Abstract:In order to investigate the influence of extreme winter weather and sea conditions on the design wave estimation of northern ports,using Huanghua Port as a case study,we build a comprehensive numerical wave model that accounts for the combined effects of sea ice and cold strong winds.The simulated maximum and average significant wave heights at the entrance of the outer channel of Huanghua Port are 0.41% higher and 5.46% lower than the measured,respectively,and the evolution trend is basically consistent.The results show that the maximum significant wave height,considering sea ice,strong winds,and the effects of wave diffraction and reflection,at the location of the disaster caused by the cold wave in 2018 in the harbor,is 1.14 m.Sensitivity analysis reveals that neglecting the influence of cold waves and strong winds during wave estimation within the port leads to a significant underestimation of the maximum significant wave height by 73.68%.In addition,if the effect of sea ice is considered,the significant wave height will be 8.77% lower compared to ice-free conditions.

Abstract:To effectively and dynamically monitor the concentration of suspended particulate matter produced by dredging projects in harbor waters with high spatial and temporal resolution,this study utilizes the advantages of the geostationary satellite GOCI II,and based on the single band and the band ratio,the inversion bands are selected through parametric correlation analysis.According to the measured suspended particulate matter concentration data of water quality samples and the remote sensing reflectance data after satellite remote sensing image preprocessing,the parameter correlation analysis method is used to select the inversion band,and the exponential,linear,logarithmic and polynomial inversion models based on single band and band ratio are established,and the optimal model is selected and verified.The model is used to monitor the variation of suspended particulate matter concentration in the channel maintenance dredging operation water area and the dumping water area of a port area on a certain day.The results show that the advantages of high spatial and temporal resolution can better adapt to the characteristics of dredging operation area and dumping area with small range and rapid water quality change.It can track and monitor the continuous change of suspended particulate matter concentration in the project area and surrounding waters,and provide reference for green dredging.

Abstract:In view of the problems of unreasonable transportation structure and high logistics cost in Yunnan Province,focusing on the Jinsha River-Yangtze River,Lancang River-Mekong River,and You River-Pearl River water transport channels,this paper researches on the multimodal transportation routes in the direction of Kunming to Shanghai,Kunming to Vientiane,Kunming to Guangzhou and Kunming to Qinzhou to calculate the cost of highway,railway and “highway-railway-waterway” multimodal transportation.Meanwhile,it compares economic analysis and selects advantageous routes,and puts forward suggestions from the aspects of infrastructure construction,financial support and policy guidance.The results show that,relying on the three major channels to carry out multimodal transport,the route is feasible.Under the advantageous route,the transport costs of the four groups of starting and ending points are 15.3%,31.6%,18.8% and 31.7% of highway transport,and 50.9%,86.0%,55.5% and 91.0% of railway transport,respectively,which has obvious economic advantages.It is of great significance to promote Yunnan water transportation project construction,transportation transformation and logistics cost reduction and efficiency increase.

Abstract:Based on the FVCOM model,a hydrodynamic numerical model is established in this paper,and the velocity changes of the enclosure gap under different gate widths and different tide levels are studied.The results show that:1) The tidal direction of the closure gap area is perpendicular to the entrance direction,the flow velocity during the high tide period is large,and the flow velocity during the low tide period is small.The aggregation effect at the end of closure gap leads to the maximum flow velocity appearing at about 20 m away from the end of closure gap on both sides,while the velocity is smaller in the middle.2) The protection period for the width of the closure gap in this project should be 200 m to 250 m,and the closure period should be 100 m to 150 m.During the protection period,attention should be paid to the erosion situation in the area near the ends of both sides of the closure gap,and the closure period should be selected during the low tide period.In summary,the width of the closure gap has a significant effect on the surrounding flow velocity.In this paper,the characteristics of the flow velocity of the closure gap under different working conditions are summarized,the recommended value for the width of the closure gap is given according to the numerical simulation results,and a reasonable time for the closure period is provided through data analysis.The research results can provide reference for similar engineering design and construction.

