Abstract:A nested tidal current and sediment transport model is established based on ADCIRC+SWAN and Delft3D+SWAN models. All typhoons affecting Tongzhou Bay are classified into 5 types according to the track characteristics，and a typical typhoon for each type is selected to drive the model and calculate the sudden siltation volume of the planned port area in the north of Tongzhou Bay and its surrounding sea areas and analyze the characteristics of seabed morphological evolution. The results show that under the current construction status of the port area，the range of sediment erosion and deposition in Yaosha-Lengjiasha sea area caused by the typhoons are within ± 0.18 m，and the average thickness of erosion and deposition is between 0.05 m and 0.10 m；in the context of considering the impact of the reclamation plan，the channel-sandbank system is not greatly affected by the storm surge，and the magnitude of the storm erosion and deposition is relative small；the deposition amount of all the three different schemes is small after a storm surge，and the maximum local deposition thickness which is mainly controlled by typhoon types is between 0.1 m and 0.6 m. Generally speaking，from the point of view of typhoon sudden siltation，the second scheme of port area reclamation is better. However，the differences among different schemes are small，and it is suggested to consider other factors to achieve the final decision.

Abstract:Aiming at the strong permeability of sandy embankment around the artificial island and the obvious influence of sea tide level on the water level of the inner river，a reasonable water level of the inner river on the artificial island should be selected to avoid artificial drainage. Through the establishment of unsteady seepage model，the relationship between seepage field and seepage flow changes with tidal level is studied. The typical tide level of the offshore sea is selected，and the net seepage discharge of various proposed inland river levels within a tidal cycle is calculated by subsection summation method. The water level corresponding to zero net seepage discharge is the optimal normal water level of the river channel，which provides a basis for determination of the scale of the inland river channel and the elevation of dredging ground in the island.

Abstract:To promote the development of high-strength and high-performance concrete technology of marine mechanized sand in marine concrete structures，we study systematically the influence of granite powder on the workability，mechanical property，chlorion penetration resistance of C80-HSHPC，and analyze the influential mechanism of stone powder on concrete performance. The results show that the workability of C80 HSHPC is good when the content of machine-made sand powder is between 4.5% and 6.5%，and the effect of stone powder content on the yield stress，plastic viscosity and other rheological properties of freshly mixed concrete is not obvious. With the increase of stone powder content，the mechanical properties of HSHPC increase first and then decrease. The chloride ion permeability and drying shrinkage increase continuously. However，the effect is not obvious when the content of stone powder is less than 6.5%. Appropriate amount of stone powder reduces the porosity of concrete and optimizes the distribution of pore structure. It is beneficial to improve the mechanical properties and durability of concrete. However，when the content of stone powder exceeds 6.5%，stone powder has negative effect on the hydration process and pore structure. The content powder of manufactured sand should be controlled at 4.5%~6.5%.

Abstract:Aiming at the anti-scouring technology of underwater foundation，we carry out a research on the preparation technology of bagged concrete. The results show that the water cement ratio has a significant impact on the compressive strength of the concrete. When the water cement ratio is not more than 0.83，the compressive strength of the concrete is more than 13.0 MPa；when the water cement ratio is not more than 0.66，the compressive strength of the concrete is more than 15.0 MPa；when the water cement ratio is not more than 0.54，the compressive strength of the concrete is more than 20.0 MPa. The sand ratio also has some impact on the compressive strength of the concrete，and the sand ratio shall be 41%～43%. The compressive strength of test mold concrete has a good correlation with the compressive strength of bagged concrete core sample. According to the experimental results，we propose the mix proportion parameters and design method of bagged concrete，which provides a technical guidance for the mix proportion design of bagged concrete for underwater foundation.

