Abstract:Taking the large-scale engineering group in the Yangtze River Estuary as the research object，we apply the CJK3D-WEM two-dimensional tidal current mathematical model to study the influence and cumulative effect of engineering group on the hydrodynamic pattern.The results show that after the implementation of large-scale engineering group such as the north passage deepwater channel regulation project，the diversion project of the north and south channel in the Yangtze River Estuary，siltation promoting circle of Nanhui beach and Hengsha east beach from 1998 to 2016，the flood tide volume，tidal range，the maximum velocity in high tide and ebb tide of Xuliujing reach have been reduced by about 10%，6%，9% and 4% respectively，and the diversion ratio of the north passage has been reduced from 60% to about 40%.The gradual implementation of the engineering group has obvious cumulative effect on the hydrodynamic changes of the upper reaches.Among many projects，the north passage deepwater channel regulation project has the greatest impact on the upper reaches，accounting for about 50%，where the first phase of the project accounts for a large proportion.The Nanhui beach encircling project has a greater impact on the upstream，and the Hengsha east beach siltation promoting and encircling project has the least impact.

Abstract:As an efficient and convenient method，water jet scouring technology has been widely used in deep sea engineering.The scour volume from a cohesive bed under a vertical submerged jet scouring has been studied.The contour embryo of scour volume was obtained by grouting method，and the scour volume of was evaluated by 3D scanning technology.Through indoor test，the relationship among jet velocity，impingement height，scour time and water content of mud sample and scour volume are explored：1）Scour volume decreases with the increase of impingement height.2）Scour volume increases with the increase of jet velocity.3）Scour volume increases with the increase of scour time，but gradually tends to balance.4）With the increase of water content of mud sample，the scour volume increases significantly.Finally，based on 54 sets of experimental data and dimensionless analysis，an empirical formula of scour volume is obtained，which may provide a reference for water jet trenching and water jet assisting pile installation in ocean engineering.

Abstract:To study flow characteristics around square columns under regular waves，this paper establishes a non-reflective three-dimensional（3D）numerical wave flume with a mass-source wave generation method and the Reynolds time-averaged Navier-Stokes equation under the constraint of a RNG k-ε turbulence model in FLOW-3D.The built numerical model works well compared with the physical model.With the results of numerical calculations，the paper analyzes the 3D motion characteristics of the free surface around columns and the distribution characteristics of the velocity field and vorticity field around square columns.The changing law of the wave transmission coefficient Kt behind the square columns is explored using a dimensionless method.The results show that the flow field around the square columns changes periodically under regular waves，and the maximum vorticity alternately appears at the upper and lower corners of a single column among the square columns.Within the scope of the numerical simulation test，Kt fluctuates slightly with the change of the wave steepness H/L but not significantly and gradually decreases with the increase in the relative water depth d/L.

Abstract:A viscous flow-based computational fluids dynamics model is proposed for the treatment of the water wave and a submerged membrane breakwater interaction.The Navier-Stokes equation is solved using the high-order difference method，and the finite element method is used for the structural dynamics equations.A modified ghost-cell immersion boundary method is used to achieve high-precision coupled solution of fluid and solid solvers.The interface reconstruction is realized by the fluid volume method，and the validity of the model is verified by comparison with the experimental results.Numerical simulation of the interaction between regular wave and a submerged fluid-filled membrane breakwater with different filling degree is carried out to find the appropriate filling degree and explore the wave elimination mechanism.The results show that：1）The numerical model developed can effectively simulate the wave deformation and structural response during the wave passing by the submerged fluid-filled membrane breakwater.2）The large vibration of the inadequate submerged fluid-filled membrane breakwater is more likely to promote the evolution and shedding of vortices near the structure，and is accompanied by the dissipation of energy.

Abstract:Mixed fiber concrete has good durability.Aiming at the PVA and UPE mixed fiber concrete，we carry out the 120 d corrosion test by high concentration chloride solution，predict and analyze the bearing capacity and damage change law of reinforced concrete beams before and after chloride ion corrosion combined with the three-dimensional numerical simulation technology.The results show that the brittleness of non-fiber concrete and concrete with 0.2% fiber（0.1% PVA and 0.1% UPE）volume content increases after being eroded by sea water，peak stress and corresponding strain decrease.However，the addition of fiber can reduce the loss rate of the flexural bearing capacity and the strain loss rate corresponding to peak stress of the concrete beam subjected to chloride ion erosion，and increase the toughness of the beam.When the loading displacement is 20mm，the final tensile damage of the beam with fibers after seawater erosion is 4.9% less than the final tensile damage of the fiber-free beam.And the final compression damage of the beam with fibers is 16.2% less than the final compression damage of the fiber-free beam.

