Abstract:The hydraulic characteristics of a square thin-wall ecological revetment structure under different porosity conditions are studied by the physical model test. The results show that the variation trend of water surface profile is basically the same under different porosity conditions. With the increase of porosity，the deceleration effect of water flow in the revetment area turns better. There is a positive correlation between turbulence intensity and porosity. The transverse distribution law of the shear stress in the front and rear sections of the revetment is basically the same，and it increases first and then decreases on the whole. The longitudinal distribution of the shear stress is smooth，and it is almost the same.

Abstract:When waves hit coastal structures，fragmentation tends to occur，and the flow pattern of the water changes from laminar to turbulent. The numerical wave flumes have been created based on open source computational fluid dynamic tool OpenFOAM，and laminar flow model and buoyancy modified k-ω SST turbulence model are adopted to simulate wave loads on arc crown walls. The convergence of numerical results is verified by comparing results of pressure at specified positions by three sets of grids. In order to compare the accuracy of the calculation results based on the laminar flow model and the turbulent flow model，the numerical results of the point pressure at the specified position and the total force on the arc crown wall are compared with the corresponding experimental data. The results show that the k-ω SST turbulence model with buoyancy correction can provide more accurate prediction results.

Abstract:This paper studies the mathematical model of tidal currents and analyze sediment siltation for the planar layout design requirement of the LNG wharf project on Zhiwan Island. On the basis of the hydrodynamic simulations and the empirical equation of siltation at the wharf，the intensity of sediment siltation under normal and extreme weather at the wharf and berths is calculated before and after the project. The calculations reveal that 1）the tidal currents are mainly reciprocating flow，and there is only a small change in flow velocity near the wharf after the project；2）under normal weather，only the berths on the southwest side of Zhiwan Island can witness siltation，but the annual average siltation does not exceed 0.02 m，and the rest of the sea area does not encounter siltation；3）little siltation occurs at the sea areas of the project under extreme weather，and the thickness of siltation in 50 years is 0.32 m in the case of wind and waves. The main conclusions of the study are as follows：1）The project is in a place featuring clear water，little sand，weak flow intensity，and little sediment siltation；2）after the completion of the project，the overall impact on the hydrodynamic sediment environment of the surrounding sea areas is small.

Abstract:Eroded shores are usually the most frequently damaged and severe sections of seawalls. With the increase of extreme weather conditions and the impact of human activities，the problem of coastal erosion has intensified，posing a greater threat to the safety of seawalls and the rear land area. Most of the repairing methods are unable to fundamentally solve the problem of the destruction of eroded seawalls. Based on the case of seawall damage to the north of Zhendong sluice in Binhai County caused by coastal erosion，we analyze the mechanism of coast erosion on the safety of the seawall，discuss the repair measures on the eroded coast，and propose the calculation method of the pile-dam transmission coefficient and the stability of the seawall through field investigation，wave physical model tests，and theoretical calculations. The research reveals that the main reason for the destruction of seawalls on eroded banks is the increase of wave dynamics caused by the increase of water depth，which leads to bottom and surface protection erosion under daily conditions and structural instability under extreme conditions. Based on this，a seawall repair plan for eroded shores with beach protection and reinforcement is proposed，which is verified by the wave physical test to be reasonable and feasible.

Abstract:By the software FLOW-3D，a three-dimensional（3D）numerical wave pool is constructed by the combination of the piston-type wave generation and the pore wave absorption to study the wave force on the vertical breakwater when the wave direction and the sloping wall change at a small angle（less than or equal to 15°）. The following conclusions can be drawn by the numerical simulation：1）For the wave force at the measuring points on the wall，it has a similar trend to the wave direction at all slopes of the breakwater and among all measuring points，and it reaches the maximum at a wave direction of 90°. 2）At the same slope of the breakwater，the variation trend of wave force with the wave direction among all measuring points at the bottom of the wall is not the same，and the slope of the breakwater can affect the variation trend. 3）The distribution of wave force on the wall is basically the same regardless of the slope of the breakwater or the action of any wave direction. 4）The distribution of wave force at the bottom of the wall is approximately trapezoidal. 5）In most wave directions，the maximum wave force at the measuring points on the wall and at the bottom of the wall occurs when the breakwater has a certain slope.

