Abstract:To better analyze the development trend of port transportation demand，this paper structurally decomposes the influencing factors of port throughput and establishes the relationship equations between throughput and gross domestic product （GDP），industrial added value，added value of primary，secondary，and tertiary industries，investment，consumption，and foreign trade volume. Meanwhile，the throughput is subdivided into main cargo categories，and the relationship equations between coal throughput and thermal power generation，crude oil throughput and processing amount of crude oil，iron ore throughput and pig iron output，container throughput and added value of the secondary industry are established. With the combination of prediction models such as regression analysis and elasticity coefficients，this paper predicts that the cargo throughput，as well as coal，crude oil，iron ore，and container throughput of China’s ports will be 17.2 billion tons，2.9 billion tons，0.83 billion tons，2.2 billion tons，and 0.32 billion TEU，respectively，in 2025. The prediction result provides a reference for the development plan of national waterway transport during the 14th Five-Year Plan period.

Abstract:In 2020，China proposed to build a new development pattern of domestic and international circulations. Waterway transport plays a fundamental，leading，strategic，and service-oriented role in economic and social development and will assume a more important mission in the new stage of development. By sorting out the current situation of China’s waterway transport development and judging the development trend during the 14th Five-Year Plan period，we put forward the development ideas and suggestions on China’s waterway transport. Key points include the following：1） seizing new development opportunities to further improve the support capacity of waterway transport infrastructure；2） improving the logistics service capacity and level to enhance the resilience of the waterway transport system；3） strengthening the logistics links between regions and within urban agglomerations to smooth the waterway transport system；4） improving the external shipping network to create a more open international logistics supply chain system；5） giving full play to the advantages of free trade ports and free trade pilot areas to deepen system and mechanism innovation；6） strengthening R&D and application of new technologies to promote high-quality development of waterway transport.

Abstract:The port is the transportation field with the highest degree of marketization in China. At present，a planning system combining development strategy，spatial planning and development planning has been gradually established. In particular，as a statutory planning system，port layout planning and port overall planning have effectively guided the development and construction of China’s ports in the past decades. In recent years，with the influence of factors such as the integration of port resources，the precision management orientation of the industry，and the increasingly complex coordination of territorial space resources，port spatial planning is currently facing many problems such as complex content and inconvenient management，which is difficult to reflect the national will and implement the corresponding authority in the context of comprehensively deepening the reform. The framework system of port planning is systematically combed to solve the outstanding problems in the preparation and implementation of the current port master plan.The concept of combining rigidity with flexibility in the planning process is explored，and the port planning principles and relevant countermeasures in the new era are proposed，so that the port planning can better serve and respond to the actual needs of local government governance and regional economic development while reflecting the national will，and truly realize the planning guided development.

Abstract:To study the effects of various factors of a submerged vertical jet on sediment scour process，a jet scouring test system has been designed and built based on the “semi-model” theory. Through image capturing and processing technique，variations of the scour hole shape with the scour parameter EC are obtained，which takes into the account the influence of jet velocity，target distance and nozzle diameter. The results show that initially the scour hole depth increases rapidly and then increases slowly towards reaching equilibrium state，during this process，the shape of the scour hole maintains geometric similarity. The size of the scour hole increases with the increase of jet exit velocity，whereas the dynamic scour hole depth is significantly greater than the static scour hole depth. In addition，the optimum jet target distance is obtained through the tests，at which the depth of the scour hole reaches the maximum. The results can provide useful reference for the practical engineering application of jet dredging.

Abstract:The study of the three-dimensional cylinder flow mainly focuses on the degree of the simulation accuracy，and the analyses of the single-cylinder wake vortex structure. However，there are less research on characteristics of the three-dimensional three tandem cylinders flow. The simulation on three tandem cylinders turbulence model from three dimensions is carried out at the different spacing ratios by taking Reynold number as 2.25×106 by FLUENT software. Gambit software is used to model the flow field，and the grid of the water near the cylinder is densified，and a three-dimensional LES simulation is carried out for three tandem cylinders in series. Three different L/D（L is the spacing between the cylinders and D is the diameter of the cylinder） are selected as 1.0，2.0 and 3.0，and three different heights of tangent planes （0 m，2.25 m and 4.40 m from the water surface） are selected in the 3D simulation to study the turbulence of the velocity field，pressure field and vorticity field characteristics. The results show that the three-dimensional simulation confirms the significant changing of vorticity of the surface，and the backflow area behind the continuous cylinder is strongly correlated with the spacing ratio. At the same time，the velocity fields of the three different tangent planes have small changes，and the pressure field changes little.

