Abstract:Aiming at the current problems that the selection of canal route schemes relies on experience and macroscopic demonstrations,this study takes the Pinglu Canal Project as an example and proposes a set of route comparison and selection methods based on quantitative analysis,aiming to enhance the scientificity of route selection and decision-making efficiency.Firstly,a comprehensive evaluation index system for route selection is constructed based on three major dimensions:technology,economy,and environment.It covers specific indicators such as route length,earthwork volume(engineering difficulty),quantity of land acquisition and demolition (coordination difficulty),and the impact on ecologically sensitive areas.The analytic hierarchy process (AHP) is used to determine the weights of each indicator.Secondly,taking the water divide section and the section of the Liuqin Expressway Bridge area of the waterway route as typical cases,the engineering costs and comprehensive benefits of different schemes are quantitatively compared and analyzed.The research shows that the proposed index system and the Analytic Hierarchy Process can significantly reduce the engineering economic cost and environmental impact.The comprehensive investment optimization ratio of the recommended scheme is more than 15% in the waterway route schemes of the water divide section and the bridge section area.The research method can provide a standardized comparison and selection framework for similar canal projects,and promote the transformation of route design from experience-driven to data-driven.Keywords：Pinglu canal;comparison factors;route plans;route-selection principles;analytic hierarchy process (AHP)

Abstract:The Qingnian ship lock is the lowest cascade of the Pinglu Canal.After the construction of Pinglu Canal,the salt water intrudes from the Maowei Sea to the downstream approach channel of the Qingnian ship lock.The Qingnian ship lock is characterized by a salt-fresh water confluence water environment.With the operation of the Qingnian ship lock,salt water will intrude into Qingnian reservoir.Because of the unfavorable impacts of salt water intrusion,it is necessary to study the salt water intrusion at Qingnian reservoir which serves as the source of water for domestic drinking and agricultural irrigation of Qinzhou City.By constructing a three-dimensional numerical model of salt water intrusion of Qingnian reservoir,the effects of fresh water discharge and the salinity of the upstream approach channel of Qingnian ship lock on the distance of salt water intrusion and the vertical salinity distribution are studied.The results show that the salt water intrusion distance increases with the increase of water salinity at the upstream approach channel,showing a positive power relationship,and decreases with the increase of fresh water discharge,showing a negative power relationship.The vertical salinity gradient decreases with the increase of water salinity at the approach channel,showing a negative power relationship,and increases with the increase of fresh water discharge,showing a positive power relationship.

Abstract:In view of the problem that how to advance the construction of overseas strategic fulcrum ports in China in the new era,both theoretical and empirical research methods are employed to delve into connotations and significance of overseas strategic fulcrum ports,the implementation status of China’s overseas strategic fulcrum port projects,and existing challenges and problems.The conclusions are that the value of strategic fulcrum ports lies in fulfilling China’s strategic needs in global economic trade,international industrial cooperation,and ensuring resource and energy security.Positive progress has been made in practice,resulting in a series of strategic fulcrum ports with different value functions,such as Gwadar Port,Djibouti Port,Piraeus Port,and Hambantota Port,which have laid a foundation for the implementation of China’s overseas strategies.However,there are urgent issues to resolve,including significant impacts from geopolitics and great power competition,a limited number of ports under actual control and operation,inadequate integration between ports and industries and urban development,and limited application of Chinese standards.From a macro perspective of the port value chain,development strategies are proposed such as overall planning for the layout of strategic fulcrum ports based on the concept of “a maritime community with a shared future”,advancing the construction of overseas strategic pivot ports through port-industry integration or port-industry-city linkage models and innovative investment and financing implementation models,and strengthening the application of Chinese rules and standards in overseas ports.These strategies provide scientific justification and practical references for China’s planning and deployment of overseas strategic fulcrum ports construction.

Abstract:To the problem of placement modes of accropode widely used at home and abroad,this paper compares and analyzes the relevant industry regulations at home and abroad,and finds that the foreign industry norms all stipulate the random placement mode,while the Chinese industry norms add the regular placement mode,specifically the queue-type regular placement mode.By using the wave cross-sectional physical model test,the stability test of three common placement modes is verified,and it is found that random placement mode has the best stability,followed by positive and negative regular placement mode,and queue-type regular placement mode has the worst stability.The current industry standards in our country use the KD value of the stability coefficient for accropode,which is not applicable to the queue type regular placement mode.Using this value will result in calculation results that are biased towards danger.

