Abstract:The purpose of the yard planning and design of automated container terminal is to make the yard operation ability and efficiency of the automated terminal,meet the requirements of the overall operation ability and efficiency of the automated terminal through the overall planning of the yard.Through the specific design of the yard,the functions of the automated yard can be realized and the requirement on the yard’s safe and efficient operation can be satisfied.The chief planning and design elements including the yard capacity,functional area,number of yards,length,width and stacking level of the automated container terminal are studied.Taking Qingdao Port automation terminal yard planning and design as an example,we expound the planning and design method of the automated container terminal yard.

Abstract:The accuracy and speed of automatic stacking crane(ASC)gantry positioning affect the efficiency and safety of yard operation to a great extent.Aiming at ASC gantry automatic positioning in automatic container terminal,the paper analyzes and compares the principle and characteristics of magnetic nail positioning,gray bus positioning,laser ranging positioning,BPS positioning and differential GPS positioning.Comparing several factors such as yard layout,capital cost and gantry speed of Qingdao Port automatic container terminal,magnetic nail + rotary encoder positioning is put forward,which is accurate,rapid and reliable.

Abstract:Recently,L-AGV begins to be applied to the newly-built automated container terminal,and the reliable container inspection scheme is necessary to the safety and efficiency of L-AGV.Aiming at the problems that high frequency of malfunction and a great impact on handling efficiency of the L-AGV container inspection scheme,we study the bottom structure of the mainstream container in China,analyze the inspection logic of L-AGV container type deeply,and propose a new method to alternative the traditional container inspection scheme.The results show that the current detection logic cannot adapt to all the operating conditions encountered by L-AGV,and the inspection efficiency is low.The proposed inspection scheme can avoid the previous question effectively,also can satisfy the increasingly needs of safety and efficiency.

Abstract:Due to the difference of stack yard layout,safe and reliable and diversified demands of users for electricity from traditional terminals,the conventional layout of power supply and distribution plane and system scheme is not fully applicable to automatic container terminals.Based on the characteristics of loading and unloading technology of automated container terminals at home and abroad,we study the differences of power supply and distribution scheme between the automated container terminals and traditional terminals,and put forward several modes of power supply and distribution of automated container terminals.Through quantitative and qualitative analysis of the operation efficiency and reliability,new unmanned substations are built in the rear auxiliary construction area with one substation to one berth power supply scheme,ring-net type box transformer supplies power to refrigerated container and AGV charging station nearby.The comprehensive power supply and distribution mode,serving as a solution to balance the terminal power supply efficiency and safety,is applied to Qingdao Port automated container terminal,and may serve as reference for the future construction of the automated terminal.

Abstract:Taking the muddy sediment nearshore of Zhoushan city in Zhejiang Province for example，a flume experiment by regular waves is carried out on the incipient motion for the muddy sediment.The results indicate that muddy sediment has three states of incipient motions,i.e.,slight suspension of thin layer,individual exfoliation of surface layer,as well as roll up and suspension of the mud.The threshold wave height decreases with the increase of the wave period under the same water depth.Taking the state of roll up and suspension of the mud as the criteria for the incipient motion of muddy sediment，experimental values of the threshold wave height are close to the calculated values by the formula of Misaki Sato and Dou Guoren,thus the average of the calculated results by the two formulae can be used for estimating the threshold wave height of muddy sediment.With the state of roll up and suspension of the mud as the criteria for the incipient motion of muddy sediment，the maximum of the processing sediment concentration is often between 0.8 and 2.0 kgm3,and the maximum of the processing sediment concentration shows an exponential increasing relation with the increase of the critical shear stress by waves.The results of this research can be used to explore the hydraulic characteristics of sediment in muddy coastal areas,and provide reference for the numerical simulation of coastal sediment and parameters selection for the engineering analysis.

