Abstract:In order to explore the morphological changes of sandy shoals under the action of regular waves,we construct the evolution process of sandy shorelines section in the wave flume.It is found that under the action of regular waves,sand shoals will have sand bar peaks,and there is an evolution process from single sand bar peak to double sand bar peak.Moreover,after formation of sand bars,they are not static,but reciprocate offshore and onshore with time.We also explore the influences of water depth,period and vegetation coverage rate on the variation of sandy shoals,and discuss and analyze the maximum scour depth,maximum siltation depth,scour area and siltation area.The results show that the increase of water depth will lead to the movement of sand dam towards the shore,the increase of the period will lead to the disorder of the shoreline,and the vegetation cover has a stabilizing effect on the shoreline.

Abstract:In order to explore a new kind structure with excellent wave effect and small force,we compare the hydrodynamic characteristics between single board and single arc board breakwaters,and analyze the relationship between the transmission coefficient and the reflection coefficient,pressure and the flow field around the structure under the different wave parameters situation.The results show that the transmission coefficient of the wave of single arc board breakwater is obviously smaller than single board breakwater when the structure is in the condition of water emergence,but it is opposite when the structure is in the condition of water below,at static water surface the two are equivalent.The reflection coefficient of the wave of the single arc board breakwater is slightly larger than that of single board breakwater in the condition of water emergence.However,the reflection coefficient of the wave of the single board breakwater is obviously larger than that of the single arc board breakwater in the condition of static water surface and water below.The pressure differences at different measuring points on the upper surface of the two structures are large,while the difference on the lower surface is relatively insignificant.

Abstract:Since there is no explanation on the calculation of the wave’s uplifting force on the caisson floor in the case that the caisson has a buried depth in the Code of Hydrology for Harbour and Waterway(JTS 145—2015),this paper carries out a comparative analysis of the influence of the caisson’s buried depth on the wave’s uplifting force between the code calculation and physical model test based on the practical projects. The result shows that the buried depth has reduction function to the wave uplifting force,and the the reduction degree shall be determined in combination with the buried depth,soil quality,caisson size,wave parameters,etc.

Abstract:In order to study the wave force characteristics of the slope type submerged embankment under different wave height and water depth conditions,based on the design and physical model data of a submerged embankment,we use FLUENT software to establish a two-dimensional wave numerical water tank,verify the reliability of physical model by the test data,calculate the wave forces of slope type submerged embankment under different submerged water depths and wave heights by a series of numerical simulations,analyze the relationship of wave force,relative wave height and relative submerged water depth,and obtain the formula for calculating the maximum wave force on the top surface of the slope type submerged embankment by fitting the numerical data combining with other forms of submerged embankments.The results show that the wave force is significantly affected by the relative wave height and relative submerged water depth,and its influence mechanism is related to the wave field fluid motion characteristics.Compared with the wave height change,the wave force is more sensitive to the change of the submerged water depth,and the wave force show different change law in different submerged water depth intervals and different action positions.

Abstract:Aiming at the cracking problem of cast-in-situ concrete breast wall of open caisson structure,we apply the means of theoretical analysis,numerical simulation,field test,prototype observation and physical model test to obtain the cracking reason of cast-in-situ concrete breast wall of open caisson structure under wave force.We establish the on-line monitoring system for the bottom pressure of the caisson roof based on the internet and optical fiber sensing technology,obtain the force and distribution law of the roof under different wave elements in real time,measure the force characteristics of the roof of the open caisson under the waves by the physical model test,verify the rationality of the monitoring data,and propose the suggestions for engineering optimization measures.The results show that the action of wave force is the root cause of the crack of breast wall in this project,so the early engineering measures should be strengthened to reduce the influence of wave force.

Abstract:In order to solve the problem that it is lack of reasonable and effective evaluation method and evaluation index in the detection and evaluation of high pile wharf,we study the structural evaluation index of high pile wharf combining with disturbing energy method.By using variationally principles and principle of minimum potential energy,we establish the index system of overall safety evaluation for high pile wharf structure based on its structural characteristics combining with disturbing energy method,and compare with the current code.The results show that the method can give the overall safety factor of the structure while evaluating the local components,which can reflect the contribution of different components to the overall safety.