Abstract:By summarizing the development of low-carbon transformation in shipping vessels,waterways,and ports along the Yangtze River under the carbon peaking and carbon neutrality goals,this paper analyzes trends such as the slowdown in freight demand growth in Yangtze River shipping,the increase in new energy sources like LNG,the promotion of new energy applications such as LNG and lithium batteries in vessels,and the ongoing expansion of shore power technology and adjustment of energy structures in ports towards low-carbon development.It proposes measures to improve institutional mechanisms and carbon emission evaluation systems,promote the routine application of new energy sources,adjust energy use structures,build an integrated transportation system,and optimize transportation structures.The research results can lay the foundation for subsequent research on carbon emission monitoring methods in Yangtze River shipping and provide technical support and decision-making references in advancing the carbon peaking and carbon neutrality efforts in Yangtze River shipping.

Abstract:Floating breakwaters can provide effective protection for marine engineering equipment and meet the increasing protection needs of offshore facilities.Computational fluid dynamics method is used to numerically simulate the wave dissipation performance of floating breakwater with wing plates,and the influence of wing plate parameters on wave dissipation effect and vortex distribution of the breakwater is analyzed.The research results show that when the angle of the wing plate is too large the strength of the vortex generated at the tip of the wing plate becomes smaller,and the wave dissipation performance of the breakwater is reduced.When the wave height is large,the reduction of the wing plate angle makes the vortex shedding time longer,thus improving its wave dissipation performance.The shorter length of the wing plate accelerates the shedding of vortex,resulting in the reduction of its wave dissipation performance.

Abstract:The sedimentation issues near high-pile wharves are critical in port construction and maintenance.The group-piles beneath the wharf affect the surrounding tidal currents and sediment suspension,leading to sediment accumulation.Detailed modeling of pile foundations requires stringent grid scales and is not suitable for large-scale simulations involving numerous pile groups.This study employs a pile group generalization method to improve the FVCOM three-dimensional water-sediment model and validate it against sedimentation data at the Tianjin Port berth piles.Based on this,simulations considering and not considering pile group are conducted to analyze tidal currents,suspended sediment,and erosion-deposition evolution near the Tianjin Port berth.The simulation results show that the improved three-dimensional water-sediment model has good verification results.Considering effects of pile group creates a distinct flow obstruction zone under the wharf,affecting the distribution and velocity of surrounding flow.During flood tide,the sediment concentration in front of and below the dock is twice that of scenarios without pile group,while sediment concentration slightly decreases during ebb tide,with sediment mainly accumulating in front of the wharf.

Abstract:This article conducts in-depth research and analysis on water pollution and treatment in Nanshan Port,Sanya City.With the operation of Nanshan Port for many years and multiple pollutions,the water area of the port is facing increasingly serious water pollution problems.By conducting field investigations and water quality monitoring,the sources of pollutants are analyzed.The MIKE21 mathematical model is used to predict and analyze the diffusion of pollutants in seven different treatment schemes.Taking into account factors such as hydrodynamic conditions,pollutant treatment effectiveness,and economic viability,a comprehensive comparison is conducted from multiple aspects to select the relatively optimal marine water environment treatment plan.The research results can provide reference and guidance for water pollution control in port areas of similar regions.

Abstract:The structure of pile-supported pier is quite common in the construction of bridges,wharves,and other structures,and its construction is relatively difficult.The cost control of various measures is one of the factors that construction units consider first.On the basis of the project of 18# to 20# berths in Zhangwan working area of Sandu Bay area of Fuzhou Port,the original design scheme of the bottom formwork supporting structure of the substation platform for this project is optimized,and the construction organization is adjusted.The consumption of supporting steel is reduced when the bearing capacity of the support structure is ensured.Finally,the substation platform is successfully cast in the project and passed the acceptance,saving construction costs of 813,000 yuan.

