Abstract:With the rapid development of the construction industry,the relevant parties of the project construction have higher and higher requirements for the cost control in the early stage of the project,especially for inland waterway shipping projects dominated by government investment.The level of cost control not only affects the decision-making in the early stage of the project,but also determines whether the project can be implemented smoothly.Aiming at how to accurately control the cost in the early stage,taking the Pinglu Canal project as an example,this paper adopts the current regulation system of the cost preparation of water transport engineering,studies and discusses the technical characteristics of cost control in the feasibility study stage,the formulation of cost preparation plan,the calculation method of unit project and the cost control risk.It is concluded that the key points of accurate cost control in the early stage is to formulate unified regulations for the preparation of project cost,coordinate the cost system of different construction industries,organize the overall structure of project cost,study and judge the construction conditions and construction schemes,accurately calculate the engineering quantity and apply the quota,and analyze the investment differences in each stage.The research results can provide reference for cost control of comprehensive inland waterway engineering.

Abstract:At present,there is no local standardization requirements of navigation aids in Guangxi,resulting in large differences during the construction of navigation aids in different projects within the same jurisdiction.It largely has limited the improvement of navigation assistance service level,as a result navigation aids standardization is imminent.Taking the Pinglu Canal project as an example,we learn from the standardization in Jiangsu,Jiangxi and other areas with developed water network,and deeply analyze main parameters and influencing factors of inland river navigational aids design.Based on these,we propose the problems existing in the design of inland river navigation aids in Guangxi and the corresponding solutions in the Pinglu Canal project，and provide reference for similar projects and local navigation aid standardization.

Abstract:We study the wave attenuation performance of single-row floating flat-plate,double-row floating flat-plate,triple-row floating flat-plate,and perforated floating flat-plate breakwaters under the action of solitary waves through physical model tests,and compare and analyze four types of floating plate breakwaters in terms of their transmission coefficients,reflection coefficients,wave energy dissipation coefficients,and mooring tensions under different relative wave heights and mooring line inclinations.The results show that the transmission coefficient of the single-row floating flat-plate breakwater is the smallest,while that of triple-row floating flat-plate breakwater is the largest.Compared to the single-row floating flat-plate breakwater,double-row floating flat-plate,triple-row floating flat-plate,and the perforated floating flat-plate breakwaters exhibit significantly reduced mooring line tension.Moreover,moderately adjusting the inclination of the mooring line can also improve the wave attenuation effect of the floating plate and change the characteristics of mooring line tension.

Abstract:The Parabolic wave absorber can achieve a good wave elimination effect in a small space,making it a commonly used wave elimination structure in basins or wave tanks.Existing studies have predominantly focused on the wave reduction effects of these devices on regular waves or random waves,which are short waves.However,the wave reduction performance for long waves such as solitary waves is still unclear.In this paper,a physical model test on the wave elimination performance of parabolic wave absorber with grids for solitary wave is carried out in the L-type basin of Hohai University.The results show that the wave elimination performance of the parabolic wave absorber for solitary waves is closely related to the relative wave height.For the grid wave-absorbing surface,the reflection coefficient directly from the wave-absorbing surface for relative wave heights between 0.07 and 0.38 ranges from 0.10 to 0.17.The reflection coefficient for waves transmitted through the grids and reflected by the right inner wall of the flume varies between 0.17 and 0.44.The reflection coefficient of the wave-absorbing surface without grids is in the range of 0.34 to 0.64.Based on the experimental results,the relationship between the reflection coefficients of parabolic wave absorber with and without perforated grids for solitary waves was established to provide a basis for the design and analysis of wave tests.

Abstract:The mooring stability conditions of breakwater cover waters have a significant impact on the safety of ships entering and leaving ports and berthing operations.How to accurately simulate the wave height distribution behind the breakwater is of great significance to engineering design.By means of test and numerical simulation,we discuss in depth mooring conditions behind the breakwater with an armor layer of accropode.Based on the physical model test,we use the SWASH model based on the non-hydrostatic equation to numerically simulate the wave height distribution in the engineering area,and represent the accropode armored breakwater by three methods in the SWASH model,such as the accropode armored breakwater passing through pore layer,topography and pore layer combination and equivalent bottom friction coefficient.Then we use the MIKE 21 BW model based on Boussinesq equation to simulate the wave height distribution in the actual engineering area,and the results are compared with those of the non-hydrostatic model.The results show that the equivalent bottom friction coefficient method in the SWASH model based on the non-hydrostatic equation is more advantageous and applicable in the study of harbor basin mooring stability in practical engineering.

