Abstract:To solve the insufficient of current soft mattress in the lower Yangtze River waterway regulation project,we put forward a new concrete cell block D type soft mattress,establish the catenary model to analyze mechanical properties of soft mattress,calculate the soft mattress anti-overturning stability,anti-sliding stability and anti-floating stability,and contrast the adaptability to terrain of the routine soft mattress with the new type.The results show that the new structure obviously improves the safety of water sinking and discharging process and the adaptability to complex terrain.It can provide theoretical support for soft mattress sinking project in complex condition.

Abstract:The plant community and plant species distribution of the Jingjiang reach river floodplain were analyzed through the exploration,tracking,etc.The experimental model plants were selected in combined with the actual investigation,then we carried out the experimental study on the influence of different vegetation on the flow structure.The results showed that the presence of vegetation had a significant influence on the flow velocity near the bank slope,which increased the resistance of the water flow,and had better protection effect to reduce the erosion of the water.The different vegetation height and different planting density had different effects on the root erosion of vegetation.At last,field test of ecological slope protection of different vegetation was carried out in the bank protection engineering section of Zhangjiazha revetment in Zhoutianhe section with obvious ecological effect.

Abstract:Through the research of integrated technology of information model for waterway regulation engineering,we carry out the secondary development of 3D GIS software CityMaker and Surfer,Autodesk Civil 3D,Mike21,and achieve that GIS data,BIM model data,data of river bed erosion and deposition,hydrodynamic simulation data,the management data of the participants in different stages of the project can be integrated efficiently and managed conveniently into GIS platform.The engineering practice shows that this technology is practicable,and can be provided reference to the application of BIM technology in waterway regulation projects.

Abstract:For the traditional waterway regulation engineering problems,such as the inadequacy of two-dimensional design accuracy,the hasty scheme research time,the tedious and error-prone statistics of engineering quantity,etc.,taking the second stage of waterway regulation of the Xinzhou to Jiujiang section of the middle reaches of the Yangtze River as an example,this paper introduces BIM technology,expounds the waterway engineering BIM 3D modeling technology,and the 3D collaborative design of the whole section.The application characteristics of BIM technology in the design of channel regulation engineering are summarized,and the three-dimensional visualization,parameterization,synergy and intelligent design of the channel project are realized,so that the design process is optimized,and the precision of design is improved.

Abstract:There are many tributaries in the middle Yangtze River,and the water system is complex.As the result of water storage of the Three Gorges,water and sand conditions under the dam have changed violently.These factors cause the difficult of water level prediction.Based on the measured data of the middle Yangtze River,we consider the tributary remittance and new water and sand conditions,and put forward the correlational analysis method and multiple regression method to forecast the river water lever of upper and lower Jingjiang reach,Chenlingji-Hankou，Hankou-Hukou reach.The method is examined by the measured data,and the absolute error is less than 0.4 m.The method can improve the water lever prediction accuracy of the middle Yangtze River.

Abstract:Based on the physical model test,we study the influence of the slope,wave steep and the style of placing the accropode on the reflection coefficient under the action of irregular waves,and compare the reflection coefficients with the Seeling formula,the Sutherland formula and the Van der Meer formula.The results show that the slope is proportional to the reflection coefficient,the wave steep is inversely proportional to the reflection coefficient,and the arrangement of the accropode has little effect on the reflection coefficient.The test values are generally larger than the calculated values of the three formulas,where the difference between the calculated values and the calculated values of the Seeling formula is small.

Abstract:In view of the lack of domestic standards for wave run-up and overtopping discharge on low pile platform vertical sea dike calculation methods，based on the Shenzhen airport runway seawall design section,through physical model experiment,the paper researches irregular wave and low pile caps erect dike foreshore and the flow meter,and analyzes the wave period,crest superelevation,the width of wave barrier cornice influence factors relationships with foreshore and the flow meter.The method of least square regression is used to calculate the wave run-up of vertical seawall.By using the method of multiple linear regression,the calculation method of sea wall surface-breaking is obtained.The comparison between the calculated value and the test value shows that there is a good correlation between them.