Abstract:In order to improve the durability of concrete for large pipe piles,we carry out the test research and application of high durability concrete preparation technology for large pipe piles.Based on the traditional concrete mix ratio for large pipe piles,we apply the slag powder to improve the performance of concrete,and ensure the concrete demoulding strength of large pipe pile by the composite of gypsum powder and slag powder.We carry out the Webe consistometer,the compressive strength,electric flux and diffusion coefficient tests for each mix ratio,and use the concrete mix ratio determined by laboratory test to apply in the actual production.The results show that adding slag powder alone can significantly improve the durability of concrete for large pipe piles,but it leads to a decrease in the demoulding strength of large pipe piles.The composite of gypsum powder and slag powder can significantly improve the demoulding strength of large pipe pile concrete and has good durability.By using a high durability concrete mix ratio for large pipe piles,the appearance quality of the produced pipe joints is good,the compressive strength of the concrete reaches C70,and the electrical flux is less than 800 C,which has high durability.

Abstract:The terminal belongs to service infrastructure,and the commonly referred to “terminal throughput capacity” belongs to unsaturated capacity,which means the ability to maintain a reasonable utilization rate of facilities (50%~70% of container terminals).Design throughput capacity refers to the rated throughput capacity calculated and determined according to the design conditions.Based on changes in equipment configuration,ship type (single ship loading and unloading capacity)，and other factors after operation,the throughput capacity needs to be regularly reassessed.In 2022,Shanghai Port completed a container throughput of 47.03 million TEUs,which is far higher than the design throughput capacity of the original terminal.In the Master Plan of Shanghai Port (Revised),it is necessary to reassess the throughput capacity of container terminals,so as to realize reasonable planning of shoreline resources and ensure the sustainable development of the port.

Abstract:When the pile is used in the wharf,the reduction of the bearing capacity of the pile due to the deterioration of various factors on the material characteristics of the pile has become an important influencing factor for the safe and healthy use of the high-piled wharf.In order to more accurately predict the damage and deformation characteristics of reinforced concrete piles in the complex hydraulic environment (ship load,wave load,etc.) of inland wharves,we design a horizontal loading device that is easy to make and operate to carry out horizontal graded loading tests on reinforced concrete pile,obtain the tensile load-strain curve at the bottom of the pile,and build a three-dimensional particle flow discrete element reinforced concrete pile model by PFC3D software.Then we calibrate micro-parameters of the model,and verify the rationality of mechanical properties of the model by results of physical tests.

Abstract:As an important logistics hub in China,the energy structure of the port collection and distribution network has a particularly significant impact on carbon emissions.Taking carbon emissions of the container collection and distribution network of Guangzhou Port as the research object,we disscuss the impact of adjusting the energy structure on carbon emissions of the container collection and distribution network of the port.By establishing a carbon emission calculation model,we analyze the impact of different transportation modes,energy types and transportation distances on carbon emissions.The results show that the use of clean energy instead of traditional energy,such as natural gas and pure electric instead of diesel and other fuel oils,can significantly reduce carbon emissions of the port collection and distribution network.

Abstract:This paper proposes an expansion plan for the port pool in the Qiwei operation area of Taixing port area,Taizhou Port,addressing issues such as limited capacity of the bulk cargo terminal and mismatch of berths between rivers and seas.The feasibility of the plan is verified from the perspectives of navigation safety and tidal sediment by using ship AIS data analysis and two-dimensional tidal sediment numerical models.The results show that after the expansion of the inner harbor basin,there is a certain mutual influence between the ships in the harbor and the navigation environment in the nearby water area.At the same time,a small amount of silk is inevitably generated at the entrance and inside of the harbor.However,after taking certain navigation risk mitigation measures,strengthening sediment monitoring and timely dredging,the proposed plan is feasible.This plan can effectively improve the berthing level and operational efficiency of ports without adding new shorelines or land resources,and its planning approach can provide reference for the renovation of other ports with transportation capacity gaps and limited shoreline resources.

Abstract:The uneven settlement of wharf surface and the unsmooth convergence between large and small berths are common quality problems in the gravity wharf.The supporting wharf of No.1-2 generating units and No.3-4 generating units of Jiahuwan Power Plant in Lufeng,Guangdong is a shore-wall gravity wharf.Compared with the caisson components of about 2,000 t of conventional wharves,the main body of the this wharf is adopted a super-large caisson with a mass of more than 4,600 t,which reduces the number of components and structural joints.By unifying the loading conditions of the main components and setting the transition plate,the uneven settlement of the wharf surface is solved.By setting the transition caisson and the prefabricated block,the foundation compaction at the convergence between large and small berths is solved.At the same time,a series of innovations is made in the integrated design of marine structure and superstructure and the selection of ancillary facilities.The practice shows that the expected results is achieved.