Abstract:Considering that the wave dissipation effect of marine protective structures under long-period wave conditions is not ideal,this paper proposes a breakwater structure of submerged embankments and arc plates.Based on the open-source fluid dynamics platform OpenFOAM,a numerical model of the interaction between waves and submerged breakwaters with curved plate breakwaters is established using the continuous equation and Reynolds averaged Stokes equation as the fluid control equations.Using a numerical model validated by experimental results,the influence of arc width and submergence depth on the wave dissipation performance of a submerged breakwater arc plate breakwater is analyzed,and the distribution characteristics of wave pressure on the upper and lower surfaces of the submerged breakwater arc plate breakwater arc plate are explored.The results show that within the wave period range set in this article,the transmission coefficient of the submerged breakwater and the arc plate breakwater decreases with the increase of submerged depth and arc plate width.Its reflection coefficient increases with increasing depth and plate width.The positive and negative wave pressures on the lower surfaces of the submerged breakwater and arc plate breakwater are approximately symmetrical about the horizontal axis,while there are significant differences in the positive and negative pressure values between different measurement points on the upper surface.The research results can provide certain theoretical and technical guidance for engineering applications.

Abstract:Taking the corroded reinforcement in memeber of the 35-year high pile wharf prototype as an research object,we obtain the non-uniform corrosion characteristics of reinforcement by 3D scanning,and study the effect of corrosion rate on mechanical properties degradation by tensile test.Base on the analysis and regression test data,we build a formula for calculating the relationship between the mass loss rate of corroded reinforcement and the maximum section loss rate,obtain the regression formulas for the mechanical properties of corroded reinforcement in offshore concrete members,such as nominal yield strength and nominal ultimate strength,and compare with existing formulas.The results show that with the increase of steel corrosion degree,the non-uniformity of corrosion is intensified,and the maximum section loss rate of reinforcement with the same mass loss rate increases correspondingly.At the same time,parameters such as nominal yield strength,nominal ultimate strength and ultimate strain degrade to varying degrees,and the yield platform disappears gradually.The proposed regression formula can more accurately describe the degradation law of mechanical properties of corroded reinforcement in marine concrete structures.

Abstract:In response to the problem that the wave incidence angle has a significant impact on the wave height in the harbor in seaports with navigational channels,based on physical models and wave numerical models,the influence of the wave incidence angle on the wave height in the harbor under different wave height,period,and channel size conditions is systematically analyzed.The results show that when wave incidence angle θ≤30°,the wave height in the harbor decreases with the increase of the period,and increases with the decrease of the water depth in the waterway.When 30°＜θ＜40°,the wave height in the harbor is basically not affected by the period.When θ＞40°,the wave height in the harbor increases with the increase of the period.In addition,when θ＜40°,the smaller the channel width and the steeper the slope,the greater the wave height in the harbor.When θ≥40°,channel width and channel slope have little influence on wave height in the harbor.When θ＜ 30°,the smaller the water depth in the channel,the greater the wave height in the harbor.When θ≥50°,the greater the water depth in the channel,the greater the wave height in the harbor.The wave height inside Jieyang Port is the maximum when the wave incidence Angle is 30°~40°,and corresponding engineering measures should be taken to reduce the adverse impact of this wave direction on the mooring stability of ships in the port.

Abstract:To solve the problem that the design technical standard of the deep rubble-bedding foundation for gravity quay is not systematically studied.The stress state,design methods and theories of gravity quay with the deep rubble-bedding foundation have been studied.Based on the introduction for a typical gravity quay with a deep rubble-bedding foundation,this paper used theory analysis,numerical simulation and design calculation methods to study on the optimization design of the deep rubble-bedding foundation for gravity quay.The stress distribution laws of the deep rubble-bedding foundation is summarized,an improved algorithm is proposed for the stress of the deep rubble-bedding foundation,the upper and lower limit values of the bottom width of foundation trench excavation and the cross-section of riprap body in foundation trench,the identification criteria of the deep rubble-bedding foundation are proposed.The results show that the stress of the deep rubble-bedding is not within the slope line of 1:1.5 on the front side of the front toe,and with the deepening of the depth,the the stress distribution shows a trend of increasing in the front and decreasing in the back,similar in the front and back,and decreasing in the front and increasing in the back.The improved algorithm is much better than the standard method,the discrimination standard of the deep rubble-bedding foundation is defined.The research conclusion enriches the design theory of gravity quay,which provides reference and guidance for similar engineering designs.

