Abstract:In view of the loss of measurement data integration information and the cumbersome updating of models in the application of BIM technology in waterway improvement projects,we use the Autodesk BIM platform to study the key technology of BIM technology applied in waterway regulation engineering and elaborate the implementation method,which was applied to the water channel improvement project in the Wuhan-Anqing waterway and the Yanziwo waterway.The study result may serve as reference for the application of BIM technology in the waterway improvement project.

Abstract:In the practice of the Yangtze River channel regulation engineering,the effects of deposition promotion and beach protection of penetrating frame groups have been proven.Previous studies focus on penetrating groups,current characteristics,and bed morphology characteristics.However,there is a lack of studies on the measurement index of the effects of beach protection of penetrating frame groups.Moreover,the effects of different plain layouts of frames on bed morphology characteristics have not been clarified.This paper concentrated on the bed morphology characteristics whose central bar was protected by the penetrating frame groups under the influence of river scouring through generalized flume experiments.The measurement indexes of effects of frame groups was proposed.The characteristics of erosion and deposition as well as the effects of deposition promotion and sand protection of different layout designs were compared and the layout design principles of the central bar under the influence of scouring were concluded accordingly.

Abstract:Since the completion of the navigation lock of the Three Gorges Dam,the navigation conditions of ships in the reservoir area have been significantly improved,the upsizing of ships has been developed rapidly.The carrying capacity of the mooring facilities in the ship lock is limited,however the large-scale development of the ship should meet the requirements of safe berthing of the lock chamber.By ship trail，we measure the mooring state and corresponding numerical values by choosing typical large-scale cargo ship passing through lock,analyze the major factors of affecting the lockage mooring force,and present effective measures to improve the berthing safety of vessel lockage.

Abstract:The accuracy of enrockment measurement in channel projects affects cost accounting directly.Thus,it is effective to improve the accuracy of enrockment measurement by adopting a reasonable and scientific method to measure the weight of the first ship.To counter the problems arisen in the engineering practice and in utilizing the method of weighting the first ship to measure stone,we carry out an analysis and propose feasible measures to improve the accuracy of enrockment measurement and control the cost of rock effectively,providing a technical support for the cost accounting and cost control of similar channel regulation projects.

Abstract:Plastic model sand has been widely used in channel physical model tests as one of the critical materials.The accuracy of its physical properties is imperative for parameter setting and result analysis.Dry bulk density,which directly affects the results of physical model calculation results and analysis of river bed scour and silt,is a vital physical index of model sand gravity features.This study analyzes the traditional cutting ring method and measuring cylinder method for dry bulk density measurement and proposes improvement measures according to test data,achieving better accuracy and stability of test results.The improved cutting ring method and measuring cylinder method are innovative and have been verified by experiments,which can provide guidance and basis for the plastic model sand test in related industries.

Abstract:To meet the need of project development in Taozi Bay,we carry out a study on the hydrodynamic sediment problem.Firstly,according to the in-situ hydrologic sediment data and wave data in Taozi Bay and nearby,we analyze characteristics of tide,tidal current,wave,sediment concentration,seabed material,etc.,and give design water levels and wave characteristics of different return periods in the mouth of Taozi Bay.Secondly,we analyze the coastline change and seabed evolution based on bathymetric charts measured in different years.Finally,we calculate and analyze the sediment movement.The conclusions are drawn as follows:Taozi Bay belongs to a typical arc coast with little sediment source,and sediment concentration under normal weather conditions is very small.The tidal current is dynamically weak，and the wave action cannot start the sediment movement and transport of the bed.The sediment movement under wave action is dominated by the transverse transport,and longshore sand transport is weak.Sediment movement is generally weak in Taozi Bay and the beach remains stable for years.

Abstract:Based on the physical mechanics experiments and a series of three static triaxial test of marine soft soil,we fit the mean stress and the generalized shear stress value of marine soft soil,consider that state line of marine soft soil is hyperbolic,take the modified Rhodes stress angle into the model,and improve the Cambridge model to make it more responsive to the static characteristics of marine soft soil.The practice shows that the modified Cambridge model of marine soft soil effectively simulates the stress-strain characteristics of marine soft soil,and shows the nonlinear characteristics of the soft soil and the characteristics of the plastic flow.Based on the modified Cambridge model of marine soft soil,we numerically analyze the foundation settlement of sea dike project based on marine soft soil,and verify the applicability of the modified Cambridge model of marine soft soil by the calculation result.