Abstract:For water mooring system,mooring pattern has very important influence on the mooring force and motion precision of the mooring system,so it is necessary to analyze different mooring methods on mooring system movement performance and the influence of the mooring cable dynamic performance to reveal the effect and mechanism of mooring pattern on mooring system.Based on the potential flow theory,combined with the large water dynamics software AQWA,with a simple rectangular pontoon structures as the typical example,based on the basic tank parameters and related technical requirements,considering the main factors influencing the mooring performance such as mooring radius,the pretension and the opening angle,the dynamic analysis and calculation model of mooring system is established.The results show that the influence of mooring radius on maximum mooring force decreases with the increase of mooring radius.Increasing the pretension of mooring cable can effectively reduce the longitudinal drift of floating body and improve the stability of mooring system.Increasing the opening angle of mooring cable can better resist the lateral environment load and improve the platform positioning ability.

Abstract:The junction located at the branch entrance of tidal river is always close to the main river due to limited land conditions,so the branch mouth flow is significantly affected by the tidal flow of the main river，and the flow pattern is complex.Thus engineering problems such as siltation,bank erosion,cross flow exceeding standard in approach channel,etc. appear easily at the entrance area.Therefore,a step structural form of levee head was designed to improve the flow condition.The results of the physical model tests show that the angle between the main river flow and pilot river flow decreases,and the erosion of river bank and the cross flow in the approach channel on the flood tide diversion case decrease as well.Meanwhile,the increase of the area of water flow and the decrease of river erosion lead to the reduction of recirculation range,which is conductive to the stability of river in the drainage tide ebb.

Abstract:Based on the characteristics of vibration liquefaction and poor stability of the dredging reclaimed silt in northern port area,we carry out laboratory experiments to study the changes of physical and mechanical properties of the dredged silt after curing.We analyze the feasibility of the solidified silt as the coffer,artificial island and roadbed filling material,and provide technical support for resource utilization of the dredging reclaimed silt.The results show that when the content of cement is from 3% to 12%,the plastic index of dusted silt after curing is from 10.4 to 15.5,the viscosity and compactness increase,the resistance to deformation increases and the permeability decreases,the silt becomes typical clay.Under the same working condition of cement content,the solidification strength of reclaimed silt increases continuously with the increase of age,and the average strength at 14 days increased to 76% at 28 days.When the cement content of dredging reclaimed silt is from 3% to 12%,the unconfined compressive strength is from 96 kPa to 624 kPa for 48 hours of water immersion after the age 28 days,relative change of intensity is less than or equal to 16.5%,water stable performance is good.It can be used as filling material for underwater coffer and artificial island and so on,which has great practical application value.

Abstract:The three-dimensional dynamic response numerical model of the foundation-pile-superstructure system under the wave dynamic load is established for the shear dilatant marine foundation.Damage constitutive model is applied on the wharf structure.The law of the dynamic response in the wharf structure as well as foundation at various wharf elevations is analyzed.The results show that:the high-piled wharf is subjected to wave impact,with the maximum internal force and the most serious damage when compared with about 0.33 in clearance ΔhH;when the relative clearance was 0.5,the damage and internal force decreased significantly;when the relative clearance is greater than 0.42,the maximum equivalent stress in pile foundation decreases with the increase of height.Although the influence of soil around pile foundation is not very big change,but the upper structure has a larger power amplification effect,even a small amount of foundation deformation changes can also cause the destruction of the upper structure within the larger,therefore the design should consider the foundation-pile-superstructure wave synergy effect each other.In view of the nonlinear deformation characteristics of marine foundation,it is suggested to build a whole model for analysis,so as to make the design more scientific and reliable.