Abstract:Aiming at the mooring safety problem of container ship stevedoring operations，based on the three-dimensional potential flow theory，the AQWA software is used to conduct frequency domain hydrodynamic analysis and time domain coupling analysis for moored container ships. The six-degree-of-freedom response amplitude operator，time-domain motion and the maximum tension of the mooring cable under various wind，wave and current loads under different loading conditions are calculated. The effects of different loading conditions on the six-degree-of-freedom RAO and the amount of movement of the container ship are analyzed. Wharf mooring safety is assessed under stevedoring operations. The results show that：1）Different loading conditions have the greatest impact on rolling motion. 2）When fully loaded，the amount of movement of the container ship is greater than that of ballast conditions，and the mooring cable has a greater load. The test results provide a simulation analysis basis for evaluating the mooring safety of ships during stevedoring operations，and also have certain guiding value for optimizing the mooring scheme of the wharf.

Abstract:Aiming at the current port development environment，we analyze the connotation of intensive green development from multiple aspects including the shoreline utilization，function layout，ecological protection，support system，etc. and put forward the intensive，large-scale and green development requirements. Taking the general planning of Xiangyang Port in Hanjiang River as an example，we summarize and analyze the present situation and main problems of the port，applies the concept of intensive green development to optimize and adjust the plan of the port positioning，the division of the port area，the functional layout，the collecting and distributing system，and the supporting system on the basis of existing plans to improve the port capacity and service level. The achievement may serve as reference for the general planning of similar ports.

Abstract:In order to deeply analyze the scale distribution and evolution process of the port group in the Yangtze River Delta，we apply cargo throughput and container throughput as the indicators to measure port scale，and use the port primacy index and the rank-size rule to study the port scale distribution in the Yangtze River Delta. The results show that the gap of ports in the Yangtze River Delta has been narrowing，and the port scale distribution has evolved from the primacy distribution to the rank-size distribution. The port scale structure of Jiangsu Province is relatively loose and the combined effect of high-ranking ports is not obvious，while the distribution of port throughput in Zhejiang Province is too concentrated. The scale distribution of the port group in the Yangtze River Delta is generally decentralized. In the future，it is necessary to accelerate the development of small ports such as inland river port and further optimize the port system structure. The port clusters in the Yangtze River Delta has formed a relatively stable and decentralized cargo transportation system，while container transportation is developing rapidly with new container ports keep emerging. The hierarchical system is still in constant change. The scale distribution of container port in the Yangtze River Delta has a higher degree of concentration.

Abstract:In view of the connection design between different structures of quay wall wharf under complex geological conditions，this paper studies and analyzes the structure selection of quay wall wharf under complex geological conditions and the key technology of connection treatment between two adjacent structures with large difference in berth grade based on actual engineering，which can solve the problems of superstructure cracking and sand leakage in structural joints，caused by different settlement at the connection of different structures of quay wall wharf.This paper summarizes the pile stabilizing and rock-socketing technology of composite steel sheet pile structure at the corner joint of quay wall wharf with large difference in berth grade，which has a certain reference value for the design and construction of similar wharf engineering.

Abstract:The natural conditions such as wave and current in shallow sea area are relatively good，and the investment in conventional mound-type breakwater is relatively high. The vertical sheet pile breakwater structure can be considered for replacement to save engineering investment. Based on the actual project，the American standard is used to calculate the wave force in front of the sheet pile breakwater，and the wave force is verified by the physical model test. Finally，the inner force of each component and the overall displacement of the sheet pile breakwater are analyzed by the geotechnical finite element software PLAXIS. The analysis results show that：1）The inner force of each component of sheet pile breakwater is relatively small，and the corresponding type of prefabricated components can be used as the main structure of sheet pile breakwater.2）The overall displacement of sheet pile breakwater is controllable. 3）It is reasonable and feasible to use sheet pile breakwater structure in shallow water area.

Abstract:The cement stabilized aggregate has been widely used in the pavement base，but it is rarely used in port engineering. Combining with a port yard base construction，we study the production mix ratio design of the cement stabilized aggregate，expound on the design process of the production mix ration of the cement stabilized aggregate from the confirmation of the target mix proportion，grading adjustment of the aggregate production respectively，cement content-EDTA relation curve，delay curve and strength-water content curve，and confirm the production parameters including aggregate gradation，cement dosage，water content，as well as rolling delay time，providing a theoretical basis for the construction of the yard.

