Abstract:Lingdingyang Bay is an important estuary bay in South China with important shipping functions，and there are important ports such as Nansha Port of Guangzhou Port，Western harbors of Shenzhen Port and Zhongshan Port on its east and west shores，and Lingding Channel and Tonggu Channel are important sea accesses for Guangzhou Port and Shenzhen Port. The major problem of harbors and channels in Lingdingyang Bay is sediment siltation. Based on the analysis of insitu data，remote sensing analysis，flume test，and measurement and analysis of silt density，we carry out a comprehensive analysis and study on sediment problems of harbors and channels in Lingdingyang Bay，including dynamic condition features for sediment movement，sediment sources and transport forms，characteristics of suspended load and bedload，sediment siltation features and mechanism of harbors and channels，hydraulic characteristic test of sediment，and fluid mud and nautical depth utilization. Maintenance countermeasures of harbors and channels are proposed based on the siltation characteristics of Lingdingyang Bay.

Abstract:We use two-dimensional shallow-water tidal equation，obtain the real tidal flow field of Puba Port on the basis of model verification against the field measured data，and analyze the effect of the Puba Port bridge project on the flow and silt in the nearby sea area and the change of water quality resulting from the dangerous goods into the sea. The results show that the increased zone of flow velocity is located between two main piers of the bridge and near the water，the reduced zone of flow velocity is located mainly in the nearby waters of the southern and northern approach bridge piers and the local waters of the main piers. The deposition area mainly is located in the south part of the bridge of Puba Port and near the north part of the approach bridge，scour area is located in the waters around the main piers. If sulfuric acid leakage accident is produced in waters around the bridge，the affecting area of the water environment is large，such accident must be avoided to ensure the water quality.

Abstract:Considering the advantage of plant roots of both water absorption and reinforcement，and relying on a dredging project，we carry out the field experiment on the use of Pennisetum hydridum for the ecological solidification of the shallow dredged soil. Observing the changes in water content，bearing capacity，soil nutrient content，and heavy metal content of the shallow dredged soil in the test area（depth of 0~90cm），we analyze and evaluate the effect of Pennisetum hydridum on the ecological solidification of the shallow dredged soil. It is found that 85 days after planting of the Pennisetum hydridum，the soil bearing capacity of the planted area increases from 11.8～27.7 kPa to 54.5～ 68.3 kPa，while the blank control area is only 33.4 kPa；The content of organic matter，alkaline hydrolysis nitrogen and available phosphorus increases by 25.5%~43.9%，6.5%~17.0%，1.5%~9.6% respectively； Pennisetum hydridum has an adsorption effect on heavy metals Cu，Zn，Pb，Cd，Ni. Among them，the adsorption effect of Cd is the most obvious. In conclusion，it is feasible to use Pennisetum hydridum to ecologically solidify the shallow dredged soil. It can accelerate the water loss of the shallow dredged soil and quickly solidify the shallow dredged soil，especially for the depth range of 30cm to 90 cm. In addition，the Pennisetum hydridum also has the improvement effect of increasing soil nutrient content and absorbing heavy metals.

Abstract:Current density is the key parameter of cathodic protection system design for the reinforced concrete，but how to select the current density parameter for contaminated concrete in a wet environment，there is no relevant research in China. We carry out the research of current density based on laboratory condition，determine the current density parameter of the concrete contaminated by salt in a wet environment，on this basis can form a design of reinforced concrete sacrificial anode cathodic protection system，and apply the scheme in a reconstruction wharf project in Zhanjiang Port to solve the problems of high chloride ion content in pile foundation concrete and serious corrosion of steel bars. The results show that the protective effect of this scheme is good. The protection distance of the intertidal zone can extend to 1 m above the water，protection distance of the under mud zone can extend to 18 m under the mud.

Abstract:When water flows through the caisson，the caisson’s compression across the water section will change the flow field around it. To explore the change of stress on the caisson under different velocities，flow，and caisson depths，we adopt the control variable method to study the flow field variation law in the process of caisson bedding and floatation based on the model experiment and CFD numerical simulation. In view of the shortcomings of the standard formula for large structure calculation，we propose the lateral compression coefficient for modification. The calculation results show that with the increase of the flow velocity，the flow force and flow velocity distribute in a parabolic curve；with the increase of the flow direction angle，the longitudinal flow force and transverse flow force of the caisson increase simultaneously；during the gradual uplift of the caisson，the flow increases at first and then decreases；when the distance between the bottom of the open caisson and the riverbed is more than 10 m，the flow force of the open caisson will remain stable regardless of the water depth.