Abstract:Qinzhou automation terminal has been in operation for nearly two years,with stable system and equipment operation and steady improvement in operational efficiency.The construction of the Pinglu Canal is accelerating,and it is expected to be completed for navigation by 2026.After opening for navigation,the excavated harbor basin at the Qinzhou automation terminal will become a connecting hub for container river sea intermodal transportation.Based on the multi factor dynamic coefficient method,the growth of container throughput after the opening of the Pinglu Canal is predicted.Combined with the construction conditions of the excavated harbor basin at the Qinzhou automation terminal,the maximum capacity of the terminal shoreline is released.By analyzing the data and results of the operation process of Qinzhou automation terminal,and focusing on the characteristics of ships in the excavated harbor basin service,this study proposes various targeted implementation plans in terms of loading and unloading process mode,shore bridge equipment selection,and terminal layout.Through multidimensional comparison,comprehensive analysis opinions are proposed to ensure smooth operation connection between the excavated harbor basin and the main berth,while also considering the overall operation of the future automation terminal after completion,providing reference for the construction of similar container terminals.

Abstract:Ningbo-Zhoushan Port has made great progress under the guidance of the original port planning and has become the world's largest port in terms of throughput.After the implementation of the original plan,the port’s internal development needs and external development environment have undergone tremendous changes.It is urgent to upgrade its strategic positioning and development concepts to adapt to the new international situation and new domestic requirements.Combined with the new round of Ningbo-Zhoushan Port master planning practice,this study implements national and regional development strategies from the port master planning level,optimizes the port development direction and functional positioning,strengthens and enhances the port's key and traditional cargo advantages,and intensively utilizes the port coastline,make up for the shortcomings of public facilities,properly handle the rigidity and flexibility of port planning,put forward the ideas and key points of the overall planning of Ningbo- Zhoushan Port in the new era,which can promote the construction of Ningbo-Zhoushan Port as a world-class port.

Abstract:A gravity block wharf of a seaport in Africa was built in 1928 and expanded in 1950.During the restoration in 1968,the concrete breast wall was removed and reinforced concrete was rebuilt.Nearly a century since its establishment,the structure has suffered severe damage.According to the survey report,the characteristics of concrete in different periods are revealed,the strength,porosity,crack degree and other characteristics of concrete structure in different periods are described.The reasons for this are analyzed,including the level of concrete technology during construction,the degree of specialization and mechanization in construction,environmental conditions of the wharf,service life and operational status,the setting of wharf protective facilities,as well as the historical background during the operation.Among them,the development level of concrete,selection of raw materials and quality of pouring during the construction are fundamental reasons that affect the performance of concrete in the old wharf,while the main reason is long-term corrosion in high acid and high salt seawater environments.By analyzing the characteristics of concrete,this study provides a basis for the determination of repair plans and the smooth implementation of repair work,and provides references for similar wharf renovation projects.

Abstract:Aiming at the current status quo that the domestic design method of steel tie rods is lack of recognition in overseas applications,we introduce in detail the calculation theory,method and process of steel tie rods body and components (connecting plates,pins) in European codes,meanwhile carry out design and calculation with examples.The results show that the tensile resistance of the steel tie rod body is controlled by the minimum value of tensile resistance between shaft and threads.In the design,some measures can be taken to avoid bending moments occurring in the rod such as one-way hinges,at which time the notch coefficient can be taken as the value of 0.9,and the threaded section's tensile resistance can increase by 50%.The diameter of pin should be determined to satisfy the requirements of the bending resistance,bearing resistance,shear resistance and combined shear and bending resistance. The diameter of pin can be slightly increased as the size of the plate openings when the size of connecting plate is designed.

Abstract:According to the principle of flow equivalence and the method of resistance coefficient,a practical simplification method of “replacing well with surface hole” is proposed.This method simplifies three-dimensional pressure-reducing wells as two-dimensional surface holes at the same position,and the calculation formula of surface hole radius is given in this paper.It is proved that the method has a promising application in terms of row wells and group wells.Based on the project of double line lock chamber,the calculation accuracy of the practical simplification method is evaluated by the comparative analysis of seepage potential distribution,seepage flow distribution and lifting pressure variation.The results show that the simplified method can effectively reduce the number of model elements and nodes,and greatly save computing resources in numerical simulations (FEM).Moreover,the outcomes illustrate that the seepage potential and the lateral distribution of discharge flow of equivalent surface hole is the same as those of relief well,and the top lines of each part in those two models are almost overlapped.The relative error between the total discharge flow of equivalent model and the right line of original model is only 1.7%,the relative error of the average uplift pressure is 5.4%.It is suggested that the equivalent orifice rate should not be less than 10%,the seepage analysis can be carried out directly according to the fully permeable of the lock chamber when the equivalent orifice rate is greater than 50% owing to the fact that the lifting pressure is basically equivalent to the situation of complete permeability.