Abstract:Concrete durability directly affects the safety and use of structures. Therefore，we comparatively analyze the provisions on concrete durability in seawater environment in codes from China，the U.S.，and Europe with regard to the design service life，division of corroded parts of concrete，and durability measures. In this way，we can explore the similarities and differences between foreign mainstream codes and Chinese codes in concrete durability design. The results reveal that the design service life of permanent marine structures such as wharves can be 50 years in all the codes. In addition，the corroded parts of concrete are vertically divided into four different zones in these codes，but there are differences in the durability measures adopted in different corrosion zones，which are mainly manifested in the aspects of cement types，concrete strength，water-binder ratios of concrete，and crack width.

Abstract:In this paper，the Chinese and Russian codes are compared and analyzed from aspects such as concrete materials，prestressed reinforcement materials，limit coefficients of control stress for prestressing，and prestress loss calculation. Taking a post-tensioned hollow slab as an example，we can draw the following conclusions：1）The Chinese and Russian codes are consistent in the classification system of concrete and reinforcement materials，the consideration of influencing factors in the prestress loss，and the calculation of some prestress loss values，while the two differ in the subdivision rules，material range，and classification quantity consideration. 2）There are differences between the two in the calculation of individual prestress loss，and in general，the calculation results are greater under the Chinese code.

Abstract:The crown wall is a crucial part of sloping revetment，being used to reduce the wave impact on the backfilling structure behind the wall. As an important force influencing the stability of wave walls，estimation of wave forces is always a hotspot of research in engineering practice. Taking a sloping revetment of an artificial island project in Southeast Asia as an example，we analyze the three widely used calculating methods for wave force acting on crown walls，proposed by Coastal Engineering Manual and The Rock Manual，and a recently proposed method using overtopping results to estimate wave forces. We also compare and analyze the features and application scope of these methods based on an actual project，and compare the results of the 2D physical model test of this project with the calculating results of the four methods. The results show that Pedersen formula gives more close results to the actual measurement results，which can provide good references for similar projects.

Abstract:The structure of pier-column permeable wharf is often exposed to complex forces under the action of waves. For rectangular caisson piers，the current domestic port engineering codes only analyze the total horizontal force of a single caisson under the action of forward and 45° oblique waves. There are neither calculation methods for the attenuation law of wave forces in pier groups，nor related results in existing studies. Taking a bulk cargo terminal project with gravity caissons in Maoming as an example，we carry out three-dimensional physical model experiments to study the wave height distribution around rectangular caisson piers and attenuation laws along the way，and analyze the horizontal，the lateral and the uplift forces and the overturning moment，as well as the attenuation law of wave force along the way of representative caisson piers. The results show that the wave height attenuation amplitude is the largest within the 5 caisson piers firstly exposed to the waves. The attenuation amplitude of the wave force on different caissons along the way shows the same trend as the wave height attenuation. The calculation method for the coefficient of cylindrical pier group in the code is not suitable for the rectangular caisson pier group.

Abstract:The substitute structure method is one of the main methods for the determination of seismic displacement demand in displacement-based seismic design method of pile-supported wharf，and equivalent damping ratio is the key parameter of that method. However，there are great differences in the calculation models used in different wharf seismic design codes，and some other models are specially proposed for wharf in literature. To analyze the influence of damping models on the seismic displacement demand，we utilize the substitute structure method and nonlinear time-history analysis method to conduct demand analysis for three wharves respectively. During the analysis for substitute structure method，we adopt four damping models from codes and literature，determine the ratio of displacements from the two methods，and perform the statistical analysis for displacement ratios. The results show that the average ratios of the displacement obtained from the nonlinear static analysis to the displacement obtained by the nonlinear dynamic time history method of the four damping ratio models are between 0.8 and 1.2，and the displacement ratios conform logarithmic normal distribution. The accuracy of damping equations for codes is generally lower than that of equations from literature. For cast-in-situ concrete and steel piled wharves，the equation from design criteria for Port of Long Beach shall be adopted for analysis. The equation from ASCE/COPRI 61-14 shall be utilized for pre-stressed concrete pile wharf with magnification factors of 1.10，1.25 and 1.65 for ensurance probabilities of around 50%，75% and 95% respectively to improve the reliability of results.