Abstract:The water-saving ship lock can reduce the working head of each stage through classifying the total head. In addition to saving the water consumption，it is also conducive to solving the hydraulic problems of the high head ship lock. Therefore it is suitable for ship locks on rivers in western mountain areas of China. Based on the analyses of the operation principle of the water-saving ship lock，the calculation method of theoretical water saving rate and its variation with the step and area of water saving pools are studied in this paper，and the main factors affecting the water level classification of water-saving ship lock are summarized and analyzed. According to the characteristics of large variation of upstream water level，high design head，complex engineering layout conditions and operation modes，the variation laws of residual head in water saving operation are calculated on the navigation ship lock of Baise water control project on the Youjiang River in Guangxi. From the aspects of operation water level，and the step and area of the storage basins，the layout parameters of the storage basins and the water level classification method of the water-saving ship lock are proposed under large water level variation. Furthermore，the hydraulic indexes under different operation modes are simulated and calculated，and the scientific and reasonable classification of water level is proved.

Abstract:For the navigation flow conditions，there are many challenges to be faced in a ship lock reconstruction and expansion project at a sharp-bended river reach. In case of the reconstruction and extension project for Shanxiu lock on the Zuojiang River in Guangxi province，flow conditions in the approach channels of various design schemes are analyzed and compared by using the two-dimensional flow mathematical model. The results show that comprehensive measures such as reasonable excavation for the convex bank，and layout of concave bank submerged dam and guidance wall can effectively improve the navigable water flow conditions.

Abstract:Combining with the engineering design modification project of the submerged section of a breakwater in a port area of Tianjin Port，we use the wave section physical model test method to study the structural stability of the double-layer twisted Wang block surface protection，optimize the cross-section，and propose some suggestions to improve the stability of structure. The results show that for the breakwater body，the stable mass of the upper single block is calculated by the recommended formula in Article 4.3.7 of Code of Design for Breakwaters and Revetments and the stability coefficient KD value of the twisted Wang block placed in a single layer，the calculation results can meet the requirements of structural stability. For the top part of the breakwater，when the elevation of the top of the breakwater does not exceed 0.2 times the design wave height above the design high water level，the mass of a single upper block must reach twice the mass of the upper protective surface block of the outer slope to meet the structural stability requirements. The blocks are placed regularly to keep close and connected，which can strengthen the wave-proof ability of the structure and improve the stability of the structure.

Abstract:A new unsteady flow，with a wavelength of more than 200 km，has been formed at Yibin Hejiangmen by the convergence of daily regulated unsteady flow from Xiangjiaba Hydropower Station and Minjiang River，which has a significant impact on the navigation elements of the shoal channel of the Yibin-Luzhou river（Xulu section）. A two-dimensional unsteady flow mathematical model is applied to analyze the propagation law of the daily regulated unsteady flow on the channel elements of Shuanjianqi in Xulu section. The results show that：1）It takes about 1.5 hours to transmit the regulated unsteady flow from Hejiangmen to Shuanjiangqi. And the maximum daily variation amplitude of Shuanjiangqi water level is about 1.053 m，which is about 30% lower than Hejiangmen. The water surface gradient in the peak period is lower than that in the trough period. Sand mining in the pebble beach of Shuanjiang has a significant impact on the unsteady flow. 2）In the process of representative daily regulated unsteady flow，the river width of Shuanjianqi is 204~585 m that achieves the channel maintenance water depth standard of 2.9 m. Moreover，and the existing navigation mark setting at the channel boundary cannot satisfy the minimum maintenance water depth，so the existing navigation mark setting scheme needs to be optimized.

Abstract:In order to explore the impact of the Nancao channel regulation phase I project on the ecological change of Jiuduansha wetland in the Yangtze Estuary，we investigate the abiotic and biological factors in the waters near the wetland in 2017，2019，2020，compare the monitoring data of hydrodynamic conditions，water quality and sediments in the wetland before and after the construction，analyze the impact of the project on the abiotic environment，use the biodiversity analysis，remote sensing interpretation and other methods to analyze the impact of project on the biological factors. The results show that the regional hydrodynamic conditions，water quality and sediment factors fluctuate before and after construction，but there is no significant change. The diversity of planktonic and benthic organisms increase，and the vegetation area expands year by year，the implementation of Nancao channel phase I project does not have a significant adverse impact on the ecological status of Jiuduansha wetland，and the project also plays a positive role in the increase of wetland diversity.