Abstract:The deployment of artificial reefs can improve the ecological environment of local water areas in rivers,creating a favorable habitat for aquatic organisms such as fish.Based on the computational fluid dynamics (CFD) method,we study the hydrodynamic characteristics of a combination of triangular prism artificial reefs in the upper reaches of the Yangtze River.Using the geometric features of upwelling and back-eddy flows as parameters,we analyze effect of different inflow velocities (1.5 m/s,2.4 m/s,and 3.0 m/s) and layout spacings (0.5 m,1.5 m,and 2.5 m) on the flow field.The results show that with an increase in inflow velocity,the geometric characteristics of upwelling and back-eddy flow show minimal variation under the same artificial reef combination condition.As the layout spacing increases,the geometric characteristics such as the maximum height and volume of upwelling and back-eddy flow initially increase and then decrease under the same artificial reef combination condition,with 1.5 m being the optimal deployment spacing.Additionally,under the same flow velocity or layout spacing,an increase in the number of artificial reef combinations leads to a gradual increase in the maximum height and volume of upwelling and back-eddy flow,with a configuration of seven reefs as the optimal combination.

Abstract:The section from Wenyan to Babao is located at the mouth of Qiantang River,the riverbed undergoes severe erosion and siltation,and the water depth is greatly affected by the terrain,which directly affects the navigation of ships.In addition,the calculation of navigation guarantee is complicated due to the influence of upstream runoff and tidal bore.Therefore,this paper analyzes the actual navigation guarantee rate of the Wenyan to Babao section of Qiantang River using the underwater terrain of various years since 2007,taking into account factors such as tidal bore,runoff,and water depth.The results show that during the period from 2007 to 2020,the navigation guarantee rates under the water depth of 3.8 m,3.5 m and 3.2 m are 60.1%-79.8%,71.9%-87.5%,and 81.1%-97.0%,respectively,which is consistent with the reality.The research method is of reference significance to the analysis of navigation guarantee rate in estuarine areas with large changes in riverbed erosion and sedimentation,and complex dynamic conditions.

Abstract:The central sea area of Ningbo-Zhoushan Port is surrounded by islands on all sides,and ships can only enter and exit through a few navigation gates.The current conditions for navigation of ships at Guanmen and Guishan Navigation Gate on the east side,as well as the maximum navigation ship types for Jintang Bridge and Xihoumen Bridge on the south side are relatively strict.By observing the tidal currents in the waters of Guanmen and Guishan Navigation Gate,we set up the working conditions for ships to queue up in sequence,and analyze the passage capacity of the two navigation gates.Then we carry out the adaptability analysis of the navigation scale and current codes of Jintang Bridge and Xihoumen Bridge,and study the starting surface of clearance scale,the height above the waterline of ships,the slope and deflection of bridges,the net height of bridges,and the real-time measurement system of the maximum height above the waterline of passing ships.The results show that the passage capacity of Guanmen and Guishan Navigation Gate is suitable for the development of port planning in the central sea area.It is suggested to build a dynamic approval system for large ships crossing bridges,in order to unleash the potential for the development of water shorelines.

Abstract:Huzhou ship lock has a large plane size,large instantaneous flow,high water delivery intensity,no energy dissipation workers in the lock chamber,berth conditions in the lock chamber to be tested,and asymmetric layout of the approach channel,which is prone to reflux,oblique flow and other hydraulic problems.Through the hydraulic physical model test with a scale of 1:30,the hydraulic characteristics of the water conveyance process of the lock,the pressure characteristics of the water conveyance gallery,the berth conditions of the ship,the flow conditions of the inlet and outlet and the approach channel are studied.The research results show that the berthing conditions in the lock chamber and the navigable flow conditions in the downstream approach channel are obviously improved after adding the sill and optimizing its layout.Under the recommended valve operation mode,all the hydraulic indexes meet the specifications and design requirements.The research results can provide reference for similar projects.

Abstract:To research the influence of seawater intrusion when the new navigable lock is used in Jinhuigang waterway,a three-dimensional numerical model is established based on the saltwater convective diffusion theory,and the verified model is used to simulate the process of seawater intrusion into the inland river in the form of heavy flow through the new navigable lock.Based on the average salinity,salt water intrusion distance,salt water exchange rate,the anti-salt effect of the new navigable lock is analyzed.The results of simulation and analysis show that seawater intrusion gradually invades the lock chamber and inland river during the process of dilution and mixing with freshwater,and the average salinity of seawater decreases with the increase of intrusion distance.With the salt deposition in the salt-collecting area,the seawater upstream velocity gradually decreases.The seawater intrusion distance is basically stable after a period of operation of the facility,and the salt exchange rate gradually tends to be dynamic equilibrium.The new navigable lock adopts the anti-salinity measures of salt collecting area and runoff flushing,which can further enhance the anti-salinity effect of the new navigable lock.The research results can provide scientific basis for the design and application of the new navigable lock in the direct waterway of river and sea.