Abstract:In order to clarify the influence of slope on different wave statistical characteristics,we simulate the wave propagation with different slopes by numerical model,analyze the nonlinear parameters and wave height distribution,and compare the propagation characteristics of waves under different slopes.The results show that under the same condition,wave height will increase with the wave propagation on the slope when the water depth becomes shallow gradually.Slope has a great influence on the wave height distribution.When the slope is steep,the wave height distribution is close to the Rayleigh distribution with the wave propagation to the shallow water.When the slope becomes gentle gradually,the probability of the same wave height decreases.However,the Ursell number does not change significantly with the change of slope.

Abstract:There are different methods for calculating the overtopping of armored rubble slopes at home and abroad.It is necessary to select an appropriate method to accurately calculate and evaluate the overtopping of sloping breakwaters.Relying on the breakwater project of an overseas container terminal expansion project,the calculation methods of overtopping of armored rubble slope commonly used at home and abroad are introduced in detail.Combined with the physical model test of 2D overtopping,the calculation values of each calculation method and the test results are compared and analyzed.The results show that EurOtop(2016)in the European Standard has better adaptability in calculating the overtopping of armored rubble slope,the average method is smaller than the test value,and the design evaluation method is larger than the test value;while the CEM method in the United States and OCDI method in Japan are quite different from the test results.The research results can provide references for the design and construction safety assessment of sloping breakwaters.

Abstract:The submerged breakwater is a kind of building with good wave dissipation effect,but in practical engineering,some single submerged breakwater can not meet the requirements of wave height behind the breakwater.The influence of double submerged breakwater structure on wave dissipation is studied by physical model test,and relevant factors affecting the wave penetration coefficient of the submerged breakwater are analyzed,such as incident wave height,relative submergence depth and wave steepness.The results show that with the increase of the submergence depth,the transmission coefficient of submerged breakwater decreases,and the wave dissipation effect of submerged breakwater turns better.The transmission coefficient of the submerged breakwater decreases with the increase of wave steepness.At the same time,the experimental results are compared with the empirical formulas of the permeability coefficients of various countries,which verify the applicability of Yang Zhengji′s formula and can calculate the wave heights behind the double submerged breakwaters separately.

Abstract:The characteristics of business management of building electromechanical equipment installation project are professional complexity,strong technology and fast equipment updating.In view of the problems encountered in the business management in the mechanical and electrical installation of the new Taipa Ferry Terminal project at Macau,this paper analyzes the “back-to-back” principle in business management,the key points of design change and fund management,the handling of business disputes and how to replace professional subcontractors,etc.It draws the conclusion that “the engineering construction technology and business are inseparable,and technology must be subordinate to business”,and emphatically expounds the points of view on implementation of the business management in the general contracting of mechanical and electrical installation,and further confirm the conclusion that business is the leading factor and technology is the support.Only by combining the two management elements organically,can the successful implementation of the project be guaranteed.

Abstract:Granite residue sand viscous soil is more and more selected as the natural foundation holding layer of building(structure),but at present,the research on granite residual sand viscous soil mainly stays in the short-term strength and deformation stage.In order to investigate the deformation characteristics of granite residual sand viscous soil under long-term load,creep test was carried out with Chaozhou granite residual sand viscous soil as the research object.The results show that the creep deformation of granite residual sandy clay increases with the increase of time,but the deformation rate decreases until the deformation is stable;with the increase of shear stress and consolidation pressure,the creep characteristics become more significant.Duncan-Zhang model is introduced to modify the integer Poynting-Thomson rheological model.The modified P-T model can better describe the creep characteristics of residual sandy clay of granite.The results are helpful for scholars to further understand the creep characteristics of granite residual sand viscous soil,and provide a reference for the treatment of residual sandy clay foundation of granite.

