Abstract:Water transportation is a critical factor affecting the economic and social development of nations and regions.As the backbone project of the New Western Land-sea Corridor and a landmark project in accelerating the construction of a transportation powerhouse, Pinglu Canal will restructure the regional transport development landscape.To build the Pinglu Canal with high standard and quality, it is necessary to adhere to the historical perspective, make the advantages of water transportation and unleash the potential of the “sea”;it is necessary to comply with the systemic perspective, utilize scientific methodologies to coordinate resources and achieve intended goals;it is necessary to conform to the practical perspective, and comprehensively apply the new development concept to drive the balanced and coordinated development of the regional economy.

Abstract:To the problem of how to fully unleash the comprehensive benefits of the Pinglu Canal and achieve sustainable investment and development during the development process, this study is based on the macro perspective of coordinated development of the Canal Economic Belt.Using systems engineering theory and interdisciplinary research methods, the transmission mechanism of the comprehensive benefits of the Canal is sorted out, and the development ideas of the Pinglu Canal Economic Belt are clarified.It is proposed to systematically handle the relationship between comprehensive planning, development entities, cooperation models, and project implementation, forming a reasonable path for internalizing the external benefits of large-scale public welfare infrastructure.On this basis, the paper focuses on the characteristics of different types of project clusters such as transportation infrastructure, comprehensive development of resources, comprehensive land use, and coordinated development of industries.A reasonable and feasible investment and financing model is constructed，and market-oriented profit realization mechanism is explored, ultimately forming a systematic solution to ensure the sustainable development of the Canal Economic Belt.This study can provide a reasonable path for the implementation of Pinglu Canal comprehensive development，and provide reference for promoting the development of similar cross water system connectivity engineering projects.

Abstract:The stability of moored ships is affected by the significant medium-long period waves in the sea area where overseas ports are constructed.We carry out a numerical simulation study on the hydrodynamic response of moored ships based on the change of wave periods,and consider different loading states and different mooring arrangements that may be encountered by the ship during the mooring process.Then we carry out the validation and analysis work using the mooring analysis model MIKE21 Maritime.The results show that the hydrodynamic response of the moored ship is mainly affected by the wave period,especially the surge and sway motions.The sway motion is more obviously affected by the mooring arrangement,and the roll motion is most obviously affected by the loading state.The breast line force of moored ship is the most sensitive to changes in incident wave periods compared to the other lines.

Abstract:For the moment,Xijiang trunk channel is facing problems on obstruction in the lower reaches,the middle reaches,the upper reaches and branches,which is impeding the healthy development of inland water transportation with the Pearl River.Based on the development characteristics of inland channel freight volume in Guangxi and relevant freight volume prediction conclusions,we conduct a analysis on blockage points of Xijiang shipping trunk channel and its main branches from the perspective of channel throughput capacity,systematically analyze the calculation formula for channel throughput capacity in different sections,and summarize corresponding problems of blockage points in the Xijiang trunk channel and its main branches based on the actual situation.We propose solutions and suggestions from the perspectives of providing better facilities,improving maintenance and operation management,promoting ship-type development,which can provide technical supports to help the governmental departments on having better sector management and improving better shipping services.

Abstract:2022 is a year of reshaping the global energy market.In the short term,LNG increment is limited,supply and demand are in a tight balance,and supply is relatively tight.To meet future LNG demand,it is necessary to increase supply side investment to improve market supply and demand adaptability.In the long run,the global transition towards low-carbon requires natural gas to balance the system.Therefore,natural gas needs to achieve decarbonization,especially in industries with high difficulty in electrification such as industry,transportation,and heating.Hainan is close to the main routes of Southeast Asia and Northeast Asia,and is the first station in the South China Sea for offshore energy channels.It bravely undertakes the responsibility of energy safety and supply assurance.Through analyzing market demand,this paper proposes the construction ideas of Hainan liquefied natural gas (LNG) receiving station to ensure national energy security.