Abstract:Bapu ship lock is a key node project of the second channel connecting Beijing-Hangzhou Canal and Qiantang River,and the operation of the locks is affected by the tidal surges of Qiantang River.To ensure the long-term stable and efficient operation of Bapu ship lock,the overall operation of the locks debugging and the real ship test are carried out for the tidal surges of different tide heights in different seasons of Qiantang River,and the operation and navigation status of Bapu ship lock during tidal flooding is measured to ensure the safety of the lock.The results show that during the small tidal flood of Qiantang River,the tidal water has limited influence on Bapu ship lock,and the Bapu ship lock can operate normally.During the big tidal flood,the conditions of the approach channel are poor,and the Bapu lock should put down the tidal gate to stop the operation,and then carry on the navigation after the tide goes out.

Abstract:According to the actual layout and structural characteristics of the equipment and facilities such as the ship chamber and the upper and lower lock heads of the Three Gorges ship lift,the technical indexes such as traction distance,traction angle and traction force are studied for different types of typical ship types.Two traction schemes for ships entering and leaving the ship chamber of the Three Gorges ship lift are put forward,which are rail trolley and electric wheel traction.The feasibility of the scheme is demonstrated,and compared with the current navigation operation time of the ship lift and the expected traction time.It is concluded that the expected average daily navigation time of the whole year is shortened from 47 min 59 s to 43 min 47 s,which is improved navigation efficiency compared with the current ship,and provides theoretical support for the subsequent ship traction projects.

Abstract:The Tongtiancao beach regulation is a key project for the regulation of the Wu River waterway.The completion of the Baima Hub on the Wu River will improve the navigability of the waterway,but the rising water level will cause some of the existing river barriers and shoals to become reefs and obstruct navigation.For the channel of Tongtiancao Beach,there are problems such as rapid local water flow,poor flow pattern,and serious water sweeping bends,this paper adopts the river model test to study the navigational current conditions of the designed regulation plan.The results show that although the waterway regulation scheme has improved the navigational flow conditions,which makes the channel of Tongtiancao Beach basically meet the scale requirements after the completion of Baima Hub,but its dredging design does not follow the river situation,which makes the direction of the channel and the intersection of mid-water current power axis larger,which is not conducive to the receding scouring and navigation channel stability.In view of the shortcomings of the designed remediation scheme,and considering the project investment and construction difficulty,the optimisation measures more suitable for this channel remediation project are proposed.The research results can provide scientific basis and technical support for similar waterway regulation projects.

Abstract:A new type of triangular prism artificial fish reef has been widely used in the channel regulation project in the upper reaches of the Yangtze River,playing an important role in improving water flow dynamics and creating fish habitats.This study investigates the flow field characteristics on triangular prism artificial fish reefs under different inflow velocities and deployment spacings using numerical simulation methods,and proposes the optimal arrangement of artificial fish reefs.The research results show that the maximum velocity of upwelling is proportional to the inflow velocity,while the upwelling volume,the maximum height-to-reef height ratio of upwelling,the volume and length of back-eddy flows are not significantly affected by the inflow velocity.Under the same flow velocity,both the volume of upwelling and back-eddy flows are inversely proportional to the lateral spacing of artificial fish reef deployment,and they initially increase and then decrease with the longitudinal spacing.The optimal deployment configuration for artificial fish reefs occurs when the lateral and longitudinal spacings are 0.5 times and 4 times the reef length,respectively.Compared with different inflow velocities,the characteristics parameters of upwelling and back-eddy flow regions are more significantly influenced by the deployment spacing of artificial fish reefs.The research conclusions can provide theoretical basis for the construction of ecological artificial fish reefs in the upper reaches of the Yangtze River.

Abstract:The deepwater channel of Dafeng Port area in Yancheng Port is located at the northern edge of the radial sand ridges in northern Jiangsu,constructing a 100,000 DWT deepwater channel relying on west trough of Xiyang channel.The Dafeng deepwater channel phase I project of first and second stages is arranged the same scale for the construction.Backsilting characteristics and sources after Dafeng deepwater channel excavation are studied based on the measured flow,sediment and terrain data.The results show that the annual silting intensity of the second stage of Dafeng deepwater channel is 0.66 m/a,which is less than that in the first stage,mainly because of the onshore treatment of dredged soil.The temporal and spatial distribution characteristics of channel backsilting in the two stages are similar.The channel deposition intensity is high in the first four months after acceptance,and then it decreases,with slightly higher backsilting in winter than in summer.The backsilting in the channel inner section is greater than that in the outer section,and the high deposition area is mainly located on the west side of the Xiaoyin sandbar gully.The main reason is that the sediment sources in the inner section are relatively abundant,including sediment brought by the scouring zone of the outer sea,sediment scoured by Xiaoyin sandbar,and sediment diffused from temporary sludge throwing area.

