Abstract:Based on the analysis of the navigation obstruction and the tendency of channel change in downstream Yangtze River,we put forward the regulation ideas and give the recommended channel regulation scheme according to the results of model experiments,which bears satisfactory effect in improving the channel condition of Luochenzhou left branch’s shallow area and the channels in Manyusha reach,while the area near the left of Sanyiqiao and Gaogang shoals need dredging regulation because the necessary width is slightly smaller.

Abstract:In the first dredging and pumping ashore project in the Yangtze River,unprecedented difficulties and technical problems were encountered during the construction.Based on the analysis of the Yangtze River,fine silt,clay and other complex project conditions,the drag head and teeth were improved,the craft parameters of dredging and the program of pumping ashore were optimized,which improved the construction efficiency and provided reference for the future dredging and pumping ashore construction of self-propelled trailing suction hopper dredger in the Yangtze River.

Abstract:The wave energy transfer caused by nonlinearity in the coastal region is investigated based on the physical experiment.Three bottom slopes (β=1/15,1/30,1/45) are installed in the flume and a set of random wave simulations based on JONSWAP spectra is generated to implement this experiment for the purpose of grasping the effect of topography.The evolution of energy for different frequency bands including the primary and higher harmonics is discussed based on the energy spectrum.Several empirical formulae regarding these dimensionless energy parameters as a function of local water depth are derived based on the data measured on each slope.The results indicate that the bottom slope plays a crucial role in the variation of the energy for the primary and higher harmonic waves.Therefore,the effect of bottom slope is considered in the final empirical formulae.

Abstract:With the completion of the Qitai operation area and the auxiliary breakwater project,Lianyungang port has become a long narrow semi-enclosed harbor region.As the entrance of the port becomes narrow and the distance from the entrance to port ends increases,the exchange capacity of the harbor water will certainly be affected.In this article,the water exchange capacity before and after the engineering is studied using a three-dimensional mathematical model and further understanding of the exchange process in the harbor waters is carried out by Lagrange trajectory method.The simulation results indicates that under the impacts of flow dynamics and the port shape,the half exchange period increases from about 5 days to 22 days after the construction of Qitai operation area and the auxiliary breakwater project.In order to guarantee the water quality in the port,the amounts of wastewater discharged into the port must be controlled strictly.

Abstract:The formulation of circulation velocity by Sun-Dongpo has a concise and reasonable structure,and the results won’t be affected by Karman’s constant and the agreement is acceptable with the experimental findings.But the actual situation of the rough bed can’t be reflected,for the inadequacy in the calculation of transverse slop and the establishment of prandtl’s turbulent stress.For the problems mentioned above,we imported Rozocskii’s formulation of transverse slop which fitted well with the real situation,built the Prandtl’s turbulent stress,and then joined them together to get the improved formulation.Not only did the improved formulation correct the defect in the usual one,but also the results matched very well with the real data,so the improved formulation could be put into use in natural bends.

Abstract:To study the specialties of wave slamming on horizontal plate structures and beam-plate structures,we establish two-dimensional regular wave numerical models based on software FLUENT.Adopting RANS equations and standard k-ε equations and using the VOF method,we reconstruct the free surface.Through typical cases of wave slamming on panel structures are reproduced,and the models are verified by experimental data.Then with plentiful simulation the impact pressure distribution rules during slamming are obtained.The statistical distribution data are analyzed and the fitting formula of distribution width is put forward,which may serve as reference for the engineering design.

Abstract:A horizontal 2D numerical model of wave based on the Boussinesq equation is used to study the simulation of wave transformation in the harbor area protected by submerged breakwaters,which the submerged breakwaters are handled as the moving boundaries.The numerical model is first tested to prove its applicability in the simulation of wave transformation over submerged breakwater by the experimental data proposed by Ohyama,et al.Then,the numerical model is used in the water area outside a fishing port which is protected by a submerged breakwater.The processes of wave dissipation are analyzed,and the wave transmission coefficients obtained by simulation are compared with the calculated values of the empirical formulas at home and abroad.The results show that the present simulation method can effectively simulate the wave transformation over the submerged breakwater.