Abstract:Navigation tunnels can achieve effective connections between navigable buildings under alpine canyon conditions,but the cross-sectional scale of the tunnel is highly correlated with ship navigation characteristics such as ship speed,navigation resistance,and sinking volume,posing a multi-objective optimization problem.This paper uses the RNG k-ε turbulence model and the GMO motion model to perform three-dimensional numerical simulations of the movement process of the 1,000-ton ships in a navigation tunnel,analyzes the spatial-temporal changes of various hydraulic characteristics in the tunnel,explores the effects of the ship’s driving speed and tunnel width on the ship’s traveling wave,lateral flow rate,ship resistance and sinking volume,and presents an empirical formula between the cross-sectional coefficient of the navigation tunnel and the ship’s sinking capacity.The research results show that when the depth of navigation in the tunnel is 5 m,the ship’s driving speed is less than 1.5 m/s,and the tunnel width is greater than 18 m,the solitary wave amplitude of the bow,ship resistance,maximum lateral flow rate and sinking value on both sides of the ship improve markedly.Furthermore,the study also finds an inversely proportional relationship between the ship’s sinking volume and the cross-sectional coefficient of the navigation tunnel.The smaller the navigation tunnel section coefficient,the greater the ship sinks,Moreover,the navigational water depth exhibits a more pronounced impact on the vessel’s sinking volume compared to the width of the tunnel.The research results can provide reference for the design of navigation tunnel sections and key navigation parameters for the 1，000- ton ships.

Abstract:Sheyang Port is located in the silty shoal in northern Jiangsu,with relatively poor water depth condition and strong silting intensity.In this paper,a two-dimensional tidal flow mathematical model is constructed to study the process of water transport capacity from the current situation to dredging to the design of the bottom elevation.The results show that with the waterway dredging deepen,the overall water velocity in the waterway shows a decreasing trend.The degree of decrease of water velocity is proportional to the dredging depth of the waterway.The maximum decrease of the rising jet is 43.4%~61.7%,and the maximum decrease of the falling jet is 39.8%~58.5%.When the dredging depth of the waterway is 6.5 m,the transport capacity of the waterway falling tide decreases by 40%~80%.When the dredging depth of the waterway is 10.5 m,the transport capacity of the waterway falling tide decreases by 80%~95%.The transport capacity of the waterway rising tide is stronger than that of the falling tide,which increases by about 80% compared with the current situation.When the surrounding sediment entered the waterway,it is not conducive to the outward transport of sediment.

Abstract:In addressing the challenges posed by the reconstruction of the Mashi ship lock,including a large lock chamber,high water head,and stringent hydraulic requirements,a physical model with a scale of 1:25 is established.The hydraulic characteristics of the water filling process,berthing conditions of the ships,pressure characteristics in the water transfer corridor,and flow conditions in the inlet/outlet and approach channel are investigated.The results show that through the implementation of optimization measures such as incorporating energy dissipating blocks in the open ditch,enlarging the turning radius of the corridor protruding body rising cans,increasing the inlet area,and decreasing the inlet elevation,all hydraulic indicators meet the specified standards and design requirements under the recommended valve opening mode.The research results can provide reference for similar engineering projects.

Abstract:After the installation of warning separation piers in the upstream zigzag approach channel of the Linhuaigang double track ship locks,there is the serious reflux and local exceeding of lateral flow velocity in the downstream approach channel.In response to the safety navigation issues,we conduct ship maneuvering simulation tests.The resuts show that the width and turning radius of the upstream approach channel can meet the needs of safe entry and exit of ships at the ship lock.The layout scheme of a curved and straight out zigzag approach channel is a control condition for navigation safety,and the safety margin is relatively small when two rows of 1 000-ton ships are docked in the berthing section.The length of the warning separation pier between the two gates is too long,which has a negative impact on the navigation of ships exiting the gate.The longitudinal arrangement range should not overlap with the mooring section.The width of the downstream pilot channel that does not exceed the standard can meet the safety navigation needs of ships.