Abstract:Three categories of toe mound design of deepwater breakwater of Sri Lanka port city are explored.During the breakwater detailed design the rockfill toe mound with V-shaped trench is used.During construction,it is found that breakwater construction schedule is severely restricted to the seaside toe rock mound:1) with existing equipment and technology,the construction efficiency of the V- shape trench in placing the first-row chinesepode is low;2) the supply of 2~5 t toe rock is insufficient.Therefore,alternative schemes for the toe design are proposed accordingly:1) the first row of armour blocks is placed flatly and reinforced by the toe rockfill in the front;2)3 rows of chinesepode units are placed on the flat rock apron in place of the 2~5 t toe reinforcement.2D physical model test is carried out to verify the feasibility of the alternative solutions.

Abstract:The majority of the overseas port construction projects are located at areas with long period swells.The action of long period swells on the breakwaters is not fully known and researched,especially for the oblique incident waves.Based on one actual breakwater construction project of one port,the 3D physical model tests are performed to study the stability of the rubble-mound breakwater under action of oblique long period swells.Based on the test results,the original plan of the breakwater is optimized,and finally the plan of the breakwater which can satisfy the requirement of stability under wave action is proposed and verified.The test results show that under the action of oblique incident waves with the same water depth,wave directions and wave heights,the damage percentage of the armor rocks of the breakwater is larger for longer wave periods.And under the same water depth,wave heights and wave periods,the impact and erosion actions of the current along the breakwater induced by the oblique incident waves are much stronger under the 15 degree incident wave direction than under the wave direction almost paralleled to the axis of the breakwater,which results in the larger damage percentage of the armor rocks.

Abstract:Aiming at the problem of the sea embankment of the Third Runway Project of Shenzhen Bao’an International Airport,such as soft soil layer is deep and thick,the construction needs to meet the demands of displacement constraint over Guangzhou-Shenzhen Riverine Expressway,and the top elevation of the sea dike cannot surpass the 15 m safety limit line,we propose the low pile platform vertical structure,and utilize cement mixing pile in the ground treatment.We reasonably determine the top elevation of the sea embankment according to the empirical formula and wave physical model tests,and adopt Plaxis 3D software(internationally accepted software) in structure force analysis,which proves that this sea embankment scheme can effectively control the lateral deformation of the soil.In view of the anti-corrosion problem that the sea dike needs to be used for 100 years,we use the heavy anti-corrosion coating,sacrificial anode and concrete coating joint anti-corrosion measures in steel structure,so as to ensure the design protection period of the sea dike.

Abstract:The accuracy of control points is related to the quality of engineering construction.Due to the poor foundation stability and large ground deformation,the control point displacement problem is prominent in the port engineering.Based on the port engineering case,this paper probes into the plane precision analysis of engineering control points based on BHCORS.The method of coordinate conversion and baseline comparison are used to check the accuracy of the control points,and the BHCORS is used to check the accuracy of out-of-control points.The comparative analysis results show that BHCORS results are characterized by high precision and strong potential,and thus widely used in the port engineering.

Abstract:Because of the confluence of flux and shunt of reflux,together with the impact of reclamation and surrounding projects,the port location in a branching intersectional sea area is special.The water flow is complicated in port water area and the port general layout has some particularity.This paper generally reviews the main influential factors of general layout of branching intersectional sea port,and carries out multi-plan comparison and demonstration of the quay line plan and reclamation scope.In addition,it also verifies the rationality of the scheme through tidal and current mathematical model tests and siltation analysis,and finally comes out with the general layout design adapting to the branching intersectional sea port.

Abstract:For the hydraulic problems of enlarged culvert at back of culvert valve of ship lock valve,based on Yinpan ship lock,emptying valve physical model with scale ratio of 1:10 is built,and the upward ramp type of enlarged culvert is optimized.Through unsteady flow test,hydrodynamic pressure characteristics of 6 types of enlarged culvert’s upward ramp are studied comparatively,then influence of upward ramp type on hydrodynamic load on enlarged culvert is discussed,and the optimum shape of upward ramp is recommend.All the above research conclusions can be used to guide the design and construction of enlarged culvert of high water head ship lock and can provide theoretical foundation and technical support for it.