Abstract:This paper presents the comparison between the British and the PIANC standard on the calculation of berthing energies,and the fender design energies are compared with that of the Chinese code.In addition,the eccentricity coefficient is further studied.The conclusions are as follows:1)The parameters such as eccentricity coefficient,hydrodynamic mass coefficient and abnormal berthing energy coefficient are different in the calculation of berthing energy in British standard and PIANC code.2)The design value of berthing energy container vessels in British standard is mostly less than that of PIANC,while that of oil tankers is greater than that of PIANC.3)When the tanker berths at the third point,the impact energy is about 1.3 times of that at the fourth point.4)The eccentricity coefficient CE value is affected by the deviation of manifold of oil tanker and gas carrier,which decreases with the increase of tonnage,and the influence degree is 12%~29%.

Abstract:Binary beetle-swarm (BAS) and its optimization algorithm (BSO) is a new biological heuristic algorithm in recent two years,which is easy to implement and fast in convergence,but it is only suitable for continuous function optimization.At present,there are few researches on the sensor placement optimization in the structural health monitoring system of high piled-wharf,and the placement method is blind.Aiming at the discrete problem of sensor optimal placement of high piled-wharf,this paper adopts the method of “0-1” coding,introduces the idea of position transformation probability,discreting BSO algorithm,and proposes a method of sensor optimal placement of high piled-wharf based on the criterion of modal confidence by BBSO algorithm.Based on the case study of a high piled-wharf,the application of the proposed method is studied and compared with the traditional BPSO algorithm.The results show that the proposed method is more suitable and effective than the traditional BPSO algorithm.

Abstract:The water exchange in the dug-in harbor basin is slow,and eutrophication pollution often occurs,which affects the normal operation and green development of the port.Based on the analysis of the causes and characteristics of water eutrophication in the dig-in harbor basin,we propose an ecological floating island technology which takes the effects of both water treatment and landscape into account,and analyze the effects of ecological floating island technology based on an inland harbor basin.The results show that the reasonable allocation of ecological floating islands can effectively control the eutrophication of water,improve the water quality and create a green landscape of the harbor basin,and it may serve as reference for the eutrophication treatment of inland river dig-in harbor basin.

Abstract:The key of seismic fragility analysis for structure is to ascertain the structure response values under various earthquake ground motion levels.Due to the uncertainty of ground motions,a large number of ground motion records need to be statistically analyzed.The computation cost will be huge,especially when the seismic analyses are directly performed on wharf structures.In order to reduce the complexity of fragility analysis of steel pipe pile wharf,we proposed a single-degree-of-freedom (SDOF) model for seismic fragility analysis of steel pipe pile-supported wharves,which utilizes curvilinear backbone curve and Masing rule to mimic the restoring force characteristics.In order to verify the rationality and effectiveness of the proposed model,a steel pipe pile wharf structure is equivalent to the single degree of freedom model,and the fragility analysis of the prototype structure and the single degree of freedom model is carried out based on the cloud diagram method.The results show that the fragility curves of the two models are in good agreement.

Abstract:Combining with the current Seismic ground motion parameters zonation map of China and the seismic design codes for water transport engineering and related industries,the influence of the change of seismic ground motion parameters zonation map on the seismic design codes of various industries is discussed.The significance of horizontal earthquake coefficient and dynamic magnification factor in seismic design of water transport engineering is expounded.According to the new version of the seismic ground motion parameters zonation map,suggestions for the values are put forward.The urgency of revising code for seismic design of water transport engineering is pointed out.It can provide reference for correct understanding of seismic design code standard of water transport engineering structure and reasonable selection of seismic ground motion parameter.It is of positive significance to promote the systematic work between upper and lower levels of the seismic design standards.