Abstract:In recent years,the number of underwater tunnels in the trunk stream of the Yangtze River has increased.In response to the problem of the buried depths of underwater tunnels,we analyze requirements of GB 50139-2014 Navigation Standard of Inland Waterway,JTS 180-4-2020 Navigation Standard of the Trunk Stream Changjiang River,and JTS 180-3-2018 Navigation Standard of Waterways for Seagoing Vessel.Then we analyze and compare requirements in the three standards combining with two cases,and put forward suggestions for revising corresponding terms of standards.The results show that waterways characteristics and conditions of different tunnel sites are different,the three standards have a large difference in requirements of the buried depth,and some terms are even incomplete to the actual situation.If executed improperly,it will have a greater impact on the vertical layout of the underwater tunnel.It is recommended that buried depths of underwater tunnels in the trunk stream of the Yangtze River should not be used to determine the control line at a certain standard in the three standards.After comprehensive comparative analysis of the current situation of the river bed of the section of the tunnel,and possible scour,the scientific and reasonable clause should be implemented after comprehensive comparison and analysis.

Abstract:Xijin hydro-junction project is situated in a C-shaped curved section of the river with towering mountains on both sides.Due to the safety and operation conditions of the built facilities,it is difficult to select the location and plane layout of the second-line ship lock.On the basis of summarizing the construction experience of similar projects,according to the characteristics of Xijin hydro-junction project,this paper puts forward the principles of lock location selection.The principles take into account factors such as the impact on existing hub facilities in terms of safety and functionality,navigable water flow conditions at the lock site,project area and demolition requirements,construction scheme feasibility,convenience of operation and management,excavation volume,and project investment.The combination of qualitative analysis and quantitative calculation method is used to compare and select an optimal position for the second-line ship lock.Combined with the physical model test,the length of upstream and downstream barrier is optimized to improve the navigable flow conditions in the entrance area of the upstream and downstream approach channel.Field operation tests confirm that the proposed lock's passage capacity meets design requirements and achieve efficient navigation goals.The principle and research method of lock-location proposed can provide reference for the general arrangement of locks in similar high head reservoir area.

Abstract:Using the measured tidal data of the entrance channel of Toumen Port,the distribution and movement characteristics of tidal currents are studied through quasi harmonic analysis.The results showed that：1) The maximum flow velocity of the entrance channel is 111 cm/s.The flow velocity of the leading section of Toumen Island is slightly higher than that of the offshore section,and the flow velocity of the spring tide is greater than that of the neap tide.The vertical distribution of flow velocity gradually decreased from the surface to the middle and bottom layers.2)The main factor affecting the sea area of the entrance channel is M2-point tidal current,which is a regular semi diurnal shallow sea tidal current.The motion characteristic of tidal current is reciprocating flow,and the tidal ellipse is relatively flat,the maximum flow rate may be between 80-145 cm/s.3) The residual flow value is not significant,with a maximum value of 9.2 cm/s.Overall,the residual flow in the offshore segment is slightly higher than that in the forward segment of Toumen Port.The direction of residual current in the forward section of Toumen Port points towards the ebb tide direction,while the direction of residual current in the offshore section points towards the rising tide direction.

Abstract:Liyushan Waterway is located in the section of the Yangtze River trunk from Wuhan to Anqing.Due to the development of the south trough flushing,the flow capacity of the north trough is reduced and the flow is dispersed.So the central beach of Huanglianzhou is extremely unstable and the waterway condition of the north channel is deteriorating.The waterway regulation project was carried out in 2015 for curbing the adverse development.To study the implementation effect of the regulation project,the variation of the split ratio of the north trough and south trough is analyzed by comparing the data of numerical model,physical model and the observation data before and after the implementation of the project.The results show that the split ratio of the north channel during low water has significantly increased after the project.The project curbs the erosion trend of the central beach of Huanglianzhou,keeps the stability of the river section and improves the conditions of the north channel.The goals of the regulation project are achieved.

Abstract:Concrete gravity revetment and reinforced concrete buttress revetment are both commonly used vertical revetment structures in restricted inland waterways.When the two are used for vertical revetment structure comparison,in addition to the plane layout,structural stability analysis and site construction scheme,the project cost is also an important factor affecting the selection of waterway revetment structure design scheme.To select a more economical vertical revetment,this paper analyzes the influence of natural conditions,use requirements and construction conditions on project cost by combining with engineering cases.The results show that when the main components of cast-in-place concrete such as cement,gravel and sand are rich in sources and low in price,the selection of concrete gravity revetment has the advantage of low cost.When the revetment structure is high,the amount of concrete used is large,and the price of steel is low,the reinforced concrete buttress revetment structure can be given priority.