Abstract:The construction of logistics parks in port areas will help to expand and improve port functions,providing robust support for industrial agglomeration and urban development.Through sorting out the current development status of logistics parks behind major ports in the country,it is found that some parks have problems such as unclear positioning,inadequate infrastructure,and ineffective coordination with port functions.Through the analysis of the causes of these problem,the key difficulties and countermeasures of the planning and layout of port logistics parks are identified.The basic methods of planning and layout are proposed from three aspects:park positioning,site selection,scale,and functional layout.Park positioning should be integrated with port development,industrial layout,and urban planning to achieve integrated development of port,industry,and park.The site selection should fully consider transportation conditions such as highways,waterways,and railways,with the aim of promoting multimodal transportation as the starting point.The functional layout should focus on the movement of goods in and out of the port,and consider factors such as surrounding relationships,transportation connections,and site conditions.The research results provide a reference basis for the planning and construction of port logistics parks,and take the logistics park in Xuwei Port Area of Lianyungang as an example.

Abstract:Based on the health monitoring data of the high-pile wharf,aiming at the problem that complex environmental factors affect the monitoring accuracy,this paper proposes an EMD-VMD-LSTM combined algorithm to process and predict the monitoring information in the high-pile wharf structure,and it verifies the feasibility of using the EMD-VMD-LSTM combined algorithm for prediction and early warning analysis of large-scale monitoring data in the field of high-pile wharf structure through comparative analysis.At the same time,based on the EMD-VMD-LSTM method and a fixed warning threshold,a method for determining dynamic warning thresholds is proposed,the early warning method combining static and dynamic warning is designed,and a multi-index and multi-level high-pile wharf structure safety warning system and corresponding warning process are constructed.The research results can improve the accuracy and efficiency of safety early warning of high-pile wharf structure,and also provide a certain reference for the safety early-warning management of similar engineering structures.

Abstract:In the context of the global ecological crisis,the international port community has put forward the concept of “green port” through the concept of green development throughout the construction and operation of the port.The purpose of green port construction is to implement the concept of green development using green technology and implementing green management,and guide the port to take a resource-saving and environment-friendly development path.By consulting a large amount of literature,this paper starts from the construction and development of green ports,and sorts out the research trends of domestic and foreign scholars on green ports and the application status of ports according to the four aspects of green port concept,green port technology,green port management and green port evaluation.In view of the existing problems in the construction of green ports in China,this paper forms improvement suggestions and promotion paths,aiming to integrate the concept of green development into the whole life cycle of ports and provide reference for the green transformation of ports in China.

Abstract:Carbon emission accounting is an important foundation for implementing the “carbon peak” and “carbon neutrality” goals.In response to the lack of a unified accounting system in port areas,based on Accounting Methods and Reporting Guidelines for Greenhouse Gas Emissions from Land Transport Enterprises (Trial) and Standard for Building Carbon Emission Calculation,we confirm the scope and content of port carbon emission accounting,take fuel,electricity,heat,water,air conditioning refrigerant and green space as the accounting content of the port area carbon emission,and calculate and summarize the carbon emission factors for the accounting content.Then we take a container terminal as an example to apply the carbon emission accounting system,and propose a carbon reduction path based on the carbon emission accounting results.The results show that the method has the characteristics of quick calculation,and can provide a scientific basis for the carbon emission accounting of the port area.

Abstract:In response to the high density,various types and varying sizes of ships within Zhanjiang harbour bay,as well as the shortage of anchoring points,to scientifically plan the anchorage,on-site research is conducted on the anchorage demand and operation status of the Zhanjiang Port.Based on the classification of anchoring points,a calculation model is established to calculate the optimal number of anchoring points within Zhanjiang harbour bay using queuing theory,and based on the calculated anchorage demand,the short-term and long-term anchorage planning plans are proposed.Compared with the method of calculating the number of anchoring points without classificating the anchoring points,the anchoring requirements in Zhanjiang Harbor obtained in this paper are more in line with reality.The layout of the anchorage location is more reasonable,the functional division is more complete,and the anchoring safety is more guaranteed,which can reduce the waste of funds caused by excessive construction of the anchorage,and has significant social and economic benefits.

Abstract:In response to technical problems encountered during the process of transforming other cargo terminals to LNG terminals in recent years,this paper analyzes key factors such as design standards,layout,berthing methods,hydraulic structures,and process requirements combined with engineering examples.The paper sorts out and summarizes 15 technical points in the transformation process of LNG terminals,and forms a set of transformation technical system which covers berth length,berthing facilities,liquid collecting tanks,compensation platforms and the compatibility of original structures and design standards,etc.,and verifies its applicability based on the different characteristics of engineering examples.Based on this system,a safe,reasonable and applicable design scheme can be quickly proposed,which can provide reference for similar projects.

