Abstract:The origin of diaphragm walls technology has been over 100 years.In China,the technology of diaphragm walls in ports has developed for nearly 50 years,and the construction of wharf using diaphragm walls technology has been over 35 years,evolving from 15,000 DWT to 200,000 DWT,the world’s maximum tonnage wharf of diaphragm walls has been built.The cast-in-place diaphragm walls’ water-side face of sheet pile in the port and waterway engineering wharf has the characteristic of permanent concealment throughout the entire life cycle,to ensure the quality of the project and standardize the inspection technology,the water transport industry has formulated the Technical Specification for Testing of Diaphragm Wall Structure in Port and Waterway Engineering for the first time.It mainly stipulates the application of the sonic reflection method,crosshole sonic logging method and magnetic logging method respectively for the inspection of the quality of the trench,the quality of the concrete of the wall section and the length of the steel cage in the inspection of diaphragm walls.It focuses on 100% crosshole sonic logging method testing for the trenching and the unit wall concrete of the exposed walls of the permanent structure diaphragm walls of the quality to achieve precise control and meticulous management,and help enhance the brand building of “Made in China-diaphragm wall wharf”.

Abstract:To address the impact of ship-induced waves on surrounding mangrove wetlands during the operation of the Pinglu Canal project,a novel wave-attenuating floating structure is designed,which combines excellent wave dissipation performance with strong environmental adaptability.To investigate its wave attenuation characteristics,a combined method of three-dimensional numerical simulation using FLOW-3D and in-situ physical model tests is employed.This method quantifies the structure’s effectiveness in attenuating wave height for typical ship waves and explores the influences of water depth,relative submerged depth,and the minimum buffer distance between the structure and mangroves on the wave dissipation effect.The research results indicate that under various relative submerged depths and water depth variations,the novel wave attenuation structure maintains a stable wave height attenuation rate of 55%-75%.The structure consistently achieves a wave height attenuation rate exceeding 55% at various positions relative to the mangrove fringe.Validated by both numerical simulations and physical model experiments,the designed novel wave attenuation structure demonstrates excellent wave dissipation capability and high stability within inland canals.It provides an effective engineering solution for mitigating the erosion of ship-induced waves on the mangrove wetlands along the Pinglu Canal banks,holding significant importance for ensuring the sustainable operation of the canal and the ecological security of its banks.

Abstract:To address the current issue where the highest peak water flow rate of ship lock water conveyance systems domestically and internationally can only support nearly 600 m3/s(based on the Madao Ship Lock of the Pinglu Canal)for safe passage of ships,this study explores how to further improve the peak flow rate of the water conveyance system to about 1，100 m3/s(based on the Xiangjiaba Ship lock of the Jinsha River).Combining relevant German experience,a pressure chamber water conveyance system is adopted.Compared with the four-section cover plate energy dissipation type of the single-sided inlet longitudinal branch corridor of the Madao Ship Lock of the Pinglu Canal,the pressure chamber water conveyance system overcomes the disadvantages of the constant-inertia water conveyance system,such as “complex layout,significant head losses along the way and locally,and compromised conveyance efficiency.”Numerical simulations are used for verification.Preliminary results indicate that the water conveyance system can meet the requirements for safe passage of ships.With the continuous promotion of China’s Western Development Strategy,the water head difference of navigational structures in mountainous areas will exceed 60 m,and even surpass 100 m.The pressure chamber water conveyance system will achieve the goal of smooth passage of ships through dams.Further validation through physical model tests is planned for the next phase.

Abstract:In view of the problem of the unclear influencing factors of rock-breaking efficiency in underwater vibrational impact rock-breaking technology,the impact effects of various factors on rock fragmentation are investigated.By the finite-discrete element method(FDEM)and coupled Eulerian-Lagrangian(CEL)method,a three-dimensional numerical model of underwater vibrational impact rock-breaking built in ABAQUS software to simulate the rock-breaking process and study the influence of different factors on rock fragmentation.The results indicate that the presence of hydrostatic pressure promotes a transition from brittle to ductile states during rock failure.Increasing the static pressure applied by the cutterhead significantly enhances its penetration capability.However,excessively high pressure exacerbates stress oscillations,necessitating optimized load combinations on the basis of engineering practice.Higher rock compressive strength increases the difficulty of cutterhead penetration.A clear negative correlation exists between water depth and penetration capability:in shallow water(5-6 m),the constraining effect of hydrostatic pressure on rock strength is weaker,resulting in lower energy loss of the cutterhead,whereas in deep water(8-9 m),penetration efficiency decreases.The penetration depth of the cutterhead exhibits a characteristic of first increasing and then decreasing with higher vibrational frequency.