Abstract:Based on the OpenFOAM,the momentum damping equation and regular wave grid boundary are implanted to form a reliable three-dimensional moving grid gas-liquid two-phase flow numerical wave flume.On the slope platform with a slope of 1：6,the gas-liquid two-phase flow breaking process of waves in the coastal shallow bank surf zone is simulated.The numerical simulation results are in good agreement with the experimental values,and the simulation of wave deformation,collapse and ambient gas changes in the shallow beach crushing area is complete,which can provide good data support for the study of wave crushing mechanism.

Abstract:Compared with widely used in reinforcement foundation of saturated soft soil,cement soil pile has less application on improvement of enrichment pozzolana muck.The reaction mechanism among cement,soil and pozzolana is the determining factor whether cement soil pile can be used in improvement of enrichment pozzolana muck.Based on the study and analysis of hydration mechanism of cement-soil gelation system and cement-pozzolana gelation system,we obtain that strength contribution by pozzolanic effect is the key factor for strength growth of cement-soil-pozzolana gelation system in the later hydration period.Aiming at structural characteristic of enrichment pozzolana muck and hydration mechanism,we test cement soil pile based on appropriate cement-soil design parameter and construction technology.The results show that 28 days unconfined compressive strength is much better than the design strength,and the pile strength is much better than the ordinary cement soil pile strength in soft soil under the same conditions.It means that cement soil pile is suitable for improvement of enrichment pozzolana muck foundation.

Abstract:In order to meet the needs of Xiamen Port construction,we propose the plan of planning Haicang deepwater port on the north area of Jiulongjiang Estuarine Bay.This area’ s natural water depth is only from 1.5 m to 5.0 m,the construction of the deepwater port should be excavated from 12 m to 15.5 m,and the feasibility of the planning depends on the siltation strength of the port.Through the analysis of the model test results and field data,we point out that with the westwardly development of the quay,the height difference between the channel and the river bottom gradually increases,and the flow velocity is slow down and the sediment deposition is caused in the harbor basin.We also need to consider the influence of the current flowing to channel “brush bottom”induced siltation.According to the characteristics of various siltation,we calculate the sediment deposition rate in Haicang Port.It is believed that it is feasible to build deep-water ports in Haicang Port area.

Abstract:Aiming at a new type of movable anti-wave structure in harbor engineering,we establish four kinds of analysis models based on the finite element method.The comparison of analysis shows that the finite element model created by coupling the degrees of freedom of the nodes at the contact surface is more applicable.We apply the above-mentioned finite element model to solve the stress,displacement and bolt internal forces of the movable anti-wave structure,and analyze the influence of the variation of the steel thickness on the mechanical properties of the composite structures.The results show that the tension and compression stress of the lower end of the steel members are relatively larger,and the situation needs to be emphasized.The smaller the thickness of the steel member is,the more sensitive the stress and displacement of the composite structures have.Combining safety with economy of the anti-wave structure,it puts forward the design and optimization points,and provides reference for the engineering application.

Abstract:The latest version of Load Code for Harbor Engineering does not consider the influence of small flow angle on flow force of tanker.However,flow force of tanker is closely related with flow velocity and angle.In order to meticulous study on the influence law,based on physical model experiment,we analyze the change regulation of flow force of 300，000 DWT tanker when the flow velocities are 1.0 m/s,1.5 m/s and 2.0 m/s and flow angle is between 0° and 15°.The results show that both horizontal and vertical flow force of tanker increase with increasing current velocity.Besides,the vertical force is almost identical to the computed result according to the code when the current angle is between 0° and 15°.The lateral force is about 2 times the computed value.

Abstract:Due to the lack of a detailed stipulation about the load design in the Chinese code concerning the yacht harbor,we carry out a research on the wind load,wave load,current force,mooring force and impact velocity by referring to the standards of different countries both at home and abroad.The research reveals that calculations of Chinese standards for the wind load,wave load and current force are reasonable，while that about the vessel’ s mooring force is not quite appropriate,and it is suggested to refer to the USA and Australian standards.As for the calculation of the impact velocity,the Australian standards is suggested to be referred to.