Abstract:The unique topography and location of the strait channels makes the interaction of hydrodynamic and sediment transport，sedimentation，topographic erosion and deposition in or between the channels. Taking the Xiazhi fishing port project as an example，based on the field hydrological survey and the measured topographic data，the dynamic sediment environment and the evolution of seabed erosion and deposition after the implementation of fishing port project are analyzed. The influence to current of the breakwater project of the fishing port is studied through the mathematical model，and the reasons for the changes of seabed erosion and deposition are explained from the dynamic mechanism. From the perspective of dynamic geomorphology，the regulation idea of increasing the width of the gate and restoring the hydrodynamic intensity is put forward. The research can provide a reference for the development of port engineering in similar sea areas.

Abstract:At present，the studies on dynamic mooring analysis and impact force of vessels under beam seas all focus on large-scale wharves，and no study pays attention to tugboats. Therefore，on the basis of an auxiliary tugboat berth project of a container terminal in Southeast Asia，the analysis of dynamic mooring stability and impact force of tugboats under beam seas are studied in this paper. The dynamic mooring analysis software aNyMOOR TERMSIM is adopted to calculate the dynamic mooring stability under beam seas，and the impact force，mooring force，and vessel motion are obtained from the calculation under normal use and extreme conditions. The result of the impact energy is compared with that from the Load Code for Harbor Engineering of China，and the regulations on the mooring conditions and motion of small vessels from different design codes at home and abroad are compared and analyzed. As a result，the recommended standards for waves and motion of tugboats are given in combination with this project. The results reveal that for small vessels like tugboats，the impact energy calculated by dynamic mooring analysis software is about 2.3 times greater than that from the Chinese design code. Under extreme conditions，the traditional DA fender or V-shaped fender could not meet the demand of wharf structure；instead，drum-shaped or conical fenders are more suitable for economic and rational wharf structure. Moreover，it is recommended that regarding the surge and sway amplitude，the motion of tugboats should be less than 1.5 m and 1.0 m under normal operation conditions and less than 2.0 m and 1.5 m under extreme conditions，respectively. The recommended limit of the beam sea height is less than 0.4 m under normal operation conditions and less than 1.4 m under extreme conditions.

Abstract:Regarding the problems of port operations caused by long-period waves，we study the successful cases of long-period wave mitigation in foreign ports，and propose five countermeasures including restraining long-period wave sources，optimizing plane layout，constructing wave absorbing structures，improving mooring configuration and developing prediction system. The study shows that rubble mound breakwater（width not less than 30 m）and vacuum mooring system（MoorMasterTM，Auto Moor，et al.）and hydraulic mooring system（ShoreTension?）are effective and low-cost countermeasures，which may serve as reference for similar projects.

Abstract:For the land-connecting structure design of piled wharf in strong seismic zone，based on a practical engineering case and using qualitative and quantitative analysis method，we compare and analyze the performance of frequently used land-connecting structure such as concrete retaining wall installed on slope，cantilever sheet pile wall and anchored sheet pile wall，and propose a new land-connecting structure of anchoring settlement slab，the characteristics of which are expounded. The research shows that，compared with the traditional land-connecting structure，the anchoring settlement slab is an economic and convenient option in strong seismic zone，which has better adaptability to slope settlement and deformation and is more advantageous to guarantee wharf operation and quick damage-repair after earthquake.

Abstract:To determine the stable mass of armour units and foot protection blocks for vertical breakwater foundation mound，we summarize calculation methods in Chinese code and other international codes and compare them with the 2D and 3D physical model test data of actual project. The conclusions are as follows：1）Under the condition of long-term large waves，the mass of slope protection stones calculated by JTS 154-2018 is large，indicating that the calculation method of the national standard is no longer applicable under the wave conditions. 2）When the waves come perpendicular to the faceline of the upright wall，the stable mass of the embankment protection block calculated by the improved Tanimoto formula is small，and it is recommended that appropriate conservative consideration should be given in the design. 3）According to extended Tanimoto’s formulas，the stable mass of armour units increases along with bigger incident wave angle（＜90°）. 4）It is suggested that the design scheme of important project should be verified by physical model tests.