Abstract:Aiming at the problem of the downward-flushing flow on the crest of a levee caused by extreme combined wave and surge conditions，the time series of flow velocity measured in full-scale flume tests on combined wave and surge overtopping are investigated，and empirical formulas for the occurrence probability and average velocity of the downward-flushing flow of different angles are proposed. The results show that the velocity of downward-flushing flow is usually greater than the average velocity at the same position. The occurrence probability of downward-flushing flow decreases significantly with the increase of its angle，while the average velocity of downward-flushing flow decreases slightly with the increase of its angle. However，the average velocity of downward-flushing flow of different angles increases significantly when the relative freeboard approaches 0.

Abstract:Swell waves increase the maneuvering difficulty and navigation risk for ships entering and leaving the port.It is of great significance to study the effect of propagation of wave on ship maneuvering，especially for swell waves in harbor areas.This paper constructs a wave-current coupling mathematical model based on the unstructured triangular grid，and studies the propagation characteristics of swell waves and law of wave-induced current generation in the near sea of Dongjiakou Port. The results indicate that the significant wave height declines more than half as the swell spreads from the open sea to Dongjiakou Port and larger initial wave height clarifies higher attenuation rate.The swell in the ESE direction is more difficult to attenuate which explains the reason why the large waves mostly occur in this direction. The wave-induced current under the low tide is larger than that under high tide and would be strengthen by the wave height.The wave-induced current in the ship working area is generally within 0.1 m/s，which is about 5% to 7% of the maximum tidal current. The effect of swell on the ship’s motion in Dongjiakou Port area mainly comes from the direct action of the wave on the ship’s hull，and the effect of the wave-induced current on the ship is small and generally negligible.

Abstract:This paper selected dredged sand from the lower reaches of the Yangtze River as raw material and prepared four concrete specimens with different dredged sand contents to study the compression-shear performance of the concrete specimens. 1） The paper carried out compression-shear tests under five different axial pressure ratios，and the test results show that the friction coefficient of the compression-shear interface of dredged sand concrete decreases when the dredged sand content is high，while the internal cohesion of the specimens increases as the dredged sand content improves. In addition，the peak value of the compression-shear displacement of the specimens increases first and then decreases as the dredged sand content rises. 2） The paper analyzed the morphology of the damaged interface of the specimens through a scanning electron microscope （SEM） and studied the micro-mechanism of the dredged sand affecting the specimen performance. 3） According to test results and existing literature，the paper proposed a failure criterion based on the octahedral spatial stress and the Ottosen model and presented fitting parameters for the criterion equation. Furthermore，the experimental data are in good agreement with the fitting results.

Abstract:An experimental study on the resistance characteristics of a hollow tetrahedron siltation promotion embankment is carried out，and the experimental results are compared with those of experiment on traditional siltation promotion embankment which is composed of riprap and armor block. The results show that：Firstly，when flow Reynolds number is small enough to bring about the non-submerged state of siltation promotion embankment，the resistance coefficient can be described using two broken lines under the same flow Reynolds number，the turning points of which are in accordance with the critical submerged criterion. With the increase of flow Reynolds number，the slopes of two broken lines get closer. Secondly，when the flow Reynolds number is too large to reach the non-submerged state，the resistance coefficient can be described using the single line alone under the same flow Reynolds number. Thirdly，the method of calculating the resistance coefficient is proposed which is also suitable for the normal permeable embankment.

Abstract:The three-dimensional wave physical modeling has been widely employed in the breakwater design. Compared with the conventional 2D wave physical model，the 3D model has the merits in full description of the wave-structure interaction. The 3D random wave integral physical model test can quantify the wave shoaling，refraction and diffraction，overtopping amount and 3D stability of coastal structures. Taking the breakwater project of port in Trà Vinh，Vietnam as an example，a 1：34.3 3D integral wave physical model is used to test and study the 3D stability of the breakwater head and body and overtopping amount of breakwater under different wave directions and return periods. The test results show that：1） The breakwater is reliable and stable when the head of the breakwater is 5 t and the trunk is 3.5 t. 2） Only a small amount of overtopping or splashing occurs at the extreme high water level and design high water level.