Abstract:For a light breakwater structure,the anti-sliding stability is an important part to calculate the stability of the new breakwater under the wave load.Due to the complexity of the structure,there isn’t any stipulation yet on the computation method of the anti-sliding stability for this new breakwater structure.We assume that the stability of an embedded new bucket breakwater mainly depends on the soil pressure on the wall,the shear stress at the bottom of the bucket,and the self-weight of the bucket and the soil in the bucket.The bucket and the soil in it are regarded as an entirety.Such a breakwater works under a similar principle as a gravity retaining wall.Supposing that the bucket rotates around the rotating centre of the bucket,the soil on the wall of the harbor side is under passive state,and the soil on the wall of the sea side is under the active state.It supposes that the soil pressure on both ends of the bucket wall reaches the passive soil pressure state and active soil pressure state respectively under the ultimate state,and at the same time,the shear stress under the bucket also reaches its ultimate state.Based on the above-mentioned hypothesis,by means of derivation and analysis,the computation method of anti-sliding stability of 3D embedded new bucket breakwater considering the influence of the rotation is established.

Abstract:Influenced by the random arrival of vessel,the dynamic traffic flow of container terminals is full of randomness.How to forecast the traffic flow is very important in the planning of the collecting and distributing systems.Most present studies forecasted the traffic flow based on the statistical information with the method of unbalance factor.But it doesn’t suit for the newly built port area very well for the lacking of statistical information.In this study,we construct a dynamic traffic simulation model for the container terminal based on the random arrival of vessel,forecast the real time traffic flow reasonably by simulating the process from the arriving of vessel to the leaving of container and verify the reliability of the simulation model.In the end,depending on the regulation of the arrival of vessel,we forecast the collecting and distributing traffic volume of different periods taking a newly built international container terminal for example.This provides a scientific basis for the instalment construction of the collecting and distributing system.

Abstract:Permeable coating is one of the ideal coatings to improve the concrete durability in view of balancing concrete’s “breathing” ability and the effect of water-proof.Three indicators of capillary absorptivity,chloride ion flux and chloride diffusion depth were used to test and estimate the effect of the permeable coating of a high-pile wharf,on the upper structures of which the permeable coating was applied.Results show that after the permeable coating is applied on the upper structures,the capillary absorptivity of the specimens is decreased by 90%,chloride ion flux is reduced to a level that is extremely low and could be even ignored,and chloride diffusion depth is decreased by over 60%.Therefore,a conclusion can be drawn that the permeable coating can enhance the durability of upper structures of high-pile wharves significantly.

Abstract:Based on a piled wharf under the horizontal load,we apply the probabilistic limit state design method to obtain the statistical parameters of load effects variables,study the resistance of structural and distribution of statistical parameters;ascertain the failure criterion,and establish the structural response model by ANSYS PDS with a wharf case.The analysis results show that the impact energy and the impact force fit the extreme type I distribution best,and the bending failure and displacement criterion are leading controls.Taking a terminal project for example,we establish the structural response model and PDS module of ANSYS finite element.The Monte Carlo method is used during reliability analysis.The sampling results of a total of 100 000 times of samples show that the failure probability of the terminal under ship impact force is 2.073 05 × 10-3,and the reliable indicator is 3.76,which meet the secondary standard specifications.

Abstract:The sedimentation rate in an alongshore trestle wharf speeded up after the reconstruction,so a two-dimensional mathematical model was applied to study the current and sediment transport,and the simulated results of current and suspended sediment were verified by measured data on site.The tidal current of Jintang channel is mainly reciprocating flow and the sediment is from the outer waters instead of the coast.Possible causes include the geographic location and terrain,the arrangement and direction of berth,the mooring of ships,the discharge of an adjacent power plant,wharf pile foundation and dredging,etc.we also analyze the influences of berth deposition on conditions including whether ships dock or not,the adjacent power plant discharges or not,wharf pile foundation exists or not and the water depth of adjacent power plant’s water intake area.It is concluded that the main cause is the unreasonable design and construction of the wharf.

Abstract:Based on the project of large internal digging harbor in Doha,and according to the engineering characteristics of the large foundation pit excavation,we analyze the key factors affecting the drainage engineering progress,i.e.the drainage design by combining the traditional foundation pit drainage design method and the modern finite element analysis technology,simulate the deep well depth and the distance between wells using the finite element software according to the actual situation and the design experience in the original specification,and put forward the optimum design,by which the reliability is improved.The results show that the application of numerical simulation technology plays an important role in saving the design cost and optimizing the design scheme.The design pattern which combines the traditional with the modern method may serve as reference for similar projects.

Abstract:Based on two phase flow and VOF models of software Fluent,a numerical wave tank is established using the UDF function of the software.The wave transmission property of regular waves near a double-barrier penetrated breakwater is studied numerically,and the results are compared with the experimental values.More groups of tests are conducted to study the effect factors of wave transmission property of double barriers penetrated breakwater when d/H＞5.Based on those factors,a modified formula is given,which can be used to calculate the transmitted coefficients of the double-barrier penetrated breakwater in corresponding situations.