Abstract:To address the challenges in resource utilization of dredged soil from the Yangtze River(high moisture content,low strength,and difficulty in forming),and the inadequacies of traditional bubble-mixed lightweight soil(insufficient tensile strength and high brittleness,rendering it unsuitable as a floating island substrate),research on lightweighting and fiber modification is conducted.Orthogonal experiments are conducted to determine the optimal mix proportion by varying the cement-sand ratio,foam volume content,and water-sand ratio.Basalt fiber(BF)and polypropylene fiber(PPF)with different parameters are then incorporated.The modification effects are investigated through mechanical property tests and microscopic analysis.Results indicate that the optimal mix proportion is a cement-to-sand ratio of 0.4,a foam volume fraction of 10%,and a water-to-sand ratio of 0.35,corresponding to a dry density of 0.77 g/cm3,a wet density of 0.84 g/cm3,the optimal 28-day compressive strength,and a water absorption rate of 12.3%.The optimal BF content is 0.5%(length:12 mm),which increases the splitting tensile strength by 18% and significantly reduces the dry shrinkage rate.The optimal PPF dosage is 0.3%(length:9 mm),which enhances the 28-day toughness by 30%,improves the saturated compressive strength,and reduces the probability of brittle failure.Both fibers improve the interfacial bonding strength to a certain extent.With a density close to that of water,this material can be used as a floating landscape carrier,providing technical support for the lightweight and ecological utilization of dredged soil from the Yangtze River.

Abstract:Considering the characteristics of inland ports,such as their relatively small scale and hinterland,high sensitivity to transportation costs,scattered distribution of port-adjacent enterprises,and weak foundation of the collection and distribution network,this research explores the overall planning ideas and methods for small inland ports in plain water network areas,aiming to address practical issues in the actual work of inland port planning,including how to select reasonable locations to support regional economic and industrial development,balance the relationship between the intensification of public docks and the reserved development of enterprise docks,and strengthen multimodal transport connections.The research proposes it is necessary to deeply integrate with local industrial development to strengthen the reliability of throughput forecasting,and conduct directional economic analysis and traffic volume estimation for water transportation.It is also necessary to strengthen the coordination of “multiple plans integration” to achieve full coverage of industries and regional balance in public operation areas,and a multi-port layout with sufficient reserved shoreline for cargo owners.When analyzing the specific location selection of each public operation area,factors such as location,planning,waterway conditions,industry,demand,and roads should be comprehensively considered.Furthermore,the concept of comprehensive transportation and logistics planning centered around ports should be improved.The methods have been applied to the planning practice of Tongxiang port area in Jiaxing inland river port.At present,the on-schedule implementation rate of public operation areas in this plan has exceeded 80%,which fully verifies the practical guiding value of the research methods.

Abstract:To address to the lack of a performance-based seismic evaluation system for high-piled frame wharves,a systematic performance-based seismic analysis is conducted on the wharf in the Gele central operation area of Dongchuan Port.On the basis of the OpenSees platform,a three-dimensional refined finite element model considering the soil-pile-structure interaction is built.Nonlinear dynamic time-history analysis is performed by inputting frequent,fortified,and rare earthquake motions to obtain the dynamic response of the structure at different earthquake levels.On the basis of domestic and international seismic design codes,a multi-level seismic performance evaluation system and quantitative control standards applicable to this type of structure are proposed,with the upper frame inter-story displacement angle and pile top displacement as key performance indicators,and the seismic performance of the structure is comprehensively evaluated.The results show that under frequent,fortified,and rare earthquake actions,the maximum inter-story displacement angles of the upper frame are 1/1 429,1/417,and 1/167,respectively,and the maximum displacements of the pile top are 0.006,0.026,and 0.060 m,respectively,all of which do not exceed the corresponding performance level limits.The overall performance of the structure is good,meeting the fortification goals of “no damage during small earthquakes,repairable during medium earthquakes,and no collapse during large earthquakes”.