Abstract:The design of pile foundation is the key point in the design of pile supporting wharves. The horizontal load of the normal pile supporting wharf is completely borne by the pile foundation，which leads to a large number of piles，large scale，and high cost. In view of the problem that the horizontal load leads to the increase of pile，we set the anchored friction plate support system at the rear of the wharf to bear the horizontal load，use the finite element calculation method to compare with the normal structure and reveal the mechanism and effect of the anchored friction plate support system. The results show that the anchored friction plate support system can greatly reduce the internal friction of the pile and the number of pile foundations，optimize the structure scale and save the project investment.

Abstract:In view of the problem of the safety assessment for the wharf hydraulic structure impacted by ship，we combine with the example of the collision between ship and wharf，and the on-site inspection results of the wharf structure，calculate the impact force of the ship out of control by using three kinds of industry-standard formulas of water transportation，highway and railway，calculate the stability of wharf hydraulic structure impacted by ship，comprehensively evaluate the safety and applicability of wharf hydraulic structure impacted by ship，and put forward the repair treatment of the damaged parts and the monitoring measures in the subsequent operation period. The results show that the safety assessment grade of the pier structure of the impacted wharf is A，and the structural applicability evaluation grade is B. The safety assessment method can provide scientific basis and technical support for accident identification，damaged structure repair，and terminal operation.

Abstract:The current force generated by large container ships when berthed at the jetty is studied. By discoursing the formula in JTS 144-1-2010 Load Code for Harbor Engineering and formula in British Standard BS6349-1，a dimensionless comparison about the calculation method of current force and the related coefficients is carried out. Combined with engineering examples，the OPTIMOOR software is used to calculate and simulate the current forces of large container ships under different current angles. The results show that：1）The current force is very sensitive to the relative water depth ratio. 2）The transversal current force calculated by the British Standard is greater than the calculation result of the national standard，while the longitudinal current force calculated by the British Standard is much smaller than the national standard. 3）When the national standard is applied to calculate the current force，the projected area of the vertical and parallel water flow directions of the underwater part of the ship needs to be corrected.

Abstract:There are strict requirements on the navigation supervision of LNG carriers，and the navigation mode and emergency anchorage have always been the key points in the process of LNG terminal’s site selection，construction，and operation management. Based on the analysis of the existing specifications，the hydrological and sediment conditions，the LNG channel，and anchorage setting status，the construction and operation of LNG terminals built or under construction，and the practice of navigation management，we put forward suggestions on the selection of LNG ship navigation mode in full tide or by the tide and emergency anchorage layout，to provide a reference for the construction，operation and navigation management of LNG terminals.

Abstract:The marine structure of 2×50，000 DWT wharf in Luoyuanwan Bay adopts a high piled structure with frontal sheet piles，which is a kind of complicate hybrid structure. In order to guarantee the structure’s reliability，space member system and plane strain finite element model is applied for the computing the deformation of the frontal sheet pile. The key parameter values of the two calculation methods and the calculation results of the frontal sheet pile deformation are introduced，and the calculation results are compared with the actual deformation data，which verifies the rationality of the key parameters of the two calculation methods.

Abstract:Tongzhouwan port area is a new port area of Nantong port to be developed along the coast of Nantong，which is of great significance for alleviating the contradiction between port and city along the Yangtze River and implementing the regional integration development strategy of the Yangtze River Delta. Based on the natural resource conditions and the distribution of environmentally sensitive areas near the planning region，we put forward the optimized and adjusted planning scheme of the Tongzhouwan port area from the environmental impact concern. Applying the mathematical model，analytic hierarchy process，and other methods，we compare the optimized scheme and the original scheme from the perspectives of resource occupation，hydrodynamic condition，water environment capacity，and ecological environmental impact. The results show that the optimized scheme better balances port development and ecological environment protection. The research result may serve as a reference for the coastal ecological port planning.