Abstract:Reasonable anchorage area location can ensure the safety of ship mooring.At the same time,it can optimize the layout of the port and improve the efficiency of port operation.This paper summarizes the current methods of solving the anchorage area location problem,and analyzes the application of GIS technology in location problems.The factors influencing anchorage area location are determined and comprehensive evaluation index system is established in this paper.The weights of each index are determined by AHP and the comprehensive score of each grid is obtained by the applicability evaluation model of sea area.Based on several constraints like marine functional zoning,a feasible scheme set of anchorage site selection is obtained and the optimal scheme is selected out by the method of optimization.Through an example analysis,it is proved that the model proposed in this paper is reasonable and feasible,and can be used as a method to optimize the anchorage area location.

Abstract:The beam height of high piling quays is large,controlled by pile foundation spacing,and the span diameter is relatively small,that is,the ratio between span and height is relatively small.Strictly speaking,it is a deep flexural member restricted by the specification.However,in practice,the common situation is that the deep flexural member is approximately reinforced according to the normal bending member.On the basis of the current specification,through an engineering example of the two kinds of reinforcement ways after analyzing ,the result is obtained:under the same situation,the calculation amount of reinforcement for deep flexural memb er increases by 30%~35% compared with that of ordinary bending components;for beams or other similar deep flexural member of high-pile beam and slab wharf,if the reinforcement is carried out according to normal bending components,the result is unsafe.The conclusion can be reference for future reinforcement design of port and waterway engineering works.

Abstract:In view of the larger berthing water area of ramp medial,the more earthwork volume and the higher investment with mountainous river ro/ro sloping wharf of the ship’ s T-type berthing,considering the terrain,landform and water flow conditions,we analyze the mooring characteristics of the ro/ro sloping wharf by changing the T-type berthing angle,and propose a working form for the ship’ s declinate T-type berthing of the ro/ro sloping wharf.The comparison of engineering examples shows that the tilting of declinate T-type berthing can further reduce the width of the water area from shore side to ramp,meanwhile reduce the amount of engineering work and save the project investment,which can provide reference for other similar engineering design.

Abstract:In view of the new water and sediment environment and the evolution of tidal flat in the Yangtze River estuary,and the dilemma of comprehensive utilization of the dredged soil in the deep water channel of the Yangtze River estuary ,guided by the concept of ecological priority and the Major Protection of the Yangtze River,we discuss the urgency and feasibility of the comprehensive utilization of the follow-up dredged soil.From the aspects of ecological environment shaping,protection of tidal flat resources and control of the Yangtze River estuary,we analyze ways and methods of carrying out the great protection of the Yangtze River estuary.Based on the project of Hengsha Avenue extension and silt protection,the concrete plan of comprehensively utilizing the dredged soil of the Yangtze River estuary deep water channel in Xinhengsha ecological landform after 2020 is put forward.

Abstract:Pengshui reach of the Wujiang River is typical canyoned mountainous river with complex navigation condition and high head due to the step development.So,the type selection of the navigation structure and reasonable layout are the key technologies for the safe passing of ships through the dam satisfying the throughput capacity requirements.By analyzing comprehensively the hydraulic junction on similar canyoned rivers in China,we propose the scheme of “lock and ship lift with the middle channel” to well deal with the difficulties in the type selection and layout arrangement of the navigation structures.Through a lot of research on the trial sailings and project consultations,we probe into the problems such as the lower construction standards of the lock and ship lift than the design ones and the difficulty of joining the ship lift due to the water surface wave in the downstream approach channel.We also put forward suggestions on the regulation scheme including optimizing the run mode of the combined dispatching,scientific management,as well as extending the length of the guide wall in the downstream approach channel,etc.,to serve as reference for the administrative departments.

Abstract:The influence of daily unsteady flow regulation on the downstream channel is the main problem to be considered in the operation of Xiangjiaba Project.Based on the two-dimensional unsteady mathematical model,we analyze the influence of daily unsteady flow of Xiangjiaba on the navigation conditions of the waterway of Luoguotan reach,and select two typical daily regulating conditions and two flood discharge conditions to analyze the variation characteristics of water level,discharge and velocity in the reach of the river.The results show that,under two typical daily regulation conditions,the variation of water level from unsteady flow ship to Luoguotan is from 1.26 m to 1.46 m,and the maximum daily variation of water level under flood discharge condition is from 2.05 m to 2.96 m.The unsteady flow has a certain influence on the reach of the river.According to the current navigation standard,the maximum daily variation of water level is from 2.05 m to 2.96 m.Under four conditions,the hydraulic index of river reach can reach the navigable hydraulic index.The characteristics of unsteady flow under the dam and its influence on the waterway and port wharf should be observed prototype,accumulate practical experience,and provide the basis for further optimization of power station scheduling scheme and downstream waterway maintenance.