Abstract:The compact clay will form clay ball during pipeline hydraulic transport.The calculation of hydraulic transport of clay ball is a difficult problem in dredging field at home and abroad.Based on the theory of slurry transportation and construction data of cutter suction dredger,this paper studies the resistance characteristics of pipeline transportation of clay ball,and analyses the deviations that may occur when various theories of soil slurry transport are used to calculate the resistance characteristics of pipelines in clay ball.Based on the analysis results,the calculation formulas of clay ball transport have been studied which can be used as a reference for engineering and theoretical field.

Abstract:Low-heat portland cement (PLH) mortars and pastes with different dosage of fly ash and slag were prepared and the compressive strength and flexural strength of the mortars were tested.Phase composition of the pastes was tested by XRD while hydration heat flow was measured by calorimeter.The results show that the application of fly ash causes decreases in mortar strength and strength development rate.The influence of slag on mortar strength is not obvious.The phase composition of fly ash pastes is similar to that of the reference mixture.However,the content of CH is decreased by the use of fly ash.The application of slag can reduce CH content more significant than fly ash and meanwhile promote the formation of AFm.Both the heat flow and hydration heat of the PLH paste are decreased by fly ash and slag.The influence of fly ash on PLH hydration evolution is not significant whereas slag promotes the hydration evolution.

Abstract:In consideration of the complexity of wave movement from near reef terrain and the difficulty of breakwater’s design near this kind of terrain,a project near the reef terrain and related seabed terrain is simulated,and the stability of breakwater’s toe rock is verified by physical model test.The test results show that it is dangerous to calculate the weight for stability of toe stones on reef terrain according to the codes.Based on the experimental phenomena and results,the optimum design of breakwater toe grooving on reef terrain is proposed.

Abstract:Offshore pile structure is strongly influenced by the wave action and has obvious dynamic characteristics.Taking a LNG terminal’s high pile mooring pier as the engineering background,the time-history dynamic analysis of the structure under wave action is carried out by using ANSYS.The results show that under the same wave parameters,the peak values of structural displacement and stress response caused by the simulated irregular waves are about 10%~20% larger than that caused by regular waves,and for the dynamic time-history analysis,the initial drastic fluctuation results can be discarded.

Abstract:Based on the physical model test of ice force in a project,we analyze the ice force of the high-pile pier structure. The results show that the reduction of ice force between piles,the cover of ice force between the front piles and back piles,and the non-simultaneous destruction of ice in front of each pile exist objectively.The reduction should be considered in calculating the ice force of the structure.The reduction of ice force on both sides of the edge pile is smaller,and that on the middle pile is larger;with the decrease of the pile spacing,the ice force also shows a trend of decrease;with the increase of the ice work angle,the reduction level of ice force on the first ice pile begins to decline,and the masking effect of the back row pile gradually weakens. The non-simultaneous failure coefficient of ice in this test is about 0.5.There are many factors to be considered in the reduction of ice force of the pile group,which is a complex subject. It is suggested to carry out model tests in concrete design.

Abstract:Aiming at the problem of the rationality of the current design method of container corner load in the pavement of China’s port,we carry out the statistical analysis of the distribution law of container weight in seven important ports in China at present,and point out the deficiencies of container corner design load in the current The Load Code for Harbor Engineering and The Design Code of Road and Storage Yard for Port Area.The former adopts the reduction coefficient method based on the container redistribution data of British ports,which is not in line with China’s situation and seriously small.The latter cannot reflect the difference of port design requirements with different degrees of importance.Furthermore,we propose some suggestions on determining the corner load of container in pavement structure design.The results improve the design method of container corner design load in China,which has important value and significance for the construction and use of port pavement.

Abstract:For high piling beam-slab quay with common cargo,cover plate and gutter are normally set up on top of longitudinal beam as the rain collection and drainage facilities.For the rehabilitation of old quay,this drainage method needs to cut gutter on top of the beam,which will damage the existing quay structure and increase the investment.Taking the drainage renovation project of an old quay in Jiangsu province as an example,we propose an underground pipe drainage method,and carry out standardized design of key nodes.The results show that the underground pipe drainage method has low investment and little influence on quay structure.It can provide references for similar projects.