Abstract:Aiming at the problem that the mountainous rivers terminal land excavation forms 30 m to 50 m high bedded rock slope reinforcement，according to the lattice anchor and anti-slide pile in the reinforcement design of row spacing，we use the Geo-slope software，establish the high bedded rock slope reinforcement calculation model based on the Morgan Stanley-Plath method，calculate the multiple sets of different row spacing of slope stability safety coefficient under the different working conditions，and select slope reinforcement combination of economic security. The results show that lattice anchor cable anchor and anti-slide pile reinforcement effect on the overall safety factor of slope depends on the size of the supporting structure in the whole slip surface resistance.

Abstract:Taking a work area berth project as the background，some difficult problems in the water supply and drainage design of the bulk cargo wharf with the long approach bridge are discussed. By comparing the relevant fire protection codes，this paper offers the view of 3，000 m radius of protection about fire pump-rooms in bulk cargo terminal and the design of fire water pipe branch-shaped network for single approach bulk wharf. Aiming at the problem of the initial rainfall depth value of the bulk wharf，from the perspective of environmental protection，combined with the local rainfall data，an economical and reasonable value is proposed. The slope of the wharf drainage open ditch cannot be set due to structural reasons，so the calculation formula of the flat slope open drain is introduced.

Abstract:In order to solve the technical problems of inland river port shore power supply with complex shore-based conditions and large water level difference change，the cruise ship terminal in Chongqing is used as the application object，and the shore power system is developed based on double power supply pontoons and suspended guide cable，which solves the problem of large changes in the ship-to-shore power supply distance caused by the large water level when the cruise ship docks at the dock.In addition，application technologies such as man-machine cooperative electronic control plug-in devices，roller-type cable trays，and integrated cloud management have been developed to improve the safety and convenience of shore power applications. These technologies have been successfully applied in many cruise terminals such as Chaotianmen，Wushan Cruise Center，and Shennyuxi in the Chongqing-Three Gorges cruise line on the Yangtze River.

Abstract:The contradiction between the limited channel width of the 12.5-meter deep-water channel in the Yangtze Estuary and the demand for safe rendezvous of large-scale super-wide ships has become one of the main contradictions that need to be solved urgently. Since December 1，2018，using the slope to encounter by large cruise ships and large container ships in the Yangtze Estuary deep-water channel has changed from trial operation to normal operation. On the premise of ensuring the on-time operation of cruise ships in the deep-water channel，it is of great significance to study the impact of using slope encountering on deep-water maintenance and dredging. According to the measured data of using slope encountering，this paper analyzes its actual influence on dredging，studies the influence of using slope encountering on waterway dredging，and puts forward corresponding measures to ensure waterway dredging，which can provide important technical support for the influence of waterway maintenance and dredging brought about by the improvement of using slope encountering level in the future and the development of countermeasures.

Abstract:This paper focuses on the new trend of the evolution of the middle and lower Yangtze River waterway continuously washed by the clear water discharged from the Three Gorges Reservoir，analyzes the channel stability after the implementation of Heishazhou goose-head curved branching waterway control project and the difference during the research stage，and expounds the influence of clear water scour on the channel regulation idea of the evolution of the curved branching waterway. The results show that under the condition of the sudden decrease of sediment inflow in the upstream，the clear water scouring increases the sediment transport capacity of the branch on the convex bank side of the branching reach，the channel continues to scour，and the navigation depth，navigation width，and diversion ratio increase，which belongs to the developed branch. Therefore，the actual engineering effect is better than the model test results，which accumulates experience for the follow-up treatment of the similar curved branching reach.

Abstract:The Zhajiao reach is a typical branching reach in the upper Yangtze River，which has low water obstruction to navigation of curving and shallow water channel with a high velocity. Based on the navigational characteristics，the regulation scheme of navigation by two branches is put forward. By a combination method of physical model experiment and two-dimensional numerical model calculation of water and sediment，the characteristics of water flow and sediment transport before and after excavation are analyzed. While excavating the new channel，the left branch diverges obviously，and the flow pattern in the beach mouth is improved. The new channel becomes the main transport path of sediment with the increase of the coming flow，and there is little sediment deposition. Meantime the bed load movement of pebbles meets the law of flood-silting and dry-scouring balance within a year，and the two branching channels stability is good.