Abstract:The inland river wharf projects in the middle and upper reaches of the Yangtze River have the characteristics of large water level difference and fast flow velocity.There are currently no operating LNG loading and unloading wharves neither at home nor abroad,and there is no relevant engineering experience for reference.Therefore,in order to promote the development of inland river LNG shipping,it is very necessary to carry out technical research on LNG loading and unloading wharves with large water level difference in inland rivers.This paper analyzes the layout and structural forms of existing coastal LNG(liquefied natural gas) wharves and inland river oil and gas chemical wharves,combined with the characteristics of LNG loading and unloading wharves with large water level difference in inland river.It proposes the plane layout of contiguous wharf and structure scheme of upright wharf with high pile frame,develops a detachable fast cable release hook and a laser rangefinder with automatic lifting guide rail.The appeal schemes that have been applied in practical engineering solve the key technical problems such as multi-boat combination,multi-layer mooring and auxiliary berthing in inland river under the condition of large water level difference,and can provide reference for similar projects.

Abstract:For the calculation of active earth pressure on the front wall of flexible sheet pile wharf,Coulomb earth pressure theory is adopted.Assuming that the active earth pressure on the front wall is generated by the sliding body of the soil behind the wall in the ultimate equilibrium state,a force balance differential equation is established for the horizontal differential elements taken by sliding soil along the wall height direction.Then the lateral earth pressure coefficient is solved by integrating the stress state of the micro soil elements on the deflection arch trace of the minor principal stress generated by the sliding trend of the sliding soil,and the theoretical formula for the distribution of earth pressure strength along the wall height of the flexible front wall is obtained by substituting the equilibrium differential equation.On this basis, the non-limit state soil mechanics parameters caused by the deflection of flexible wall of the sheet pile wharf are introduced to solve the earth pressure strength under non-limit state.The method proposed is basically consistent with the experimental results of mathematical models,and has certain reference significance.

Abstract:The high-pile wharfs of the main ports in the coastal areas of China are confronted with significant siltation issues,resulting in extensive damage to pile foundations and high maintenance costs.Based on the fact that the displacement of soft soil on silty bank slope is the main cause of silting in high pile wharf,the long-term monitoring of the displacement characteristics of soft soil on bank slope is carried out by using a combined measurement method involving stress sheets and flexible inclinometer.The study discusses the cumulative displacement of soft soil under loading at the rear of the wharf and examines changes in displacement rates of soft soil before and after dredging cycles.The results show that there will be settlement in the soil layer under the action of overloading,forcing the soil to move in the horizontal direction.It is observed that the lateral displacement of the coast gradually increases towards the seagoing side within one year,and the displacement rate is different before and after the dredging cycles of the wharf.Long-term monitoring of bank displacements is crucial for the management of coastal port project.Accurately analyzing the process can help reduce the risks caused by coastal erosion,landslides,and siltation problems of high-pile wharfs.

Abstract:Aiming at the problem of fish migration in Lize Shipping Hub of Jialing River， this paper proposes the design scheme of vertical slot fishway which is more widely used,and uses three-dimensional water flow mathematical model to compare and analyze the hydraulic characteristics of four fishway layout types(changing the width of the pool chamber,the width of the vertical slit,and changing the dimensions or angle of the bulkhead and guide plate).The results show that under the conditions of the pool chamber width of 3.0 m,vertical seam width of 0.5 m,the partition length of 2.1 m,the guide plate length of 0.7 m,and upstream slope of 77° and 45° for the partition and the guide plate,the curvature radius of the main flow in the pool chamber is larger,the strength of the reflux zones on both sides is weaker,the flow velocity is more stable after passing through the rest room,and the water flow connection is smoother.The water flow conditions in the pool room and rest room meet the upstream requirements of fish.The research results can provide reference for similar fishway projects.

