". Among the different moderator variables: gender has no significant difference to each aspect. Age, working seniority and LINE experience have very or extreme significant differences on each aspect. Work unit and grades only have significant differences on some aspect. Voluntary has significant difference only in "social influence."

In 2017, Xi'an city has released the latest standard of car-fuel and motor vehicle submission, at the same time, Xi'an city has issued traffic restriction of 2017. But after 2015, the air quality of Xi'an city has aggravated. This paper will conduct empirical research through single difference of 2016-2017 era. The result shows that mixed policies dimension aggravating the concentration of NO₂ and PM2.5 decreases, but still remarkably aggravate it at 1% significance level. This result further manifests that policy has some effects, but can't work out ideally.

Water quality assessment plays an essential role in sustainable management and development of river systems. However, this process is highly complicated that requires professional expertise. The fuzzy water quality index (FWQI) based on fuzzy logic is computational method categorizing water quality into various categories for different water uses. In this study, a method based on fuzzy inference systems (FIS) to assess water quality in the Nhue River, an inter-provincial irrigation network in Northern Vietnam, using fuzzy logic is proposed. Nine fuzzy variables namely dissolved oxygen (DO), biological oxygen demand (BOD₅), chemical oxygen demand (COD), pH, ammonium (${{\rm{NH}}}_{4}^{+}$), phosphates (${{\rm{PO}}}_{4}^{3-}$), total suspended solids (TSS), turbidity, and total coliform (Tco) on the potable quality of the river water are employed for the quality assessment. The fuzzy inference system is composed by 3250 rules with a score from 0 to 100 and five verbal categories. The FWQI was validated by comparison with Vietnam national water quality index. The result of the study clearly shows that the Fuzzy Inference System (FIS) approach was a practical, simple and useful tool to assess surface water quality in river as well as irrigation networks.

Ecological restoration, as one of the important technologies for landfill treatment, has attracted much attention from governments and the academy of science and technology. In this paper, the focus is the analysis of the trends of ecological restoration technology of landfill, we make a comparative analysis of domestic and foreign patents from the perspective of application trends, major technical fields, main patentees, competition and risks by comprehensively using the platforms and tools such as the Chinese Patent Database, Derwent World Patent Index Database, and the European Patent Office Patent Literature Database. Our work is of referential significance for the development of China in this field.

Microbial electrochemical systems (MESs) are a promising clean energy source to directly convert waste chemicals in domestic wastewater to available electric power with synchronous pollutant removal. The physiological and biochemical behaviors of electroactive microorganisms (EAMs) is the key factor of the MESs. Dibutyl phthalate (DBP), as the emerging pollutant, widely exists in municipal wastewater which has strong ecological toxicity. So, utilization of MESs in the engineering practice of wastewater treatment must consider the impact of DBP on the physiological and biochemical behaviors of electroactive biofilm. The output voltage and power density of the MES decreased significantly with the increase of DBP in the synthetic wastewater. In addition, the EAMs resisted the stimulation of DBP by secreting more extracellular polymer substances (EPS) by microscopic observation. The composition and structure of the EPS also changed, mainly reflected in the increase of β-polysaccharide content and the expansion of its coverage area.

There is a close relationship between standardization and technological innovation. Based on the analysis of the function mechanism of standardization on technological innovation, this paper has established measurement indexes of the influential effect of standardization on technological innovation. As structural equation modeling (SEM) has its own advantages over statistical methods such as correlation analysis, regression analysis and path analysis, this study attempts to measure the influence degree of standardization on technological innovation by adopting SEM method, and has established a measurement model and a structural equation model for the standardized technological innovation effect. In addition, the study has discussed the fuzzy DEA method to analyze the standardized technological innovation effect of DMUs, established the fuzzy DEA-based index system for evaluating standardized technological innovation effect, constructed the fuzzy DEA model for evaluating standardized technological innovation effect, and provided the solution process of the model.

The Internet revolution has had a significant impact on the global economy and society. Human beings are moving from the industrial age to information civilization. As one of the representatives of the new economic form in information civilization, the flow economy will become a new economic development model. Both the exhibition economy and the airport economy have the attributes of flow economy, and both of them are developing rapidly in China. They both are in a state of integration and development. The integration of exhibition economy and airport economy is based on the functional synergy of industrial chain integration, and the spatial integration of urban exhibition clusters and airport economic zones. Based on the theory of industrial chain integration, industrial integration and economic symbiosis, this paper puts forward the concept of the integration of exhibition economy and airport economy. We try to construct functional synergy model and spatial integration model, and propose the mechanism of industry chain sharing, co-governance and symbiosis and comprehensive cost-oriented mechanism. Finally, suggestions were made on the location selection of the airport exhibition industry, the exhibition industry and the airport industry linkage, and the regional competition and cooperation of the airport exhibition industry.