Abstract:The flow conditions at the inlet of a ship lock are related to the efficiency of the water conveyance system and the safety of ship berthing.The layout of the inlet is an important part of the hydraulic design and model testing of the ship lock.This paper focuses on two common types of inlet layout,combined with the specific conditions of the water conveyance system of a ship lock,and uses numerical simulation methods to compare and analyze the impact of these two types of inlet layout on the water conveyance system from the aspects of water conveyance hydraulic characteristics and flow state.The results show that for the lock wall long corridor ship lock water conveyance system,the engineering measures of diagonal pulling of the outer guide wall of the water inlet have more advantages in controlling the ultra-high inertia and the maximum rising speed of the gate chamber water surface,enhancing the stability of the flow process of the inlet branch hole,and improving the flow state of the water inlet relative to the outer guide wall of the inlet.The results can provide technical reference for the layout of the inlet of the lock water.

Abstract:When water flows past the pile group,there will be a descending water flow and a horseshoe shaped vortex in front of the pile,which significantly strengthens the sediment carrying capacity and transport capacity of the water flow.Based on the local scour flume experiment of unsteady flow pile group,this paper studies the local scour distribution and maximum scour depth of pile group under unsteady flow.By using computational fluid dynamics software Flow 3D to simulate and calculate the flume experiment,and investigate the development process of local scouring around the pile group under unsteady flow.The research shows that the scouring range of upstream single piles is from 2D in front of the pile(Pile diameter) to 1D behind the pile,and from 2.5D on the outside of the pile to 1D on the inside of the pile.The scouring range of downstream single piles is from 1D in front of the pile to 1D behind the pile,and from 1.5D on the outside of the pile to 1D on the inside of the pile.Additionally,there are differences in the transverse scouring sections in various areas of the pile group.The maximum scouring depth and scouring volume increase logarithmically with time until the scour equilibrium is reached.Moreover,20% of the time for local erosion can achieve 50% of the scouring equilibrium state,and 50% of the time can reach 80% of the scouring equilibrium state.

Abstract:In view of the problems that the navigation buildings of the Three Gorges-Gezhouba cascade hub are in full load operation for a long time,and the number of ships waiting for locks is large and the time is long,the country is studying to promote the Three Gorges water transport new channel and Gezhouba shipping capacity expansion project.The construction period of the Gezhouba shipping capacity expansion project will have a significant impact on the passing capacity of the Gezhouba ship lock.To improve the passing capacity of Gezhouba shiplock during the construction period,the research is carried out on the electric intelligent working boat towing ships to pass through the lock in groups.Three operation schemes for the group passing through the 1# and 2# shiplocks of Gezhouba are proposed,and theoretical calculations and analysis are conducted,and comprehensive demonstration is carried out from multiple dimensions such as safety,efficiency,and economy.It is concluded that the bidirectional matching cycle operation mode of Gezhouba 1# and 2# shiplocks is the optimal scheme,and the group passing of ships through the lock can significantly improve the efficiency of ship entry and exit,and improve the passing capacity of the Gezhouba shiplock during the construction period of the Gezhouba shipping capacity expansion project.

Abstract:Based on the monthly mapping of the construction section of the deep-water channel of Yangtze River Estuary from 2016 to 2019 year and the observation data of floating mud under normal weather conditions during the flood and low season of the deep-water channel in North passage from 2016 to 2020 year,the transport characteristics of floating mud,the change characteristics of silt back and high-frequency depth are studied,and the fine dredging and maintenance plan of the channel is proposed.The results show that under normal weather conditions,the depth difference of high and low frequency depth in the flood season is larger than that in the dry season,and the thickness of floating mud in the middle part of the northern channel is much larger than that in the dry season,and the sediment quantity of the channel increases with the increase of the depth difference of high and low frequency depth.It is suggested that the fine-maintenance dredging scheme should be implemented first in flood season.After trial application,it can effectively reduce the interference of floating mud,high and low frequency depth difference and other changes on channel assessment measurement and channel maintenance dredging,and it improves the fine-management level of channel maintenance and dredging.

Abstract:The contents and methods of prototype observation for channel improvement projects in mountainous rivers are deeply analyzed,and a set of prototype observation methods for channel improvement in mountainous rivers is proposed.Taking Minjiang River (Longxikou Junction to Yibin Hejiangmen) Waterway Improvement Project Phase I construction drawing design as a case study,the technical difficulties and key points of control survey,topographic survey and hydrographic survey are expounded.The measurement method and efficiency of prototype observation at three flow levels,namely,dry,medium and flood,are discussed,and the working period of measurement is reasonably arranged,which solves the problem that each item of hydrographic survey needs to be measured at the same flow level.The research results have reference significance for the prototype observation of channel improvement in mountainous rivers.