Abstract:To address the complex dynamic issues for barges loaded with heavy,high-center-of-gravity and large windward area cargo,such as large steel cylinders,during quayside mooring—including excessive motions,extreme mooring line tensions under effects of wind,wave,and current,a systematic numerical study is conducted.A coupled “frequency-domain and time-domain” approach is employed.A frequency-domain hydrodynamic model of barge is developed in OrcaWave using 3D potential flow theory to obtain key parameters like added mass and wave excitation forces.A fully-coupled time-domain model,integrating the barge,cargo,quay,and mooring lines,is built in OrcaFlex.Simulations are performed for four sea states with varying wave periods and wind speeds.The results quantitatively demonstrate that wave period is the dominant environmental factor governing mooring system safety.Long-period waves are the primary cause of the large-amplitude,low-frequency motions of heavy load barge that induce extreme loads in the mooring system.

Abstract:东江作业区；挖入式港池；规划；布置方案；水流；淤积;二维数学模型

Abstract:In response to the complex risk factors and difficulties in risk identification and management in overseas port construction projects,risk identification,risk level assessment,risk trend analysis,and risk correlation research have been conducted.Engineering statistical information extraction and quantitative analysis methods are adopted to extract 24 risk events from 73 overseas port construction projects.The occurrence probability,processing cost,and project delay of each risk event are calculated to draw a development trend chart.By applying conditional probability calculation and regression analysis methods,the correlation among risk events is determined,and three risk chains are finally obtained.The research results indicate that extreme high temperatures,tidal changes,changes in property owners,import restrictions,and caisson transportation and installation are high-risk events.Since 2017,the occurrence probability of natural and social environmental risks has shown an upward trend,the cost of handling extreme heat risks has significantly increased,and the delay in construction caused by owner and social risks has significantly increased.Chinese project managers can use methods such as improving contract details,strengthening preliminary planning discussions,and cooperating with design to develop material substitution plans to control the top nodes in the risk chain and curb the spread and propagation of risks.

Abstract:Floating breakwaters are widely used in coastal engineering due to their effective wave attenuation capabilities.To address the long-period and large-amplitude wave environment faced by offshore photovoltaic(PV)farms,this study optimizes floating-box breakwaters by attaching inclined wing plates to the bottom of the floating boxes and adopting a double-floating-box configuration.Based on the time-domain wave height response signals under irregular wave conditions obtained from scaled model tests,the wave transmission coefficients are calculated to compare and analyze the wave attenuation performance of floating breakwaters with different structural forms,and the mooring chain forces as well as the motion states of the floating boxes are further measured.The results show that both measures can reduce the wave transmission coefficient and improve the wave attenuation performance of the structure.For every 0.5 m increase in the water entry length of the inclined wing plate,the transmission coefficient decreases by approximately 15%.Selecting the local optimal solution from the experiments,a double-floating-box floating breakwater with inclined wing plates attached to its bottom is designed.This structure exhibits smaller mooring chain forces and has an obvious restraining effect on the surge,heave,and pitch motions of the floating boxes,which is an effective approach in engineering design.

Abstract:Addressing the insufficient operation capacity of the fixed-side interaction mode adopted by the Guangzhou Nansha Phase IV Automated Terminal,this study proposes a collaborative solution integrating process optimization and layout innovation,based on researching the impact of the yard loading-unloading system and yard planar layout on the interaction capacity of external trucks.By subdividing the functions of interaction zones,reconstructing the operational logic,and optimizing the process flow for the coordination of fixed-point operations with loading and unloading activities,this study further proposes multiple expansion design schemes for interaction zones.Among these schemes,a yard layout featuring an end interaction zone with a U-shaped path based on single-cantilever rail-mounted gantry cranes is selected,which enables the efficient connection of operational links and the rational redistribution and utilization of terminal resources.A simulation model is adopted to verify the optimized scheme,and the results show that the operational capacity of interaction zones for external trucks is increased by 102.00%,which represents a significant breakthrough in overcoming the efficiency constraints of automated terminals with a fixed-side interaction and parallel layout.The collaborative optimization of processes and layout enables a multi-fold improvement in the efficiency of external trucks at low cost,which not only provides an upgrade path for Nansha Phase IV terminal but also serves as a reference for the automated transformation and new construction design of similar terminals.