Abstract:The Nanhui mudflat is located in the intersection area between the Yangtze River estuary and the Hangzhou Bay.It is controlled by two tidal currents from the Yangtze River estuary and the north coast of the Hangzhou Bay.In recent years,the tidal currents,sediment transport,morphological process of the Nanhui mudflat have changed significantly,which is mainly caused by the reclamation project of the low tidal flats.Based on the yearly measured bathymetry data (from 2006 to 2008) and 9 cross-sectional bathymetry data in each season from November 2007 to November 2008,combined with the sediment characteristics,we discuss the features of recent morphological process and interannual change in the Nanhui mudflat after the reclamation project and the hydrologic and sediment variations of the river basin,specially the seasonal scouring and silting characteristics.The results show that the annual erosion and siltation of Nanhui Dongtan is siltation,Nanhui South Beach is erosion.In different seasons of erosion and siltation in the Nanhui shoal,the process is different.In the plane,Nanhui beach isobath in winter and summer is mainly by silting,and in the spring and autumn,it is dominated by erosion.Vertically,the Nanhui Dongtan section in the spring,summer and autumn season is alternation of scouring and silting,it is silt in winter.Nanhui mouth section is scouring in autumn,and silt in winter and summer season.But Nanhui South Beach section is scouring in autumn and winter,silting in spring and summer.The sediment grain size of Nanhui east beach is generally finer.The median diameter of Nanhui mouth near the intersection of east and south beach is relatively coarse,and the median grain size of Nanhui south beach shoal is the coarser.

Abstract:Changzhou ship locks No.3 and 4 are the water-economizing locks，which are located in the important transportation corridor of southwestern China.In view of the high reliability requirements and the special characteristics of the control technology of the water-economizing ship lock,we study the control system scheme.Through the research of technological process and the analysis of controlled object,we design two sets of lock control network architecture,and obtain a set of lock control system with a comparison of functional and reliability,which meet the requirements of the Changzhou ship locks No.3 and 4.The new idea is put forward for the design of the control system of the ship lock,which provides a guarantee for the safe and reliable operation of the ship lock in future.

Abstract:The second-line ship lock project of Xijin Water Conservancy Project plays an important role in the development of the Xijiang River shipping and watershed economy.In order to study the interaction between the second-line ship lock layout and the layout of the original ship lock,hydraulic model test was carried out to study the water flow conditions under two different layout schemes,by comparing the three indices of longitudinal,transverse and backflow velocities of the first and second line ship lock gates.The comparative analysis shows that when using the common layout scheme of the first and second shiplock gateways,in the case of flood flow,the horizontal and return flow velocity in the area can’ t meet the standard requirements.When using the next navigation channel door to separate the type of layout,flow velocities of the second-line lock under the entrance area of the lower approach channel at all levels of navigation traffic basically meet the code requirements.

Abstract:The operation requirement of full-balanced vertical ship lift must maintain the full balance of the ship-chamber at all times.Once the balance system is broken,the consequence of running the ship lift will be disastrous. The paper systematically discusses how to level the ship-chamber after tilting from the point of view of safety and economy.The imbalance of ship-chamber can be adjusted via braking and lifting system. In the meantime,the stress and strain of driving system of the ship lift can be released.By adjusting the water level of ship-chamber,the ship-chamber’ s gravity will be greater than that of the counterbalance.By releasing brakes at different partitions,we can lower down the higher position of the ship-chamber and level the tilted ship-chamber.After achieving a basic balance,the ship lift will run automatically on its self-balancing system,and the ship lift will eventually regain a full balance.The case study has solved the problem of leveling after tilting of the ship-chamber and it provides a guidance for the operation and maintenance of similar ship lifts.

Abstract:To counter the problem of serious ship backlog and low efficiency in Wangjiatan of Changshou waterway during the late falling stage,we carry out a feasibility study on opening emergency sub-waterway in the left channelof Zhongshuiqi.Based on the analysis of fluvial process and status of channel conditions in Wangjiatan,it is concluded that by removing some of Zhongshuiqi and exploding part of the Niuleiba reef,the current situation of channel bending and poor flow conditions of Chaipanzi in the left channel of Zhongshuiqi can be improved.After implementation of the project,the emergency sub-waterway is maintained when the local water level is 151.0～155.0 m(at the late falling stage and flood season).The maintenance dimension of channel is 3.0 m×50 m×560 m.