Abstract:The construction of a new ship lock project on the existing hub in the sharp bend river section has many restricted factors in the layout of the ship lock and complex navigation conditions.In order to analyze navigation flow conditions of the ship lock approach channel,we establish a 180 normal physical model of the Yuanhe Shizhou hub,and conduct tests on navigation flow conditions of the upstream approach channel of the ship lock.Then we compare the flow velocity distribution in the entrance area of different lengths of the separation dike,and analyze navigation conditions of the entrance area of the ship lock in combination with self-propelled ship model tests.The results indicate that extending the separation dike has a significant effect on reducing the peak lateral flow velocity in the entrance area and improving the flow pattern.When the separation dike is extended by 250 meters,the maximum navigable flow of the upstream approach channel of Shizhou ship lock can reach the standard requirement of a once-in-20-year flood.

Abstract:In order to understand the fish passing effect of Angu vertical slot fishway and 1# imitation natural channel,we carry out the pass and turn-back tests of two kinds of fish in two fishways.Taking Onychostoma sima and Hemibarbus labeo as research objects,we install the PIT monitoring equipment in the fishway to record the behavior of two kinds of labeled fish in the vertical slot fishway and 1# imitation natural channel.The results show that 14 species of fish are collected in the fishway during the survey,with a total of 131 individuals,belonging to 2 orders,5 families and 13 genera.The fish in the fishway are mainly Saurogobio dabryi,Zacco platypus,Trilophysa bleekeri and Platysmacheilus nudiventris,accounting for 29.77%,16.79%,16.03% and 12.98%,respectively.During the operation of the fishway,the flow velocity at the inlet of the vertical slot fishway is the highest in June,which is (0.242±0.019)ms;in May,the flow velocity in the vertical slot pool is the highest,which is (0.493±0.009)ms;the flow velocity of 1# imitation natural channel in May is the highest,which is (1.378±0.473)ms.The flow velocity of 1# imitation natural channel in each month is higher than that of the inlet of the vertical slot fishway and the fishway pool.The pass rate of the vertical slot fishway is 22.58%,and the turn-back rate is 19.82%.The pass rate of 1# imitation natural channel is 18.06%,and the turn-back rate is 27.08%.The fish uses fishway more frequently between 20 and 8 o’clock.The most frequent use of fishway is between 2 and 3 o’clock,and between 20 and 21 o’clock

Abstract:After the impoundment and operation of Xinglong hydraulic complex,the impact on the low water level and water level uplift relationship downstream of the dam is preliminarily manifested.We systematically analyze the changes of discharge and water level characteristics of hydrological stations and water level stations in the lower reaches of the Han River from 1970 to 2022.The results show that after the operation of the Xinglong hydraulic complex in the Han River,the downstream of the dam shows a cumulative decline trend of the low water level for the same discharge with a smaller decrease towards the downstream.When the water surface gradient of the Hanchuan to Hankou section and Xiantao to Hankou section is lower than 0.020‰ and 0.025‰ respectively,the water level uplift effect of the Yangtze River significantly affects the water levels of the Hanchuan and Xiantao hydrological station;when the water surface gradient is higher than 0.060‰ and 0.065‰ respectively,the water level uplift effect of the Yangtze River water level does not affect the water level at Hanchuan and Xiantao hydrological stations.Comparing with the period from 2003 to 2012,the number of days with a gradient higher than 0.060‰ and 0.065‰ in the Hanchuan to Hankou section and Xiantao to Hankou section during the period from 2013 to 2022 shows an increasing trend.The combination of the water regime of the Han River and the Yangtze River during the period from 2013 to 2022 is conducive to the stability and development of the water depth conditions in downstream channels of the Han River.