Abstract:In order to investigate the impact of sand excavation within Shimeitang and Chenjiazui mining areas on channel hydrodynamics of the lowest Lishui River and Songhu River,we adopt data of riverbed terrain and hydrology in 2021 and 2022 to build numerical model of planar 2D flow motion,and calculate hydrodynamics changes in the two channels for different hydrological conditions before sand excavation and after.The results show that the initial sand excavation scheme does not endanger Lishui channel and Songhu channel,but water level during dry season maximally declines by 0.16 m within the Lishui channel as the isolation beach of Shimeitang mining area entirely collapses after sand excavation,endangering the navigation safety.Among all optimized schemes,water-level drop within the Lishui channel decreases with mining-area contractions during dry season for the extreme situation of isolation beach collapse and water level no longer declines under the recommended scheme.However,the maximum water-level differences between the two channels reach 0.20 m and 0.30 m during water flood and recession stages,and the two mining areas produce a maximum flow velocity of 1.00 m/s on adjacent beaches and result in scour of beaches.During flood season,high flow velocities occur in mining areas and vicinities,and deposition may happen as sediment is carried into the shipping channels.Therefore,regular monitoring is advised to be implemented on riverbed of channels,and protection project is also needed to prevent beaches to collapse.

Abstract:Many tributaries are distributed along the Pinglu Canal,and the aggradation of the sediment transported from them in the canal affects the canal construction and navigation safety.Xinpingshui is an important target in tributary-sediment-control efforts of the Pinglu Canal.For clarifying the sediment transport pattern of Xinpingshui,the flow-sediment transport characteristics in this tributary for different hydrological regimes are investigated on the basis of in-situ monitoring and theoretical analysis.Measured data are applied to propose an empirical prediction method for the sediment transport rate of Xinpingshui flow.The results show that every cross-section of Xinpingshui exhibits a wide and shallow U-shape,with sediment particles of riverbed displaying a pattern of coarsening followed by fining along the river.Without rainfall,the sediment transport capacity in each reach of Xinpingshui is greater than the measured sediment transport rate in both dry and flood seasons,indicating the flow may scour the riverbed and transport sediment to the canal.During the flood season,rainfall can significantly increase the flow sediment content near the confluence of Xinpingshui,resulting in the measured sediment transport rate exceeds the sediment transport capacity,which may cause riverbed aggradation here.The sediment transport rate of Xinpingshui flow is positively correlated with discharge.

Abstract:To implement the important directive spirit of the Yangtze River Economic Belt to “jointly protect and not engage in large-scale development”,this paper explores the ecological comprehensive utilization of dredged waste soil in the waterway regulation project of Wuhan-Anqing section of the Yangtze River trunk line,adopts eco-friendly structure and green construction technologies to construct ecological beach projects,reduces the impact of dredging on ecological environment,promotes the restoration of vegetation on the beach,and enhance the ecological function of the beach.The ecological beach consolidation project mainly includes three parts:embankment,filling of dredged soil inside the embankment,road laying,and ecological beach protection.After the implementation of the Daijiazhou ecological beach consolidation project,the beach has become stable,forming a good ecological greening effect,achieving the coordination and unity of ecology and beach consolidation,and achieving the construction goals of the project,and the regulation effect is good.

Abstract:Huai’an east ship lock in the Huaihe River estuary waterway is surrounded by numerous waterways,water conservancy and transportation facilities,making the construction and operation environment extremely complex.According to the navigation conditions,impact on the flood discharge of the Huaihe River estuary,impact on the navigation of the Beijing-Hangzhou Canal,impact on surrounding buildings,external transportation conditions,and land acquisition and demolition situation,it is recommended to choose a scheme of the southern ship lock position.At the southern ship lock position,according to the navigation conditions,capacity,efficiency,impact on the flood discharge of the Huaihe River estuary,impact on the flood control embankment,construction conditions,and project investment,a curved in and straight out layout plan is recommended.After conducting overall physical model tests on the ship lock,it is demonstrated that overall layout plan is reasonable.Layout plans for upstream and downstream navigation adjustment sections and berthing sections meet requirements of navigation water flow conditions specified in the code.After optimizing the length and permeability of the upstream and downstream side flow barriers,dredging of the local water area in front of Yundong sluice gate is carried out,and compensation engineering measures are taken for the cut-off of floodwaters in the Huaihe River estuary,which can meet the requirements of the ship lock’s own navigation water flow conditions.The construction of the project will not have any adverse effects on the flood discharge of the main irrigation canal in northern Jiangsu Province,the operation of the Yundong sluice,the operation of the aqueduct,and the power generation of the Yundong power station.It will have little impact on the flood discharge of the Huaihe River estuary and the operation of the culvert.