Abstract:According to the factors such as hub scheduling and artificial sand excavation after Xiaoxitan hydropower station is built,the characteristics of water and sediment,and river level and discharge are changed.Combined with the engineering arrangement of diversion embankment,we carry out the condition analysis and rechecking of the downstream navigation flow under the changing terrain conditions.Using numerical simulation method,we establish a numerical simulation model of two-dimensional hydrodynamic hub downstream,optimize diversion dike layout and the size parameters by numerical calculation and program results,and put forward the hub downstream approach channel of diversion dike layout suggestions,which can meet the requirements of the navigation flow conditions change terrain conditions.It also can reduce the influence of the original design scheme on the flood discharge capacity of the river.

Abstract:A method for determining the width of the excavation groove is proposed based on the relationship between the river facies and the maximum sediment transport rate of the pebble river.Taking Dongxikou waterway regulation in the upper reaches of the Yangtze river as an example,Einstein’s formal and flexible sediment transport rate formulas are used to calculate the width range of the excavation groove corresponding to the maximum sediment transport rate at the remediation water level,and the stable river width is calculated by using the method of river relationship.The results show that the width ranges of stable excavation groove determined by the two methods are basically the same.The optimal size of Dongxikou channel is determined by optimizing the section design of the excavation groove through mathematical model,which can meet the requirements of stability of the gravel channel and ship navigation.

Abstract:Taking the new Xinxiagang double-line ship lock project as an example,the finite element analysis model of ship lock chamber and surrounding soil is established by ABAQUS.According to the prototype observation data during the construction period,model verification is carried out.Based on the observation data and numerical analysis,the mechanical behaviors of single-anchor piles and opposite-pull plate piles during the construction process are discussed.The internal forces and deformation of two different sheet pile structures with the excavation of the soil in the chamber and the earth pressure distribution on both sides of the sheet pile wall are studied.The results show that during the construction period,the deformation of the single-anchor piles on both sides is basically the same,and the deformation of the opposite-pull plate piles in the middle is basically the same and the integrity is good.When one side of the chamber is excavated,the working condition of the opposite-pull sheet pile on the excavation side is the same as that of a single anchor sheet pile,and back piles playing anchor role.The horizontal displacement,earth pressure are gradually increasing with the soil depth.

Abstract:At present,in the special design of bridge ship collision protection or ship collision force research,more attention is paid to ship collision force research and bridge response under ship collision,but less research on the maximum deformation of the hull.Based on ANSYSLS-DYNA software,we simulate multiple ship collision conditions composed of four pier types,four types of different load mass inland river representing ship,three speeds and two collision angles.We extract the maximum deformation of the ship for each working condition,analyze its correlation with the ship load tonnage,impact speeds,pier types and impact angles,and compare it with empirical formula.The results show that impact velocity and impact angle are the main controlling factors,there is no obvious relationship with pier type.

Abstract:The traditional research on the influence of navigation conditions cannot fully and accurately reflect the comprehensive influence of waterway flow conditions and boundary conditions on ship navigation and the interaction between ship and waterway flow conditions.Using the small scale ship model measurement and control technology,the experimental study is carried out on the navigable water flow in the upper and lower waterways of Dadu River Moshui navigation-power junction and the upstream wharves berthing and unberthing.This paper carries on the quantitative and qualitative analysis combined with experimental study results,proposes hub upstream and downstream channel maximum navigable discharge of 4 500 m3/s,which provides a scientific and reliable data basis for key project plan design optimization and unberthing upstream port scheme selection.

Abstract:According to the criterion of gravity similarity,we study the navigation safety of the gate area of a low water head hydropower project in a wide shallow riverway by using the overall model with a scale of 1:100.We use the ADV velocity measurement system to measure the flow velocity,control the flow rate by a standard water weir,and adjust the water level of the model by a differential tail gate.Because of the layout of the river terrain and the hydropower project,the flow velocity in the entrance area of the upstream channel is too large and the downstream forms a large range reflux.In the experiment,discharge velocity is reduced,and the overall water flow in the river is improved by the measures,such as expanding the dredging area,removing two downstream islands and increasing sluice gates.The navigation flow condition of the up and downstream channel and its entrance area of the ship lock are greatly improved by prolonging the navigation wall,changing the water permeability of the navigation wall and optimizing the topography of the channel area,which can ensure the safety of the ship.