Abstract:Container terminal is the collection and distribution center of domestic and foreign trade container cargo.Aiming at the problem of container’s overturning at the terminals，based on the concept of one floor storage yard and one floor container in the whole stereoscopic yard，we apply AI design，scenario hypothesis，formula calculation and data analysis，design an automatic stereo yard schedule，and introduce the core equipment，functional area and the operation process.The results show that this scheme will be able to achieve “zero turnovering rate” in the true sense，reduce the configuration，use cost and carbon emissions of machinery and equipment，which is conducive to improving the efficiency，throughput capacity and economic benefits of the terminal，as well as enhancing the competitiveness of the terminal and port enterprises.

Abstract:On the basis of the systematic analysis of the development and construction characteristics of the natural gas transportation and reserve system around the Bohai-Rim region，the key layout issues of liquified natural gas（LNG）terminals in the region are put forward.It is proposed for the first time that the layout of LNG terminals around the Bohai-Rim region should take the four-month winter demand index as its main basis for the supply of terminal capacity.Furthermore，indicators such as the layout scale of regional LNG berths are advanced.On this basis，focusing on the urgent need for natural gas supply around the Bohai-Rim region over the“14th Five-Year Plan”period，this paper presents the regional LNG terminal layout and site selection ideas and recommends key port sites for development in view of port site conditions.

Abstract:We propose an evaluation method of the emission reduction design scheme for the ro-ro terminal.Based on an evaluation index system considering the economic，environmental and social attributes，we introduce the analytic hierarchy process and weighting TOPSIS method to evaluate the ro-ro terminal design scheme，and take a ro-ro terminal as an example to verify the effectiveness of the method.The results show that each scheme in the example has good discrimination under the evaluation model，and shore power is the optimal technology，and then low sulfur diesel and land-based scrubber thirdly.Therefore，the evaluation method can provide decision support for the ro-ro terminal when selecting emission reduction design scheme.

Abstract:Overhead vertical wharfs have become one of the main structural types of wharves in the upper reaches of the Yangtze River in recent years.Due to their large number of components，complex external damage factors and lack of effective means to know the damage，many wharves are in sub-health service status.As the key component of the whole wharf structure，the pile foundation is an important“window”to“peep”the stress state of wharf structure and the effects of external damage inducement.By constructing a neural network inversion model to analyze the collected finite element calculation data，a simplified calculation model is established using Python-MANSYS，and the applicability of the simplified calculation model is verified by comparison with the solid element model.The data sample space of parametric analysis is obtained by sampling，and the data needed by inversion model is extracted by dimension reduction.On this basis，the relevant parameters of the main damage inducement are inverted，and the inversion results and model performance are analyzed.

Abstract:The Xianrendao port area is an important large-scale comprehensive port area in the Bohai-Rim region，which has the spatial pattern of being encircled by double dikes，with many large-scale berths and dense ship flow.Liquefied natural gas（LNG）terminals are of particularity and exclusiveness.To tackle the problems in the LNG terminal siting and planning in the encircling basin，taking the Xianrendao port area as an example，we integrate multiple model technologies to study navigation safety，navigation impact，land safety，berth layout，space utilization，etc.Then the scheme of site selection and the berth and water area layouts of the terminal is proposed.This research provides key technical support for the construction of an LNG terminal in the Xianrendao port area.

Abstract:Under the circumstances of world-class port construction and high-quality development of water transport，integrated port-industry-city development has been taken to a new level and become a focus of port and port city development.To resolve the problem of achieving integrated port-industry-city development，we study the connotation and mechanism of integrated port-industry-city development，analyze three key issues in promoting this work，and propose solutions. Furthermore，we probe into the key issues in different types of integrated port-industry-city development in light of planning practice. Under the new system of territorial spatial planning，the research ideas and conclusions of this study provide a reference for promoting the implementation of integrated port-industry-city development.