Abstract:On-site investigation and numerical simulation are used to find out the reasons of ground collapse in the rear of a seawall.Firstly,the reasons of ground collapse are initially discussed according to results of on-site investigation.Secondly,constitutive model of seepage in saturated soil is built up，by which the seepage gradient of the interface between land backfilling materials and seawall material is solved by finite element method.Seepage failure is judged by making a comparison of the simulated seepage gradient and allowable hydraulic gradient,therefore,the reasons of ground collapse can be further verified.Finally,effective measures are put forward by the reason analysis.Results show ground collapse is caused by seepage failure of backfilling material.The ground collapse is caused by the infiltration failure of backfill,which is the result of the combined action of the inverted filter structure damage on the inner slope of the seawall and the precipitation infiltration in heavy rainfall weather.The further development of the ground collapse can be effectively prevented by mending the filter structure and preventing rainfall infiltration.The research provides an important reference for anti-seepage design and ground collapse mending.

Abstract:In the design of gravity wharf,a lot of block stone will be consumed as the pressure-relief prism.In view of the shortage of stone in northern tidal plain river network area in recent years,a design scheme of using the waste concrete block as the pressure-relief prism is proposed.Combining with the design alterations of an inland general cargo berth project,the feasibility of the scheme is demonstrated comprehensively from the engineering technology and economy,and the structural stability of the wharf is verified by the settlement and displacement observation in the trial operation period.The results show that it is feasible to use the concrete block as the pressure-relief prism,which can realize the recycling of resources.

Abstract:The pile foundation+low and wide bearing platform is an unconventional structure,which has both the retaining structure of sheet pile and the pile foundation characteristic of the piled wharf,for which,the current code has no stipulations on the calculation standard,thus it is difficult to implement the structural design of this kind of structure.Based on a practical engineering,we discuss the design conditions and structural design contents for calculating the mud surface line,etc.Based on the elastic foundation beam method,we adopt the finite element software ANSYS to calculate the structure and analyze the stress characteristics of each component.It is concluded that the unloading effect of the low pile cap is better than that of the high pile cap and the internal force of the front sheet pile is directly related to the width and elevation of the cap,but not affected by the rigidity of the cap,the structure and arrangement of the pile foundation.

Abstract:In view of the analysis and calculation of the water layout dimensions of harbor basin and channel,the PIANC specification proposes that in the conceptual design stage,the water layout dimension should be calculated rapidly by using formulas according to the natural condition,the basic parameter of ship and the influence of surrounding berth.In the detailed design stage,the simulation test should be used to simulate the actual working condition and accurately determine the channel layout and dimension.Taking the LNG terminal project in Southeast Asia as an example,this paper compares the formula of PIANC specification with the calculation of water layout dimension by simulation test.The results show that the simulation test can simulate the ship’s trajectory under different working conditions more accurately and truly than the formula calculation.The achievements can provide references for the similar projects.

Abstract:The mode of sediment transport is complex in a fine sediment tidal estuary.The different forms of sediment transport are very important for the study of estuarine evolution and channel siltation.Under tidal and wave conditions,this paper discusses the characteristics of bedload transport of non-cohesive sediment,movement of near bed high concentration suspended cohesive sediment layer and fluid mud layer,and characteristic,occurrence condition and transport rule of other sediment.Based on the hydrodynamic condition in the South Channel of the Yangtze Estuary and the result of previous flume study,this paper estimates the transversal sediment transport of high concentration suspended sediment from the nearby shoals into the channel when the salinity of the main channel is higher than that of the shoal.The result is basically in agreement with the actual result of channel sedimentation.