Abstract:The flow field in the entrance area of the downstream approach channel of Baoying Hub is complicated and chaotic.In order to ensure the safety of the inland ship’s navigation,we conduct a numerical simulation study on the overall waters of the downstream riverway of Baoying Hub,and compare and analyze the navigable flow conditions before and after the implementation of three optimization schemes,such as widening riverway,widening riverway+arranging diversion piers in the entrance area,and widening riverway+arranging partition dikes.The results show that in the original plan,the maximum rates of transverse and longitudinal flow are 0.95 m/s and 3.60 m/s when the flow is maximum,which exceed the safety limits of 0.65m /s and 1.60 m/s.The extension of the partition dikes causes the bad flow pattern of large backflow and cross flow at the end.Arranging diversion piers on the basis of the widening river is selected as the best optimization scheme.Compared with other schemes,this scheme can strengthen the momentum exchange of mainstream and local flow fields in the entrance area,reduce the rate gradient and the angle between the main stream and the entrance area,and significantly improve the flow conditions of the entrance area to ensure the safety of ship navigation.

Abstract:The Yangtze River trunk line is the core of the national comprehensive transportation system of the Yangtze River transportation channel.It is also an important support for the construction of integrated three-dimensional transportation corridors and green ecological corridors along the river.Against the backdrop of the 13 th Five-Year Plan for the Development of Water Transportation,the Wuhan-Anqing section of the waterway remediation project has become an important project to accelerate the management of the Yangtze River main waterway system and comprehensively alleviate the bottleneck of navigation.The study is based on the collection and research of relevant real-life cases and related materials,combined with the ecological environment and characteristics of the improvement project in the Yangtze River basin,as well as the impact of the waterway improvement project on the environment.The green waterway evaluation indexes of the Yangtze River are obtained by the expert scoring method,and according to the weights of the indexes given by the hierarchical analysis method,the green waterway renovation project of the Wuhan-Anqing section is evaluated as a typical case and a conclusion is drawn,aiming to provide evaluation references for waterway renovation projects and other inland waterway projects.

Abstract:With the continuous rapid growth of freight volume of Changzhou Hub in recent years,the four existing locks can no longer meet the increasing requirements of freight volume crossing,and the fifth-line lock need to be built to meet the needs of freight volume development.Based on the method of integral hydraulic model test,this paper studies the navigation flow condition in the entrance area of downstream approach channel of Changzhou fifth-line ship lock,and it puts forward the measures to improve the navigation conditions of the downstream approach channel.The results show that,affected by the unconnected riverbed topography in the entrance area of the downstream approach channel of the fifth-line ship lock,the oblique flushing of the discharge flow from Waijiang River and the jacking of the convex nozzle in the downstream bend,there are bad flow patterns such as large cross flow and backflow in the entrance area,and the navigable flow conditions are poor.By adoption of measures such as adjusting the river bottom elevation of the downstream connection section of the entrance area,removing the downstream curve convex,dredging and expanding the beach on the left bank of the Waijiang River,which can effectively improve the navigation flow conditions in the entrance area of the five-line ship lock,and adjust the routes of ships entering and leaving the lock,so as to meet the safety navigation requirements of ships.

Abstract:：Unstable flow pattern inside the ship lock is caused by filling and draining the ship lock.In extreme cases,jets can disrupt the free-surface flow field,which poses a serious threat to the safety of the ship at berth and affects the efficiency of ship lock navigation.Influenced by many factors,Mujing ship locks are now facing technical problems such as deterioration of water flow conditions at the entrance and exit of the approach channel,mutual influence of water flow in the approach channel during filling and draining,influence of reciprocating flow,exceeding of navigational water flow conditions in the shared approach channel,and poor navigational conditions for ships.The RNG k-ε turbulent model is adopted to simulate the layout of the water inlet in the water delivery system for ship locks,and hydraulic characteristics and localized hydrographic conditions are studied.Based on the design scheme of water delivery system of Mujing ship locks,the key technical problems of hydraulics during the operation of ship locks are analyzed and discussed in detail,and optimization measures are proposed.The results show that the width of the throat and the order of arrangement significantly affect the flow pattern of the water inlet.The width and spacing of the throat can be changed to effectively improve the water inlet conditions,stabilize the water flow pattern and improve the problem of uneven inlet flow.