Abstract:The proposed Zhangkan Navigation-power junction in the Minjiang River is located on the S-shaped curved channel.The flow conditions in the downstream entrance area of the ship lock are difficult to meet the navigational standards due to the influence of the curved channel and complex riverbed topography.In view of the flow conditions of the project,a two-dimensional numerical simulation method of water flow is adopted.On the basis of fully utilizing the original topography of the downstream entrance area,three optimization schemes are proposed by changing the shape of the guidance wall of the approach channel,extending the guidance wall of the approach channel and deflecting to the left bank,and adding diversion piers.The results show that the arrangement scheme of adopting R=125 m curved guidance wall and one diversion pier can not only effectively reduce the cross-flow and back-flow velocity in the entrance area,but also destroy the formation conditions of back-flow in the connecting area through the gap between the diversion pier and the guidance wall,thus improving the condition of back-flow caused by the curved guidance wall in the connecting area under the high flow rate.The optimized downstream flow conditions in the entrance area and the connecting area meet the navigational standards,and the research results can provide references for similar projects.

Abstract:Longweizhou Project will be constructed by the method of stage diversion.The first-stage cofferdam surrounds the eight-hole spillway gate and fishway,and utilizes the point bar to excavate the diversion channel.The second-stage cofferdam surrounds the ship lock,and utilizes the eight-hole spillway gate for diversion.To satisfy the navigable flow conditions during the operation period,the point bar cutting and channel dredging works are implemented simultaneously.This paper adopts numerical simulation to explore the surface water level variation caused by the implementation of cofferdam during construction period,channel dredging,beach cutting and operation of Longweizhou Junction.The results show that the first-stage and second-stage cofferdam cause the upstream surface water level to increase 0.28 and 0.20 m,and the downstream water level to decrease 0.08 m and 0.12 m,respectively,and the transverse gradient of water level in the upper section of the cofferdam is large.The channel dredging and point bar cutting work can effectively expand the channel section area and increase the channel storage capacity,which leads to the obvious fall of surface water level,and weakens the backwater caused by Longweizhou Project.

Abstract:The Shipai bend section is a typical sharp bend section between the Three Gorges and Gezhouba dams of the Yangtze River.Affected by the complex riverbed topography and sharp bends,the flow pattern is complex and changeable.Especially in the flood season,with the increase of flow velocity and flow rate,the bad flow patterns such as swirling water,oblique flow and scissors water frequently occur,which seriously affects the safety of ship navigation.In order to reduce the navigation risk of this section in flood season and improve the navigation rate,this paper adopts the combination of numerical simulation and measured data.Firstly,based on MIKE21 software,a two-dimensional numerical model of the curve is established.Then combined with the measured data,the reliability of the model is verified.Finally,the verified numerical model is used to analyze the flow characteristics of Shipai curve section under different flow rates.The variation rules of the occurrence probability,location and scale of navigation-obstructing flow patterns such as swirling water,oblique flow and scissors water under different flow rates are clarified,which provides an important reference for the navigation control and navigation safety of this section during flood season.

Abstract:To do a good job in the preliminary argumentation of the construction of the Xianggui Canal and accelerate the implementation of the canal connectivity project,From the perspective of logistics channels,based on the preliminary planning scheme of the canal and a large number of survey results,this study adopts qualitative analysis and quantitative prediction methods to analyze the important position of the canal in the transportation pattern from the perspectives of inland waterway transportation,comprehensive transportation and international logistics.It researches the impact of the canal on the logistics pattern of Yangtze River shipping from the perspectives of waterway network,port hubs,transportation organization and cargo flow,and predicts the freight distribution of Yangtze River shipping to the canal channel in 2035 and 2050.

Abstract:Based on a large number of measured topographic data,this paper analyzes the characteristics of riverbed evolution in the lower reaches of Xinglong Hub in recent years,and explores the main influencing factors.The results indicate that the riverbed evolution of the studied river section is the result of the combined effects of changes in upstream inflow and sediment conditions,construction of water conservancy hubs and implementation of waterway regulation projects.Under the premise that the upstream water and sediment conditions do not change much and the regulation buildings in the reaches are stable,the overall river regime will remain relatively stable.By analyzing the plane shape,longitudinal erosion and sedimentation,and lateral changes of the studied river section,it is possible to better understand the evolution law of the riverbed in the engineering river section,and provide scientific basis for predicting the evolution law of the riverbed in the lower reaches of Xinglong Hub.