Abstract:The Three Gorges Lock is a five-level continuous lock,and the operation of adjacent locks restricts each other,thus it usually takes more time for ships to pass through the Three Gorges Ship Lock since the lock gates have to wait for adjacent one to be close.In order to further improve the lock’s traffic capability,the simulation model of the five level uplink shiplock is established based on large amount of operation data.By using the model to simulate the waiting situation,the paper analyzes the relationship between the number of ships in the adjacent locks and the waiting time,and then studies the effect of the sequence of fleet entry on the traffic efficiency.The results show that when the number of ships in the former lock is more than that in the latter, if the difference between the number of ships is smaller,the waiting time becomes shorter.Therefore,by optimizing the sequence,the time of waiting can be effectively shortened and the intervals can be reduced,thus the daily operation efficiency can be improved.

Abstract:The Xiaoqing River is an important regional channel and also a part of the layout of the “one vertical and three horizontal” inland waterway in Shandong Province.The restrictive factor of the re-navigation project of the Xiaoqing River lies in whether the shipping water resources can be guaranteed.Aiming at the problem of shipping water resources in the Xiaoqing River,this paper analyzes the current situation of water resources in the Xiaoqing River,obtains the guaranteed rate of 95% ~ 98% of the designed flow for many years,and then draws the conclusion that the existing water resources of the Xiaoqing River basically meet the requirements of water consumption of the supporting ship locks along the route by comparing the water consumption of ship locks along the route.Considering the uneven distribution of water resources in the Xiaoqing River within a year,in order to improve the navigation guarantee rate of the Xiaoqing channel and meet the multiple functional requirements of farmland irrigation and ecological landscape,a water replenishment scheme based on water diversion from the Yellow River and supplemented by the Dongping Lake was proposed,providing necessary technical support for the re-navigation project of the Xiaoqing River.

Abstract:In order to promote economic development along the coast,the middle reaches of the Dongjiang River will carry out capacity expansion and upgrading projects,which will be upgraded from grade V to grade III.However,because of the dense shoal and narrow channel,the effect of multi-shoal linkage should be taken into account in the regulation.The regulation method is different from that of single shoal,which makes the regulation difficult.Based on the hydrological and topographic data and the analysis of the beach characteristics of each obstructed sandy shoal,the regulation principles and measures of dredging as the main method and regulation and dredging as a combination are put forward.Through model tests,the scheme of excavating double-section channel is proposed to solve the problems of water flow return,flow velocity increase and flow pattern deterioration caused by the excavation of channel in long reach,and the distribution of dredging siltation is obtained based on the movable-bed test.The test results show that the regulation effect is good,and the whole river reaches basically meet the design requirements after the implementation of the scheme,which can provide reference for similar waterway regulation projects.

Abstract:With the impoundment operation of the Three Gorges Project and the successive application of Xiangjiaba and Xiluodu reservoirs in its upstream,the sediment inflow in the downstream reaches of the reservoir is greatly reduced,the scouring of clear water is serious,and the evolution characteristics of the river channel are significantly changed.The situation has an impact on flood control,navigation and the utilization of the shoreline.Based on the analysis of prototype data,we study the characteristics of water and sediment movement and riverbed evolution in Xiong-Cheng reach(Xiongjiazhou to Chenglingji)of Jingjiang River under the condition of scouring sand.On this basis,we predict the scouring and silting volume,scouring and silting distribution and river regime change of Xiong-Cheng reach after 30 years of operation of the Three Gorges Project by combining with solid model tests.The results show that the Xiong-Cheng reach will continue to scour in the future,and the deep trough will continue to deepen and widen,which is not conducive to the stability of the channel.

Abstract:The closed-type harbor is a new idea for the port construction in strong tidal and sandy estuary,and the key technical problems are the flow condition and sediment deposition in the approach channel.Taking the Shangyu closed-type port in Qiantang River estuary as an example,we analyze the flow condition and siltation intensity of the approach channel by empirical formula and numerical calculation.The results show that the flow condition of the approach channel at Shangyu closed-type port can basically satisfy the requirements of ships entering and leaving the port.The siltation intensity of the approach channel increases gradually from the navigation lock to the entrance area,and the siltation intensity near the entrance area is maximum.However,it decreases gradually from the entrance to the outside of the approach channel.The average siltation intensity of the approach channel is about 0.06 md.Jetting flow is adopted to raise the suspended silt at the bottom of the approach channel,and trench excavation in the leading dike of the approach channel is implemented to transport the suspended silt out of the approach channel.