Abstract:The channel layout is greatly affected by topographic and geologic conditions，tidal current，and surrounding environment. Taking a public waterway project as an example and adopting tidal current and sediment mathematical model tests and ships maneuvering tests，we demonstrate on the plan layout of a channel from aspects including the natural conditions of the project area，the relationship between the project and the environmental protection zone，and the mid-long-term development planning of the port，and determine the optimal axis plan. We also discuss the design innovations when determining the channel dimensions to provide technical reference for the layout of similar long-distance channel projects with many comprehensive constraints.

Abstract:Rubble spur dike is a common hydraulic structure used in water regulation whose hydrodynamics characteristics of the spur is an important reference to related engineering assessment. Fluid-solid coupling model is a powerful tool used to simulate corresponding hydrodynamic process and describe the mechanical characteristics. A CFD-DEM numerical model is established，which is a coupling of water flow model in a porous medium with free surface and discrete element method. The validity and simulation accuracy of the model are verified based on experimental data. Using this numerical model，the numerical simulation of the flow around the rubble spur dike is carried out，and the influence of the structural water permeability on the local flow and the force of the rubble body is studied. The results show that：1）As the water permeability of the spur dike increases，the wake area extends along the flow direction. 2）The velocity distributions of the main flow zone and the wake zone under different water permeability conditions of the dam body are obviously different，but the shear velocity distribution in the wake zone has a certain similarity. 3）The force analysis of the spur dike structure shows that as the water permeability of the dike body increases，the force area of the block spreads from the dike head to the dike body，and the force area gradually increases.

Abstract:Aiming at the construction scale of Paihe second-line ship lock in the Yangtze-to-Huaihe water diversion project，according to the ship characteristics in engineering construction area，the ship lock passing capacity indexes of different chamber dimension schemes are calculated by using the stochastic simulation method of ship arrangement. In combination with the adaptability factors of chamber dimension schemes to ship combinations，the design schemes of chamber dimension are initially selected. Furthermore，comparative analysis is carried out from the perspectives of ship lock construction site conditions，passing capacity requirements，ship type adaptability and operation scheduling strategy，to comprehensively demonstrate the ship lock construction scale.

Abstract:In view of the collapse and retreat of the embankment or revetment in the upper reaches of the Yellow River，which leads to the widening of the river channel and the siltation of the waterway，a waterway regulation plan for bank collapse obstructing reach is studied. A two-dimensional mathematical model of water flow is used to calculate the changes in hydrodynamic conditions in the navigation channel before and after the bank collapse in the Heixiatan section of the Yellow River，and the different channel regulation schemes are analyzed. The results show that：1）The flow conditions（velocity，flow pattern，etc.）in the navigable channel before the river bed morphology changes due to bank collapse or sand mining in the excellent river section can provide an important reference for the navigable flow conditions after implementation of the waterway regulation plan. 2）According to the observation of the effect after the implementation of the project，using the regulation project to appropriately adjust the width of the middle and low waters to make the flow velocity in the navigable channel close to the flow velocity before the bank collapse，is very effective in maintaining the stability of the navigable channel.

Abstract:Daijiazhou waterway is one of the most complicated shoal segments in the 6 m-depth waterway regulation project at the Wuhan to Anqing section of the Yangtze River main line，and the difficult reach for the 6 m-depth waterway arrival to Wuhan. In view that the water depth of Daijiazhou reach is less than 6 m，we analyze the channel condition and changing trend of Daijiazhou reach under the new water and sediment conditions，and propose the regulation idea，principle and scheme. The result of the physical model experiment shows that Daijiazhou waterway can realize the construction target of 6.0 m×110 m×1 050 m after implementation of the regulation engineering，and a small amount of maintenance dredging is required in unfavorable hydrological years to achieve the 200 m channel width in the future.