Abstract:Chayuqi is a transitional shoal in the upper reaches of the Yangtze River,located in Luzhou and belonging to the natural river section.In 2013,the Xiangjiaba Hydropower Station completed water storage,and in 2015,the minimum maintenance water depth of the upper reaches of Yangtze River waterway increased from 2.7 meters to 2.9 meters.Prior to the ban on mining in 2016,the disorderly excavation of sand and stones caused significant damage to many upstream beach sections,resulting in dispersed water flow and weakened erosion capacity during the dry season.Against various backgrounds,the smooth navigation of navigation channels in the upstream of the Yangtze River faces significant challenges during the dry season,and the Chayuqi shoal section is one of the representatives.This article analyzes the changes in water and sediment conditions before and after the impoundment of Xiangjiaba Hydropower Station based on measured data,summarizes the evolution laws of the beach section in recent years,and analyzes the maintenance and dredging strategies of the beach section based on the implementation of channel maintenance and dredging in recent years,dredging effects,and related issues.It provides relevant suggestions for the design and construction of the beach section maintenance and dredging,as well as the treatment plan for adding and disposing buildings,which can provide technical support for the future maintenance and management of the the beach section.

Abstract:Aiming at the problem of poor sealing effect caused by the damage and leakage of the pressurized water seal of the lower head work gate for Three Gorges ship lift,this paper establishes the model of pressurized water seal using the finite element analysis software ABAQUS,and analyzes the influence of different sealing rubber materials on the free extension of seal head,tightness of back cavity,water tightness of seal head,head offset and friction resistance of seal head when the height of seal head is increased.The results show that the contact stress,normal stress and maximum offset of the pressurized water seal head all decrease with the decrease of the hardness of the rubber material.The lower the water head,the higher the sensitivity of the material hardness.Both the contact stress and normal pressure increase with the increase of the height of the wing head.Finally,the method of optimizing the pressurized seal rubber material is proposed to improve the effect and service life of pressurized water seal.

Abstract:The navigable water flow conditions of the approach channel are crucial for shipping safety.To study the rectification effect of different types of separation walls,this paper relies on the Wuxi Hub second-line ship lock project to establish a fixed bed physical model.By measuring the surface flow velocity distribution,the navigational flow conditions of the ship lock is evaluated.The rectification effect of the full-solid separation wall,the combination of solid and multi-type permeable separation wall,and the row pile rectification and other schemes are systematically compared and studied.The combination scheme of row piles and pile foundation insertion plate separation wall is proposed.The results show that extending the length of separation wall can reduce the transverse and longitudinal flow velocity and improve the water flow conditions in the approach channel effectively.Reasonable arrangement of floating separation structure can meet the water flow conditions of the approach channel,and the rectification effect is better than that of full-solid separation wall.The rectification effect of pile row scheme is better.The combination scheme of pile row and pile inserted separation wall synthesizes the advantages of floating separation structure and pile row rectification technology,which can guarantee the rectification effect and reduce the project cost.

Abstract:The flow condition at the navigation wall of high-lift lock is complicated,and there are some problems such as berthing and safety of mooring facilities for large ships.Taking the berthing conditions of the navigation wall of Gezhouba No.2 ship lock as an example,this paper analyzes the water filling and discharging of the ship lock under different working heads through model test and mooring force test，studies the berthing conditions and change laws of ships in different berthing positions of the upstream and downstream navigation walls during the opening and closing of the lock herringbone gate,and puts forward countermeasures for ship mooring force exceeding the design value.The results show that the mooring conditions of the upstream navigation wall are good and the mooring force of the ship is low.The downstream navigation wall is greatly affected by the discharge of lock water and is closely related to the working head of lock water,and the berthing conditions are poor.Measures such as optimizing the operation of lock valve and discharge process,avoiding the influence range of the lock water discharge,and increasing the number of ship mooring lines can be taken to reduce the mooring force of a single mooring post.The mooring facilities and the berthing conditions of the downstream navigation wall are expected to meet the requirements.

Abstract:The service environment of high pile wharf is complex,and the wharf structure will be damaged to varying degrees during the operation period of decades,affecting the safe operation of the wharf.During the operation of the wharf,the ship load is the main load of the high-pile wharf structure,which has a great impact on the safety and durability of the wharf structure.In this paper,the berthing capacity of a wharf in Nanjing Port is simulated by finite element method,and the three-level safety early warning threshold in the berthing process of ships is proposed.Combined with long-term online monitoring,it provides technical support for the safe service of the wharf structure.The results show that when the ship hits the 1# rack,the impact force of the ship reaches 238 kN,the wharf structure response reaches the third-level warning index,the wharf displacement is 3.8 mm,and the top strain of the pile foundation is 69×10-6.When the impact force of the ship reaches 323 kN,the wharf structure response reaches the second-level warning index,the wharf displacement is 5.1 mm,and the top of the pile foundation is 100×10-6.The impact force of the ship reaches 471 kN,the wharf structure response reaches the first-level warning index,the dock displacement is 7.5 mm,and the top of the pile foundation is 156×10-6.The online monitoring and early warning results show that the wharf structure has the berthing capacity of 5,000-ton ships,which can meet the structural safety requirements of 8,000-ton ships under the premise of standardized berthing.