Abstract:Bailongtan hydropower station is located in a sharp bend channel,surrounded by dense buildings.Restricted by various factors such as river regime,terrain and surrounding buildings,the general layout conditions for ship lock renovation and expansion are complex.Multiple schemes are compared for the lock position and general layout from several aspects,including navigation conditions,impact on surrounding buildings,construction conditions and investment,to determine the optimal general layout scheme.Combined with the physical model tests,the layout scheme of reducing the bending radius of the channel and zigzag layout of berthing section is adopted to solve the problem of limited space for approach channel.Through engineering measures such as adding groyne,installing permeable walls and excavating partial channel,the navigation conditions of upstream and downstream entrance areas are effectively improved,providing reference for the ship lock renovation and expansion in curved channel and narrow spaces.

Abstract:The second-line ship lock of Longtoushan hub is located in a slightly curved river section,and the downstream is affected by Longtoushan rock head,resulting in complex overall water flow conditions.The position of the ship lock is determined to be arranged by comparing advantages and disadvantages of the layout near the first-line ship lock and the layout near Gandong levee.The distance between the axis of the second-line ship lock and the axis of the first-line ship lock is determined by analyzing the cross-section of the lower ship lock head.Corresponding optimization measures are proposed by the physical model test.The results show that the position of the second-line ship lock is arranged near the first-line ship lock,and the distance between the axis of the second-line ship lock and the axis of the first-line ship lock is 100 m.Measures of the reconstruction and expansion of upstream and downstream baffle walls,as well as the dredging of the right bank beach downstream,can improve navigable conditions of the first-line ship lock and optimize the planar layout of the second-line ship lock.

Abstract:When the plane valve of the water delivery system of a III-class ship lock is closed,the blockage occurs,resulting in the breakage of the boom.In this paper,dynamic principle and finite element method are used to analyze the causes of buckling failure of valve boom.Under the condition of water delivery valve blockage,the valve,boom and headstock gear form a planar four-link mechanism,which is easy to cause buckling failure of the boom under pressure at the collinear dead point.Through the calculation of linear buckling characteristic values and nonlinear post-buckling analysis,it is concluded that the critical buckling load of the boom is 80 kN,which is lower than the overpressure alarm value of the hydraulic headstock gear.The buckling mode shows that large deformation occurs after the boom is destabilized under pressure,resulting in plastic deformation and fracture of local materials after yielding,which makes the boom break.The critical buckling load of the boom is more sensitive to the material plate thickness of the hinged single lug plate.Increasing the plate thickness or using double lug plate structure can significantly improve the ability of the structure to resist buckling instability.The research results can provide reference for similar structural design.

Abstract:To clarify the occurrence law of different types of typical obstructive flow patterns,and predict the typical obstructive flow patterns that may occur in the future based on the known objective conditions,this study focuses on summarizing and sorting out the characteristics of different flow patterns and carries out the research on the prediction method for the surface flow pattern characteristics of sharp bends channels to address the safety risks of navigation caused by obstructive flow patterns.The prediction method based on CNN-GRU-BP combined neural network is used,and compared with the measured values and traditional numerical methods.The results show that the combined network prediction method has good prediction performance for the surface flow characteristics of the channel,and it can obtain the characteristic values of different flow patterns in real time,accurately,and purposely under the input nonlinear influencing factors,which can provide data support for the navigation safety control of the actual channel,and technical support for the prevention and resolution of related navigation safety risks.

Abstract:With the development of smart waterway construction,flow velocity monitoring plays an important role in the accurate acquisition and real-time management of hydrological information.In response to the relative lack of research on flow velocity monitoring in complex water environments,an array radar flow measurement system is proposed and adopt.The array radar flow measurement experiment is conducted on-site in a certain water area of the Yangtze River to verify its monitoring effectiveness under complex water conditions.The system utilizes P-band radar and utilizes line array digital beam-forming technology and Bragg scattering principle to achieve non-contact real-time monitoring of water flow velocity.Fuzzy clustering algorithm is used to screen the Doppler characteristics of each waterway,and the data are compared with acoustic Doppler current profiler(ADCP) synchronous flow measurement data.The results show that the array radar flow measurement system has excellent flow measurement performance in complex water environments,providing an efficient and reliable technical means for flow velocity monitoring in the context of smart navigation.After removing the adverse effects of ship upward movement,the accuracy of radar wave surface flow field data is high,and the overall deviation of flow velocity obtained based on radar waves at experimental observation points is not greater than 7.00%,comparing with the ADCP synchronous flow measurement data.