Abstract:In view of the difficulties in the structural design of overseas wharf in open sea and strong seismic areas,taking the project of 2×300 MW coal-fired power plant in Mariveles,Philippines as an example,we analyze the characteristics of the structure bearing wave load and earthquake load,carry out the differential selection of structural displacement limit standard under different working conditions,study the influence of adaptability of cemented geology to pile foundation,and determine to select the wharf structural form of the full straight piles with lower berthing and mooring platform.The results show that this design scheme can adapt to the environmental impact of large waves and strong earthquakes,the foundation can well adapt to the geological conditions,and the structural displacement can be well controlled during the operation period.

Abstract:Aiming at the problem of AGV power system and battery charging mode selection of automatic container terminal,the application performance data of diesel internal combustion engine,lead-acid battery and three kinds of lithium battery were collected,and the application advantages of lithium battery power mode in the new generation of automatic terminal horizontal transportation system were obtained through comparative analysis and research.In view of the battery solutions,opportunity charging,shallow type circulating charging scheme of container AGV applied in China,the construction cost,efficiency and safety performance to the green port construction were comparatively researched.The application advantages and economic benefits of the shallow type circulating charging schemes were put forward,which provided reference for the design and selection of other automatic container terminal horizontal transportation systems.

Abstract:Taking the livestock entry project set up in Zhoushan sea area as an example,we expound the general layout and handling technology of the entry,isolation and slaughtering of the livestock project and analyze the key points of water area layout of the specialized livestock port project. According to the construction conditions of the port site,characteristics of the livestock ship type and loading-unloading process requirements of the live cattle,we determine comprehensively the plane shape of the port,the position of the front line of the port,the scale of the working platform,as well as the section layout of the approach bridge.

Abstract:lifting and rolling are two types of heavy cargo’s handling technology.In order to realize the complementary advantages of the two technology,improve the efficiency and the adaptability of wharf operation,we design the lift-roll integration handling technology for the heavy cargo wharf in a real construction project.The plane layout,handling technology design and some key problems are discussed.Terminal passing capacity is calculated to verify the feasibility and effectiveness of the design,which can provide reference for similar projects.

Abstract:In view of the large randomness,poor accuracy and low efficiency of stacking and reclaiming operation in bulk material handling stockyard,this paper presents a fully-automation control system for stacker-reclaimer.This system is based on Lidar machine vision technology.3D laser scanner is used to acquire the real-time point cloud data of the object stockpile shape in order to accomplish the on-line real-time modeling for the target stockpile,and control the stacker-reclaimer to fulfil automatic operation.An operation path planning algorithm based on visual image processing algorithm is designed,which can continuously guide the automatic operation of stacker-relaimer by predicting route in advance in real time.Practice shows that the control system improves the machine’s working efficiency and reduces operation cost remarkably.

Abstract:Based on the fixed wall thickness tower structure form of 200 m high-lift ship lift,the variable wall thickness tower structure form is proposed based on the principle of consistent concrete consumption.Using the finite element software ABAQUS,two kinds of tower structure models,fixed wall thickness and variable wall thickness,are established respectively,and the dynamic response of tower structure is compared and analyzed.The results show:1) Under the action of self-weight load,wind load and 8 degree earthquake,the maximum displacement of the fixed wall thickness column structure and the variable wall thickness column structure are 38.5 cm and 34.7 cm,respectively,which meet the specification limit.2) Under the action of three seismic waves,the top acceleration of the two columns are larger than the bottom acceleration,showing an acceleration amplification effect.They are amplified by 2 times approximately.3) The compressive stress concentration occurs at the interface between the raft foundation and the tower column structure,and the tensile stress concentration occurs in the left and right sides of the raft foundation,and in the middle part and the inner part of the cylinder.Stress concentration is likely to occur at the junction of the tower column and the retaining wall.4)The maximum displacement at the top of the variable wall thickness column structure,the maximum tensile and compressive stress of the raft foundation and the maximum equivalent stress of the section are much smaller than the fixed wall thickness.Therefore,the structure of the wall thickness column is better.