Abstract:The No.1 harbor basin of the Tongzhou Bay port area is built at Yaosha，which is on the southern edge of the radiation sandbar，and siltation after channel excavation of the harbor basin is the focus of engineering design.In design，by studying the natural features of the engineering sea areas such as tidal current，wave，sediment，and substrate，and analyzing primary factors affecting siltation，we propose some countermeasures，such as layout of sand barriers，determination of the depth reserved for siltation，maintenance dredging，and draft control.The research reveals that since the No.1 harbor basin is built on a shallow silty beach，channel excavation of the harbor basin will result in siltation.However，the No.1 harbor basin has its entrance facing south and is well sheltered，so there is only a low risk of sudden sedimentation.In the first stage，we can cope with siltation by trial dredging in the harbor channel，reserving sufficient water depth for siltation，equipping an efficient dredger and controlling draft.In the future，we can consider whether to build a sand barrier or not by combining the results of siltation observation，the difficulty of maintenance and the influence of ships’ entering and leaving the harbor basin.

Abstract:Based on the analysis of the existing problems of dust control in open coal yards，the importance of dust suppression by watering in open coal yards is discussed.A mobile intelligent water curtain system for storage yard has been developed，which can realize large-scale walking，large capacity water storage，automatic source searching and water supplement，quantitative and accurate watering on the surface of coal pile.The system adopts the integrated design with the large-scale mobile single machine of the storage yard，uses the cantilever of the mobile single machine to establish the boom spray system and realize the full coverage and uniform sprinkling on the surface of the coal stack，and combines with the sprinkling pipe network of the spray gun of the storage yard to realize the automatic source searching and water replenishment of the water supply unit at multiple fixed water intake points.The results of engineering application show that the mobile sprinkler system greatly improves the clean production level of the yard，effectively inhibits the dust emission of the yard，and realizes the efficient water sprinkling on the surface of the coal stack at all seasons，which provides a new reliable technical method for the coal dust pollution control of large open storage yard.

Abstract:In recent years，a series of ecological slope protection projects have been implemented in the middle and lower reaches of the Yangtze River，which have strong ecological functions.In order to protect the stability of the bank slope in the middle and lower reaches of the Yangtze River and provide a good living environment for aquatic animals and plants，a new type of ecological slope protection structure is proposed.Through physical model test，the protection effect of the new ecological slope protection structure on different types of bank slopes is observed，and the change mechanism of erosion and deposition of different types of bank slopes is analyzed.The influence of different flow incidence angles on the stability of curved river bank slopes is observed，thus reasonable bank slope protection measures are put forward for different types of bank slopes.The results show that：1）Under the same conditions，the slope protection effect of the curved river is worse than that of the straight river. 2）The erosion range of the curved river slope is positively correlated with the flow incidence angle.3）Different slope protection optimization schemes are proposed for different types of bank slopes，and the effect is obvious.

Abstract:The construction and management of the waterways at the Yangtze River Estuary are facing a new situation of profound changes in the river regime and new requirements such as ecological priority.To further improve the comprehensive carrying capacity of the waterways，we analyze the main changes in the river regime of the Yangtze River Estuary in recent decades and sum up the regulation（design）ideas for the deep waterways at the estuary.The physical process of viscous fine-grained sediment movement in fresh and salt water mixing and tidal environments and the mechanism of waterway siltation at the Yangtze River Estuary are sorted out，including the stratification of salinity and sediment concentration，turbulence suppression，baroclinic effect of suspended sediment，longitudinal and cross flow sediment transport，bedload like transport of suspended sediment near the bottom of the high concentration layer，gravity flow transport of floating mud，and laminar transport of non-cohesive sediment.On this basis，we point out some noteworthy problems in the construction and maintenance of the waterways at the Yangtze River Estuary and further research directions.We also put forward suggestions for studies of the sediment budget at the open boundary of the estuary and the influence of organisms on the stability of the riverbed.The conclusions and suggestions can serve as a reference for deepening waterway regulation at the Yangtze River Estuary.