Abstract:The breakwater is an important barrier to a wharf，and its high investment often becomes the key factor of scheme decision-making in the feasibility study stage of a project. For optimal design of the breakwater for a wharf project in eastern Guangdong，we collect the measured offshore wave data near the project. On this basis，we establish the transformation relation of wave elements between offshore wave measuring area and wharf front area considering the numerical simulations of waves. In this way，we can obtain the operational time corresponding to different schemes，which can provide reliable data for decision-making of the breakwater construction scheme. The results reveal that offshore waves incident in the same direction have the same transformation coefficient. This feature can be used to simplify the statistical work of operational time and improve the efficiency of scheme selection.

Abstract:Breasting dolphin spacing recommended by current codes is relatively simple. When berthing ships have a large range，ships meeting the lower limit may find it difficult or even impossible to berth. To determine the breasting dolphin spacing of large oil wharves with a butterfly layout，this paper compares relevant codes and guidelines in China and other countries，collects data from real ships related to berthing，and analyzes the influencing factors and upper limit of breasting dolphin spacing according to specific projects. The results show that it is necessary to consider the length of ship parallel bodies and the length difference between ship bow and stern parallel bodies caused by the off-center of the manifold center when oil tankers are ballasted in the layout of breasting dolphin and take these indicators as control factors to calculate the upper limit of breasting dolphin spacing.

Abstract:Based on the data of normal siltation，hydrology，sediment，and topography in the 12.5 m deep-water channel of the Yangtze Estuary from 2010 to 2018，this paper analyzes the siltation changes and influencing factors of the channel. The results show that：1） The normal siltation volume of the Yangtze Estuary is large and fluctuates every year. The average annual normal siltation volume is about 65 million m3. In addition，the volume gradually decreases after 2012 and is currently stable at about 50 million m3，with an annual siltation intensity of about 1.3 m/a；2） Siltation volume and intensity show obvious spatial and temporal distribution characteristics，which are reflected by uneven distribution in flood and dry seasons and massive siltation in the middle of the channel；3） Factors affecting the spatial and temporal distribution of channel siltation mainly include the sediment source and sediment transport intensity，structures of water，sediment，and salt，and sediment deposition conditions in flood and dry seasons，as well as structures of water，sediment，and salt and sediment exchange capacity of shoal and passage in the middle channel of the North Passage. Furthermore，the middle channel of the North Passage is mainly affected by the sediment over the south dike；4） The inter-annual siltation change generally shows a decreasing trend. Specifically，the south channel to the Yuanyuan shoal section is related to the decrease in altitude difference between the beach and passage and the reduction of upstream sediment transport volume. For the North Passage channel，the project of heightening the sediment barrier in the south dam field has effectively improved its water and sediment environment，and the siltation is reduced by 17.6%.

Abstract:The intermediate channel is a special restricted channel，and the ship navigation resistance is the key parameter to determine its scale. This paper analyzes the applicability of the existing calculation methods for ship navigation resistance and selects YU Zhongqi’s formula considering factors such as the channel width and draft ratio as the reference formula for the calculation of ship resistance in the intermediate channel. The paper designs the test plan of the ship navigation resistance in the intermediate channel and carries out the navigation test on a 3 000-ton bulk carrier model. According to the test results，the paper revises YU Zhongqi’s formula and uses Flow3D to simulate the ship navigation in the intermediate channel under different section coefficients and extract the resistance to verify the accuracy of the corrected formula. The calculation results of the revised empirical formula are compared with those of the numerical model and the physical model separately，and the maximum error is no more than 16.89%. The results show that the formula has high calculation accuracy and has an important reference value for the design of intermediate channels.

Abstract:To explore the mechanical properties of the flexible mattress in the process of counter flow sinking，based on the mechanical properties that the geotextiles can only withstand tensile stress and the geometric nonlinear deformation characteristics of the mattress，we establish the nonlinear finite element model of the flexible mattress by the nonlinear shell element Shell181 to simulate the geotextiles，and verify the the accuracy of the model by comparing with the catenary theoretical calculation results. We analyze the influence of the simplified concrete block modeling method in the existing research on the calculation results，and carry out the nonlinear finite element numerical simulation of the counter flow sinking process of Zhangjiazhou head after improving the construction process by the verified model. The results show that the maximum tension of the mattress appears within the range of 1 m on both sides during sinking process，and the lateral reinforcement bar with the length of 4 m on the edge of the mattress can effectively reduce the risk of tearing. The tensile safety factor of geotextiles and reinforcement bar is greater than 2，the displacement of flexible mattress is small，and the construction scheme is safe and effective.