Abstract:The Fuling to Fengdu reach is an important waterway connecting the upper and lower Yangtze River,so the analysis and prediction of waterway freight volume are of great significance to the construction plan of the waterway.This study proposes the use of freight data of the main ports along the Yangtze River,and calculates the waterway freight and its flow direction based on the location relationship between ports and waterways.Results show that the waterway freight volume of the waterway has increased from 12.41 million tons in 2 000 to 160.44 million tons in 2016,with the proportion of up and down water freight accounting for 66% and 34% respectively,contributes 94% of the freight volume of the Three Gorges Ship Lock,and the main cargo types such as mineral construction materials,ore,steel,coal,oil and containers accounting for 73% of the water freight.It is proposed to use regression analysis method,elastic coefficient method,exponential smoothing method and input-output method to consider the impacts of multiple factors such as the hinterland GDP,industrial structure,and transportation structure on waterway freight volume.The prediction indicates that the waterway freight of the waterway will continue to increase,but the growth rate will gradually slow down.The waterway freight will reach 323.33 million tons in 2045,and the main cargo accounts for 86% of the total waterway freight.The analysis and prediction methods and results of waterway freight in this study can provide support for the construction plan of the waterway.

Abstract:Aiming at the problems of the west waterway of Tongzhou Shoal,a large-scale regulation project was carried out in the west waterway of Tongzhou Shoal from 2011 to 2016,through which favorable conditions for the formation of stable double-branch river in Tongzhou Shoal branch channel.Based on the hydrological and topographic data measured in recent years,we analyze the new changes in the evolution of the west waterway of Tongzhou Shoal and the effect of the regulation project from the aspects of diversion ratio in the west waterway of Tongzhou Shoal,Tongzhou Shoal body,waterway erosion and deposition,as well as the waterway scale.The analysis results show that Tongzhou Shoal body is basically stable,the diversion ratio is increased by 2.4% in the west waterway of Tongzhou Shoal,the -5 m river channel is completed and the -10 m river channel below the Sigan River is completed,and the expected effect of the project is achieved basically.

Abstract:Back silting easily occurs after channel excavation,and the study on the amount of back silting is particularly important for the later maintenance of the channel.Taking the back silting of the approach channel of Gaolan Port as a research case,and based on the historical evolution of the seabed in the Huangmao Sea area,we analyze the source of channel sediment in Gaolan Port area,and study the characteristics of sediment erosion and sedimentation near the channel.The research reveals that the seabed in the cross waters where Gaolan Port locates has always been in a state of sedimentation in recent years.From 1977 to 1989,the average sedimentation intensity was 3.42 cma,and from 1989 to 2003,the sedimentation rate slowed down to about 0.86 cma.The annual siltation amount of the waterway in Gaolan Port area consists of two parts:perennial siltation and sudden silting caused by typhoon;obvious sudden silting occurs once or twice a year,and the amount of sudden silting is generally 30% to 50% of the annual silting amount,the thickness of sedimentation is 0.32～0.60 m,and the magnitude and distribution of sudden sedimentation volume are related to the typhoon path and intensity.The research results may serve as reference for determination of the time and frequency of channel maintenance.

Abstract:This paper selects the annual runoff and annual sediment transport data of Qianjiang station,Dajingjiangkou station,Wuzhou station,and Gaoyao station from 1957 to 2016 in the mainstreams of Xijiang River,applies Mann-Kendall test,5-year sliding test,cumulative anomaly methods to carry out quantitative and qualitative analysis,uses the simulated annealing algorithm for nonlinear regression analysis at the same time,and obtains the changes of annual runoff and annual sediment transport.The results show that the distribution of runoff and sediment transport volume is uneven throughout the year.The runoff and sediment transport volume of Qianjiang station are significantly decreasing.The annual runoff volume of other stations is increasing,and the annual sediment transport volume is significantly changing decline.The runoff at Qianjiang station changs abruptly in 2002.The annual sediment transport volumes in Qianjiang,Dahuangjiang Estuary,Wuzhou and Gaoyao stations have significant mutations in 1991,1997,1994,and 1999 respectively.The annual runoff variation trend shows slight fluctuations,the annual variation range is small,and the annual sediment transport volume shows a downward trend.