Abstract:Based on the analysis of the Rao River waterway conditions and characteristics of the navigation-obstructing shoals,we establish a one-dimensional flow mathematical model to study the river section,which is verified by the measured data.By the mathematical model,we calculate the key parameters of the dredging depth channel in shallow shoal section and the variation of water line under the designed flow condition before and after the project,and analyze the changes of hydrodynamic conditions and the variation of flow velocity in section of the navigation channel.After the project,the water level and hydraulic gradient of the river section decreased.The average velocity of the navigation channel section in the shoal section of the lake area decreased,and the flow velocity of the lower reaches of the Shuanggang section increased.The annual back silting thickness of the navigation channel of shoals in the lake area after dredging of the navigation channel was calculated using the standard formula.The research results are available for reference by the design unit.

Abstract:According to the measured data of the reach between the Pangxieqi and the Huoyanqi in the upper reaches of the Yangtze River,the distribution types of the vertical flow velocity of the river are summarized.We studied the vertical flow velocity distribution of “3”type by fractal theory.The influence of flow rate,water level and channel slope drop on the fractal dimension are discussed.The results show that:the vertical flow velocity distribution of the river segment can be divided into:“3”type,“anti-3”type,“C”type,“anti-C”type,“1”type,“S”type,“7”type,“anti-S”type and“class index”type,and the “3” type of the vertical flow velocity distribution has the highest frequency.There is a fractal phenomenon in the “3” type of the vertical flow velocity distribution and it has a first-order accumulated variable-dimensional and fractal phenomenon.It is essentially a result of the deviation of logarithmic flow velocity distribution under the action of a variety of factors.The fractal dimension of vertical flow velocity distribution is positively correlated with flow,water level and slope,but the three factors have little effect on fractal dimension.

Abstract:The reefs at the bottom of the river increase the turbulence of the water,which is conducive to the formation of fish eggs.The river with a large number of reef sections is usually an important place for fish to perch and spawn.Nevertheless,the reefs also have the possibility of impeding navigation.Cleaning up the reefs in the waterway has a certain influence on the turbulence intensity of the water body and changes the habitat of fish.Therefore,it is necessary to fully demonstrate the practice of waterway clear up reefs in important fish habitat sections.Using the turbulence kinetic energy as an index to evaluate the turbulence intensity of water body,the three dimensional numerical simulation of turbulent flow is carried out in the middle reaches of the Xijiang River where are also known as the river section of the rare fish reserve.At the same time,the turbulence kinetic energy of water body and the volume of turbulent water in different intensity are calculated before and after removing the reefs,and the change law and reason are analyzed.The results show that :the turbulent kinetic energy intensity has a positive correlation with the depth of water;the reef cleaning up project causes that the volume of water containing low turbulent kinetic energy increase and the volume of water containing high turbulence kinetic energy decrease;the variation of turbulent kinetic energy in the bottom water body is higher than that in the surface;the change rate of the volume reduction of high turbulent kinetic energy water is greater than that of the increase of the volume of the weak turbulent kinetic energy water.

Abstract:In view of the navigation obstruction problem in the 6.0 m channel of Dongbei waterway of the lower reaches of the Yangtze River,based on the river topography and hydrological data,the riverbed evolution characteristics and waterway conditions of Dongbei waterway are analyzed,and the countermeasures of waterway regulation in this section are also discussed.The results show that the overall waterway conditions of Dongbei waterway are good,only shallow packets appear in the river center in local years,resulting in insufficient water depth and width of the channel.In order to improve the conditions of Dongbei waterway,the waterway regulation project may consider to raise the low beach on the left side of the third continent on the basis of the construction of the northeast waterway regulation project,stabilize the mainstream flow path of the transition section,narrow the channel of the transition section appropriately,concentrate the water flow on the shallow area,or consider to adopt the dredging measures only in the locally shallow years.

Abstract:The veneer of main track is an important moving part of the flat valve,which affects the stability of the ship lock’ s operation.In view of the service life of the veneer of main track,we collect the related historical maintenance data，fit the parameters of the reliability distribution function by linear regression analysis method，and apply the hypothesis test to obtain the service life model for veneer of main track of valve in ship lock.The average service life of veneer of main track on the Grand Canal in the north of Jiangsu province is 6.42 years,which is calculated by the model.The results provide reference and basis for the service life of other ship lock facilities in the future.