Abstract:Considering the growing enlargement trend of ships in the upper Yangtze River，it is of great significance for waterway construction planning to assess the impact of this trend on typical pollution emissions.Therefore，we collect and calculate the data on the tonnage，traffic flow，fuel consumption，and typical pollutant emissions of ships in the upper Yangtze River and analyze the comprehensive impact of ship enlargement on typical pollutant emissions.The results are shown as follows：1）The average tonnage of ships in three provinces and one city of the upper Yangtze River increased from 249 to 874 tons from 2008 to 2019，with a significant decrease in the traffic flow and a significant increase in the freight volume.2）The waterway class of the upper Yangtze River has upgraded from Class Ⅳ to Class Ⅲ，and the typical air pollution emissions per unit turnover of ships in ideal conditions have been reduced by 31.2%.3）The increase in waterway freight turnover leads to the growth in total pollution emissions from ships，but the calculations on the average tonnage of enlarged ships show that the waterway transport from 2008 to 2019，a replacement for land transport，lessens the pollution emissions by about 1.9 million tons，which registers a growth rate of 7.7% in pollution emission reduction compared to that on the average tonnage of ships in a constant state.4）It is proposed to upgrade the waterway class of the upper Yangtze River to Class II and further promote the development of ship enlargement.In this way，the typical air pollution emissions per unit turnover of ships can be reduced by 36.4% relative to the Class III waterway，which can facilitate the transport industry to achieve the goal of “carbon neutrality.”

Abstract:For the evaluation of the green construction of waterways，this paper studies an evaluation index system on the green construction of the Yangtze River main waterway.The regulation characteristics of the Yangtze River main waterway and the main construction processes of the waterway regulation projects are sorted out，and the ecological environment impact of waterway regulation is analyzed.On this basis，we put forward evaluation objectives and principles on the green construction of the Yangtze River main waterway by the system analysis method and obtain an evaluation index system including 40 indices in 7 aspects，i.e.，resource conservation，habitat protection，biological protection，water environment protection，atmospheric environment protection，acoustic environment protection，and environmental management.The proposed system can provide a reference in guiding and improving the green construction of inland waterways.

Abstract:As a flood control building，the embankment can easily lead to dangerous sections due to the harsh surrounding environment.In view of the dangerous sections of the Xinyi River embankment，relevant geological and hydrological data are collected.In combination with on-site investigations，the causes of the dangerous sections of the Xinyi River are systematically analyzed，and control measures for different dangerous sections are proposed.The results show that：1）The sudden rise and fall of water level in the flood season is the important external cause for the dangerous sections of the Xinyi River，and the strong permeability of the embankment foundation and the uneven soil quality are the important internal causes.2）According to these causes，the dangerous sections of the Xinyi River can be divided into three types.3）Different control measures are proposed in light of different types of dangerous sections，and the correctness of the control plan is demonstrated by the Shawan dangerous section.

Abstract:With the development of economy and continuous advancement of infrastructure construction，there have been more intensive sand and quarrying activities in some rivers.At present，with the increasing awareness of ecology and environmental protection，disorderly mining activities have basically disappeared，but the impact will not be eliminated in short term.The impact of sand quarrying of Hongdengqi Beach in the upper reaches of the Yangtze River is reflected in weakened function of the channel regulation building and deteriorating waterway conditions，which threaten the safety of navigation.In the channel maintenance，the original function of the channel regulation building will be restored by taking engineering measures to prevent the shallow channel of the river section hinder navigation，which has achieved good results and laid a foundation for further improvement of the channel.

Abstract:The existing design method for the channel width of immersed tube floating by tug towing has limitations.In response to this problem，a study is carried out on the floating channel width design based on numerical simulation.The floating channel width of the Shenzhen-Zhongshan Bridge gained from numerical simulation results grows with the time of tugs being in place，while decreases as the rectifying force increases.It is about 17 m smaller than the value calculated depending on the Design Code of General Layout for Sea Port.The design method of floating channel width based on numerical simulation takes into account the cooperative maneuver of tugs，enriches the width design method for immersed tube floating，and can provide a reference for similar projects.

Abstract:When the river channel recovers to its natural state during the falling stage and flood period of the Three Gorges Reservoir，the reef hinders navigation in Wutailiang and restricts the development of the waterway.Therefore，reef removal is urgently needed.According to requirements for short-term waterway construction and long-term capacity expansion，a one-time reef removal scheme was drawn up.Numerical simulation methods were used to predict and analyze the implementation effect.The results are as follows：1）After the implementation of the project，the water depth and the flow capacity in the reef removal area increase.2）The flow regime of the local water area is significantly improved and the flow tends to be smooth.The transverse flow of the channel is reduced to less than 0.25 m/s.3）The water channel with a depth of 4.5 m is above 300 m wide，which has achieved the expected regulation goal.It proves that the scheme is reasonable and meets expectations.