Abstract:The driving system of the gear rack climbing type ship lift requires accurate positioning and installation under the loading condition,and can adapt to the structural deformation of the chamber under the empty chamber condition.Considering the main longitudinal beam,cross girder for safety mechanism,cross girder for driving,chamber gate,pinion bracket assembly,synchronous shaft system and other structures,we establish the finite element model of the chamber and driving system of 200 m-grade gear rack climbing type ship lift,analyze the deformation of the chamber structure and the installation position of the driving system under the three conditions including the bottom support of the chamber,the suspended of the chamber(4.7 m water depth) and the suspended of the chamber (empty),and propose the optimization suggestions.The results show that the deflection of the main structure of the chamber is within the allowable range during installation,there is a height difference between the inner and outer main reducer bases,the deformation difference between the two ends of the synchronous shaft III is large,and the deformation of the part of the end of the synchronous shaft IV close to the center of the chamber is large.It is recommended that the base of the inner main reducer should be raised by 5.16 mm.The base of the bevel gear box near the chamber center of the synchronous shaft III shall be raised by 10.49 mm.The fixed self-aligning bearing base and bevel gear box base close to the synchronous shaft IV shall be raised by 24.32 mm.

Abstract:The construction and operation of the hub will affect the formation of physical conditions in the process of water level,and lead to the inconsistency of the statistical samples of the design lowest navigable water level.However,rejecting the water level sequence before damage will lead to the lack of representativeness of the statistical samples.Taking Linhuaigang second ship lock as an example,we aim at the inconsistency of water level samples caused by the construction and operation of the junction and the impoundment in dry season,comprehensively consider the variation trend of upstream water,the influence of human factors on water level,the short-term and long-term operation plans and the actual situation of the project,determine the typical data of calculating the design lowest navigable water level,and obtain the design lowest navigable water levels above and below the gate.The results show that,the design lowest navigable water levels above and below the gate are 19.27 m and 17.14 m,which are calculated by the data from 2007 to 2018.

Abstract:With the rapid development of shipping,large ships occupy the channel through the access channel for a long time,thus it is necessary for large ships to set up meeting area in the approach channel.The relevant calculation of meeting area in current norms is not clear.In view of the objective reality of Zhanjiang Port's long course,large scale and complex navigation environment,this paper analyzes the conditions of water depth,wave and velocity in the proposed meeting area based on the survey of the current ship type and scale.This paper puts forward the combined navigation schemes of 300,000 t and 150,000 t ships,calculates the navigation width of the channel under the two forms of unified section and compound section,and determines the length,width,turning radius,design bottom elevation and other parameters of the meeting area，then selects the plane layout scheme of the meeting area with good water depth and proper location.

Abstract:The lock capacity of ship lock is an important economic index,and its influencing factors are very complex.Based on the comprehensive evaluation method combining analytic hierarchy process and Delphi method,we systematically study the influence factors of lock capacity,and determine the weighted value of each index on the lock capacity.The results show that these factors including operating water level of ship lock,series and lines of ship lock,effective scale of ship lock,scale of ship and ship loading coefficient have a greater impact on the lock capacity.The achievements can provide the references for the similar projects.

Abstract:The characteristics of deformation and mechanism of furrowed crushed stone foundations for immersed tunnel are studied by plate loading tests on large-scale models with a length of 2 m,a height of 0.8 m and a width of 1.2 m which cover three conditions,i.e.loading on full-paved stone foundation,on the top between furrows,and over a furrow.Measurements include the applied load,surface displacement,furrow space and the stresses of reinforcing bars in concrete loading girder,and lateral displacement of test tank.The test results show that in all three tests,the surface settlement and the load bear a linear relationship under a load up to 750 kPa,indicating that the stone foundation is in the elastic stage of compaction;the loading curves in three tests are basically coincident and the final settlements are almost identical.It can be considered that the furrows pose no significant effect on the mechanical properties of stone foundation;during the loading process,the furrow space decreases linearly with an increase of the load,and then the furrow is gradually flattened;however,we should pay attention to the furrow effect in design that the stresses of the reinforcing bars of reinforced concrete load ding girder in furrowed stone foundation are about 20% to 30% higher than those in the full-paved stone foundation,and there will be a sharp stress increase upon a certain load;a numerical modeling method for the furrowed stone foundation is also established and the modeling results show that the load-displacement curves of the full-paved and furrowed stone foundation are basically the same,which also prove that the deformation and bearing capacity of the stone foundation are identical.