Abstract:Underwater dredging construction under confined space conditions has a high requirement for equipment and technology，and a great impact on the overall construction schedule and cost of the project. Taking a wharf project as an example，this study optimizes the overall construction organization of the wharf，adopts the technology of sinking piles first and then dredging，and conducts combined construction with a small excavator，a modified cutter suction dredger，and underwater intelligent dredging equipment. The aim is to systematically solve the problem of underwater dredging under confined space conditions and thereby reduce the construction period of the project. Resorting to the section method and a two-dimensional tidal-current sediment mathematical model，this paper puts forward construction quality assurance measures for dredging soil between piles of a high-piled wharf and conducts a quick evaluation of the states of soil dredging between piles and mud dumping. The following observations can be made from the results：1）The quick evaluation method for dredging volumes can effectively deal with the problems of over-excavation and under-excavation in the confined space. 2）The influence of sediment siltation in the wharf area can be reduced by setting the mud dumping point 35 m away from the wharf front on the sea side.

Abstract:The key issues for a floating LNG terminal is discussed. Based on a project of floating LNG terminal with FSU（floating storage unit）+ FRU（floating regasification unit）receiving system in the West Africa，we discuss the key issues concerning the layout design of a floating LNG terminal. The results show that the layout location，operation criteria，safety distance，berth layout and arrangement，as well as the working platform form are quite different from the conventional ones. Thus the special attention shall be paid in the design.

Abstract:Spur dikes are one of the commonly used waterway regulation structures，and scattered riprap spur dikes are especially popular in actual projects. This type of spur dike has a certain degree of water permeability，and different porosity has different effects on improving the water level near the permeable spur dike. Resorting to the computational fluid dynamics software FLOW-3D，this paper studies the influence of porosity on the water level changes at different parts of a permeable spur dike，including its body，the front of its head，and its main flow area. The results show that the variations of water level with porosity at those parts are similar. In the upstream section of the spur dike，the water level first decreases and then rises as porosity increases when the latter is lower than 15.4%. When the porosity is higher than 15.4%，it decreases to a certain value and then stabilizes. At the axis of the dike body，the water level fluctuates up and down with increasing porosity. The water level behind each permeable spur dike is higher than that in the case of solid spur dikes. Nevertheless，water levels behind the dikes are not positively correlated with porosity.

Abstract:Because of the special flow structure in the entrance area of the approach channel of the hub ship lock，the sediment deposition in the entrance area is still an important problem affecting the normal operation of the river ship lock. According to the structural characteristics of the three-dimensional flow in the entrance area of the approach channel of the hub ship lock，a complete three-dimensional non hydrostatic mathematical model which can simulate the flow structure in this area with high efficiency and high precision is developed. The characteristics of its flow structure are analyzed and studied. From the perspective of eliminating the backflow and the navigation flow in the return gate area，the engineering measures that can effectively slow down the sediment deposition in the gate area of the approach channel are put forward，so as to provide technical support for the improvement of the navigation energy of the hub and the safe and efficient operation of ships.

Abstract:A large number of shoal groups form and obstruct navigation in the Jialing River channel from Caojie to the estuary during the dry season. The construction of the Three Gorges Reservoir area further adds to the complexity of the flow and sediment variation of this reach. Under the influence of topographic changes year by year，the effect of channel regulation fails to meet the standards of the planned channel maintenance dimensions. To solve the shoal-induced navigation obstruction problem of the long reach below the hydropower station，this paper analyzes the influence of the backwater in the Three Gorges Reservoir area on the channel dimensions of this reach by two-dimensional hydrodynamic numerical simulation. Then，it obtains the distribution characteristics of the navigation-obstructing shoals in the Jialing River estuary channel under different water levels and proposes the minimum flow requirement of the maintenance dimensions and the corresponding guarantee rate for each key shoal section. The results show that the water levels of different shoal sections of the Jialing River reach from Caojie to the estuary vary greatly under the same flow and that the problem of shoal-induced navigation obstruction is prominent at present. The minimum discharge that meets the requirement of the Class-Ⅲ channel dimensions is about 1 620 m3/s under the current topographic conditions.