Abstract:The exit of the Babao ship lock connecting the Grand Canal and Qiantang River is located in the strong tidal bore reach of the Qibao bend，where the water flow and sediment conditions are extremely complex. Comprehensive regulation measures should be taken to meet the navigation requirements. In view of the river regime change，channel depth，flow conditions for navigation，sediment deposition in the downstream approach channel of the ship lock，and the navigation assurance rate at the exit of the lock，comprehensive methods and means are applied for an in-depth study，including the riverbed evolution analysis，mathematical model calculation of tidal flow and sediment，physical model test，and ship model and vessel maneuvering test. The comprehensive regulation scheme for the beach at the exit of the lock is verified. The results show that by clearing the residual dam，shortening the length of spur dikes，adding navigation dikes，and other engineering measures，we can make the main channel close to the exit of the ship lock，significantly improve the navigation assurance rate of the entrance area，and ensure that the sediment deposition in the downstream approach channel of the ship lock and the entrance area is within the controllable range.

Abstract:Dredged soil in deep-water channels of the Yangtze Estuary is all dumped into marine dumping areas after 2020，which leads to waste of dredged soil resources. This paper uses a three-dimensional mathematical model of tidal current and sediment （SHIWM-3D） and numerically simulates the scheme of comprehensive utilization of dredged soil to the Hengsha shoal for sand stabilization and beach protection. In addition，the paper comprehensively analyzes the fluid flow distribution，sediment transport and diffusion，sediment deposition effect of dredged soil，and its influence on sediment deposition in deep channels. The results show that：1） Some sediments are deposited directly after the dredged soil is blown onto the beach，while others are diffused and transported with tidal currents. 2） Scour and siltation states appear in the Hengsha shoal during spring and neap tides，respectively，and the dredged soil is generally deposited in the shoal. 3） The deposition of the deep channels is slightly affected when the dredged soil in channels is blown onto the Hengsha shoal. 4） It is feasible to apply dredged soil in Yangtze Estuary channels to Hengsha shoal，which provides a direction for sustainable and comprehensive utilization of dredged soil in Yangtze Estuary channels after 2020.

Abstract:The unfavorable water flow in the approach channel area of the Longtan hydropower station affects the access safety of ships. To improve the flow velocity of the upstream and downstream approach channels and the entrance area，this study optimizes the extension scheme of the navigation wall of the upstream and downstream approach channels. Specifically，we build a physical ship-lock rectification model of the Longtan hydropower station to study each typical working condition in the operation process. The following conclusions are drawn：1） When the flow rate of the upstream river channel is greater than 1 100 m3/s，and the ship lock is fully opened，the water flow conditions in the entrance area of the upstream approach channel still cannot meet the requirements of the specification. 2） After the downstream approach channel changes the main navigation wall from permeable to impermeable，the flow conditions of the approach channel and the entrance area can meet the requirements of the specification.

Abstract:Based on the Mantingdashaba Wumingzhou regulation scheme of the Lancang River class IV waterway construction project，this paper expounds the general situation of waterway hazards and the characteristics of navigation obstruction. Considering the impact of sand mining on the waterway conditions and waterway regulation in the bend shoal reach，the changes of channel conditions before and after sand mining and the expected effect of the original recommended scheme are analyzed from the aspects of water level，velocity，gradient，beach elimination index，etc. It is believed that sand mining will bring adverse effects on the stability of dredging navigation channel and the ship’s self-propulsion on shoal the beach. Some measures are proposed，such as adjusting the regulation buildings to guard the navigation channel，harnessing water to attack sand，adjusting water surface and gradient distribution，etc.，in order to improve the hydraulic condition of the waterway and maintain the stability of the navigation channel after dredging. The conclusions are as follows：1） Sand mining will have adverse effects on the waterway conditions and waterway regulation of the shoal reach. 2） To ensure the waterway conditions and the effect of waterway regulation，it is necessary to adjust the layout of regulation buildings to solve the new problems of navigation obstruction.