Abstract:The designed highest navigable water level is one of the key technical parameters of ship lock construction,which directly affects the capacity,construction period and investment of the ship lock.For the value of the highest navigable water level of Zhuzhou second-line lock project design,we analyze the designed water level of the junction and the flood time in different recurrence periods according to the hydrological characteristics of the flood surge and collapse and the short peak time at Zhuzhou junction,and expound the navigable flow condition at the lock’s entrance area,waterway navigation condition and the investment of the second-line lock project under different characteristic water levels. Adopting the method of model test verification and investment calculation and comparison,we come to the conclusion that the highest navigation water level of Zhuzhou second-line lock design should adopt the flood standard once every 10 years.The research method can be used as reference for the lock expansion project in the mountainous and hilly areas.

Abstract:Renewable energy has the advantages of environmental friendliness and recyclability.Comprehensive utilization of renewable energy is an inevitable trend in the development of green container port construction.This paper firstly presents a simulation-based method to quantify the energy consumption of loading and unloading production in ports.Then,the environmental and economic benefits of renewable energy to replace the traditional energy is quantified with the environmental and economic benefit calculation method.Finally,taking wind power generation as an example,this paper obtains and analyzes the environmental and economic benefits of the energy replacement for trucks,quay cranes and yard cranes.

Abstract:In view of the gap between the throughput capacity of domestic LNG terminal jetty and the advanced international level,the main factors affecting the handling capacity of domestic LNG terminal jetty are determined by analyzing the statistical data of a LNG terminal jetty,which are channel management constraints such as channel depth limit (tide ride) and night berthing limit,then four simulated working conditions are determined accordingly.The simulation software is used to simulate the ship’s entry and departure stages under different working conditions,and the capacity and waiting time under different berth utilization rates are obtained.Through the analysis of the simulation results,the paper points out the most influencing factors of domestic LNG terminals jetty throughput capacity,reasonable utilization rate of LNG terminals jetty,and throughput capacity of Q-Flex type and above LNG terminals,which can provide reference for the construction and management of LNG terminals jetty.

Abstract:In order to study the effect of navigation aids optimization and evaluate the guiding effect of navigation mark adjustment on different ship types under different water conditions in specific water areas,we propose the method of quickly extracting the specified ship trajectory in the data based on the non-relational database MongoDB and according to parameters such as range,time zone and ship type,and visualize it on the front end based on WebGL,and develop the ship trajectory big data analysis system.Selecting the Nanjing Yangtze River Bridge as the test river section,we analyze the trajectory big data of the two seasons before and after the voyage optimization adjustment in 2017.The system reveals that after the navigation mark optimization and adjustment,the ship is launched through the six holes of the bridge during the flood period,and the angle between the track and the normal axis of the bridge axis is reduced,thus the expected effect is achieved.The results show that the method can quickly and automatically extract and display ships’ big data,which can be used to assist in optimizing the navigation mark distribution.

Abstract:With the emergence and application of BIM technology,new requirements are put forward for the development of geotechnical investigation informatization in engineering circles,especially visualization and transmission of investigation information.Using the world’s leading graphics development component HOOPS and combining database and network technology,we develop a computer aided system based on CS architecture for the geotechnical investigation on port and waterway engineering.According to the characteristic and operation procedure of geotechnical investigation on port and waterway engineering,the system provides multiple functions including investigation data integration and processing,3D geological modelling,statistical analysis of investigation results,data check and proofreading,as well as data interfaces with common software,which can increase the reorganization efficiency of investigation data,improve the quality of investigation achievement,and provide reliable 3D geological model for downstream specialties.The system converts the assist mode from original 2D chart into 3D scene and produces 3D investigation results,which provides useful support and reference for 3D design with BIM technology in port and waterway engineering investigation and design enterprises.