Abstract:The slope stability of muddy submarine channel is very important for the safe operation of the channel.Due to the uncertainty of channel slope instability and collapse，it is impossible to predict and evaluate the degree of instability，which seriously affects the safety of passing ships and management and maintenance of the channel.Based on the engineering experiment simulation，this paper obtains the full cycle voiceprint image of channel slope instability and collapse.By analyzing the energy change of voiceprint image，the instability process is divided into five stages：very stable，stable，unstable，extremely unstable and collapse.The voiceprint image features at each stage are extracted based on the Gabor transform，and the discrete cosine transform is used to reduce the dimensionality of the features.The voiceprint image features after the dimensionality reduction are input into Fisher function to build the instability degree evaluation and prediction model.The results show that the recognition accuracy reaches 90% when the features of voiceprint image samples to be evaluated are input into the prediction model.Therefore，it is feasible to build Fisher model based on Gabor characteristics to evaluate and predict the instability degree of muddy submarine channel slope，which is of great significance to the study of channel slope stability.

Abstract:The river bed in the middle reaches of the Yangtze River is mostly sandy，and the river bed evolution is violent，which is controlled by the nodes of rocky mountains，rock spurs and artificial revetment projects on both banks.The evolution of the upper and lower reaches has obvious relevance features.Taking the Mu’ezhou channel as an example，we analyze its evolution characteristics and relevance features with the downstream Huguang channel.Considering the adverse change trend of the current channel and the implemented channel regulation project，we study the regulation scheme of the associated evolution reach.The implementation of the beach protection project in the Mu’ezhou channel addresses the lower and medium beaches scouring in the Mu’ezhou beach and the shallowing in Wangjiapu of the Huguang channel.Adopting a mathematical model and a physical model，we verify the effect of the scheme with post-flood observation data since 2020.The results show that after the scheme implementation，the scouring of Mu’ezhou beach is effectively controlled，and the shoal channel pattern turns stable.Moreover，the channel width of 6 m water depth basically meets planning requirements.

Abstract:There is about 34 km non-connection channel between Guiping navigation junction and Changzhou hydro-junction in Xijiang channel.Jiangkou building stone ground supplying material for the construction of Datengxia hydro-junction is as the reservoir end of Changzhou junction and near the upstream reach.To study the impact on the upstream hydraulic navigation environment induced by the sand mining project，we simultaneously consider the upstream flow and downstream reservoir water level variations，establish the 156 km two-dimension numerical model from three river mouths of Guping to Changzhou junction including the upstream 16 km Qianjiang river and Guiping junction，and analyze the impact on waterway hydraulic condition by sand mining project.The results show that since the sand mining project，the upstream water level of entrance area at approach channel decreases 0.09 m，mainstream in the reach of Bulingsha is altered left because of the beach mined.Generally，except the designed discharge，the impact on the waterway hydraulic environment induced by sand mining in reservoir end is relatively small.

Abstract:According to the spatial distribution characteristics of waterway engineering，wide-area waterway engineering is divided into several regions，and the dynamic scheduling is carried out by the data organization technology of three-dimensional scenes in different regions.Plug-in tools are employed for the surface reduction of building information modeling（BIM），which ease the workload of manual surface reduction.In addition，the technology of loading geographical information system（GIS）multi-source data by Unity is proposed to solve the problems in practical project applications，such as loading failure of large-scale three-dimensional BIM + GIS data of waterway engineering in Unity，sluggish rendering，and huge workload of making model lightweight manually.In addition，a roaming system is developed utilizing the Unity engine，which enables the loading of three-dimensional BIM + GIS data of super-long waterway and high-quality roaming visualization.The system is of great value to the promotion and application of BIM technology in waterway engineering.

Abstract:With the completion of the Beidou Navigation Satellite System（BDS）Augmentation system for the Yangtze River trunk line，the method and effect of its application in waterway surveys need to be studied and certified.An experiment is conducted on the application of a post processed kinematic（PPK）technology based on the Beidou continuously operating reference stations（CORS）system for the Yangtze River trunk line in waterway surveys，and the accuracy of the experimental results is counted.On this basis，the method of applying this technology to waterway surveys on the Yangtze River is discussed，and its measurement accuracy is analyzed.The results show that when base stations in the Yangtze River CORS system are used to solve PPK positioning data，the positioning plane accuracy can meet the requirements of relevant specifications，whereas the elevation accuracy is unstable.