Abstract:On the basis of historical evolution analysis，this paper focuses on the change，cause and effect mechanism of the the inlet section of the northern branch of the Yangtze River in recent years. This paper simulates and studies the effect of planning and remediation scheme of the inlet section by the mathematical model. The results show that，affected by the changes of runoff and sediment from the upper reaches and the implementation of the surrounding remediation projects，the sandbar in the inlet section of the northern branch of the Yangtze River has experienced the development and change of tongue-shaped sand body → Chongtou shoal → Chongtou sand，and the inflow conditions of the northern branch deteriorates. The deep troughs on both sides of the sand body show an alternating trend of “ten years east of river and ten years west of river”. The current main trough is located on the Chongming side，and its direction and the main flow of the south branch reaches an intersection angle of 105°，and the main flow path is extremely curved.Under the circumstance that most of the planned renovation projects in the middle and lower sections of the North Branch are implemented，the treatment of the entrance section becomes the key to the rise and fall of the North Branch. After the implementation of the planned dredging project for the entrance section of the North Branch，the flow path of the entrance section returns，and the diversion ratio of the North Branch increases 0.1%，the implementation of the project is conducive to the stability of the river and achieves the purpose of treatment.

Abstract:To reduce the normal siltation amount of the Yangtze Estuary deep-water channel，the jetty heightening project in the southern groin field of the siltation reduction project of the Yangtze Estuary deep-water channel is carried out in two stages：the previous project and the perfect project. Based on the measured data before and after the siltation reduction project in the deep-water channel，the changes of water and sediment flux，sediment concentration，flow field，surrounding river regime and siltation reduction in the channel are comprehensively analyzed. The results show that：1）after the previous project of the siltation reduction project，the water and sediment flow over the southern groin field decreased significantly，the sediment concentration in the north channel decreased significantly，the lateral water and sediment transport in the south side of the channel was effectively suppressed，and the actual normal siltation amount decreased by about 17.4%. 2） After the perfect project of the siltation reduction project，the water and sediment flow over the southern groin field are basically blocked，the sediment concentration in the middle and lower parts of the north channel also decreases，the tidal current direction of the north channel becomes more smoother，and the normal siltation amount decreases by about 5.6%. 3）The project achieves the expected channel siltation reduction target，the engineering treatment scheme is reasonable，and the channel siltation reduction effect meets the expectation.

Abstract:The cargo volume of Changzhou hydro project has leapt to the first place in the world’s natural waterway. However，the descending trend of the low water level downstream the hydro-project causes a sharp decline in the navigation assurance rate of the first and second ship locks，which restricts the overall carrying capacity of the hydro-project. Based on the hydrological data and the results of river physical model test，this paper studies the change of the carrying capacity of the first and second ship locks. The results show that since the operation of the hydro-project，the tonnage of navigable ships of the first and second ship locks generally declines，which the first and second ship locks can only pass through 500 t and 100 t levels respectively by 2019 under the design flow （1 090 m3/s in the Waijiang river）. After the implementation of the 3 000 t level navigation channel regulation project from Guigang to Wuzhou in future，only when the discharge of Waijiang river reaches 1 875 m3/s and 2 470 m3/s respectively，the national standard ship type and Xijiang ship type can pass the ship locks smoothly（the first and second ship locks）. It is an important way to comprehensively improve the overall carrying capacity of Changzhou hydro-project for deeply releasing the utilization rate of the first and second ship locks，by optimizing the joint scheduling of upstream reservoirs to increase the dry season flow and the combined scheduling of the first and second locks under different discharge conditions.

Abstract:The navigation flow conditions at the entrance area of the upstream approach channel laid at the downstream of sharp turns are complex. In order to address this issue，this paper carries out a hydraulic model navigation test for a navigation-power project to compare and analyze the flow field distribution at the upstream entrance area under different flow rates and different angles between the separation levee and the guide wall. In addition，the paper explores the relationship between the flow conditions at the entrance area of the upstream approach channel and the angles between the separation levee and the guide wall. The results indicate that the separation levee can effectively reduce the flow velocity gradient in the upstream approach channel and the main channel，alleviate the squeezing and friction caused by the main flow on flows at the entrance area，and then slow the transverse flow and backflow velocities at the entrance area to eliminate flow patterns not conducive to navigation. Furthermore，there is a threshold value for the angle between the separation levee and the guide wall. Specifically，when the angle is smaller than this value，both the longitudinal and transverse flow velocities decrease as the angle increases. On the contrary，once the angle is larger than this value，a partial inflow of mainstream appears，and flow patterns at the entrance area get worse.