Abstract:In view of the long-term risks of settlement,displacement,scouring,and collapse in breakwaters of hazardous chemical terminals,a comprehensive monitoring study on the basis of multi-source data integration is conducted,and a two-year engineering application is carried out on the breakwater of a liquefied natural gas project in Jiangsu.Twenty-five global navigation satellite system monitoring points are deployed for millimeter-level settlement and displacement monitoring.Underwater topographic data are acquired and processed by the fusion technology of multi-beam and side-scan sonar to generate high-precision 3D topographic maps.Surface sliding and collapse of the breakwater is identified by combining unmanned aerial vehicle imagery with high-definition camera surveillance.Finally,all monitoring data are integrated through a cloud platform to achieve real-time collection,monitoring,and comprehensive analysis.The results show that the integration and comprehensive analysis technique of multi-source data greatly enhances the accuracy and timeliness of breakwater monitoring,achieving a transition from single-point,low-frequency manual monitoring to multi-dimensional,automated,and intelligent monitoring.This technique provides reliable technical support for the safety management of hazardous chemical terminal breakwaters and offers valuable reference for the safe operation and risk management of similar port facilities.

Abstract:The common leading mark design involves aligning the front and rear marks with the central axis of the navigation channel.The central channel marks,along with light buoys distributed on both sides of the channel,guide vessels safely in and out of the port.However,in northern ports,the winter freezing period brings large volumes of floating ice,which can damage or displace these floating marks.This poses a risk to navigation safety in channel segments where the effectiveness of central leading marks is compromised.Additionally,relying solely on central leading marks provides limited navigational assistance for two-way traffic during vessel meetings.To address these issues,Multi-group leading marks can be installed to meet different pilotage needs.However,current design standards for leading marks primarily focus on parameters for central channel marks,offering little practical guidance for designing multiple sets.The entrance channel of the Huanghua Port Coal Terminal accommodates two-way traffic for 70,000 DWT vessels,making its leading mark design a typical reference for multi-group leading marks design in northern ports.This study examines the parameter selection process in multi-group leading marks design through project examples,highlighting key considerations.It proposes a method for determining the lateral spacing of multi-group leading marks and outlines design principles for side leading marks.The study also summarizes the navigational environmental characteristics during ice periods in northern ports and analyzes suitable scenarios for deploying multi-group leading marks.Finally,it identifies the main technical points for leading marks design in northern areas of China,providing reference and guidance for similar projects and the revision of industry standards.

Abstract:This study investigates the application of static pressure pile planting technology to address challenges in the reinforcement and reconstruction of sheet pile-gravity composite wharves,including complex strata,sensitivity of existing structures,and restricted construction space.By adopting methods such as pile-pressing force decomposition analysis,equipment selection comparison,and construction process optimization,a static pressure pile planting system for steel sheet piles is established to adapt to the triple constraints of “structural protection + complex strata + limited space”.Results indicate that when penetrating various structures and complex foundation conditions,the GIKEN SCU-600M static press,combined with staged auger drilling technology using spiral drill pipes,can effectively reduce pile-end resistance,control the pile-pressing force within the range of 150-350 kN,and achieve stable penetration.After the establishment of this construction system,the construction efficiency is improved by approximately 31%,the average single-pile construction time is shortened from 3.23 h to 2.22 h,the positioning accuracy reaches ±3 mm,and the verticality error is controlled within 1%.Static pressure pile planting technology can achieve low-disturbance,high-precision,and high-reliability construction under complex conditions,making it particularly suitable for port reconstruction projects with strict structural protection requirements.The research outcomes are replicable and have popularization and application value in the reinforcement of port structures,providing a quantifiable technical reference for similar projects.