Abstract:The connection joint of pile-gravity composite structure is the place where the force is concentrated and the stress is large.The connection between the two materials is involved,which is the most critical and weak position of the structure.We use the ABAQUS finite element software to build the model of pile-gravity berthing dolphin,analyze the dynamic response of connection joint under impact load,and study the influence of different factors.The results show that the displacement and the peak value of tensile damage coefficient of the front row connecting joint of pile-gravity composite structure are greater than the latter two rows under the load of ship berthing.The maximum principal stress peak appears at the front of the joint of the front pile and the caisson.The buried depth of the pile should not be less than the pile diameter,and the effect of increasing the pile embedding depth on the stress characteristics of connecting joint is not obvious.Increasing the diameter of the pile is the most effective measure to improve the force characteristics of the joint.Increasing the caisson height is the most economical and reasonable to improve the force characteristics of the connecting joint.And the connection node with the structural measures can increase the force.

Abstract:In the dock and deep sea engineering,the shear key is often used to connect the steel pipe pile and the upper structure,which can improve the bearing capacity and structural integrity of the steel pipe pile.The spacing of shear keys is an important factor affecting the mechanical performance of steel pipe pile heads.Taking the steel pipe pile with two shear keys at the pile head as the research object,eight sets of finite element models are established,and the test values in Gebman test report and numerical model values are compared.The results showed that:1)The error between the experimental value and the digital modulus value is small,and the change trend is consistent.2)The bearing capacity of steel pipe piles and the composite stiffness of steel pipe piles increase at first and then decrease with the increase of shear key spacing.When the shear key spacing is between 1.0D and 1.2D,the steel pipe piles are in best performance.3)The optimal design spacing of the shear key is always around 1.0D.With the increase of the pile diameter,the optimal design spacing of the shear key can be appropriately reduced.The research results provide an important reference for the shear key design of steel pipe pile head in actual engineering.

Abstract:The double-row steel sheet pile cofferdams are widely used in river engineering in Shanghai.To study the deformation characteristics of this type of cofferdam,we establish the Plaxis finite element model to analyze the effects of the cofferdam width to height ratio,the steel sheet pile insertion ratio,the type of the steel sheet pile and the tie rod arrangement.The results show that increasing the width-height ratio of cofferdam can effectively reduce the horizontal displacement of the steel sheet piles,and the suggested values of the width-height ratio are given for different water retaining heights.It is recommended to set the insertion ratio of steel sheet pile as 1.1~1.5 when the water retaining height is about 4 m.The cofferdam can be arranged with only one tie rod and there exists an optimal position to ensure the overall deformation coordination of the steel sheet piles.This research may serve as reference for the design of double-row steel sheet pile cofferdam.

Abstract:For the seismic design of slope engineering in strong earthquake areas,the displacement analysis methods are adopted widely in the international standards or guidelines.Due to the complexity of the earthquake,it is important to choose appropriate calculation method for displacement estimation.Based on the problems,this paper compares the several simplification methods for displacement calculation commonly used in international standards and manuals,including Ambrasys & Menu formula,Jibson formula,NCHRP 611 formula,Bray and Travasarou formula,Makdisi & seed method,and Shang-Yu Hsieh & Chyi-Tyi Lee formula.In addition,the SLIDE software is used to verify the advantages and disadvantages of different simplified calculation methods.Furthermore,combined with the characteristics of seismic waves,an equation for the slope residual displacement based on Arias intensity is proposed,and a simplified formula is fitted by using the results of displacement analysis of several groups of seismic waves and different geological slope heights of a project in Manila.The conclusions of this paper can provide reference for the simplified method of seismic slope displacement calculation under similar conditions.