Abstract:Considering the limited attraction flow for fish near the navigation and electricity junction in the mountain river，flow conditions near the fish way entrance are investigated by two-dimensional flow numerical simulation for the Lize project in the Jialingjiang River. The flow fields at the entrance of the fish way under 5 different layout schemes are compared and analyzed. The results show that the combination of guide wall on the bank side of the fish way entrance and reverse arc breakwater head and diversion pier on the main channel side can significantly improve the flow conditions at the fish way entrance. For this project，the straight guide wall is designed to be 6 m long，and then it is connected with the bank slope with an arc （R=18 m）；the reverse arc breakwater head is cut at an angle of 45°；two diversion piers are employed outside the beveled edge wall and both dimensions are 1.2 m × 0.8 m，which are separated by 1.2 m.

Abstract:The channel and beach in the mountainous alluvial river are obvious，and shallow and rapid beaches are prone to occur in continuous curved reaches during normal water level and dry seasons. Simple channel dredging for such regulation projects，however，may lead to flow concentrating in channels with higher velocity. To solve the above mentioned problem，we take the third-level channel project of the Xinkaihe beach on Minjiang River as an example to build a fixed-bed physical model for a river of about 10 km. Then，we analyze the riverbed evolution laws，navigation obstruction characteristics，flow characteristics before regulation，and the effects of the channel-regulation design scheme and optimization measures. Moreover，we summarize the regulation principle and scheme of navigation-obstructing shallow and rapid beaches during normal water level and dry seasons. The results show that the longitudinal flow velocity in the channel is less than 3.5 m/s，and the water surface slope is below 2.45‰，which can meet the requirements of channel regulation.

Abstract:Stability calculation for armor block in regulation structures under current scour is important for the design of an inland waterway regulation project. As more and more Chinese design companies are involved in overseas projects，design engineers must master different standards and calculation methods commonly used in projects both in China and abroad. This paper introduces the Pilarczyk method commonly adopted in foreign projects，the Escarameia and May method recommended by HR Wallingford，the American standard Maynord method，and methods proposed in the Design Code for Waterway Engineering and Code for design of levee project of China. Through comparison，the paper summarizes the differences between these calculation methods and further verifies them through engineering examples. The results show that calculation based on Chinese codes is relatively easy to be implemented，but it only considers fewer influencing factors. On the contrary，the commonly used foreign methods are more comprehensive and have a wider application range，but they involve a relatively complicated process.

Abstract:Qichun waterway regulation project is a preliminary task of the 6 m deep channel project in the Wuhan-Anqing section of the mainline of the Yangtze River. In recent years，the evolution characteristics of riverbeds in the Qichun waterway generally lead to shallow areas at the entrance of bends. Meanwhile，as erosion ditches and right channels in the head of the Lijiazhou side shoal develop rapidly，channel conditions tend to be worse. In order to curb the adverse waterway development，the waterway regulation project started in 2017. After the completion of the project，this paper comprehensively analyzed the changes in waterway and channel conditions based on the measured data before and after the project. The result reveals that after the implementation of the regulation project，the Lijiazhou side shoal gets protected，and the hydrodynamic force in shallow areas improves. The high shoreline in the key position is stable，and the adverse change trend of channel conditions has been basically restrained. As a result，the construction goal is achieved，with positive project effects.

Abstract:The initial water level of the Minjiang Laomukong navigation and hydro-power junction is 358 m in the preliminary design，and this paper objectively analyzes its shortcomings. Based on the principle of multi-objective decision，the optimization of the water storage level of cofferdam during the construction period for water retaining trial navigation and the initial power generation is studied，and a systematic simplified algorithm is proposed. The research conclusions obtained by the simplified algorithm are as follows：1） The optimized water storage level is 7.28 m lower than the preliminary design （one unit is used for power generation in the initial stage），and the power generation period is 21.6 d ahead of schedule，with significant relative benefits. 2） It can reduce the operation risk of the second section cofferdam in Phase II，save the total construction period and other spillover effects. 3）It also expands and obtains the results such as the optimal storage level when two units generate power in the initial stage.

Abstract:Considering the deep-water channel maintenance characteristics of Fujiangsha Waterway in the lower reaches of the Yangtze River，this paper combines the basic theory of channel evolution and water-sediment movement and the analysis of the measured maintenance data to analyze the distribution of the recent channel maintenance of Fujiangsha Waterway and its response change characteristics. The results show that under natural evolution and the control of artificial management engineering for many years，Fujiangsha Waterway has formed a trend of the coexistence of three channels maintained by dredging，namely，Fuzhong，Fubei，and Funan. There is a good positive correlation between upstream runoff and dredging amount in the shallow dredging area of the channels，and the dredging area of the channels features fast dredging in flood seasons and slow dredging in dry seasons. It is suggested that the silt reduction measures for Fubei Waterway should be strengthened in the next stage.