Abstract:To address the prominent shortcomings in safety and emergency management at Zhapo fishing port in Yangjiang,such as outdated monitoring methods,slow emergency response,insufficient collaborative linkage,and lack of scientific support for decision-making,a smart emergency command system based on digital twin technology is constructed.The system takes the five-dimensional digital twin model as its theoretical framework,integrates technologies such as the internet of things(IoT),BIM+GIS,big data,and artificial intelligence,and forms an intelligent management closed loop of “sensing-perceiving-analyzing-decision-making-controlling”.Practice shows that,compared with traditional emergency management models,this system successfully transforms the static emergency plans for “people,ships,ports,and venues” into dynamic,visual,manageable,and traceable digital solutions.In typhoon emergency scenarios,the recall response time for fishing vessels is shortened from 2 hours to 40 minutes,with an efficiency improvement of 65%.This verifies that the system can effectively promote the transformation of fishing port emergency management mode from “passive response and experience-based decision-making” to “proactive early warning and scientific regulation”, providing a replicable technical path and practical model for the construction of smart fishing ports in China.

Abstract:To address the inefficiency,pollution,and safety risks of traditional floating cranes in water transshipping bulk cargo such as coal and ore,this study explores a novel transshipment technology solution to implement the requirements of the “Yangtze River Protection” strategy.Through a comparative analysis of existing transshipment models and vessel characteristics,combined with advancements in continuous loading and unloading equipment,it is proposed that a self-unloading vessel scheme is suitable for sand and gravel transshipment.For coal and ore cargo,an innovative integrated system centered on a chain-bucket continuous unloader,ship loader,and pontoon platform has been developed.Two technical solutions are designed:Scheme 1 features a separated layout of “chain-bucket unloader + belt conveyor + fixed ship loader,” while Scheme 2 integrates unloading and loading functions into a highly compact chain-bucket combined loader-unloader.The results show that both transshipment schemes can achieve an operational efficiency of 2,000 t/h,representing a 300% increase compared to traditional floating crane transshipment(500 t/h),while also enabling zero spillage and zero dust emission during operations.Among them,Scheme 2 demonstrates superior performance in energy consumption and environmental protection due to its highly integrated equipment design.This study provides an innovative technical pathway for the green and efficient transformation of heavy bulk cargo transshipment operations.

Abstract:The upper reaches of the Yangtze River feature numerous rapids and hazardous rapids,where navigable safety poses significant challenges.There is an urgent demand for monitoring hydraulic parameters and providing services to vessels navigating these channels,but there is a lack of practical application of suitable monitoring technologies.We analyze multiple flow monitoring technologies and their adaptability,conducting field comparison tests between unmanned aerial vehicle(UAV) radar-based flow measurement and UAV surface imaging velocimetry.Then we propose a framework for intelligent application.The results demonstrate that the UAV radar-based method can simultaneously measure flow velocity and water level with high accuracy,velocity measurements achieve over 96% precision,and water level errors are within 0.1 m,making it suitable for monitoring hydraulic parameters in rapids.The UAV imaging velocimetry method effectively captures planar flow fields,proving more applicable for monitoring complex flow patterns in hazardous rapids.By developing an intelligent service system and applying the integrated use of on-site water flow monitoring data and mathematical model calculations,timely,accurate,and more comprehensive water flow information support can be provided for shipping.

Abstract:Aiming at the technical challenges faced in the expansion and upgrading of navigation-obstructing dam locks during the capacity enhancement of China’s inland waterways,taking the renovation project of the Yanzhou Hydro-junction on the Lishui River as the research object,systematic research is conducted on key technologies such as optimization of the overall hub layout,arrangement of an unprotected approach channel,determination of the minimum navigable water level at the final cascade,innovative shared layout of power plant and lock structures,application of high-performance materials,and construction diversion in narrow riverbeds.Through methods such as hydraulic model tests and analysis of measured hydrological data,a new hub layout scheme is proposed,which adjusted the original Z-shaped dam alignment to a straight-line alignment,increasing the navigable flow discharge from the original 7,000 m3/s to the 2-year recurrence interval flood standard of 8,910 m3/s.Innovatively adopting a shared structure for the ship lock and power plant building,saving a width of 20 m.Ultra-high performance concrete(UHPC)is applied in the bridge pier structures within the stilling basin of the sluice gate,which has three times the abrasion resistance of ordinary concrete.The staged diversion method combining precast concrete enclosure cofferdams with curtain grouting is applied in the ship lock project,successfully overcoming the construction challenges of highly permeable gravel bedding in a narrow riverbed.The conclusions indicate that this project has achieved multi-objective coordination including navigation safety,hub operation,flood control scheduling,and ecological environmental protection,providing a quantifiable and promotable technical path and engineering example for similar renovation projects of navigation-obstructing locks.