Abstract:The rationality and stability of mooring system are the key factors to ensure the reliability of buoy. We establish the catenary equation to deduce the calculation method of buoy chain length，give the critical value in the state of nature catenary，and analyze the anchoring stability by judging the state of the anchor system and calculating the anchoring force. Taking the setting of buoy in the Yangtze Estuary deepwater channel as an example，we analyze the stability of the mooring by this method，and propose the measures of increasing the mooring stability of buoy such as changing the mooring mode，reasonably configuring the chain length，and increasing the anchor force. The results can provide the references for the design of buoy.

Abstract:The research is carried out on the regulation measures of the continuous curve shoal dangerous waterway of Dahuatan in the canalized section of the Xiangjiang River. The mathematical model of two-dimensional flow and ship maneuvering motion of project river section is established using unstructured mesh. After verifying the reliability of the model through the actual measured water level of the prototype，the main parameters such as the water depth，flow field，rudder angle，drift angle，and minimum speed of the ship model control of the engineering river section under different flow conditions are calculated. The results show that without the implementation of cut-off and waterway regulation buildings in project river section，the navigation standards can also be met by optimizing the waterway route，broadening the navigation width，and combining with appropriate dredging and revetment engineering measures.

Abstract:Due to the influence of the river topography，large-scale oblique flow and cross flow，which threatens the safety of shipping seriously，will appear in the ship lock entrance area when the downstream navigable water level of Honghua multi-line ship lock is low. According to the results from the hydraulic model study of scale 1100 and self-propelled ship model test，we take comprehensive measures such as deepening trench diversion in large area，lowering sandbank elevation in obstructive sections，lengthening the separation levee length and making divider by backfilling according to the characteristics of flow pattern at the low navigable water level，by which the velocity of vertical flow，horizontal flow and backflow in the entrance area is reduced effectively. It is verified that the optimization measures not only meet the navigation requirements at the downstream low water level，but also effectively increase the maximum navigable flow and navigation efficiency of the ship lock. It is shown that the ship handling parameters are all within the required range by the test results of ship model. The research results can be used as reference for related pivotal projects.

Abstract:In view of the complex layout conditions of Huai’an East Ship Lock，which is restricted by the surrounding buildings already built and to be built，we carry out a comparative analysis on the lock location scheme，the double-line lock’s staggered layout and parallel layout schemes，and whether all the management areas involved in the upstream approach channel are expropriated，and obtain the location of the south gate while choosing the staggered arrangement’ of the double-line ship lock and all expropriation of the upper approach channel as the optimal scheme. It is proposed that the ship lock layout should be determined combining with the surrounding constraints，navigation conditions，navigation safety，flood control，ship lock operation and management，land acquisition，demolition and investment，etc.，and the next-stage research direction is presented. The research result may serve as reference for the ship lock arrangement under complex surrounding environment.

Abstract:To solve the problem of tilting of gravity lock chamber wall，we carry out the techno-economic comparison among several reinforcement schemes taking a lock project as an example，and adopt the finite element method to study the influence law of design parameters of the recommended schemes. The result shows that the pre-stressed soil anchor reinforcement scheme is economical in cost and has little influence on the surrounding environment，the tensile force of the anchor cable is less sensitive to the influence of the gravity lock chamber structure，and the wall stress is less at about 2/3 height of the wall. When the distance between the anchor cables is large，the soil mass between the anchor cables will appear certain tensile stress. Rational design of pre-stressed soil anchor parameters can effectively control wall and soil stress，and obtain good reinforcement effect. This method can be used not only in ship lock overhaul project but also in the reinforcement and reconstruction of sluice，box culvert and other similar hydraulic structures.

Abstract:Located in Wuhan-Anqing section of the Yangtze River trunk line，the Liyushan waterway is the essential artery for the transportation of waterborne materials in the upper，middle and lower Yangtze River，and its channel passage capacity is a key part for the smooth flow of logistics in the Yangtze River basin. In recent years，the development of scouring depth of the south channel has caused a decrease of the discharge capacity at the north channel and the dispersion of water flow. The Huanglianzhou central bar is extremely unstable，and the north channel conditions tend to deteriorate. To curb adverse development of the waterway， waterway regulation was implemented in 2015. After completion of the project，the regulation effect was evaluated based on the regular observation and analysis，combined with relevant mathematical model and physical model results in the design and construction stage. The result reveals that the scour of Huanglianzhou central beach and south channel is generally controlled，the adverse change trend is restrained，and the condition of the north channel is improved，the structure of regulation buildings is stable，and the channel regulation goal is realized.