Abstract:There is still no uniform carbon emission calculation method in the construction stage of waterway regulation project.To solve the problem of carbon emission quantification in this stage,a carbon emission calculation method based on carbon emission factor method is established.By means of literature review,engineering investigation and theoretical analysis,this paper discusses the thinking and calculation method of carbon emission factor of energy,labor,ship,construction machinery and transportation service.Considering the characteristics of the construction stage,it is divided into construction scheme stage and implementation stage,and then the calculation method of carbon emission in the construction stage based on the carbon emission factor of the unit engineering quantity and the actual resource consumption is proposed.This method is conducive to the optimization of construction scheme based on low-carbon concept,as well as the calculation and evaluation of carbon emissions during and after construction.

Abstract:With the use of Xinglong Hub’s water storage,the riverbed of the downstream section of the hub undergoes scouring along the waterway,and the water level decreases to varying degrees under the same discharge.To determine the lowest navigable water level designed for the 2,000-ton level waterway regulation project of the Xinglong to Caidian section of the Han River,the paper uses the comprehensive duration curve method to calculate the navigable discharge of the waterway design,determine the lowest navigable water level of the waterway design through the recent water level-discharge relationship and the water surface gradient during the dry season.Based on the trend of changes in the navigation water level,the paper proposes the terrain,design discharge,water level-discharge relationship adjusted according to erosion and sedimentation changes in the later stage to conduct real-time review and adjustment of the designed lowest navigation water level,ensuring the rationality of the design water level after the water level drops.

Abstract:According to the periodic changes of water level in the Three Gorges Reservoir area,the traditional slope-buttress anchorage structure is affected by the surrounding soil erosion,which leads to the serious deterioration of the structural design stress conditions,and the exposed high strength concrete structure is easy to cause the damage of the bottom of the ship.This article is based on the actual project and takes the 5,000-ton dry bulk cargo ship as the representative ship type under the environmental conditions of the water flow velocity of 1.0 m/s and the wind velocity of 22.0 m/s once every 50 years in the Three Gorges Dam area.The design of the slope-buttress anchorage structure for large ships in the dam area is studied.The slope-buttress anchorage scale,ship berthing mode,mooring force calculation,slope protection structure,construction technology and other aspects are systematically discussed.The design method of setting protective belt on both sides of mooring pile,arranging mooring facilities as embedded structure,and the top of mooring pillar not exceeding the slope surface is adopted.The results show that the structure of anchorage position against slope can not only meet the requirements of anchorage structure stability,but also effectively prevent water loss and soil erosion around the structure.It can be replicated and promoted in the construction project of ship mooring facilities in the reservoir area with large water level drop and small water flow velocity.

Abstract:After the construction of the Three Gorges Reservoir,the water and sediment conditions in the middle and lower reaches of the Yangtze River have changed.The hydrological and sediment boundary conditions of the four rivers in the south of Jingjiang River from the Yangtze River to Dongting Lake have changed accordingly.The three outlets have decreased by 23% compared with before the construction of the reservoir,and the sediment distribution has decreased by 88.8%.The three channels have generally changed from erosion and deposition balance to erosion,of which the Songxi River erosion accounts for 47%.The Songxi River channel continues to widen under the medium water level.The erosion of some branches,bends and transitional reaches is more intense,and the thalweg swings greatly,which hinders navigation due to the instability of the beach and trough.Aiming at the channel problems caused by the change of the relationship between the Yangtze River and Dongting Lake,based on the study of the new water and sediment conditions and evolution process after the construction of the Three Gorges Reservoir,the characteristics and trends of navigation obstruction and riverbed evolution are analyzed.The Songxi River channel is mainly based on dredging and beach protection,and the beach stabilization and channel stabilization are carried out in sections.Taking the typical Peijiachang reach as an example,the engineering scheme is formulated,and the model test is carried out to verify the treatment idea and scheme effect.The research results aim to provide reference for the channel management of similar rivers and lakes.

Abstract:We present the establishment of a simulation model utilizing multi-agent simulation modeling technology to encompass the ship entry and exit process,mooring,navigation,and wharf berthing operation in the Beihai district of Beibu Gulf Port.By quantitatively analyzing indicators of port throughput capacity and channel service level,we propose the long-term recommended scale and navigation standard of the main channel outside the gulf combining with the analysis of channel plane scale.Based on the analysis of the bottleneck of port throughput capacity and optimization of navigation standards for branch channels,we propose suggestions for optimizing the navigation standards of partial channel of Beimu Channel.The results show that the recommended navigation standards for the main channel should reach (100,000+50,000)t two-way navigation for ships by 2035,and further achieve (100,000+100,000)t two-way navigation by 2050.The navigation standard of the first section of Beimu Channel is optimized from one-way navigation of 150,000 t ships to two-way navigation to balance 20,000 t ships,which has a good effect on improving the port throughput capacity.