Abstract:To develop an optimal dredging construction organization plan,it is essential to consider various influencing factors along with their uncertainties,all of which interact with one another.We develop a simulation model for dredging operations in waterway dredging projects to describe uncertainties involved in vessel arrivals and departures,as well as in the dredging process of trailing suction hopper dredgers.Based on the objective of minimizing the total cost,we analyze the impact of dredging section length and the dredger fleet on dredger operation expenses,carbon emission cost and comprehensive cost.The results indicate that the proposed method based on simulation and optimization can develop a rational construction organization plan for dredging project.

Abstract:The study of optimizing the shape of the diversion channels is crucial for saving project investment and ensuring construction safety.This paper applies a two-dimensional water flow mathematical model to study the effects of the incoming flow conditions and the optimization methods for the the shape of diversion channels on the overflow capacity of the diversion channels and the hydraulic characteristics of engineering reach.The results show that when the cross-sectional area of the same size diversion channel is expanded,compared to increasing the width of the channel bottom,the height of backwater in the upper reaches of the diversion channel is lower and the turbulence in the internal and outlet of the diversion channel is weaker.With the increase of the section area,the difference of the maximum relative backwater height in the upper reaches of the diversion channel between the two schemes increases.The maximum relative backwater height increases with the increase of flow rate.In the scheme of increasing channel depth,the maximum flow velocity inside the diversion channel is smaller,and the flow return state is better,and the flow velocity and backflow strength are smaller.

Abstract:The joint scheduling of ship lock groups in the river basin is used human dispatch and scheduling because of its many influencing factors and complex process,without forming an integrated intelligent scheduling system.We carry out the study on influencing factors of ship lock dispatch and scheduling strategy,abstract traditional multiple ship locks scheduling decision by human judgment into a mutual coupling problem of timetable problem and spatial bin packing problem,and give a specific scheduling algorithm process.Based on this,we design the integrated scheduling scheme for three gradients of Shuanggang,Bazizui and Jiepai ship locks in Xinjiang River Basin,and use the intelligent algorithm to automatically generate the integrated plan for multiple ship locks in the basin.The results show that this integrated scheduling system for ship lock group in the basin achieves good application results in practice,which can effectively improve the level of scheduling intelligence and increase the efficiency of navigation.

Abstract:At present,the negative pressure source of the prefabricated vertical drains (PVD) in the soft soil foundation reinforced by vacuum precompression method is usually located at the top,due to the attenuation of the vacuum along the vertical direction,the effect of ordinary vacuum preloading on deep soil is relatively poor.Therefore,a drainage method combining the PVD and the reverse prefabricated vertical drains (RPVD) is proposed,the negative pressure source of the PVD is at the top of the drainage plate,and the negative pressure source of the RPVD is at the bottom of the drainage plate.The PVD and RPVD combined with vacuum precompression is applied to a foundation treatment project in Wenzhou,and the monitoring results of surface settlement,vacuum degree and pore water pressure show that the average consolidation degree reaches 93.1%.Under the same working conditions,the surface settlement value obtained by the PVD and RPVD combined with vacuum precompression numerical simulation is larger than the value of surface settlement obtained by PVD combined with vacuum precompression,and the growth rate reaches 12.9%.Under the same working conditions,the dissipation of pore water pressure in the range of 3-10 m obtained by the PVD and RPVD combined with vacuum precompression numerical simulation is significantly better than that of the PVD combined with vacuum precompression,and the foundation reinforcement effect is better.PVD and RPVD combined with vacuum precompression method is worthy of further popularization and application in engineering.