Abstract:For Heishazhou waterway bending,branching,branch and other characteristics,combined with the proposed suitable dam layout scheme,we use a two-dimensional mathematical model to calculate the flow distribution ratio of branching channels respectively under the conditions of the different longitudinal dike dam and jetty head angle layout,analyze the calculation results under the different arrangement conditions,and summarize the change rule of diversion ratio to obtain the layout optimization arrangement scheme.Heishazhou waterway divides into three channels of the south,middle and north.The right slot of south channel is the main navigation channel,and the flow distribution ratio of right slot increasing is a key point of waterway regulation project.The calculation analysis of the dam and jetty head angle can provide theoretical basis for the layout scheme of optimization.

Abstract:After the completion of the Mingyuexia Yangtze River bridge,the left bank of the Hongmiaojiao reef under the bridge will affect the further improvement of the channel scale of this section of beach.In order to avoid this situation,in view of its river situation and beach situation and considering the long-term development needs of shipping in the Yangtze River,a deep reef blasting plan is proposed based on the original 3.7 m reef blasting scheme.The scheme is demonstrated by using a two-dimensional plane mathematical model,which is validated by the measured surface line and velocity distribution.The results show that the model validation is good,and can correctly simulate the actual water flow movement of the beach.After the implementation of the scheme,the average flow velocity of the section of the designed lowest navigable water level and the change of flow velocity along the path are all less than 0.01 m/s.The gradient along the distance has no obvious change,only in the upper reaches of the reef-blasting area,the water surface decreases slightly by a maximum of 0.01 m.The flow field in the reef blast area is improved obviously,the angle between the flow direction and the channel decreases obviously,and the navigation conditions of the ship are improved.

Abstract:Because there is not enough space,it is necessary to set the supporting structure to reduce excavation.At present,there is little study about complex lock chamber structure with supporting at home and abroad.Based on the practical engineering,this paper uses the elastic foundation beam method and the finite element method to analyze two kinds of chamber structures,and studies the influence on the internal force of the chamber floor caused by the support.The result shows that the maximum positive moment of the bottom plate of the lock chamber occurs at the high water level period and the maximum negative moment occurs at the overhaul period.The support can reduce the internal forces of the docking chamber structure floor and improve the safety of the structure to simplify the construction of the bottom plate.The effects of different materials on the internal force of the chamber bottom floor are different.The effect of the jointed wall support on the internal force of the floor is higher than that of the steel sheet pile.

Abstract:To counter the severe problem of coastal erosion in China,we study the main contents and commonly use methods of beach protection and siltation promotion.Based on the analysis of the advantages and disadvantages of both engineering measures and ecological measures and combining with actual cases,we summarize the existing application modes of beach protection and siltation promotion.According to the comparison of multiple aspects,we find that ecological measures can make up for the deficiencies of traditional engineering measures and make full use of the ecological environment to form a flexible barrier for the bank protection and revetment.This feature meets the needs for the construction of ecological civilization in China,thus the ecological measure has a good application prospect in beach protection and siltation promotion projects.

Abstract:In order to forecast and control the deformation of existing underground tunnels induced by canal excavation,based on a metro-crossing canal excavation example of Zhejiang section of the Beijing-Hangzhou Canal in Hangzhou,we study the theoretical deformation values of the tunnel structure under both common excavation scheme and the scheme with certain heave resistance measures.A series of construction measures are attempted,including block excavation,foundation reinforcement and uplift frame structure to resist the shift of underlying metro line 1,based on all the geological conditions and design requirements that have been known.Moreover,a 3D finite element model is established to simulate the whole excavation process,and the results prove that the measures designed for controlling the deformation of subway shields are effective and can fulfill the requirements of safety operation of metro tunnel.