Abstract:Aiming at the difficulty in ensuring the modeling accuracy and efficiency of BIM technology in the application of high-pile wharf in inland rivers,Visual Studio 2017 is adopted to carry out secondary development on Bentley′s Microstation graphics platform through development methods such as C++,C # (Addin),and C++/CLI mixed programming,and a BIM software module suitable for parametric design of pile foundation in high-pile wharf in inland rivers is developed.The module includes functions such as automatic design of the platform grid for high-pile wharf,creation of grid plan,preview of graphics and models,parametric modeling of pile foundations,import and export of pile foundation parameters,and summary of pile foundation parameter tables.By intuitively inputting the required parameter set for model creation,high-precision and high-efficiency parametric 3D design of pile foundations is realized,thereby simplifying the process of creating a type of model and reflecting the application advantages of BIM technology in parametric design,model visualization and statistical engineering quantity.

Abstract:Aiming at the uncertainties and low accuracy of current water level prediction models,this paper proposes a probabilistic forecast framework of channel water level by integrating machine learning and Bayesian model averaging method.Taking Jingjiang River section of the upper Yangtze River channel as the research area, random forest (RF),support vector machine (SVM) and artificial neural network (ANN) are used to predict the water level of Shashi station and Xinchang station.The results show that RF has the highest prediction accuracy,followed by SVM,and ANN has a relatively lower prediction accuracy,but all of the three machine learning models provide relatively excellent prediction accuracy.Based on the prediction results of three machine learning models,Bayesian model averaging method is used to forecast the water level ensemble probability.Compared with RF,BMA water level prediction results are further improved,and the possible range of future water level under 90% probability is accurately obtained.The method proposed in this study effectively improves the forecast accuracy of waterway water level and realizes probabilistic forecast,which can provide technical support for ship navigation safety.

Abstract:In view of the problem of the limitation of the traditional two-dimensional design method and the presentation for the miter gate,combining with the Qingshan ship lock project in the Lishui River,we design the miter gate based on the BIM characteristics of modular,parametric and collaborative,create BIM models of miter gates,carry out collision checking,engineering drawings export,and automatic engineering quantity statistics,and generate a variety of visual design results.The application can reduce the design intensity of the designers,and effectively avoid the design changes and rework problems.Compared with the traditional 2D design mode,the use of BIM technology for the miter gate design can effectively improve the design efficiency and quality of drawings,reduce the cost of communication,control the cost of the project.

Abstract:The foundation soil layer of a certain engineering stockyard in Zhanjiang Port is a deep soft soil foundation composed of recently manually backfilled plain fill soil and original marine sedimentary silt and muddy soil.The plain fill soil is extremely uneven and in an undercompacted state.The silt and muddy soil layers have low bearing capacity,high water content,and are high-pressure compressible soft soil.The foundation treatment adopts preloading.After the completion of the project,long-term settlement observation is conducted on the settlement of the stockyard.The observation data shows that the four stockyards all have different sizes of settlement.This article summarizes the main characteristics and laws of post construction settlement of the stockyard,and analyzes the main influencing factors that cause settlement.To reduce post construction settlement and uneven settlement of the stockyard,targeted treatment measures such as stockyard operation management,soft foundation treatment design,and drainage design are proposed based on the function,area,load,and geological data of the stockyard,which can effectively eliminate the impact of later settlement on the normal production and operation of the stockyard.The aim is to provide reference for the design and management of similar projects in the future.

Abstract:The double-row piles which have the advantages of convenient construction,good mechanical behavior,small deformation,and are widely used in the various types of temporary and permanent projects.This paper takes the upgrading project of high-slope waterway from level three to level two as an example,performs finite element analysis on the double-row piles based on the construction process,and then explores the reasonable pile length and pile spacing,hereby analyzes the changes in displacement and bending moment of double-row piles during the excavation process of the waterway.The calculation results show that 1) The growth of pile length will significantly reduce the maximum horizontal displacement of double-row piles,but has little effect on the maximum positive and negative bending moments of double-row piles.2) The growth of pile spacing will slightly increase the maximum horizontal displacement of double-row piles,but significantly increases the maximum positive and negative bending moments of double-row piles.3) Taking into account a variety of factors such as structural displacement,structural stress and construction cost,the pile length of front and rear piles is equally determined to be 22.0 m,and the pile spacing of front and rear piles is determined to be 1.0 m and 3.0 m,respectively.4) As the excavation depth increases,the maximum horizontal displacement and maximum positive and negative bending moments of front and rear piles significantly increases.