Abstract:Based on RNG k-ε two equations turbulence mathematical model of VOF method，the hydraulic characteristics and downstream navigable flow pattern of the Wulaoyan water drop project of the Yangtze River to the Huaihe River diversion project are numerically simulated 3D，the transverse velocity and flow pattern characteristics of the navigable area at the confluence are studied，and the reasons why the navigable flow conditions at the confluence in the original design scheme do not meet the specification requirements are analyzed. The original design scheme is adjusted and optimized by measures such as retreating through water drop project，reducing the confluence angle and optimizing the connection radian between wing wall and main canal. The results show that the transverse flow velocity and return flow velocity in the confluence area of the optimized engineering scheme meet the design requirements. The maximum reflux velocities under the 5-year and 20-year navigation conditions are 0.10 m/s and 0.16 m/s respectively，and the maximum transverse velocities are 0.13 m/s and 0.27 m/s respectively，which can be used as the recommended scheme.

Abstract:For the improvement in the safety construction of the shipping system，it is necessary to build a seaworthiness analysis model for waterways and apply it to ships during navigation to evaluate the rationality of route planning and provide automatic and intelligent guidance for safe navigation of ships. Since the previous two-dimensional （2D）data cannot meet the needs of spatial analysis，we can obtain the navigable area of ships by performing spatial operations on the 3D track zone，3D underwater terrain，and 3D waterway element model that are constructed by AIS track line data and ship model parameters. On this basis，the collision risk index （CRI）for ships is introduced as the basis of early warning and decision analysis，and the seaworthiness analysis model is built. Taking the three-dimensional waterway of the Beijing-Hangzhou Canal （the Grand Canal）as the research object，we conduct the simulation experiment to verify the reliability and stability of the model.

Abstract:By consulting the channel map of Yibin-Chongqing section in the upper reaches of the Yangtze River，this paper counts the morphological parameters such as the height of straight side beach and the ratio of beach width to channel width under the condition of dry water level，and designs two kinds of water surface slopes（α= 0.167 and 0.200），the variation laws of water depth and velocity of main sections under different hydraulic conditions are studied by using generalized model test. The results show that the water depth is the main factor affecting the change of water depth difference and velocity at the same measuring point of the main section，that is，the closer the distance to the beachhead，the more obvious the backwater phenomenon，the increase of water depth，the weakening of turbulence，and the smaller the change of water depth difference at the same measuring point. When the flow and other hydraulic conditions are the same，the water depth increases，the turbulence decreases，and the changes of vertical average velocity，near bottom average velocity and section average velocity along the section decrease accordingly. The research results will provide a reference for the flow characteristics and evolution mechanism of the staggered beach.

Abstract:The water flow situation in the confluence area of straight braided reaches is complicated. If the entrance area of a ship lock is arranged in the mixing area of the confluence river，navigation problems such as flow pattern disorder occur，which is not conducive to the navigation safety of the ship lock. Therefore，the three-dimensional（3D）numerical flow simulation technology of the Mike 3FM module is used to obtain a sufficient understanding of the characteristics of the flow pattern at the entrance area of the ship lock at the bar tail. Specifically，we study the 3D flow pattern at the entrance area of the ship lock in the Taoyuan junction built in the lower reaches of the Yuanshui River and mainly obtain the distribution characteristics of the planar flow pattern of the discharge flow at the entrance area of the ship lock at the bar tail in the braided reach in the middle flood period，as well as the laws of the main flow zone，mixing zone，and dynamic axis of the confluence. The research can provide a theoretical basis for relevant research on the design of a new ship lock and the upgrading and reconstruction design of an old ship lock in braided reaches.