Abstract:A mathematical model is employed to predict and analyze the effectiveness and impacts of the Phase II Project of the South Passage Channel Regulation in the Yangtze Estuary.The results indicate that,after the project implementation,the ebb current velocities significantly increase along the south side of the spur dike and in the main channel of the bar area,providing critical hydrodynamic support for dredging the shallow section of the bar and maintaining an 8-meter-deep main channel.The spur dike reduces tidal dynamics in the Jiangya North Passage to the north,forming a sheltered area that effectively stabilizes the hydrodynamic boundaries of the South Passage and the Jiuduansha Wetland.Following the project,the channel morphology in the bar area becomes more stable,with enhancing flow dynamics in the main channel,promoting scouring,and a stabilized thalweg—collectively improving channel stability and facilitating construction and maintenance.The results validate the correctness and feasibility of the regulation strategy focusing on “nourishing shoals,stabilizing channels,guiding flow,and blocking sediment.” Moreover,the project shows negligible impacts on adjacent hydraulic structures and the North Passage deepwater channel,with minimal influence on the South Harbor,the South Passage coast,major hydrological facilities,and floodgates.

Abstract:The confluence reach of the Jiuzhou River and the Pinglu Canal is characterized by a large confluence angle,a high discharge ratio,and a considerable elevation drop.During sudden tributary floods,these conditions readily induce flow disturbances and excessive transverse velocities,posing a serious threat to navigation safety.A 150 scale physical model is built to conduct systematic experiments.One baseline design scheme and three optimized alternatives are developed to analyze flow velocity distribution,transverse velocity,sediment deposition patterns,and water surface fluctuations.The results indicate that the maximum transverse velocity in the baseline design reaches 0.49 m/s,significantly exceeding the regulatory limit.Although optimization scheme I reduces the velocity to 0.44 m/s,some non-compliant zones remain.Optimization scheme II effectively controls transverse velocity but causes severe sediment accumulation in the gentle-slope zone.In contrast,optimization scheme III not only ensures compliance with transverse velocity standards but also directs sediment deposition into the settling basin while creating additional low-flow zones suitable for fish habitats.The combined arrangement of multi-stage energy dissipation basins and steep slopes can simultaneously safeguard navigation safety,manage sediment,and support ecological protection.The proposed “navigation-sediment-ecology” integrated management approach offers a practical reference for similar regulation scheme for mountainous confluence reaches.

Abstract:The contact relationship at the pile-soil interface is a key issue that should be considered in numerical calculations of the stress and deformation of hydraulic structures since the significant differences in the mechanical properties between the pile foundations and the foundation soil.To address the pile-soil interface contact problem,a large-scale multifunctional pile-soil interface shear apparatus independently developed is used to conduct experimental study on the frictional characteristics of the contact interface under different normal force and pile material conditions.The experimental results indicate that the interface shear stress increases with the growth of shear displacement until it reaches a peak value and then stabilizes.This peak value is proportional to the normal stress and is related to the roughness of the pile material.Based on contact mechanics,a calculation model for the pile-soil interface friction coefficient is established,considering both the undamaged and damaged states of the interface soil.The error between the calculated values of the model and the experimental data from interface friction tests is less than 5%,accurately reflecting the frictional characteristics of the pile-soil interface.This model is applied to analyze the bearing characteristics and structural stress-deformation of PHC piles in a lock chamber.The single pile load-displacement relationship and the overall structural displacement calculation results are consistent with field load test results and monitoring data.This model will contribute to enhancing the accuracy offorce and deformation analysis for hydraulic structures.