Abstract:When alluvium river is subjected to resistance，the hydraulic and pattern parameters of the river will produce a series of changes to establish a relative equilibrium state to adapt to different water and sediment conditions，resulting in the emergence of different river patterns. According to Darcy’s formula，the dimensionless longitudinal and transverse stability index of the river are obtained with experimental and dimensional analysis method，and the comprehensive stability index is obtained as the river pattern judgment parameter by introducing the river pattern parameters and the deformation of the formula based on the resistance rule. Data analysis of natural river data shows that the proposed river type parameters can distinguish different river patterns by several river hydraulic parameters.

Abstract:To solve the problems of the traditional manual lubrication of the open gear of miter gate hoist of a large single-stage ship lock，such as low efficiency and high consumption，this paper systematically analyzes the current situation of the operation characteristics，lubrication mode and lubrication film-forming effect of the miter gate hoist of the lock，and designs an external tanker type automatic lubrication system for the open gear combined with the research results of the comparison and selection of automatic lubrication modes. The practical application shows that the open gear automatic lubrication system can reliably realize the automatic lubrication of the open gear of the miter gate hoist and precise quantitative oil supplly，thus improve the lubrication effect of the opening gear of the miter gate hoist and increase the service life of the equipment.

Abstract:To improve the dispatching level of inland river ship locks and alleviate the blockage of ship locks，taking the single-stage single-line ship lock，which is the most widely used in the development of river water transport cascade in China，as the research object，the navigation simulation model of ship locks is constructed using Arena simulation platform，and the simulation is carried out for the problem of ship passing through the single-stage single-line ship lock using the Xinglong ship lock on the Han River as an example. On this basis，to evaluate the impact of relevant factors on ship waiting time，a large number of single-factor and multi-factor influences of ship’s sensitivity experiments have been carried out. The data fitting method is used to study the change rule and the prediction model of ship waiting time under the action of single factor，and the BP neural network method is used to construct the prediction model of ship waiting time under the action of double factors. The inspection results show that the ship waiting time prediction model has good prediction accuracy. Combined with the lock reservation system and the prediction model，the optimal scheduling of the ship lock is proposed，which can provide an effective reference method for the management department to carry out the scientific scheduling of the ship lock.

Abstract:Aiming at the problem of the river diversion and closure project of soil-rock cofferdam at a navigation and electricity junction in the Han River during flood season，the numerical simulation method is adopted to optimize the scheme，study the hydraulic characteristics of the berm advancing process and the impact of the closure on the bank slope，and reasonably determine the particle size of underwater riprap. The results show that：1）The reliability of the numerical simulation method is verified by comparing the measured data. 2） The water retaining capacity of the first stage cofferdam is predicted successfully，and the prediction accuracy of the water level is as high as 0.5 m. 3） The bidirectional vertical blocking method is adopted for the second stage upstream cofferdam，which reduces the scouring of bank slope by the closure. At the same time，the predicted flow velocity and the particle size of riprap can meet the construction requirements of the site，which provides a scientific basis for the construction organization design. The above conclusions have been successfully applied to the actual construction of the project and ensured a successful closure of the project during flood season.

Abstract:Taking the logistic system of a bulk cement terminal in port area A as the research object，a logical model is established based on the discrete event dynamic system theory to realize the logistics function of the bulk cement terminal. The selection scheme of cement silos with different strategy combinations is given to solve the mismatch between the maximum loading capacity of the terminal and the horizontal transportation capacity through analyses of the number and capacity of terminal silos，vessel waiting time，berth utilization，terminal capacity and so forth. Meanwhile，this paper sorts out the relationship of each subsystem. It uses simulation technology to determine silo configurations to improve the shipping capacity of the cement terminal and the overall benefit of the cement plant. The research results can provide an important basis for optimizing terminal shipping capacity and a reference for selecting the number and capacity of silos in the loading and unloading system of such bulk cargo terminals.