Abstract:The two-dimensional（2D）pier design process of fixed mast cranes is exposed to problems such as insufficient cooperation between specialties，inaccurate expression of drawings，and low standardization of design.Therefore，utilizing a project at a heavy cargo wharf，this paper applies the digital 3D collaborative design technology to the construction design stage of the pier foundation of mast cranes.Through the deployment of collaborative work environment and parameter-driven design，this paper expounds on six application points including multi-disciplinary collaborative design，optimal layout of pile foundations，structural calculations，parametric layout of embedded parts，statistics of engineering quantity，and standard drawings.The practical applications show that the 3D collaborative design of the parallel working mode improves the collaboration between specialties and shortens the design cycle.In addition，the parametric design makes scheme optimization and selection more convenient and efficient，and the accumulation of family libraries promotes the standardization level of design.

Abstract:This paper studies how to generate the real 3D model with high degree of fineness and high positional accuracy in areas covered by a wide range of waters（especially including strip-shaped features which surrounded by water on three sides such as breakwaters or LNG mole），which takes the application of oblique photogrammetry technology in port engineering as an example，systematically summarizes the technological process of the application of this technology，and calculates the accuracy of the real 3D model which created from the process，which shows the high-accuracy effect that the accuracy of flat surface and elevation are better than two pixel size.This paper verifies the feasibility of the technical process and the reliability of the accuracy of the generated real 3D model，which can provide reference for similar projects.

Abstract:BIM，GIS，and oblique photography contribute independently to the engineering field，but their integration lacks practical experience.BIM focuses on engineering-scale building information；GIS technology focuses on resource information at the urban and watershed scale；oblique photography aims to reflect the real scene of a specific area with high precision.Technical integration will effectively expand the radiation range of engineering construction information and assist engineering decision-making.It helps optimize the construction plan and improve the quality of engineering construction.This paper probes into the integration of BIM，GIS，and oblique photography.Exemplified by Shuangqiao hydro-junction project，the paper matches the BIM model，diorama and spatial data，model data visualization and interaction，and engineering roaming under the GIS platform.The research provides a demonstration experience for the application of BIM + GIS+oblique photography in waterway engineering and gives support for the realization of digital project management at urban and watershed levels.

Abstract:Muddy clay is common foundation soil in wharf engineering，and its creep properties are closely related to the stability of wharf foundations.To study the creep mechanical properties of muddy clay under different confining pressures，we carry out consolidated drained triaxial compression creep tests.On this basis，we introduce the Mesri and Log-Modified models to simulate the creep mechanical behavior of muddy clay，obtain the empirical creep models，and compare the identification effects of the two models.The results show that with the increase in axial pressure under the same confining pressure，the axial strain increases gradually，and the initial and steady creep rates show a linearly rising trend.With the same loading level，the increase in confining and axial pressure promotes the growth of axial strain，and the initial and steady creep rates under high axial and confining pressure are always greater than those under low axial and confining pressure.The isochronous axial pressure-strain curve of muddy clay is approximately hyperbolic and has prominent nonlinear characteristics.Moreover，the identification effect of the empirical Mesri creep model is better than that of the empirical Log-Modified creep model.

Abstract:To obtain mechanical indexes of non-homogeneous soils，a study of piezocone penetration test（PCPT）in non-homogeneous soils is conducted.The problem that the PCPT test can not satisfy the design depth is solved by introducing the construction technique of rig-led hole with multiple pipe guards，so that the cone tip resistance（qc），sidewall resistance（fs），probe inclination（l）and dynamic pore water pressure（u2）of non-homogeneous soil can be measured.With the layering statistical analysis and calculation of the above indicators，we calculate the undrained shear strength and internal friction angle indicators of the non-homogeneous soil，which provide critical geotechnical parameters for the foundation design of construction projects.

Abstract:In recent years，the change of water and sediment in the Yangtze River has led to the intensification of bank erosion，and the underwater throwing revetment has become an important part of the renovation project.The new protective material bagged sand pillow comes into being，and the accuracy of its throwing drift distance prediction directly affects the quality and efficiency of the project.We take the regulation project of Baguazhou reach in Nanjing in the middle and lower reaches of the Yangtze River as an example，analyze the mechanism of water depth，flow velocity and sand pillow mass on drift distance，theoretically deduce the calculation formula of drift distance based on dynamics，and determine the formula coefficient by the field throwing tests under different flow velocities and water depths.The results show that the calculated values derived by the empirical formula in this paper are in good agreement with the experimental values，and the relative error is within 20%.