Abstract:The anti-overturning stability calculation of hydraulic structures is a core issue in engineering design.However,the ambiguous division of stabilizing and overturning moments in design codes results in non-unique calculation outcomes,even when the same code or different ones are adopted for anti-overturning stability calculation.In response to the ambiguous division of stabilizing and overturning moments in current codes,this paper analyzes the controversial points of anti-overturning formulas in the Technical Specification for Retaining and Protection of Building Foundation Excavations,Specifications for Design of Highway Subgrades,Code for Design of Hydraulic Structures of Shiplocks, and Code for Design of Retaining Walls for Hydropower Projects,and proposes a theoretical framework centered on base stress analysis.The study demonstrates that anti-overturning stability is essentially attributed to the control of base tensile stress.By analyzing the distribution of the compressive area of base stress using the material mechanics method,the critical ratio between stabilizing moments(vertical load moments)and overturning moments(horizontal load moments)is derived.This ratio is an indirect characterization of the base stress distribution state,which ultimately verifies the rationality of the formulas in the Code for Design of Retaining Walls for Hydropower Projects.The research results provide a theoretical basis for unifying the calculation standards of anti-overturning stability and recommend taking base stress verification as the criterion for anti-overturning stability.

Abstract:To explore the influence of heavy rainfall on the lateral seepage characteristics of permeable ship lock chambers,this paper adoptes the ANSYS thermal analysis module to establishe a two-dimensional mathematical model of permeable ship lock chamber,considering the irrigation and drainage for navigation,and studies the seepage characteristics of permeable ship lock chambers under no-rainfall and multi-level rainfall conditions.The results show that under no-rainfall conditions,the seepage pressure head at observation points shows a stable periodic variation state after the chamber stable operation,the seepage pressure head amplitude and permeation gradient at the observation points far from the chamber are small.Under light rainfall conditions,the permeability characteristics of the chamber changes insignificantly.However,under heavy rainfall conditions,the seepage pressure head of other observation points rises significantly,except for the observation points controlled by the water level in chamber.The increase and attenuation of the seepage pressure head deviation lag behind the rainfall process.The permeability characteristics of the observation points behind the gate wall change significantly,the seepage pressure head deviation reaches 2.36 meters,and the maximum permeation gradient ratio reaches 2.33.The heavy rainfall has a significant impact on the permeability characteristics of permeable lock chambers and the impact is a hysteretic nature,the seepage characteristics of the soil behind the gate wall are more affected by heavy rainfall.

Abstract:To address the issues of adverse flow conditions and significant siltation in the confined waters of the Longhuazui bend in the Huangpu River,a study is conducted on the bend’s evolution analysis and regulation plan layout.By using technical methods such as data comparison,three-dimensional mathematical models,and ship simulation techniques,a waterway regulation plan is proposed,involving dredging and cutting the shoal of the Longhuazui Bend while filling and stabilizing the deep channel along the concave bank.The model calculation results show that the regulation plan is highly effective.After implementation,the main improvements in navigation conditions for the bend are as follows:1)The turning angle of the water flow within 500 m of the accident-prone bend is reduced by 5.8°.2)The maximum cross-flow during ebb tide is reduced by 30%.3)The siltation on the convex bank is reduced by about 35%.The results of the ship maneuvering simulation model show that after the implementation of the plan,the intensity and frequency of the ship’s steering personnel controlling the ship’s turning have been significantly reduced.The research shows that the menthod of combined “cutting the shoal and filling the bottom”in narrow bends can effectively improve the flow pattern of the bend and reduce siltation on the convex bank.This method has been applied to the Huangpu River,and the research results can provide valuable references and guidance for the optimization of the Huangpu River waterway conditions and similar waterway regulation in the future.

Abstract:To the high reliability requirements of the ship lock control system,an in-depth study is conducted on the application of redundancy technology in the Hunan Water Transport Construction Project- Ship Lock Project.A multi-level redundancy designis adopted,with a dual PLC(programmable logic controller)hot standby architecture deployed at the control layer.Periodic data mirroring is achieved through a dedicated synchronization module,eliminating single point failures.At the network layer,a physically isolated dual-fiber ring network is constructed,reducing the communication packet loss rate to zero.At the data layer,dual engineering node servers are used for hot standby,forming a full-stack fault-tolerant system covering the control layer,network layer,and data layer.Combined with practical engineering cases,a practical analysis and comparison are conducted.The results show that the multi-level redundancy design can significantly improve the fault tolerance of the system,achieving an annual availability rate of 99.99% for the ship lock control system and ensuring zero unplanned downtime for the “Golden Waterway”.The relevant experience and methods can provide reference for similar projects.Based on actual on-site requirements,a dynamic redundancy adjustment mechanism can be adopted to achieve partial equipment redundancy,thereby achieving the effect of “high reliability-low cost-strong adaptability”.