Abstract:Low pile cap revetment is a kind of structure constituted of pile foundation,cushion cap,retaining wall,which cushion cap is below ground.This paper uses elastic foundation beam theory and finite element method to design the revetment structure separately，and verifies the accuracy of two methods.On this basis,this paper studies on the variation of the horizontal displacement of the low pile cap revetment under the complex surcharge load by controlling surcharge load parameters(distance,width and value of surcharge load) and pile foundation parameters(length,diameter and spacing of pile).The results show that the horizontal displacement is affected by the surcharge load located at a range of four times retaining height to frontier of the wall,and the length of the pile has little effect on the horizontal displacement.The achievements can provide references for similar projects.

Abstract:As a new type of structure in port and waterway engineering,large cylinder structure is limited understood in the field due to the complicated mechanism.In order to study the factors which affect the overall stability and horizontal displacement of the large cylinder structure,a 3D numerical model is established based on PLAXIS 3D software which is used to simulate the overall stability and horizontal displacement of the large cylinder structure under the conditions of the different density, strength and stiffness of foundation soil,the different density,strength of filling soil,and the different embedded depth of large cylinder structure.The results show that the overall stability of large cylinder structure increases with the increase of foundation soil density,friction angle and embedded depth, decreases with the increase of filling soil density,and is independent of the filling soil friction angle and the foundation soil elastic modulus.The horizontal displacement of large cylinder structure decreases with the increase of soil density,friction angle,elastic modulus and embedded depth,increases with the increase of filling soil density,and is independent of friction angle of filling soil.The results can provide basis for the design of large cylinder structure.

Abstract:The lateral deformation characteristic of coarse grained soil is an important basis for quantifying the settlement of port filling under different loads.Based on 12 sets of lateral confinement tests with different stress ratios,we obtain the changing trend of loading and unloading times and stress ratios on strain increment of coarse grained soil under lateral confinement condition,establish the calculation models of strain and plastic strain of coarse grained soil,and verify the rationality of the models in two-dimensional and three-dimensional space.The results show that there is a maximum depth of influence of surcharge stress in soil.When the stress ratio is the same,the strain increment and plastic strain increment under the lateral limit condition are independent of the incremental load value.The strain and plastic strain of coarse grained soil change exponentially with the increase of stress ratio,and the limit stress ratio is between 2.124 and 2.461.It is suggested that the upper part of the foundation should be strengthened by dynamic consolidation for many times during the construction and filling of the port,the maximum heap load should be controlled and the stacking yard should be evenly paved in the operation stage so as to reduce the uneven settlement of the filling area.

Abstract:The construction of prefabricated drain is the most difficult link in quality control of soft soil foundation treatment.In the actual construction,only the sensory is often used to judge whether the quality is qualified or not.Combining with a vacuum preloading in Lianyungang project,we summarize drainage board construction each link of quality control strategies,analyze the site construction quality problems and technical difficulties from a technical point,and propose the formula for calculating the laying depth of prefabricated drain and the method for controlling the deviation of prefabricated drain position,verticality and return of prefabricated drain in actual construction management.The results can provide references for the similar projects.

Abstract:Soil of the dredging and reclamation project of Ram Port in Kenya is mainly composed of coral-like limestone mixed with clay.Aiming at the problems that suction mouth plugging and pump blocking usually happen,and the cutter is damaged easily to affect the construction seriously when it excavates hard coral rock,we study the type of cutter head,anti-rock device and excavation technology.Based on theoretical analysis and field test,we strengthen the cutter head and cutter tooth to improve production efficiency,and install the rock and gravel removal device to bring excellent stone-proof effect.The time utilization rate is over 75%,and the construction cost and the construction period are reduced by these measures.