Abstract:After Xiangjiaba ship lift is put into trial navigation，due to the poor matching between the actual navigation of 1 000 DWT ships in the lower reaches of Jinsha River and the main scale of the designed ship，the loading rate of the ship is low. To improve the traffic capacity of ship lift and the economic benefit of ship transportation，it is very necessary to carry out prototype observation of ship draught and gradually release the control standard of ship draught. Through prototype observations of entering and leaving the chamber of a large number of ships with different draughts and speeds，some factors about the draught control standard，such as the fluctuation of channel water level，water depth variation of ship chamber，speed and sinkage of ships entering and leaving the ship chamber，are systematically analyzed. The results show that there is still a safety clearance of more than 30 cm even if the ship draught is raised to 2.4 m.

Abstract:Hydraulics investigations of filling and emptying systems should be one of the most concerned contents when constructing and administrating for ship lock projects with water-saving basins. Compared with conventional ship locks，the water filling/emptying operation process of water-saving ship locks is more complicated. On the basis of a large amount of research data，we systematically discussed the types and hydraulic characteristics of ship locks with water-saving basins，water delivery system forms，valve opening and closing methods，and water delivery hydrodynamic characteristics，etc.，and summarized and analyzed the research results and progress in various aspects. In the future，we can focus on the following aspects to carry out in-depth research：flow rate distribution law of ship locks with water-saving basins through side ports in a long culvert filling/emptying system，types，number and cross-section type of the culvert connecting with double lane ship locks，combined valve operation schemes，and performance of reducing the intrusion of saltwater.

Abstract:Whereas the bottom protection of spur dike can compress the general ineffective scouring range to increase the effective action efficiency of spur dike，a method for determining the bottom protection width of spur dike based on the waterway scour efficiency has been proposed. The main conclusions are drawn as follows through theoretical analysis，numerical simulation，and physical model test research：the effective action efficiency coefficient of the spur dike is the ratio of the increase in the single-width flow of the movable bed waterway to the increase in the single-width flow of the fixed bed waterway. Calculation formula for the effective scouring efficiency of the spur dike is established，which can be used to calculate the bottom protection width of the spur dike. The formula shows that the effective scouring efficiency of the spur dike is constant；when the bottom protection is from the spur dike root to the edge of the waterway to form a fixed bed condition，the effective scouring efficiency of the spur dike can reach 100%. By this method，the width of the bottom protection can be reasonably determined. Therefore the general invalid scouring range of the spur dike head can be reduced，and the effective scouring efficiency of the spur dike on the waterway can be increased. In this way，the improvement effect of the navigation channel after the engineering is better.

Abstract:Affected by the geographical location，hydrometeorology，topography and geomorphology，flood disasters occur frequently in Chongming Island of Shanghai. Especially，due to the lack of drainage outlets in the north and central part of the island，it cannot meet the requirements of drainage during the rainstorm.To scientifically evaluate the influence of the four sluices outward relocation project of Chongming Island on the dynamic conditions of water and sediment in this area，we carry out numerical modeling of hydrodynamics and morphology. Combined with the measured hydrological and sediment data in this area in recent years，we analyze the characteristics of hydrology，sediment，and river regime evolution in this reach，and study the characteristics of water and sediment movement in the engineering reach. Meanwhile，we establish a three-dimensional numerical model of water，and sediment in the engineering reach to simulate and calculate the implementation effect of the plane scheme of flood control and de-watering project along the north side of Chongming Island in the lower section of the North Branch based on model calibration and verification. The results show that the implementation of the project has little influence on the flow condition of the surrounding water areas and the bed evolution of the surrounding water area and the North Branch channel. This study provides technical support for engineering construction.

Abstract:In view of the characteristics and main problems in the operation of the hydraulic ship lift，a scientific work plan，and strict quality control measures are formulated to complete the first overhaul of the Jinghong hydraulic ship lift. While carrying out the routine maintenance of metal structures，electromechanical devices，and electrical equipment，we focus on overhauling the unique hydraulic drive system of the hydrodynamic ship lift and propose a safer and more scientific way of locking and unlocking the ship chamber. The handling method of synchronous shaft torque exceeding standard is mastered，and the problem of operation stopping due to the torque’s exceeding standard is solved. Through the first overhaul，the overall technical state of the equipment and facilities is improved greatly，and rich experience has been accumulated，which has laid the foundation for the compilation of the maintenance code for the hydraulic ship lift.