Abstract:The regulation structure’s surface maintenance in Yibin to Chongqing section of the Yangtze river is affected by unsteady flow caused by hydropower stations in the Jinsha River and Minjiang River.Based on the hourly water level data of Lizhuang station and Zhutuo station in recent years,we analyze the characteristics of the water level change of two stations.The best time of regulation structure surface maintenance in Yibin to Hejiang section and Hejiang to Chongqing section of the Yangtze River is put forward.In order to ensure the quality of structure surface,the thickness of regulation structure surface could be decreased,or section construction could be adopted.

Abstract:Dynamic compaction is one of the most frequently-used and most economical deep foundation treatment methods.Controlling the dynamic compaction quality effectively is the key to ensure the stability and safety of the foundation.At present,the overall information control level of dynamic compaction quality is still low in China,which is artificially controlled by supervisor and constructor,and it is difficult to control the dynamic compaction quality efficiently.Started with the information collection,storage,display and navigation of dynamic compaction,we put forward a real-time automatic construction navigation technology of dynamic compaction with high precision,which realizes the online,real-time monitoring and visualization management.The application of real project shows that the technology satisfies the inspection requirements of acceptance inspection,realizes the fine control of dynamic compaction,and improves the dynamic compaction construction quality.

Abstract:Aiming at the problems such as poor real-time performance,low efficiency and limitations of the existing aids to navigation,the exploration of the effective control of aids to navigation was conducted.UAV remote sensing technology,the establishment of a navigation aids equipment operation information database and the establishment of a visualized three-dimensional geographic information management platform,eventually formed a complete set of UAV aids monitoring and monitoring system.Using the UAV remote sensing technology,we established the beacon equipment operation information database and built the visualization of three-dimensional geographic information management platform,finally formed a complete set of unmanned aerial vehicle (UAV) beacon surveillance monitoring system.The result of the test application is good,which is of great significance to the improvement of navigation standards supervision.

Abstract:The water level in the coastal areas will fluctuate with the tides,and by doing field monitoring of the soil in the region of the soft base and the changing areas of the water level,we study the effects of water level changes on the surface of the earth,the pressure of the pore water,and the effects of the process.The result shows that the water pressure dissipation is incomplete in the soil in the changing area of the water level,the receding tide causes the drop of the water level,the soil will form a dark surge in the discharge of water,and the small particles in the soil will be taken out to weaken the stability and strength the soil.So,we shall consider the change of the field’s water level and may take measures such as filling a cofferdam and building a clay sealing wall along the field line,driving the steel sheet pile,or arranging evenly the dewatering well on the edge or in the middle of the field to avoid the influence of the change of underground water level on the engineering quality.

Abstract:In view that the theoretical research on the vacuum-surcharging preloading technique for reinforcing marine soft soil subgrade is lagged behind the engineering practice,we analyze the variation law of the surface settlement and environmental effect in the process of strengthening of marine soft soil subgrade by the vacuum-surcharging preloading method,which is based on the field monitoring data.The results show that the vacuum-surcharging preloading treatment can speed up the rate of foundation settlement and shorten the construction period;inward lateral displacements chiefly occur at 2 m below the ground during the vacuum preloading stage;the reinforced soil more easily to produce the lateral extrusion deformation outside the reinforcement area during the preloading stage and the horizontal soil environmental influence scope is more than 8 m.

Abstract:By the conventional vacuum preloading method,it is easy to form a lard layer of a certain thickness on the surface and the consolidation effect for the lower soil is poor.So,based on an engineering project,a field experimental research is carried out.The pressurized vacuum preloading method is adopted and a comparison is conducted between it and the conventional vacuum preloading method to further analyze the reinforcement mechanism and effect.The research result shows that the pressurized vacuum preloading method can not only meet reinforcement requirements by the conventional vacuum preloading reinforcement method,but also be characterized by a lower soil moisture content,quick dissipation of pore pressure,large settlement,high bearing capacity,as well as quick increase of foundation soil strength,which may shorten the construction period while improving the soil reinforcement effect.Thus it is a feasible solution for consolidating the newly filled soil.