Abstract:Given that the new broken-line layout of the approach channel is likely to restrict ships’ passing through the lock，this study conducts a simulation test on the maneuvering of ships’ passing through the upstream approach channel. It utilizes a full-mission large ship maneuvering simulator to build an electronic chart display and information system（ECDIS）and a visual system，develop a mathematical ship motion model，simulate the navigation environment，create a simulation test model of a proposed project，analyze the ship maneuvering theory，and perform calculations. Then，it analyzes the simulation test data to verify the safety and maneuvering convenience of the ships passing through the lock and provide suggestions on the seaworthy conditions for ships during the operation period. The following observations can be made from the test results：1）The layout of the broken-line upstream approach channel of the Linhuaigang double-line ship lock is reasonable. 2）The distribution length of the left warning partition piers can meet the passing-through requirement of 2 000-ton ships after appropriate adjustment. 3）The personnel concerned should pay attention to the meteorological conditions during the operation period to ensure the safe passing-through of ships.

Abstract:The tie rods and their front and rear wedge blocks are essential parts of the top pivot on a miter gate. During the removal process of the original miter gate’s top-pivot tie rods，there are problems such as high safety risks and low removal efficiency in loosening the front and rear wedge blocks of the tie rods. Therefore，a safe and effective scheme for removing the top-pivot tie rods on a miter gate is proposed：1）The equipment and process flow are designed for rapidly loosening the wedge blocks of the top-pivot tie rods on the miter gate through research on the removal technology of top-pivot tie rods on a miter gate. 2）The loosening equipment for wedge blocks is checked by calculations and analyzed by the finite element method to verify the reliability of the design. 3）The in-plant and on-site tests of the loosening equipment are conducted，and the feasibility and practicability of the design are verified by the engineering applications. The proposed scheme can effectively reduce construction safety risks and improve the removal efficiency of top-pivot tie rods on a miter gate.

Abstract:Considering the navigation conditions of the entrance area in the downstream approach channel and the connecting section of the Fedongzi ship lock，we study the influence of the lock and dam dispatching mode on the flow characteristics of the entrance area and connecting section. A mathematical model is employed to study the flow conditions in the entrance area and connecting section when the lock and dam of the Fengdongzi navigation project are open in different positions and quantities. The results indicate that when the lock gates on the left bank are open at the same flow rate，the flow conditions in the entrance area and connecting section are more favorable to the safe navigation of ships；assuming the discharge condition of lock gates is met，the flow conditions are better when fewer lock gates on the left bank are open.

Abstract:The research on the flow and sediment movement in the action areas of waterway regulation structures and the resulting deformation and damage of such structures is an important part of waterway regulation research and has important practical significance. This paper summarizes the research on the structural forms of the three types of waterway regulation structures，namely spur dikes，beach protection（bottoms），and revetments，in the middle reach of the Yangtze River and the flow and sediment characteristics of their action areas. It reveals that relevant theoretical derivation and numerical calculation are fruitful. Then，it exemplifies the representative research results and compares them from the two aspects of the research perspective and factors considered. It suggests that further research can focus on the damage threshold under the combined effect of the location and scale of bed scouring，the development mode of bed scouring and repair methods，and the impact of extreme hydrological conditions on the operation and damage of waterway regulation structures，etc.

Abstract:The old bridges constructed in the curved branching reach under complicated navigation environment face great risks under some water conditions. To study the effect of navigable opening adjustment on the improvement of safe navigation，we take Fengcheng Highway Bridge in Ganjiang River as an example and establish a 2D hydrodynamic numerical model of 14.7 km long to calculate and analyze the river flow characteristics and navigation flow conditions in the openings and around the bridge under several scenarios from the drought season to the flood season before and after the operation of the downstream Longtoushan Navigation-power Junction. Based on the calculated results，we demonstrate the bridge clear width scale and the feasibility of its adjustment in accordance with the code. The research results may serve as a reference for the improvement of the navigation condition of other old bridges in the curved branching river.