Abstract:In view of the contradiction of the increasing throughput，limited tidal navigable window period，high demand for navigation，and complex navigation environment in a foreign estuarine port area，we carry out the waterway throughput capacity analysis by the simulation test method. Based on the bottom elevation of the built waterway and the distribution of high tide water level，the tidal window period of different ship types in different directions is deduced；Based on the software SIMIO，a simulation model including terminal，internal anchorage，waterway，transfer barge，offshore transshipping platform，and floating crane is established with consideration of the influence of tide and tidal current on ship navigation. Through the test，it is verified that the“port-transfer barge-transshipment facility” system including the waterway can achieve the target throughput. The analysis results provide an important basis for the short-term production scheduling and long-term expansion planning of the port area，and also may serve as reference for similar projects.

Abstract:The study focuses on the application of 3D geological modeling based on BIM technology in the environmental dredging project，which has higher requirements on engineering digitization and design refinement，to change and upgrade the design approach effectively. Relying on the pilot project practice of endogenous pollution treatment for the Baiyangdian lake in Xiongan New Area，we carry out the three-dimensional forward design of geology using MR-Geo software developed based on the MicroStation platform. A geological model with attribute information of soil is created，with which the applications in the scheme comparison of dredging，drawing output，sectioning analysis of dredging model，and process simulation are realized. The value for the improvement of design quality and efficiency using BIM technology in environmental dredging projects is embodied，which provides a reference for the dredging engineering industry to further promote the application of BIM technology.

Abstract:Aiming at the problems of “many points，long lines，wide areas”，high safety risks in maintenance operations of the public channel of the Shanghai Port，we use on-site investigation，theoretical modeling，and system development to carry out the key technology research on the intelligent management of the channel maintenance and support，and propose a method of abnormal real-time detection of ship operation based on AIS data，which can realize the goal of “one picture full perception，one-click whole situation” for the whole process of channel maintenance and support. The result is fully applied in Yangshan Port，Waigaoqiao Port，Luojing Port and other public channel maintenance and support in Shanghai Port. This method has significant economic and social benefits and broad prospect for promotion and application.

Abstract:To ensure the dredging efficiency of the cutter suction dredger，the slurry production prediction of the dredger is an effective auxiliary method. Based on the data obtained from the actual operation of a cutter suction dredger in a certain place，this paper carries out data preprocessing and principal component analysis（PCA）to simplify the complexity of the prediction model. The particle swarm optimization regularized extreme learning machine（PSO-RELM）is used to establish the instantaneous production prediction model of the dredger.The prediction results show that PSO-RELM has better generalization performance than conventional extreme learning machine ，and can improve the production prediction accuracy of the cutter suction dredger. Thus，visual charts is generated to assist the dredger operator to adjust the dredging strategy.

Abstract:In existing Guangxi shipping information systems with monolith architecture，scattered and closed data resources formed the information island，which led to difficulties of data gathering，sharing，and exchanging，and resulted in the hard implementation of comprehensive supervision and one-stop service. To overcome these deficiencies，an idea of constructing the integrated application of digital shipping is proposed based on the systematic demand analysis of the Guangxi shipping informationization. Based on the middle platform and micro-service technologies，the detailed functional framework and technical architecture are designed for the integrated application of Guangxi digital shipping. The proposed idea is helpful to the rapid development of Guangxi shipping and may serve as a reference for the implementation of the top-level plans about “Strong Transportation” and “Digital Guangxi” in the Guangxi shipping field.

Abstract:Compactness affects the long-term stability of port foundation engineering. To study the nonlinear creep characteristics of foundation soil under different dry densities conditions，the consolidation drained triaxial compression creep test of foundation soil is carried out. The results show that：1）With the decrease of dry density，the higher the moisture content of the soil after air pumping saturation，the greater the axial strain，and the more significant the creep behavior. 2）The long-term strength of soil increases with the increase of dry density，and the increase in dry density inhibits creep development. 3）The isochronal deviatoric stress-strain curve of foundation soil shows linear characteristics at low-stress levels and nonlinear characteristics at high-stress levels.Based on the experimental results of this paper，through the study of the relationship between viscoelastic modulus and dry density and loading time，the viscoelastic modulus considering different dry density is defined，and the fractional-order viscoplastic body is constructed based on the fractional calculus theory to obtain a new nonlinear creep mechanical model of soil under different dry density. The parameter solution method is given to verify the feasibility and rationality of the model. The empirical relationship between instantaneous modulus of elasticity and dry density is analyzed，and the recommended range of model parameters for similar silty clay foundation soil is given. The research results provide some reference for the study of creep characteristics of silty clay foundation soil and the long-term stability analysis of port foundation engineering.