Abstract:In view of the engineering problem of port construction in the area with poor geological condition,poor or even bad sea condition,the object-oriented method is adopted to extract the knowledge of construction entities and establish the construction knowledge graph system of pile-supported wharf.The key information of construction knowledge of pile-supported wharf is represented by triplet,and the knowledge fusion is carried out according to three levels of knowledge graphs of prefabricated component,construction process and quality control requirements by the entity alignment method of graph convolutional network.The construction factor similarity calculation method is used to calculate the Levenshtein distance between the target data and the typical process condition data in the knowledge graph under specific engineering conditions,and the overall construction process flow is determined.The constraint rule decision tree is used to impose constraints on the construction body in terms of production resources,technical standards,safety risks and comprehensive evaluation,and key construction parameters in the specific process are clarified,then the logical route of construction technology is optimized.The Unreal Engine is used to create the offshore construction inference system of pile-supported wharf,and the intelligent planning of pile driving process and the intelligent decision of pile stopping condition under different construction conditions are realized by designing blueprint script.

Abstract:In view of the problem that current loading control processes of a trailing suction hopper dredger is high personnel dependence and low efficiency,prioritized experience replay (PER) and random network distillation (RND) are combined,and a reinforcement learning control algorithm is proposed on the basis of priority replay and random network distillation soft actor-critic (PRND-SAC).By designing appropriate state space,action space,and reward function,the PRND-SAC controller is compared with the traditional SAC controller.Furthermore,comparative experiments are conducted between the PRND-SAC controller and actual operational data on the basis of a full-process loading phase simulation environment.The results demonstrate that the proposed controller converges quickly and stably.Furthermore,compared to the traditional SAC controller,the PRND-SAC controller not only enhances the stability of the control process but also significantly increases loading efficiency.

Abstract:In order to solve problems that traditional contact-based sensing instruments are interference with berthing operations and maintenance difficulties while measuring berthing loads on ships,and non-contact methods of laser rangefinders and sonar sensors are affected by lighting and environmental conditions,we propose a method for load sensing during coastal berthing on the basis of digital image measurement.Relying on a wharf project at Ningbo-Zhoushan Port in Zhejiang Province,we use the method to compute the deformation displacement of rubber fenders by analyzing speckle patterns in two images taken before and after deformation.By leveraging the known specifications of the rubber fender and the deformation displacement data,we calculate the impact energy and fender reaction force,allowing for the estimation of berthing loads.The results of field tests demonstrate that compared to conventional strain gauge measurements,the error margin of this method is less than 10%,validating its effectiveness in sensing berthing loads through on-site application.

Abstract:The riverbed terrain of the Shipai bend between the two dams of the Three Gorges and Gezhouba Water Conservancy Hub on the Yangtze River is complex,with significant changes in flow rate and a wide distribution of surface obstruction flow patterns,posing safety hazards to the navigation of ships.However,the existing problems of flow field measurement technology are limited measurement range,significant environmental impact,and insufficient real-time performance,which cannot meet the needs of complex channel surface flow field measurement.In response to the above issues,this article conducts research on real time twin method for surface flow fields.LSPIV technology combined with multi view cameras is used to construct a real-time twinning system for surface flow fields in sharp curved waterway environments.And on-site comparative tests are conducted in the curved water area of Shipai,obtaining twin data of the flow field in the surface water area.The results show that this method can accurately and real-time restore the actual water flow state on the surface of the waterway,and has a good agreement with the measurement values of the unmanned aerial vehicle radar speed measurement equipment,providing technical support for the safety of hub navigation.