Abstract:We analyze the status of dangerous goods passing through the Three Gorges ship lock from 2015 to 2020 from three aspects，such as classification，management process and transportation characteristics of dangerous goods，use the EGM（1，1）model to predict the trend of the throughput of flammable and explosive dangerous goods in bulk in the 14th Five-Year Plan period. The results show that most of the dangerous goods are in bulk，flammable and explosive，and most of the dangerous goods are upward. The quantity of the dangerous goods types is decreasing year by year，and has been reduced to 32 in 2020. The predicted throughputs of bulk，flammable and explosive dangerous goods will maintain a slow growth trend in the 14th Five-Year Plan period. By the end of the 14th Five-Year Plan period，the throughputs of bulk，flammable and explosive dangerous goods will respectively reach 11.2 million tons and 8.5 million tons. There are obvious deficiencies in the management of dangerous goods passing through the lock，which need to be solved in the follow-up management，such as insufficient basis for defining flammable and explosive dangerous goods，and fire resistance and explosion resistance of the lock need to be further evaluated.

Abstract:By analyzing some typical forms of ecological slope protection technology at home and abroad and the problems that easily occur，we know that there are obvious differences between domestic and foreign ecological slope protection technology. Most of the foreign ecological slope protection technologies use natural raw materials such as grass，shrubs，wood，and stones，focusing on the restoration of the opposite bank slope ecosystem，but the erosion resistance of plant slope protection is limited，and the protection strength is not high；while the domestic ecological slope protection technology will take both the protection intensity and ecological performance into account in choosing materials，which is not limited to natural raw materials. In the more severely scoured bank sections，more semi-hard slope protections are used，but it is necessary to further explore a better combination of hard materials，soil and organisms. With the continuous development of various technologies，ecological techniques for riverbank protection should be more conducive to the protection and restoration of the river ecosystem while increasing the strength of the bank slope.

Abstract:To address the common problem of the poor apparent quality of exposed concrete in the second-phase permanent projects of ship locks，this study takes the floating bollard groove as the research object to investigate the feasibility of changing the concrete pouring process from two-time pouring to one-time pouring. Specifically，it simulates and analyzes the mechanical properties of the one-time pouring formwork structure with finite-element software and compares the results with those of engineering examples. This research shows that mechanical properties calculated through finite-element software simulation meet the specification requirements and are consistent with the actual results，which verifies the feasibility of one-time pouring. The proposed method has been successfully applied to the Xiangqi second-line ship lock，and it can provide a reference for the construction of similar floating bollard grooves of ship locks.

Abstract:During the dredging and loading process of a trailing suction hopper dredger，the slurry blocks the pipeline when its transportation flow rate is too low，which not only affects dredging efficiency but also causes safety hazards. In response，this paper focuses on the model predictive control of slurry pipeline transportation. It proposes a predictive control method based on the radial basis function-autoregressive exogenous（RBF-ARX）model，and this method controls the flow rate of the slurry in the pipeline of a trailing suction hopper dredger by changing the speed of the slurry pump. It then builds a model of slurry pipeline transportation based on the RBF-ARX model and designs a predictive controller based on the RBF-ARX model to simulate the slurry transportation process. The results show that compared with the proportional-integral-derivative（PID）controller，the proposed model predictive controller has a better dynamic control effect and higher robustness.

Abstract:Aiming at the problem of digital integration of bucket foundation structure design and construction，the application of BIM technology in the design and construction of bucket foundation structure is studied. In this paper，based on the breakwater project of District 4 in Xuwei Port District of Lianyungang City，combined with the design specification of bucket foundation structure and relying on BIM technology，the bucket structure breakwater design and structural calculation are combined，and the bucket structure family library construction and bucket structure are given. Based on the method，the integrated software for BIM design and calculation of bucket foundation structure are developed，and the design and construction connection interaction method based on BIM design results and the visualization method of bucket foundation structure construction and installation monitoring are proposed. It improves the quality and efficiency of the design and construction of the bucket foundation breakwater structure，and lays the foundation for the promotion of the new prefabricated bucket base.

Abstract:Compared with traditional two-dimensional（2D）design，3D BIM design has a better visualization effect and higher design precision. In port engineering design，the software Civil 3D is used to create terrain-related BIM models of earthwork and carry out multi-disciplinary collaborative design on the basis of the Vault platform. This technical solution can achieve the “component-level” management of Civil 3D models，ensure the dynamic association of models among disciplines，improve the efficiency of communication and coordination in the design process，and improve the quality and precision of design results. The Civil 3D collaborative design solution based on the Vault platform can provide a reference for BIM applications in port engineering.