Abstract:In view of the problem that Larsen type latch is easy to be torn during the driving construction of the steel pipe-sheet pile combined structure,based on the combined structure of the steel pipe-sheet pile of Lekki Deepwater Port Terminal project in Nigeria,the finite element method is used to numerically simulate and analyze the three bite conditions of Larsen type latch tension,torsion angle and inclination conditions.The research results show that the lower the occlusion accuracy of Larsen type latch,the greater the occlusion stress of the latch,and the more adverse influence on the Larsen type latch.Reference limits for the accuracy of the steel pipe-sheet pile combined structure are proposed under different occlusion states,such as tension,torsion angle and verticality conditions.Finally,it is suggested to strengthen the research on the pipe-sheet pile sinking process,improve the accuracy control and monitoring of pile sinking,reduce the unfavorable occlusion stress of the lock occlusion,and minimize the risk of lock tearing.The reference limits of the accuracy can provide a basis for the construction technical standard of the steel pipe-sheet pile combined structure,and an important reference for improving the construction quality of the steel pipe-sheet pile combined structure.

Abstract:Dredger fill with high moisture content,has disadvtanges of low strength,high compression,and underconsolidation.It is unsatisfactorily reinforced by strong tamping and consolidation with filler.Relying on Daxiaodeng land creation project in Xiamen,we apply different parameters of vibro-compaction to the reinforcement of artificial dredger fill sandy soil foundation,such as vibration frequency,vibration mode and construction method,and determine the frequency parameter and vibration mode suitable for dredger fill sandy soil foundation.The results show that dredger fill sandy soil foundation is effectively reinforced by vibro-compaction method.After the construction treatment,the bearing capacity of the foundation and the standard penetration hit number are improved.After being worked,the foundation has a bearing capacity of 150 kPa,and the standard penetration hit number for about half of test area exceed 30,which meets the standard for subsequent construction.The soil reaches medium density state.It proves that the vibro-compacting method is suitable for the reinforcement of dredger fill sandy soil foundation.The method can reduce the construction consumption,and improve the economy and benefit.

Abstract:To solve the problem of construction on the bank slope in the late construction stage of an inland framed wharf on island platform,BIM technology is used to simulate construction of filling,excavation and stone throwing in the project of the comprehensive terminal in Hexi operation area of Zhangshu port area in Yichun Port,and an implementation plan is proposed that contains island excavation by partitions,collaborative operation between excavators and dredgers,stone throwing with self-dumping and string bag.Engineering practice shows that compared with the steel platform,the construction by island platform saves the total construction period by about 40 days and the construction costs by about 7 million yuan,in which the new construction technique for complex spatial bank slope can shorten the construction period by 10 days.The research results can provide reference for similar projects.

Abstract:Multi-point anchoring pilling vessel and flatbed barge are usually adopted for piling work on water in domestic port and waterway projects.Before driving piles,the anchoring positions of each cable of the two vessels should be planned to avoid collisions between cables and surrounding structures,as well as scratches between cables.It is also necessary to ensure that each cable has sufficient length to ensure sufficient anchoring force.The anchoring conditions of an offshore oil terminal in West Africa are poor.A flatbed barge with hydraulic support studs (hereinafter referred to as the stud barge) is used instead of a conventional flatbed barge,becoming a new form of “piles carrier”.This article introduces the analysis method for the stability of the stud barge based on its application in this project,using a coupling method of finite element analysis and static mooring analysis to verify of the stud barge structure.The stud barge is anchored with studs,which is convenient to operate,especially suitable for shallow water and weak topsoil.This paper can be used as a reference for relevant industries when selecting offshore construction ships.