Abstract:The plan layout of the second-line ship lock of the Wan’an Junction comprehensively considers the safety and stability of the adjacent building structure，navigable conditions，construction conditions，demolition and earthwork excavation，etc. The first and second line ship lock axis spacing is 230 m. Through numerical simulation and physical model tests，we analyze and optimize the navigable conditions of the upstream and downstream approach channels，and propose to extend the mooring section of the upstream approach channel of the second-line ship lock and the mooring section shared by the first and second-line ship locks，widen the bottom of upper approach channel and deepen the dredging at the turn，extend the dike between the first-line ship lock and the sluice lock，and adopt the full side discharge method，to improve the navigable conditions of the upstream and downstream approach channels. It can provide reference for the plan layout of ship locks in similar high-head reservoir areas.

Abstract:In view of how to reasonably set up AIS virtual AtoN，this paper simulates and analyzes the channel capacity and system blocking rate of AIS system，taking the Yangtze River basin and Shanghai port as examples. The results show that：1）The setting of AIS virtual AtoN occupies part of the communication time to reduce the channel capacity. 2）The more the number of ships in the system，the greater the increase of system blocking rate，and the more serious the impact of AIS virtual AtoN setting on system communication. Based on this conclusion，the threshold values of the number of AIS virtual AtoN that can be set in different water conditions are analyzed，and the suggestions for reasonable setting of AIS virtual AtoN are given，which can be used as a reference for setting virtual beacons in different waters. Under the condition of ensuring less influence on ship communication，the reasonable setting of AIS virtual AtoN can better play its navigational warning function and ensure the safety of ship navigation.

Abstract:The BIM technology is introduced into the waterway regulation design of Jiguantan. Firstly，taking the data classification as the starting point，we describe the modeling idea of the river terrain model；secondly，based on the modified river terrain surface，we construction the beach characteristic analysis and regulation scheme BIM model，through the integration of which， the DWG design results and three-dimensional visualization sand table of waterway engineering are formed. The conclusion is that this set of technical system can be well applied to the river evolution analysis，navigation hindrance and flow analysis，regulation engineering scheme modeling，etc. Corresponding model treatment method may serve as reference for similar projects.

Abstract:The initial geo-stress field is an important initial condition for finite element analysis of structure-soil interaction. The accuracy of initial geo-stress balance results directly affects the accuracy of numerical analysis results of structure. The operation of the automatic geo-stress balance method is the simplest，and the results of it are greatly better than other calculation methods. However，owing to being confined seriously by the foundation and structure type，the soil foundation parameters and contact conditions，the application of it in practice is very limited. We adopt the software of ABAQUS based on following the actual timeline for geo-stress balance in the process of numerical simulation strictly，apply the way of setting life and death elements to implement the replacement of the foundation-structure space element before and after the initial geo-stress balance，establish a general automatic geo-stress balance method and its procedures，and adopt a series of typical complex soil-wharf structure calculation models to verify the proposed method. The results show that the automatic geo-stress balance method and its procedures established in this paper are easy to implement but with the highest accuracy compared with other methods，and it can conveniently and effectively achieve the initial geo-stress balance for various complex calculation models.

Abstract:The cyclic load caused by the ship traveling wave is one important reason which leads to the instability of inland waterway revetment，thus it has significance to study the mechanism of soil instability and failure under cyclic load for the design of inland waterway revetment. Plant revetment protection technology can enhance the soil strength by the root combining closely with soil. Based on the remolded plain soil and remolded root reinforced soil of Naji Reservoir，we apply the triaxial cyclic loading test，simulate the long-term action of ship traveling wave load，study the relationships of cyclic loading vibration time，strength，confining pressure strength and soil strain of remolded plain soil and remolded root reinforced soil under cyclic loading. The results show that the residual strain of remolded plain soil and remolded root reinforced soil increases with the increase of cyclic load under different confining pressure. Under the same cyclic load，the internal friction angle and cohesion of remolded root reinforced soil are higher than these of remolded plain soil，and the existence of root improves the resistance effect of soil to ship traveling wave，and improves the shear strength of soil under the cyclic load.