Abstract:Aiming at the problem that the construction efficiency of a 10，000 m3 dredging ship is low during open sea dredging,we take a comprehensive demonstration of the influence factors of construction efficiency.We apply the method of mathematical model,analyze the impact of different types of mud pumps on construction by comparing the size of three types of mud pumps on site,combine the parameters obtained from the construction with the principle of fluid mechanics,and analyze the influence of the blade wall thickness of the mud pump impeller and the size of the drag head grid on the stone excavation.The results show that the main reason for the low construction efficiency is the minimum flow area of mud pump impellers in dredging equipment.The results can provide reference for similar projects.

Abstract:The port construction is continuously developing towards the deep-water area.When the breakwaters are built in the sea area with poor natural conditions,the mass of protection block is increasing,and the steel bar is usually used to enhance its anti-cracking ability.In order to solve the precast construction difficulty of super-large accoropode caused by the reinforcement,we add anti-cracking fiber instead of reinforcement.By model test and theoretical calculation and numerical simulation method,we analyze the cracking risk of super-large accoropode in prefabrication and hoisting process.The results demonstrate the feasibility of removing the steel rebar of super-large accoropode.

Abstract:Aiming at series of problems of the traditional concrete armor block installation methodology including the lack of block installation accuracy,insufficient interlock and unguaranteed installation quality under severe wave condition and high-standard installation requirement,we introduce the components and working theory of the Echoscope system,a real-time 3D sonar imaging system,and describe the specification and requirement of ACCROPODETMⅡ based on the breakwater engineering of a new port expansion project abroad.Using the real-time 3D imaging sonar of Echoscope and GPS-RTK positioning technology,we solve the problems of armor block’s placing under adverse wave condition,and improve the installation efficiency significantly as well.

Abstract:In view of the problems such as drag teeth is hard into the soil,drag head is blockage and shutdown when the large trailing suction excavate stiff clay,we adopt special high-pressure flushing system（maximum pressure 38 MPa）,add three high-pressure flushing auxiliary device,and design the suitable injectors in the drag head based on the original drag head model of the large trailing suction hopper dredger.The drag head for high efficiency excavating clay has been successfully developed,which effectively solves the problem of drag head blockage and shutdown,and raises the efficiency of trailing suction hopper dredger construction.It can provide the reference for similar problems.

Abstract:In view of the design problems concerning the quick release hook including beyond-scope use of a single hook and over safe load tension of a single hook,this paper probes into the way for the quick release hook to guarantee the safe mooring of ships.Analyzing the reasons of beyond-scope use of the quick release hook from three aspects including the ship’s mooring,the wharf berthing ships’ tonnage,as well as the standard content for the old and new terminals,and studying the reason of over safe load tension of a single hook from the wind and surging effect and the ship loading & unloading and the flood and ebb,this paper puts forward the countermeasures including strengthening the use management for the quick release hook,updating and renovating the quick release hook,as well as the periodic testing and setting terminal chock.

Abstract:To ensure smooth implementation of the project and control the content of fine sand particles to less than 20%,the standard SPT was adopted prior to construction and during construction.The soil type and fine particle content are studied.At the same time,through the actual dredging efficiency analysis of the dredger on site,the relationship between SPT standard penetration number and dredging capacity of different types of dredgers is obtained as follows:when value N is greater than 30,it is difficult to excavate,and necessary to introduce the large cutter suction dredger or trailing suction hopper dredger.For the same-quality soil,the content of fine blower filler material by the trailing suction hopper dredger is far lower than that by the cutter suction dredger.Therefore,according to the SPT drilling data,it is of great significance to arrange the construction vessel and construction technology reasonably for the progress of project implementation and cost saving.