Abstract:In view of the deviation between the design and calculation results of underwater compacted sand pile composite foundation and the engineering practice，the mechanical characteristics are analyzed and studied. The test of soft soil foundation reinforced by compaction sand pile in the Yangshan deepwater port area is simulated and analyzed. Research conclusions of settlement characteristics，bearing capacity，transmission and variation law of load along the depth of the composite foundation as well as the load-sharing effect of sandpile and soil between piles are obtained. Several different related parameter settings of the composite foundation model are calculated and compared，and the influence of the changes of parameters on deformation and force characteristics of the composite foundation is analyzed. This study provides a reference for the design of underwater soft soil foundation reinforcement of offshore deep-water ports.

Abstract:For the settlement calculation of soft soil，the difference between stress consolidation degree and strain consolidation degree is neglected，and the soil stress history is not considered in the derivation of the corresponding conversion formula. We use the settlement calculation method considering e-lgp compression curve，consider the soil stress history，derive the conversion formula between stress consolidation degree and strain consolidation degree，analyze the difference between stress consolidation degree and strain consolidation degree，and the main influencing factors，and carry out the verification based on the reclamation project in Philippines，Pasay. The results show that consolidation degree is not equal to the strain consolidation degree，the difference between them is influenced by the compression characteristics of soil，natural gravity stress，stress history，and overlying additional load.

Abstract:The large-area vacuum preloading soft foundation treatment of Binzhou Port encountered a large area of reinforcement，a large thickness of silty sand interlayer，and a large buried depth during the construction process. In response to these problems，a process is adopted. That is：the outer boundary of the reinforcement area is sealed with a clay sealing wall；and the pressure film trenches between the partitions in the reinforcement area are artificially shallowly excavated，and the adjacent internal partition sealing films are alternately bonded at the pressure film trenches and then pressed with sandbags. The test results of the reinforcement effect show that the soil quality in the reinforcement area has been significantly improved. The technology can reduce the excavation workload，shorten the construction period，and save costs，which can provide a reference for similar projects.

Abstract:Harbor yard is often reclaimed through dredging and filling. Limited by the filling process，it is easy to cause the fine particle content around the outlet to be high. Since the soil is not horizontally layered，it is impossible to directly use the layer wise summation method and empirical formula to calculate long-term settlement. In order to solve this engineering problem，firstly，through the creep test of sandy soil，the relevant parameters of rheological elements with different fine particle content and different types of fine particles are obtained；then the rheological element parameters are used for analysis and calculation in Flac 3D；and finally，the commonly used empirical calculation method is adopted to fit the long-term post-construction settlement. The comparison of Flac 3D results with experimental data and empirical calculation methods shows that the long-term settlement of sandy soil can be calculated by combining numerical simulation and hyperbolic method.

Abstract:Combining with the deep foundation pit slope project of the second ship lock of a hub，we establish a generalized model，analyze the stability of the weak interlayer slope by the strength reduction method，and compare with the code to obtain that the slope should be reinforced. We study the influence of the pile position on the stability of the slope when carrying out anti-sliding support for the interlayer slope，and analyze the internal force distribution law of the anti-sliding pile under different pile positions. The results show that when the anti-sliding piles are arranged from the bottom of the slope along the slope face to the top of the slope，the safety factor of the slope first increases and then decreases，and the plastic strain of the plastic zone first decreases and then increases. The critical point of the direction of the anti-sliding pile’s shear force reversal and the maximum value of the bending moment were both located near the weak interlayer. When the anti-sliding pile is located in the middle of the slope，the slope safety factor is the maximum，the plastic zone is the smallest，the shear force and the bending moment of the anti-sliding pile are the largest，and the anti-sliding effect is the best.