Abstract:In order to adapt to the increasing throughput of ports and the trend of large-scale development of container ships,new forms of layouts and operation modes of container terminal have emerged.The high-bay storage system(HBS),as a storage solution that reduces land usage by increasing storage density,provides new ideas for the development of three-dimensional storage yards.In response to the construction requirements of conserving and intensively utilizing land resources,we take the high-bay storage system as an research object.By considering the complexity and uncertainty of its operation process,we build an intelligent agent simulation model for the HBS operation,verify its effectiveness,and analyze the efficiency of yard crane operations under different working conditions,which can provide decision support for the reconstruction of container yards in China.

Abstract:The Yangtze River estuary is the outlet of the largest river in China,the changes and predicions of sediment content directly affect the ecological environment,waterway maintenance and flood control safety in the estuary area.This study develops a machine learning-based model for predicting sediment content dynamics in the Yangtze River estuary region.Considering that sediment content is affected by a variety of hydrological environmental factors,this study collects hydrological data for a year in the Yangtze River estuary area,including flow velocity,tide level,sediment content,etc.and uses time series analysis methods to extract key features and patterns,and a long short-term memory network(LSTM) is selected,trained and tested.The analysis results show that the LSTM-based model shows high accuracy in predicting sediment content in the Yangtze River estuary region.The mean absolute error of the model is 0.146 5,and the coefficient of determination is 0.931 4.

Abstract:To meet the continuous deepening of the digital application requirements for the entire life cycle of water transportation engineering during the 14 th Five Year Plan period,aiming at the current lack of corresponding standards and accurate modeling methods in BIM design for mountain opening and slope protection in large-scale port engineering,based on a project in Ningbo.this paper sorts out the BIM specifications and standards in related fields and industries,and compiles the BIM information model construction rules for the formation of land areas of large-scale port projects and slope protection.Problems such as boundary processing,model optimization,data penetration,information deepening,and data transfer are solved through the flexible choice of Autodesk software and secondary development technology.A systematic and standardized BIM design and application method for mountain opening and slope protection in land area formation is studied.The results show that the method not only greatly improves design efficiency and achieves 3D visualization,but also makes up for the lack of BIM design applications for mountain opening and slope protection in large-scale port engineering,which provides ideas for digital information transmission at different stages of large-scale port engineering.

Abstract:The multi-row pile quay wall is a new permanent structure composed of multiple piles,relieving slab,flood control walls,backfill sand,etc.,which can also serve as a working wharf.The retaining effect of covered pile has been widely studied in sheet pile wharf,but it is still lacking in multi-row pile quay wall structures.Relying on the Changxing harbor Pool Project,this paper establishes a multi-row pile quay wall structure through the three-dimensional finite element software PLAXIS 3D,and studies the influence of whether there are covered piles,the row spacing between the front pile and the covered pile,the spacing between the covered pile,and the stiffness of the front pile on the internal force and deformation of the multi-row pile quay wall.The following conclusions are drawn when there are covered piles,the overall displacement of the multi-row pile quay wall is small,and the bending moment of the front pile is less.The spacing between the front and rear rows of piles，the distance between the covered piles,and the stiffness of the front piles all affect the internal force of the front piles.The internal force of the front piles decreases as the distance between the front rear rows of piles and the distance between the covered piles decrease,and decreases as the stiffness of the front piles decreases.Considering the site conditions and project cost,the sensitivity of different parameters to the retaining effect of the curtain is evaluated:the stiffness of the front pile > the spacing between the front pile and the covered pile > the spacing between the rear row covered pile.On this basis,an optimized design scheme is proposed,which can reduce the bending moment of the front pile by 50% compared with the original scheme,providing a certain reference for subsequent engineering applications.

Abstract:The construction depth of steel pipe pile into deep soft rock is uncertain.Based on an actual project,a test study on the construction of steel pipe pile driving into deep soft rock is carried out by drivability analysis,full size pile driving test and bearing capacity test.The results show that for steel pipe pile into deep soft rock,the pile tip should adopt open form,so as to minimize the soil plug effect during the pile driving process and ensure the depth into soft rock.The soil plug effect coefficient during piling in mudstone can be smaller than that under static load condition,and the soil plug effect coefficient in argillaceous limestone can be referred to that under the static load condition,the soil plug coefficient for open-end steel pipe pile with diameter of 1,000 mm can be 0.45,and 0.33 for diameter of 1,200 mm.When the hammer energy is limited,the final hammering penetration of steel pipe pile into deep soft rock can be appropriately reduced compared with the final hammering penetration of conventional geology,and 1 mm per stroke can be used as the final penetration standard.