Abstract:The deep soft foundation（fak≤100 kPa）of storage tanks and other buildings requires large bearing capacity and limited differential settlement deformation,the spacing of piles may be too little or the length may be too long if the single CFG pile is used in foundation treatment.Therefore,the combined composite foundations are needed,the combined composite foundation with the vibro-replacement stone columns is one of them.According to the strengthening mechanism of the combined composite foundation with the vibro-replacement stone columns and the CFG piles,the stress characteristics and the action of CFG pile and stone columns and CFG piles are analyzed.The results show that CFG pile can improve the foundation bearing capacity and reduce the settlement.Based on optimization theory,the optimization design method is established for the combined composite foundation.Finally,the optimization design method of the combined composite foundation is discussed by an engineering case,which shows that the bearing capacity,settlement and economical efficiency meet the engineering requirements.

Abstract:Aiming at the complexity of the backfilling of the Yangshan Phase IV land area and the high requirements for the use of automated storage yards,a comprehensive construction method for vibro-compaction,dynamic compaction,and vibration rolling compaction was proposed for the reinforcement of the backfill layer,and a test was conducted.Through the test the technical parameters and construction technology of the ground reinforcement method were determined,a vibration monitoring system was developed and the influence of dynamic compaction on the bearing platform was monitored.The test results show that the settlement of vibration foundation can reach 90.6 cm,the settlement of dynamic foundation can reach 59.1 cm,and the impact of dynamic compaction method on the vibration and settlement of the platform is within the safe range.After static & dynamic penetration and compaction,the reinforced foundation can meet the design requirements and can provide comprehensive foundation for the subsequent ground reinforcement.

Abstract:In view of the current cross influence between the coastal bridge and the general earth-rock seawall in the deep silty foundation in the coastal area,by the pile type comparison (bored pile,large-diameter thin-walled pile and U-shaped prestressed sheet pile) and pile foundation layout scheme comparison and selection (closed row,2 times pile diameter interval and all-round arrangement) and other in-depth comparative analysis,combined with vertical bearing capacity and horizontal bearing capacity calculation and comparison,a new type of ribbed structure seawall structure with double row long and short densely packed pile foundation is proposed.The deep silt foundation is all-round solidified and strengthened in shallow layer.The new structure can effectively avoid the adverse impact of the settlement of the general earth embankment on the negative frictional resistance of the pier of the coastal bridge,effectively ensure the safety of the bridge,and at the same time save the construction period of the cross section bridge and the cross section seawall.Through the analysis of monitoring data such as actual settlement after completion,it is considered that the new structure effectively ensures the safety of the bridges at the intersection.

Abstract:Since the foundation soil bearing layer of the proposed open-pit coil steel yard is deep silt and silt soil,the vertical and lateral displacement caused by the large-area coil steel surcharge loads will seriously affect the safety and use of RMG pile foundation.Therefore,it is necessary to treat the foundation soil.The method of finite element numerical analysis is used for analyzing the effect of large-area coil steel surcharge loads on the RMG pile foundation under the following three conditions:without treatment,mixing cement pile treatment and loading preloading,and the stress and deformation of pile foundation under three conditions are obtained.Based on the comparative analysis from multiple aspects,we determine the proper foundation treatment scheme for this site.

Abstract:The two times treatment technology ( shallow & depth ) is used to reinforce the fresh hydraulic reclaimation silt foundation,and the construction cost is high and the duration is long.Based on the vacuum consolidation mechanism of fresh hydraulic reclaimation silt foundation,we put forward the new idea of optimizing the vacuum preloading drainage system.Based on Guangzhou Nansha port phase III relamation silt foundation improvement district II project,we study a new type of vacuum preloading and drainage system.The results show that fresh hydraulic reclaimation silt foundation which is reinforced by the new type vacuum preloading drainage system,can reach the design requirements.The new system solve the problem such as drainage plate to plug,vacuum pressure transfer efficiency low when traditional vacuum preloading drainage system is applied in fresh hydraulic reclaimation silt foundation ,and can effectively shorten the time limit and save cost.Based on the characteristics of vacuum pressure transmission and final consolidation effect,scheme 3 (the original raw materials of anti clogging type whole drainage plate + special joint + horizontal drainage plate + silty sand cushion) is more applicable to fresh hydraulic reclaimation silt foundation.