Abstract:Aiming at the problem of the 3，500 m3/h cutter suction dredgers changing flow rates with pipe nozzles under the condition of short-distance pipeline delivery，we carry out research on the optimization of inboard pumps and impeller blades of submerged pumps to reduce the head and power of dredging pumps，and apply the modified impeller in the dredging construction project of Haimen in Nantong.The results show that replaced with the new impeller for the dredging pump，the Xinhailu dredger can use double pumps in series to transport silt soil mud.The power of two dredging pumps drops about 500 kW，which can save 13.4% of fuel consumption（saving 30 t fuel in 180 h of construction）of the dredger and achieve energy conservation.

Abstract:Aiming at the flow field in the high-pressure flushing nozzle of the drag head on trailing suction hopper dredgers，this paper conducted the numerical simulation of the submerged jet of the nozzle by CFD technology.The jet pressures under different nozzle diameters，exit jet velocities，target distances，and jet angles are analyzed.When the other parameters remain unchanged，the pressure on the mud surface increases with the rise in the jet velocity，slightly increases with the enlargement of nozzle diameter，and decreases with the increase in target distance.When the jet angles are 90°，60°，and 45°，the pressure on the mud surface is the largest under 90° at the same jet velocity，while 60° is the best jet angle in terms of soil breaking amount.

Abstract:The stack yard of a terminal project in Tanzania uses blown-filled land，mainly for temporary storage of light cars，and applies coral soil as the base back filler.We carry out the comparative analysis of Chinese and British standards of water CBR（California bearing ration）test，on-site CBR and compaction test of the back fillers，such as coral soil，coral stone and coral stone adding cement，and summarize their rules.The results show that for stack yards with lower bearing capacity requirements designed by British standard，the coral soil mixed with clay can be used as the base layer.The coral soil mixed with a certain amount of clay can meet the indoor water CBR value under the design compaction requirements.The coral soil back filler can meet the requirements for light container yards due to its high porosity and low strength，while heavy container yards must be investigated separately.

Abstract:Aiming at the common phenomenon that mass concrete frequently produces temperature cracks，we study and summarize the concrete temperature control measures and temperature control standards according to the concrete engineering，study the temperature control standards and requirements by the finite element simulation and analysis，determine them by engineering experience，summarize the temperature control measures including controlling the raw material temperature，setting the cooling water pipe system，and monitoring the temperature change in real time，and obtain the recommended values of main indexes such as mould temperature，internal maximum temperature，internal and external temperature difference，cooling rate，temperature difference between cooling water and concrete，opening time and water stop standard.The results show that controlling the raw material temperature and setting the cooling water pipe system can improve the crack resistance of concrete，well control the development of the structure temperature crack，and improve the safety and durability of the structure.

Abstract:Taking a dredging project in a foreign country as an example，we analyze the construction data on transporting slightly weathered rocks by the 1 m diameter dredging pipelines of the self-propelled heavy-duty cutter suction dredger “Tiankun Hao”.Then，we calculate the head and efficiency of the dredge pump under the given working condition，obtain the relationships of density and flow velocity with friction coefficient，and give the recommended values of the soil conversion coefficient and the experimental coefficient.The results show that the technology，by giving full play to the characteristics of the heavy-duty cutter suction dredger that it can directly excavate and transport the slightly weathered rocks by pipelines，improves the construction efficiency on the basis of saving costs and protecting the environment and thereby ensures that the project is completed on time.

Abstract:In a port engineering project，monitoring data reveal the presence of leakage channels under the cut-off wall. Grouting under the wall has been proven highly effective against the leakage.The key technical points are summarized regarding the design and construction for the leakage treatment under the cut-off wall in the project，encompassing the anti-leakage standard，determination of the sealing range，layout of grouting holes，grouting depth，grouting sections，grouting pressure，and grouting technology.Taken together，they form a set of technology for the treatment of leakage under cut-off walls.The sealing range determination based on water level observation breaks through the traditional technology，which can provide a reference for subsequent projects.