Abstract:The shear resistance of sandstone-mudstone particle mixture is an influence factor for the foundation treatment of port engineering in mountainous areas. We carry out the direct shearing tests of consolidation drainage to 48 groups of samples with different mudstone particle contents，normal stresses and water bearing states by the direct shear apparatus，analyze the effect of different mudstone particle contents on the form of shear stress displacement-curves，reveal the relationship between deformation and strength，and establish the empirical calculation method of shear strength. The results show that the particle contact can be divided into homogeneous particle contact and heterogeneous particle contact. Under the effect of stress concentration，mudstone particle breakage is an important factor affecting strength and deformation of sandstone-mudstone particle mixture. The stress-strain curve of sandstone-mudstone particle mixture is mainly strain hardening，and its shear strength decreases with the increase of mudstone particle content.

Abstract:The sand with carbonate content is characterized by porosity，irregular particle shape，easy cementation，easy breakage and so on while its origin，structural mechanism and engineering mechanical properties are quite different from ordinary quartz sand，especially the carbonate content has a significant impact on the bearing capacity of pile foundation. In this paper，the influence mechanism of carbonate content on the bearing capacity of pile foundation is summarized，and the calculate method recommended by API which is the internationally recognized pile design code and Imperial College（ICP）are introduced. Finally，the influence of carbonate content on the bearing capacity of pile foundation is calculated through an engineering example of an artificial island project in Saudi Arabia.

Abstract:Aiming at the problem of how to determine a reasonable and reliable driving stop criterion for driven piles under complex geological conditions，the determination method of driving stop criterion for driven piles based on Euro codes is studied. Relying on a certain wharf project，using a combination of high-strain dynamic pile monitoring and static load testing，the corresponding relationship between the ultimate bearing capacity and penetration/pile tip elevation is established，and finally the driving stop criterion is determined to guide the construction of the project’s pile driving. The results show that the driving stop criterion for driven piles determined based on Euro codes is based on whether the bearing capacity meets the design requirements，and the reliability of the criterion is high.

Abstract:In view of the problems of low efficiency and poor adaptability in the actual construction of “Xinhaima” ship，we compare and select the performance parameters of dredge pumps of the same ship type，optimize the impeller design of dredge pump，apply the dredge pump scheme of smaller impeller diameter and higher rotation speed with the characteristics of wide blade wall width，wide spherical area and etc，and analyze the engineering application effect of dredge pump. The results show that the high efficiency dredge pump can expand the applicability of the ship，improve the efficiency of dredging and bow blowing，and reduce the energy consumption of the ship，which can provide the references for the dredge pump selection of trailing suction hopper dredger.

Abstract:The common pile foundation construction methods in old wharf reconstruction mainly include water construction method and land construction method.Aiming at the problems of high cost and low efficiency in water construction and high requirement of wharf structural strength in onshore construction，we propose the construction technology of onshore piling platform based on rail walking combining with the Q21 wharf reconstruction project of Ashdod Port in Israel，realize the high quality construction of steel pipe pile and sheet pile，and analyze the key parameters and calculation method by using finite element software.The results show that the structural strength and stiffness of the track type pile driving platform can meet the requirements under different working conditions. This technology can provide the references for the onshore construction of wharf pile foundation.

Abstract:In view of the problems such as the blockage of drag head and weak ability of breaking soil when excavating hard clay，we compare the properties of hard clay and soil in the Yangtze River and find that the hard clay has the characteristics of large cohesion，fine particles and high shear strength. Based on the numerical simulation and adopting the technology of ultra-high pressure jet to solve the above problems，we develop a set of efficient excavating hard clay drag head system with independent intellectual property rights（with the maximum pressure of 38 MPa），which adopts the mode of “high-pressure head，low flow“ to reduce the excavation resistance，alleviate the problem of rake blocking，and increase the soil breaking capacity，to provide a technical support for channel dredging projects.