Abstract:Based on the limit equilibrium theory,combining with the horizontal slice method,we convert the vertical inter-slice force relationship of Bishop method to the horizontal soil strip,derive the theoretical calculation formula of the stability safety factor of homogeneous bank slope under the action of water flow traction force,and compare the results with the simulation results of ABAQUS finite element software’s strength reduction method.Then we analyze the influence law of water flow traction force on the banks with different slope ratios combining with engineering practice.The results show that the calculation results of theoretical calculation formula and simulated by software are basically consistent,and the error does not exceed 2.1%.The water flow traction force of river will increase the sliding moment and reduce the stability safety factor of the river bank slope soil.When the soil is in a critical stable state under the action of multiple factors,such as rain and soil degradation at toe etc,the water flow traction force can become the key factor for landslide initiation.When the river bank slope is sliding instability,the water flow traction force will cause the sliding body to slide further towards the channel,which can increase the harm of landslide to the safety of the channel.The steeper the slope is,the greater the influence of the flow traction force on the slope stability safety factor is.In the analysis of bank slope stability of high and steep rivers,the water flow traction force is an external load that cannot be ignored,which is as important as heavy rainfall,debris flow and other factors.

Abstract:To study the influence of channel excavation on the new and old revetment structure,the influence of channel excavation on the force and deformation characteristics of old retaining wall and newly constructed steel sheet pile is studied by using a large-scale geotechnical centrifugal model test platform based on 4-to-3 project of Dongzong Channel,and the distribution law of soil pressure on both sides of the sheet pile during channel excavation is obtained.The results show that with the increase of excavation depth,the earth pressure on the bank side (active side) decreases gradually,and the earth pressure on the water side (passive side) partly decreases under the influence of sheet pile displacement,deformation and heavy liquid of centrifugal model test,the earth pressure increases at the bottom.The excavation unloading causes the old retaining wall to move to the water side and turn backward.The limit excavation depth of the design condition is about 3.6 m,and the horizontal displacement of the cap beam at the top of the steel sheet pile reaches 0.069 m.For sheet piles with 3 lengths of 6,8 and 10 m,the limit excavation depth is about 0.5-0.6 times the pile length,and the limit excavation depth gradually decreases with the increase of pile length.The threshold values of excavation depth under different sheet pile lengths are obtained,which can provide technical parameters for engineering construction.

Abstract:To study the underwater reef damage characteristics of the high frequency hammer in the sensitive area of the Yangtze River channel,theoretical analysis and numerical simulation are used to analyze the damage characteristics and influence rules of the reef under the impact of the high-frequency hammer.The results show that the rock mass around the impact drill rod is mainly shear damage,while the rock mass away from the drill rod is mainly tensile damage.The penetration depth,crushing depth and crushing width increase with the increase of working pressure and impact frequency,and decrease with the increase of reef strength.The high-frequency crushing hammer should not break the reef with too high strength.When the impact frequency is greater than the critical frequency,the improvement of the crushing parameters is not significant.The working pressure is the main factor affecting the reef breaking effect of the high frequency crushing hammer,followed by the impact frequency,and finally the reef strength.The mathematical relationship between the drilling depth of drill rod and the volume of rock mass is established,and the calculation method of reef breaking efficiency of high-frequency hammer is put forward.The research results have reference value for optimizing reef breaking parameters and improving reef breaking efficiency.

Abstract:Due to the insufficient water depth,high wave and limitation of construction equipment,it is difficult to implement conventional methods such as mechanical pile-pulling and underwater pile-cutting by divers in the removal process of the steel tube pile for temporary steel trestle.Based on an overseas project,we study the new construction method of underwater steel tube pile cutting in-pile body.By laying steel casing outside the steel tube pile,we set up a construction platform,and use the construction method of cutting the steel tube pile inside at the mud surface elevation through remote control of the cutting gun system,and effectively remove the steel tube pile.At the same time,we obtain the construction quota through studying and analyzing the resource usage of labor,materials,construction equipment required by the construction method.

Abstract:In order to guide the practical application of sediment interception using a bubble curtain,we use a theoretical derivation to provide calculation formulas for the required aeration rate per unit width and a method for calculating the diameter of the bubble curtain’s perforated pipe,apply these new calculation formulas and methods to the sediment interception operation for the harbor basin dredging of the comprehensive terminal project in the Hexi operation area of Zhangshu Port in Yichun Harbor,and summarize a construction process for the sediment interception with the bubble curtain.The results show that the bubble curtain has a good sediment interception effect,but the optimal aeration rate per unit width for sediment interception is lower than the theoretical value.Overall,the bubble curtain device has a simple structure,easy installation,good sediment interception effect,and does not hinder normal vessel passage.Combined with silt curtains to prevent the spread of suspended sediment,it works even better.