Abstract:The improper operation，fatigue operation and position judgment deviation during the operation of bucket wheel stacker reclaimer often cause stack collapse during the reclaiming operation. The collapse will occur in the safety accident such as serious overload and even equipment overturning when the bucket wheel is partially or completely buried. We adopt 3D laser scanner to scan the surface of the stack，carry out the real-time point cloud data processing and online three-dimensional reconstruction，analyze and recognize the shape of the real-time working surface of the stack. By calculating the position relationship between the current reclaiming surface and the upper working surface，the technology can automatically judge whether there is a risk of collapse and whether the full-automatic reclaiming operation can be continued. The results show that the proposed anti-collapse technology can well prevent the stack collapse in the reclaiming process.

Abstract:To raise the application level of building information modeling（BIM）in ship lock engineering and improve the efficiency and benefit of information utilization，this study clarifies the Standard for Application of Building Information Modeling in Port and Waterway Engineering Design and compiles BIM design rules for ship lock engineering that meet the requirements of the standard. It then establishes an overall implementation process for the BIM design of ship lock engineering according to application practice. Taking a certain ship lock engineering as an example，this study puts into practice the hierarchical organization，model content，collaborative design，classification and coding，model storage，and result delivery of BIM and verifies the feasibility of the standard-based implementation workflow and the applicability of the standard in the BIM design of ship lock engineering. The results show that the Standard for Application of Building Information Modeling in Port and Waterway Engineering Design can regulate the BIM design of ship lock engineering，improve the quality of design results，and achieve digital delivery and application. It also provides a reference for the implementation of the BIM technology in ship lock engineering and digital twin construction of ship lock engineering.

Abstract:Due to the proposal of the Belt and Road Initiative，project construction is now faced with the confusion caused by the different standards of different countries. As the manufacturing process determines the mechanical properties of the pile foundation components，understanding the manufacturing processes of different national standards is an important basis for reasonable design. This paper discusses the Chinese code for wharf construction，the American code for concrete cylinder piles，and relevant codes in the European standard to reflect some differences in the manufacturing processes of prestressed concrete pipe piles. The main results are as follows：1）As for the pre-tensioning method，the Chinese code prefers the centrifugal casting process，while the American code uses a centrifugal or static pressure grouting process. In terms of the post-tensioning method，the Chinese code specifies a composite or centrifugal process，whereas the American code opts for a centrifugal casting process and the European code does not provide specific provisions. 2）The Chinese code offers more detailed regulations on the processes of steel bar processing，tensioning，grouting，and prestressed manufacturing. In contrast，the American and European codes are universal and generally require that a large number of other codes or manuals be looked up. The comparison results can provide a reference for Chinese construction enterprises to participate in foreign wharf projects.

Abstract:To master the underwater rock breaking characteristics of rock drill rod and clarify the rock drilling parameters of foundation trench rock treatment of deep and medium channel immersed tunnel，we apply the multi-factor orthogonal test to study the effects of lifting height，chiseling times，row spacing and bit spacing on average fragmentation，non-uniformity coefficient，fractal dimension and reef clearing thickness. The results show that the average block size is positively correlated with the lifting height，row spacing and bit spacing，and negatively correlated with the number of chisels；The non-uniformity coefficient is positively correlated with lifting height，row spacing and bit spacing，and negatively correlated with chiseling times；The fractal dimension is positively correlated with the number of chiseling，and negatively correlated with the lifting height，row spacing and bit spacing；Reef clearing thickness is positively correlated with lifting height and chiseling times，and negatively correlated with row spacing and bit spacing. Based on the results of multi-factor test and research，the on-site rock drilling parameters are set as follows. the lifting height of rock drilling rod is 27 m，the number of chisels is 3 times，the row spacing of rock drilling points is 2.5 m，the spacing is 1.7 m，thus the rock fragmentation is appropriate and reef cleaning is not difficult. Overall，good construction results are achieved.