Abstract:Sheet-pile dock wall is widely used in dock design at soft soil area because of its economy,but there are some problems,such as excessive displacement of front wall,unclear displacement limit,calculation results are not adapted to the actual situation.This paper takes a sheet-pile dock wall of an overseas project as an example,uses PLAXIS software to carry out numerical simulation calculation combining with the construction process and structural characteristics of the dock wall,and compare with the actual measured data.Then the paper carris out the structural calculation under different working conditions on the basis of optimization model,and deduces rules of structural displacement and internal force change.The results show that the hardening soil model is more accurate to calculate the structure of sheet-pile dock wall in ultra-deep soft soil area.Among the soil parameters of hardening soil model,the secant modulus E50 is the most sensitive.When there is no test data,E50 is recommended as 2~2.5 times SPT blow count,unloading-reloading modulus Eur is recommended as 3 times E50.Considering the interaction between pile of dock slab and soil in front of the dock wall,the maximum horizontal displacement of the dock wall is reduced by about 30%.The effect of pile foundation of dock slab should be considered when calculating of dock wall.

Abstract:The construction parameters of deep cement mixing(DCM) on land and underwater soft foundation are usually determined by test pile,and the underwater DCM is mostly four-axis,so the construction parameters are difficult to determine.In this paper,the DCM piles in reclamation project is studied,the key parameters of the cement mixing pile,such as BRN,W-shaped construction curve at the bottom and cement slurry jet technology are studied,and the cement soil-cement strength is tested through triple tube coring.The results indicate that the cement content in the silt is optimized from 320 kg/m3 to 300 kg/m3,and the unconfined compressive strength of the cement-soil mixing pile is greater than 1.0 MPa after 28 days curing,which meets the design requirements.The pile’s strength can be improved by adding two W-shaped curve to remix the hard clay layer at the bottom.To fully stir the clay,the penetration speed should not be greater than 0.3 m/min and the withdraw speed should not be greater than 1.0 m/min.The stirring blade rotation speed should match the drill penetration or withdrawing speed to improve the mixing effect and the quality of pile.

Abstract:When coarse particles such as coarse sand and gravel are transported by dredged pipelines,due to factors such as complex composition of particle size,large fluctuations in concentration and local resistance,it is easy to cause problems such as transportation efficiency,siltation blockage and difficult operation.To realize the safe and efficient transportation of coarse particle materials,the coarse sand with a median particle size of 0.82 mm is taken as the research object.To study the flow pattern,loss of frictional drag,critical velocity and slip ratio(transportation efficiency) of coarse sand,pipeline transportation experiments are carried out under different concentrations and flow rates.According to the requirements of dredging construction,the optimal flow pattern and velocity range are determined.The flow state has the advantages of not being easy block,low wear,high transportation stability and high transportation efficiency.The research results on the characteristics of mud and sand transportation and the method for determining the optimal flow pattern have theoretical reference and application value for the safe,stable and efficient transportation of coarse particles.

Abstract:The propagation law of underwater drill hole blasting vibration for waterway regulation is affected by elevation effect and water fluctuation effect at the same time.According to a waterway regulation project 13 groups of underwater drilling and blasting vibration test results,this study analyzes the propagation law of underwater drilling and blasting vibration velocity and vibration frequency,and explores the underwater drilling and blasting vibration prediction formula that can reflect the effect of elevation and water fluctuation at the same time.The results show that：1)The highest accuracy of blasting vibration velocity prediction is carried out by using the maximum value of the three-way component.2)The main vibration frequency of the vertical Z-component attenuates with increasing distance,which should be paid attention to in the practice of blasting safety monitoring.3)Compared with Sadovsky formula,the modified formula considering only elevation effect and the modified formula considering only water fluctuation effect,the modified formula considering both elevation effect and water fluctuation effect has the highest prediction accuracy,and the regression equation and regression coefficient are significant,which can more accurately reflect the vibration propagation law of underwater drilling and blasting.The research conclusions have reference significance for the safety monitoring of underwater drilling and blasting vibration in waterway regulation.

Abstract:At present,the underwater visual installation of accropode block is mainly carried out by underwater camera or sonar imaging method,which requires high visibility of the underwater environment or high cost of the sensor,and it is difficult to achieve quantitative control of key parameters.Based on the analysis of the construction process and acceptance requirements of the accropode block,the intelligent guidance system for the installation of the accropode block is developed by installing sensors on the objects such as the crawler crane and the accropode block and building the calculation program of spatial points.The verification work is carried out on site by the typical section in the breakwater construction field,and the visual installation of accropode block in the whole section of the breakwater is realized.The system permits the installation work of the accropode block in the high water level condition,increases the construction period and improves the efficiency of construction work.