Abstract:Considering the low efficiency of large-scale channel terrain rendering，this paper constructs the triangular terrain grid through discrete water depth data of channels and uses the idea of LOD to control and display the density of grids. Specifically，the method based on the Delaunay triangulation is used to construct the channel terrain，and the alpha-shapes boundary extraction method is employed to optimize the Delaunay triangulation. A grid division method is proposed to control the density of grids. Moreover，a suitable variation model is selected through the comparison of the fitting effects by the Kriging interpolation model to solve the problems of insufficient sampling of water depth points and low efficiency of scene rendering. The application results indicate that the method can be used for real-time rendering of large-scale channel terrain.

Abstract:The construction area of a trailing suction hopper dredger has dense trajectories and separate mud dumping and dredging areas. However，these trajectories have different densities，and traditional trajectory recognition technology fails to effectively recognize the construction behavior and mode of the dredger and thus cannot be successfully applied. In view of these problems，this paper proposes an unsupervised framework for recognizing the construction behavior of the dredger. Firstly，the paper solves the problem of trajectory jump based on the Kalman filter algorithm and improves the quality of trajectory data. Then，the paper uses the HDBSCAN algorithm to identify mud dredging and dumping trajectories with different densities simultaneously and solves the problem of difficult parameter setting by the traditional DBSCAN algorithm in the case of uneven density between classes. Finally，the paper establishes a GMM model based on directional factors，so as to further identify the mud transportation and return trajectories. The results show that the above method can quickly and accurately identify the construction trajectory of a trailing suction hopper dredger.

Abstract:The foundation soil of port is mostly unsaturated soil. The strength characteristics of soil under different matrix suction are different and difficult to predict accurately. Taking unsaturated silty clay of a port foundation project in Fujian Province as the research object，we carry out soil-water characteristic curve test，saturated and unsaturated triaxial compression test. According to the near linear characteristics of section AB in the soil-water characteristic curve，we assume that the volume water content is linearly related to the matrix suction pair value，take the data of points A and B as the known conditions，and establish the relationship between matrix suction logarithm and relative saturation Se. Based on the Vanapalli strength prediction model，we construct a new unsaturated soil strength prediction model，give the parameter solution method，and predict the strengths of three kinds of unsaturated soils by the new prediction model based on the test data of unsaturated organic matter silt and expansive soil in relevant literature，which is compared with the traditional prediction method. The results show that the strength identification effect of the new prediction model is good，and it is feasible and applicable to the strength prediction of unsaturated silty clay，organic clay and expansive soil.

Abstract:Regarding the coral reef soft-soil at Tusdeer Port in Saudi Arabia，this paper analyzes the formation causes of coral reef soft-soil combining with the regional geological characteristics，and determines the engineering properties according to the results of laboratory test and in-situ cross plate test. The results show that the formation of coral reef soft-soil has regional characteristics. The gentle and serrated lagoon shallow basin landform are conducive to the deposition of fine particles. The distribution of soft soil is often discontinuous and relatively small scale. The carbonate content of soft soil is high，but there are regional differences. The proportion of silt in coral reef soft-soil is 56% to 79%，and characteristic properties of this soil are quite different from those of general coastal soft soil，river or lake soft soil. The cohesive force of coral reef soft-soil is 2 kPa to 5 kPa，which is lower than that of coast and delta soft soil，and the internal friction angle is 22°to 31°，which is higher than that of coast and delta soft soil. In the range of depth from 2 m to 5 m，the strength of in-situ vane of coral reef soft-soil is about 20 kPa，and the sensitivity is 1.5，which belongs to low sensitive soft soil. The coral reef soft-soil has poor engineering properties，which are harmful to the project. The adverse influence of coral reef soft-soil site on project should be fully considered，and the complexity of geologic conditions should be carefully evaluated.

Abstract:Aiming at the problems of horizontal displacement of tall and large buttressed dock walls，the low efficiency of formwork construction and the poor quality of concrete construction，we study the cast-in-place concrete buttressed dock wall in the dock project of the Dongfang Project，use the finite element analysis method to simulate the offset of the dock wall and set a 5 mm construction pre-offset，design tall and assembled integral wood formwork according to Technical Specification for Safety of Building Construction Formwork，heat old concrete by electric heating wire to reduce the shrinkage of new and old concrete and add pouring points. These measures meet the accuracy requirement that the installation error of the gantry crane track at the top of the dock wall gallery is not more than 5 mm，save more than 60 days of construction time for the dock wall structure，and reduce concrete constraint cracks and the occurrence of common quality problems such as honeycomb，hemp surface，gap interlayer and so on. The research has certain reference significance for the construction projects of similar tall and large dock wall structures.