Abstract:In order to understand the variation law of pore water pressure and soil pressure around the pile during pile sinking in the water-rich and weak stratum,and then to guide the on-site construction,we carry out the on-site monitoring and analysis of soil pressure and pore water pressure during pile sinking.The results show that the pore water pressure and soil pressure of the piles increase significantly during pile sinking;the pore pressure ratio exceeds 60%,and the highest reaches 88%,which easily causes the effective stress loss at the pile circumference and reduces the stability of the pile body;the influence of the soil pressure around the pile is wide.The effect range of the project is 20 times the pile width in the horizontal direction.The influence range of pore water pressure is 30 times the pile width in the depth direction.The influence increases sharply while the range is within 10 times the pile width.The pore water pressure and soil pressure could dissipate 48% after 7 days.During the on-site construction,the effects of pile-soil compaction and pore pressure could be reduced by controlling the rate of pile sinking and changing the order of pile driving.

Abstract:With the rapid development of fuzzy control technology and artificial intelligence technology,the development of trailing suction hopper dredger tends to be smart,efficient,energy-saving and cost-reducing.Based on the new trailing suction hopper dredger under ECO mode,we study the dredging performance of trailing suction hopper dredger under ECO and MANUAL modes on the intelligent systems of TSC,EPC and AVC,and compare the data of loading time,production,fuel consumption and other indicators under the two modes through sea trials.The results show that in the ECO mode,the labor cost reduces,and the production stability of the trailing suction hopper dredger significantly improves,the efficiency increases 10% and the fuel consumption reduces 6%.

Abstract:In the construction using mega TSHD(trailing suction hopper dredger)in cohesive soil,the TSHD is prone to clogging of the drag head and solidification of the muddy soil in the hopper.In view of this phenomenon,we study the reconstruction of construction equipment and the optimization of construction technology.By introducing the mega TSHD ‘Junyang 1’ with advanced equipment such as submerged dredge pump,strengthening high-pressure jet and reforming the drag head,the influence of drag head blockage can be reduced.The construction technology of "mud sand cushion hoper+ cohesive soil loading" is adopted.The mud and a small amount of sand are used as the lubricant between dredging clay and mud hopper to reduce the retention of cohesive soil in the mud hopper of the ship.Thus the time of throwing mud can be shortened and the construction efficiency of the ship can be improved.

Abstract:The traditional method to deploy grab dredgerpump barge to remove the fluid mud at the narrow area like wharf front,is complicated and lack of efficiency.In order to solve these problems occurred during implementation of the New Deep Water Terminal Dredging Project,Kuantan Port,Pahang,a new method known as utilizing flat-bottom barge to assist TSHD in dredging the fluid mud at the wharf frontage is introduced.The results show that by deploying flat-bottom barge between TSHD and the wharf front area,mooring the TSHD along the barge,the barge will work as a buffer to prevent the TSHD from crashing the wharf structure,which enables the TSHD to take advantage of its large-power pump to remove the fluid mud at the wharf front area.This method simplifies the operating procedures and significantly enhances the dredging efficiency at such an area,so it may serve as reference for similar projects.

Abstract:During dredging construction of clay by the cutter suction dredger,the cutter head or suction mouth is often blocked by clay,especially under the condition of clay mixed with block stone,blocking is more serious.By taking measures such as installing stone guard ring on the cutter or installing grid on the suction mouth,we solve the problem of the clay and stone’s blocking of the the cutter and mud pump.

Abstract:Aiming at the design issues of lifting lug for large pre-fabricated caisson hoisting construction,we verify the strength of lifting lug and local concrete combining with oversea marine project,and propose the technical specifications for hoisting.Based on the European and American codes,we verify the strength of local concrete including compression strength,breakout strength,pullout strength,side-face blowout strength and pry out strength.The results show that the strength of lifting lug and local concrete satisfy the requirements.The strength of local concrete is the key problem in the design of the caisson wall as a thin-walled structure.In the process of hoisting construction,necessary measures should be taken to ensure that the lifting lug bears reasonable force.