Abstract:Transporting high-concentration,large-grain rock mixtures via mud pumps in heavy cutter suction dredgers’ rock excavation condition,impeller geometric parameters significantly constrain performance and pose a high risk of clogging.A study is conducted on the impellers of“Tiankun”dredger’s underwater and onboard mud pumps.By applying the relationship formulas between impeller parameters and medium characteristics,combined with numerical simulation analysis of flow fields and external performance,supplemented by model pump tests for validation,the effects of impeller outlet widening and blade optimization are investigated.An analysis of the head,power,and efficiency of the impeller before and after optimization is conducted.The rotational speeds of the underwater and onboard mud pump impellers are determined.The results demonstrate that increasing the impeller outlet width by 10% and optimizing the blade design improve the flow passing diameter by over 5% and the flow volume by more than 15%,significantly enhancing the passage capability for large particles.The total power consumption of the optimized impeller meets the requirements for simultaneous operation of high-power equipment such as cutters,water pumps,and mud pumps.This optimization solution provides parameters and technical pathways for impeller design and serves as a reference for improving the performance of similar equipment in complex solid-liquid conditions.

Abstract:Large precast concrete bucket foundation for port and waterway engineering has multiple compartments sharing the same top slab,coupled with each other,and the difficulty of leveling construction is high.Excessive foundation inclination might increase resistance and even prevent sinking to designed depth.Thus,continuous and timely leveling control is vital during the sinking process.Current leveling control relies on manual operation,leading to issues such as delayed and passive leveling and low efficiency.To overcome such issues,research on automatic penetration technology is conducted based on the structural characteristics of large multi-compartment bucket foundations.A control mode dominated by foundation inclination and supplemented by pressure is proposed,and the 15 compartments bucket foundation is divided into 8 quadrants and 9 states.Using the PID（proportional，integral and derivative)method,an algorithm based on the real-time monitoring data to adjust the proportional valve opening is developed to control water extraction flow and inner pressure.An automatic leveling control program is then formulated.Engineering application results demonstrate that the automatic penetration technology can increase the penetration rate of large multi-compartment bucket foundations to 1.5 m/h.This reduces the installation time from the original 16-18 h under manual control to 12 h,with an efficiency increase of approximately 30%.Additionally,the elevation difference at monitoring points during installation is consistently maintained within 0.15 m,effectively enhancing control precision and ensuring stable and safe penetration.

Abstract:The East Artificial Island of the Shenzhen-Zhongshan Link serves as the foundation for the large interchange between the tunnel and the Guangzhou-Shenzhen coastal expressway bridge,and it is located directly beneath the existing coastal expressway.A total of 41 piers of the expressway are situated within the island and are affected by the construction of the artificial island filling.To ensure the normal operation of the coastal expressway,both the horizontal and vertical displacement control values at the pier tops must be maintained within 5 mm during construction and after the completion of the artificial island.In response to the challenges of bridge deformation control during the construction of the artificial island,key measures such as strengthening the foundation of the island-wall structure,setting up isolation protection piles for piers,backfilling in sections with proper foundation treatment,and reasonably controlling the backfill height difference are adopted in the design scheme of the artificial island.The geotechnical finite element analysis software midas GTS NX-2017 is used to analyze the influence of the island filling process and island wall structure construction of the artificial island on the deformation of the abutments.Real-time monitoring of bridge settlement and displacement is conducted to guide the construction process.These measures successfully facilitated the formation of the East Artificial Island under the coastal expressway bridge,ensuring the smooth completion of the Shenzhen-Zhongshan Link and the normal operation of the coastal expressway,which provides reference significance for other engineering constructions.