Abstract:Aiming at the problem of the calculation method of sheet pile embedded depth,the calculation method is different in different codes.We carry out a comparative study for the calculation method of embedded depth in Chinese code JTS 167-3—2009 and the US Engineer Corps Engineers design manual EM1110-2-2504,which analyzes the similarities and differences on earth pressure,shear strength parameters of the soil,angle of wall friction,distribution modes and calculation method of earth pressure of anchored wall and cantilever wall.We illustrate the difference in design steps and results according to the two codes by a typical project example.The results show that,the embedded depth is greatly affected by soil conditions to tend to a certain extent but there is no definite conclusion,and the influence degree of soil friction angle and cohesion in front of the wall is different.

Abstract:In low pile platform structure calculation,the pile-soil interaction is usually only considered without the base slab-soil interaction.Based on engineering practice,we establish the simplified finite element model for low-pile-platform structure to analyze the influence of internal force of base slab and pile when the bearing capacity of soil between piles is considered.The results show that the moment of base slab and axial force of pile can be reduced by 35%~40% if load-bearing capacity of soil between piles is considered in the simplified model,while the bending moment and shear force of pile foundation are determined by horizontal force and soil m value.The axial force of pile decreases with the increase of soil bedding coefficient,but the damping gradually decreases.

Abstract:The foundation of the release sluice of Yakou hydro-junction in Hanjiang River project is uneven sandy gravel soil.The foundation surface is partly a thin layer of fine sand,and the sandy gravel soil contains a fine sand lens or large pebble locally.In view of the problem of large settlement and uneven distribution of sandy and gravel soil,a treatment scheme for the composite foundation with long spiral drilling and grouting piles was proposed,furthermore the pile forming test was carried out in representative areas of the site.The results show that the foundation treatment scheme is feasible,stable in quality and environmentally friendly,suitable for the application of the project and valuable for popularization.

Abstract:During the construction of the dredger,a lot of sediment continuously enters the dredger cabin.If the process of sediment loading cannot be controlled reasonably,dredger may lose balance,which affects construction schedule and even causes safety accident.At the same time,the cabin outlet drains outwards and some part of the sediment is out of the cabin with the flow of water,which causes overflow loss.Reasonable arrangement of the loading operation is the key to ensure the safety of construction and reduce the overflow loss.MIKE 3 HD and MT model is used to simulate the process of sediment into the cabin,and calculate the sediment distribution in cabin and curves of loading capacity under different working conditions.According to the results,MIKE 3 model can simulate the loading well and run fast,which can be used to assist the dredger construction operation in advance control.

Abstract:It is very common that the vibro-compaction of ground improvement is applied in deep hydraulic reclamation project.The particle size distribution of barged-in fill sand soil,and densification current and holding time of vibro-compaction process have a great impact on densification achieved.It is very critical to monitor the influence factors to assure the compaction quality.In accordance with the analysis of quality monitoring and control of Kuwait LNGI project,we conclude that the suitability of vibro-compaction for reclamation material can be assessed by suitability number (SN) and graph of range of suitable soil using particle size distribution result in reclamation stage.After reclamation completed,the CPT before compaction should be done and applied to detect the zone of unsuitable material.Accordingly,the densification current and holding time should be adjusted properly to achieve the acceptance criteria.As approved in compaction trail area,when the 180 kW power of vibrator and 3.75 m of spacing is applied,a withdraw with increment of 1 m and compaction with 40 s of holding time or 420 A electric current can be suggested in order to achieve the design densification.

Abstract:It is a difficult problem for the design and construction of a wharf to guarantee the wharf stability and strictly control the post-construction settlement and displacement under super-large service load.The wharf area at berth No.10 in Zhaoyin harbor district of Xiamen Port is subjected to up to 300 kN/m2 vertical uniformly distributed load,and equipped with the mobile overhead crane with a lifting capacity of 26 MN.For the super-large service load,a large-scale 5 800 t caisson with shearing key,16 000 m3 reinforced concrete platform and super-wide gengon with 41 m top width are designed and constructed.Pertaining to the requirements of strictly controlling the post-construction settlement and displacement of the wharf,the surcharge preloading is implemented for the main part of the wharf,and the post-construction effect reaches the expectation.