Abstract:There is a large amount of coral soil in Tanzania,and the C value of California bearing ratio as well as the compaction degree can reach more than 80% and 98% respectively,but it is easy to soften after encountering water,and the C values quickly decreases to about 30%.Based on a renovation and expansion project,aiming at the problems of coral soil with high dry strength and softening in contact with water,this paper optimizes the original design of interlock block pavement structure,adopting the coral soil as the base (base) material instead of the traditional cement stabilized or granular base (base) material,and proposes the design of the sole-covered sub-base of pavement structure with Tanzania coral soil,makes checking and analysis based on the finite element calculation theory together with laboratory test research and field typical construction research.The results show that the C values of sole-covered sub-base are most between 70% and 85%,which effectively improves the water stability of coral soil,and the internal force of the concrete slab is less than the tensile strength and shear strength of the designed C28/35 concrete surface layer,which meets the application requirements,and greatly reduces the project cost.The research results can provide reference for similar projects.

Abstract:Taking the 800 mm PHC pile supported by the stratum of hard clay with sand as the research object,the influence of soil resistance calculation method,soil recovery coefficient and block coefficient of pile end on pile sinking penetration is studied by using GRLWEAP piling analysis software.According to the analysis results,the long-term static resistance of soil can be calculated according to the API specification of the United States.For the clay stratum with less than 30 penetration blow numbers,the recovery coefficient is 1.5-2.0,for the clay stratum with more than 30 penetration blow numbers,the recovery coefficient is 1.0,and for the medium to dense sand stratum,the recovery coefficient is 1.20-1.12.The block coefficient of pile end ranges from 0.5 to 1.0 according to the depth of pile foundation entering the bearing stratum.The penetration calculated by this method is close to the actual pile sinking record,and the relevant calculation parameters and analysis results can provide reference for similar projects.

Abstract:To provide dry construction conditions for the main project of Xiaoxiang Ship lock,a transverse cofferdam needs to be filled in the upstream to form a main pit construction cofferdam with Songjiazhou on the right bank and Xiaoxiang West Road,which involves seepage and anti-seepage analysis of the combined cofferdams.The connection between the transverse cofferdam upstream and the longitudinal cofferdam on Songjiazhou is susceptible to the impacts of the groundwater seepage caused by the main stream of Xiangjiang River on the north-east side of Songjiazhou.The seepage problem in this project involves mostly saturated-unsaturated soils,and the seepage of water in saturated-unsaturated soils needs to be considered comprehensively.Based on the saturated-unsaturated theory,this paper uses GeoStudio software to model the upstream lateral cofferdam and the combined cofferdam on the right bank of Songjiazhou in three dimensions with regard to the structural form and rock distribution characteristics of the cofferdam of the Xiaoxiang Ship Lock Project.The numerical simulation results are analyzed for seepage and anti-seepage analyses from the perspectives of pore water pressure,water head,and seepage vector.

Abstract:To explore the application effect of UAV LiDAR in beach topography measurement in the Yangtze Estuary waters,UAV LiDAR field measurements are carried out in different areas of the Yangtze Estuary waters on the basis of exploring the principle of UAV LiDAR measurement.Through data calculation and comparative analysis,it is found that the measured data are greatly affected by the vegetation cover of the mudflat,which makes it difficult to read the mudline of the mud flat.Selecting colder seasons such as autumn and winter to carry out UAV LiDAR measurements is conducive to improving the accuracy of the data,while some areas covered with good perennial vegetation are recommended to be measured by multiple flights to improve the effective data volume.In addition,when carrying out UAV LiDAR data measurements,it is necessary to synchronize traditional means such as GNSS-RTK measurements to verify the accuracy of the data,and the combination of UAV photographic data is conducive to the discrimination of various types of feature elements.

Abstract:：In high pile projects with prefabricated beam and slab structures,if prefabricated components cannot be hoisted by crane ships due to environmental limitations,a temporary bridge with a wide bridge deck and high load-bearing capacity needs to be built,and large crawler cranes need to be used for components hoisting.However,the high standard design of the temporary bridge will lead to a significant increase in construction costs,resulting in project losses.A walking type hoisting machine and supporting hoisting technology are developed around the idea of the hoisting machine walking at different elevations and operating sequentially in different zones,and the techology can achieve full range hoisting of prefabricated components.The hoisting machine can walk on pile caps,avoiding the problem of building high standard temporary bridge.The hoisting technology is applied in engineering practice,and it has advantages of safety,efficiency,economy,and environmental protection.