Abstract:The concrete cofferdam structure is stable,occupies a small riverbed area,and has good anti erosion effect.It is widely used in the construction organization and design of hub stage diversion.However,it faces difficulties in later demolition,difficulty in removing demolition waste,and significant impact on surrounding buildings.This article focuses on the impact of longitudinal cofferdams construction on discharge capacity of the Yakou Shipping Hub in the Han River.CATIA software is used for three-dimensional numerical simulation,and flow field,discharge capacity,and water level effects are analyzed on the retention and removal plans of longitudinal cofferdams under different characteristic flood flows.This provides a scientific basis for the selection of retention and removal plans for longitudinal cofferdams.The results show that retaining the longitudinal cofferdam will reduce the water flow velocity and discharge capacity of the adjacent area’s discharge gate hole,increase the height of the central blockage of the river to a certain extent,but still meet the requirements of the hub discharge capacity control standard.After safety and stability review,the longitudinal cofferdam can be retained,providing experience reference for the construction organization design of similar hub projects.

Abstract:With the increase of prefabricated docks projects,the placement state of underwater piles is becoming the focus of attention.However,due to the isolation by seawater,there are relatively few efficient,low-cost and high-precision methods for monitoring the condition of piles.This paper proposes a method to obtain underwater pile point cloud by using multi-beam bathymetric system (MBS),which includes the GNSS RTK multi-beam sounding technology,the survey line layout taking into account the shapes and distributions of underwater piles and MBS measurement principle,and the clustering point cloud of the monitored pile by K-means++and the pile point cloud segmentation and filtering by considering the pile shape and MBS backscatter strength.The practical application results show that based on this method,the high-precision point cloud of the pile can be obtained,the state parameters of the pile are obtained,and the accuracy of the deviation in the x and y directions of the pile center is less than 5 cm,and the radius deviation is less than 4.5 cm,which verifies the correctness and effectiveness of this method.

Abstract:Mud performance is of great significance to ensure the quality and safety of underground diaphragm wall construction.Orthogonal test is used to analyze the relationship between mud performance index and sediment thickness.Based on the correlation between mud performance and salt concentration,influnce factors of mud performance under high salt conditions are discussed,suitable mud mix proportions are determined for different geological conditions in the construction area.The results show that the sediment thickness of the construction area near the sea is thicker and the time for the sediment to reach stability is longer.The greater the density,viscosity and sand content of mud are,the greater the final sediment thickness is,and the increase of density and viscosity will prolong the time for sediment to reach stability.Mud density is positively correlated with salt concentration,while viscosity and pH are negatively correlated with salt concentration.Mud performance can be controlled by adjusting the mix proportion of mud materials.Sodium bentonite will increase the mud density,viscosity,sand content and pH value,soda ash will increase the mud viscosity and pH value,and polyaluminum chloride can increase the mud density and reduce the mud sand content and pH value.In the high salt environment near the Red Sea area,the recommended mud mix proportion is 10% sodium bentonite,0.2% soda ash content,0.08% polyaluminum chloride,89.72% water with pH 8.

Abstract:In traditional high pile wharf structures,the pile core and pile cap often adopt cast-in-place process.Due to the influence of tidal fluctuation zone,the reinforcement and concrete in the cast-in-place process are subject to seawater soaking and erosion,which makes it difficult to control the quality of the structure.Moreover,the marine operation needs to catch up with the tide construction,and the risk of personnel is high.Relying on the berth 18-20 project in Ningde,Fujian,this paper introduces a T-pile cap construction process using high pile wharf socket.By installing the T-shaped pile cap socket into the steel pipe pile and using UHPC material grouting to form a whole with the steel pipe pile.The T-pile cap is a new type of structure,and the installation and grouting process solves the technical problem of assembling straight piles for high pile wharf.The application results show that the process can improve the assembly rate and construction quality of the wharf,and the application effect is good.

Abstract:Soil cofferdam and steel sheet pile cofferdam are both commonly used cofferdam structures,when the two are used for comparison and selection of construction scheme,in addition to the plane layout,structural stability analysis and construction schemes,the project cost is an important factor to be considered in the construction scheme selection.To choose a more economical construction cofferdam scheme,this paper analyzes the influence of construction scheme,land requisition,main material supply and other aspects on the project cost by combining with an engineering case.The results show that when the waterway engineering is short of soil and unable to absorb the excavated soil after the cofferdam is demolished,the steel sheet pile cofferdam has the advantage of saving land and cost.For the waterway engineering with sufficient soil supply and the excavated soil can be absorbed after the cofferdam is demolished,the soil cofferdam can give priority to be used.