Abstract:The fine content of fine sand will have a great impact on the reinforcement effect of the dynamic compaction method when treating the silty fine sand foundation by the dynamic compaction method. Aiming at the problem of the influence of fine content in silty fine sand on dynamic compaction reinforcement effect，we study the applicability of dynamic compaction method with different fine content of silty sand，obtain the influence of fine particle content on dynamic compaction settlement，excess pore water pressure and reinforcement effect by the model test in the laboratory，and put forward the corresponding construction suggestions. The results show that the fine content has much influence on the effect of dynamic consolidation of homogeneous silty fine sand. Ten percent of the fine particle content is the turning point. When the content of fine particles is more than 10%，the higher the content of fine particles is ，the lower the applicability of the dynamic compaction method is.

Abstract:Aiming at the problems of strong weathered rock geological condition，reef cover area more than 169，000 m2，limited construction space，navigable control，and blasting site only 470 m away from the nearest structure in the third phase of reef blasting construction of Meizhou Bay waterway in Fujian Province，we study the single-stage explosive quantity，vibration wave intensity，hole network layout，and tidal change. We applyφ115 mm blast hole，2.0 m×2.5 m hole network layout and inter-row millisecond blasting technology，use the tidal effect to further reduce the negative impact of blasting，and successfully complete the construction task. The results show that when the single-stage explosive quantity is not more than 300 kg，the vibration wave generated by blasting construction does not adversely affect the surrounding production and living areas，and the use of tidal water can reduce the vibration wave to a certain extent.

Abstract:Bored pile is one of the basic structural forms of waterway regulation engineering structures，which has the advantages of high bearing capacity，high strength and stiffness，small deformation of pile body，etc. However，as a concealed project，it has the problems of difficult construction monitoring and a low level of information management and control. Relying on the waterway regulation project of the Yangtze River Estuary of the Grand Canal，and based on the Beidou positioning technology，contact instrument combination method，resonant tuning fork sensing technology，BIM technology，and intelligent construction site platform，we apply corresponding intelligent construction equipment to realize the intelligent control of pile location measurement and placement，hole inspection，mud monitoring，concrete pouring and quality traceability in the bored pile construction. The integrated management and control platform integrates various monitoring equipment to form an intelligent monitoring mode for the whole process of cast-in-place pile construction，realize the digitalization，refinement，and intelligence of the construction and management on the site，and improve the construction quality and technical management level of engineering construction projects.

Abstract:The main engine-driven trailing suction dredger is often overloaded due to short hydraulic filling pipeline，large pipe diameter，and high concentration of hydraulic filling transportation，resulting in insufficient propeller power and potential safety hazard. Therefore，we study the overload and power distribution by theoretical calculation and equipment performance operation analysis and put forward measures such as throwing bow and stern double anchors and optimizing power distribution of the main engine. The results show that after the power distribution of the diesel engines is improved，we can effectively solve the problem of overburden and greatly improve the productivity of the dredger suction.

Abstract:Combining with the characteristics of the underwater installation of trapezoidal hollow members in deep water with high flow velocity in Yizheng waterway regulation project of phase II project of 12.5 m deep water channel below Nanjing in the Yangtze River，we develop the installation special spreader，supporting measuring rack and measuring positioning system，and improve the composite dike component installation technology in the traditional waterway improvement. The installation equipment can improve the installation accuracy and construction efficiency，effectively solve the problem of axis deviation，misalignment，and difficulty in seam width control in the underwater installation environment，and achieve the expected goals of installing large components in deep water with safety，efficiency and high precision.

Abstract:The steel-concrete immersed tube prefabrication yard of Shenzhen-Zhongshan Bridge is upgraded from the Hong Kong-Zhuhai-Macao Bridge. The original caisson dock gate and entrance need to be widened and renovated. We propose three sets of overall plans including the large and small dock door，widening both sides of the old dock door，and building the new dock door，put forward three schemes including welding of rebar lap，planting bar joint，and pre-stressing joint for the plans of widening both sides of the old dock door，carry out the numerical analysis on the stress of the broadened dock door structure，and propose the schemes of steel-concrete structure and all concrete structure for the plan of building the new dock door. Based on the actual site condition and the analysis results，we compare and select the above schemes for the construction design. The results show that the three upgrading schemes of dock gates are feasible in construction technology. The widening dock gate scheme has great advantages in construction period and cost. The floating dock gate with full concrete structure is finally selected in the specific project implementation.