Abstract:Overseas projects in the sea area often face a main direction swell with a period of over 10 s.The Ashdod breakwater in Israel faces the open Mediteranean sea and is affected by long period swell.Based on studies on the physical model tests of breakwaters,we analyze the influence of swell on the stability of breakwater combining with the drain rate of the core rock,1～3 t and 3～6 t armor rock of breakwater under the action of impacts and erosions of waves with long periods and big heights during the construction of the breakwater.We also get the critical instability wave hight of the core rock,1～3 t and 3～6 t armor rock to find out the best installation opportunity.The result may serve as reference for similar projects.

Abstract:With the reduction of high-quality coastline resources,the construction of new wharves faces much more problems such as harmful unfavorable geologiccal conditions and complicated wind and wave conditions.So,the wharf’s piles should be much longer and have better endurance capacity mechanical performance,which means the design of new wharfs have higher demands than the traditional designcalls for higher requirements of wharf design.In this case,the combination pile of steel and concrete,as a new type of wharf pile,is employed as the foundation of crane’s block,As a new type of future candidate pile,the pile combined of steel and concrete is which has a better performance and lower cost comparing with the the previous additional steel pipe pile,concrete pipe pile and the PHC pile with higher performance and low in cost,which was employed in the foundation of crane’s block in this project.Additionally,the this place of geologic condition of the project site is very poor,where the soft silt-layer is thick,and which makes the length-diameter ratio of some piles’s proportion of length to diameter so big.To guarantee the safe construction of the super long pile,we carry out an in-depth analysis on the pile’s lifting,transportion and pilingthe process of lifting,transporting and piling is deeply analyzed.

Abstract:According to the design conditions of a siltation promotion project located in the Yangtze River estuary,the near-bottom hydrodynamic characteristics of a new hollow tetrahedron siltation promotion embankment is studied by model-test method.Test results show that:1)The maximum value of the near-bottom turbulence intensity,the minimum value of the near-bottom average horizontal velocity,and the direction changing of the near-bottom average horizontal velocity occurs almost at the same place;2)For a concrete dam type,the maximum value of turbulence intensity occurs almost at the same place under the same unit discharge condition when the relative water depth changes;3)Compared with traditional embankment which is composed of riprap and armor block,embankment structures with better permeability can be more beneficial for the stability,because the maximum value of the near-bottom turbulence intensity is farther away from the dam axis which makes the local scour hole further away.

Abstract:Nowadays,the water dynamic researches about collateral hole of bottom-brake and long-corridor filling and emptying system mainly use the physical model test and field prototype observation method,which need to consume a large amount of manpower and material resources.There are relative few researches with numerical calculation method which is fast and convenient and not affected by test conditions and the achievement effect of scale.Therefore,it is of important academic value and practical significance to do the water dynamic researches about collateral hole of bottom-brake and long-corridor filling and emptying system through the ship mooring force of lock chamber by numerical simulation,get the dynamic characteristic of systemic study and summarize the principles of arrangement,provide the theoretical basis for the design and optimization of the filling and emptying system,and provide reference for similar engineering design and construction.

Abstract:The application conditions and protection mechanism of soft mattress are different from the permeable frame.In order to give a full play of the advantages of both,we put forward the joint structure for the bottom protection.Studying the protective effect of the submerged breakwater by the water tank test,and analyzing the economic efficiency of the joint bottom protection,we get to the conclusion that the joint structure can weaken effectively the local scour at the edge of the bottom protection.To achieve similar effects of bottom protection,the joint bottom protection can save project investment of more than 5%.

Abstract:The low waterway grade of Mengli hydro-junction is not able to meet the requirement of the current freight growth.So,it is necessary to build the second-line shiplock on the right bank of the first-line shiplock to increase the shipping capacity.The overall fixed-bed model is established to study the effect of the guide wall length and the layout form on the flow conditions in the entrance area and the approach channel.According to the model test results,the navigation flow conditions of the modified scheme II，with the separately arranged first and second-line shiplocks,the guide wall length of 375 m and the holes in the wall head,are best among all the modified schemes:the navigation conditions of second-line shiplock are improved while the ones of the first-line shiplock almost keep unchanged,and the unfavorable flow conditions in the entrance area and connecting section are improved.

Abstract:The excavation engineering in the vicinity of the existing building lock has a certain effect on the safe operation of it.In order to understand the influence of slope excavation in the foundation pit near the lock and ensure the safety and normal operation of it,we establish a 2D finite element model of the slope excavation in the foundation pit near the lock combining with nonlinear finite element simulation analysis method,ideal elastic-plastic constitutive model and D-P yield criterion.Base on the analysis of the influential factors including the distance between foundation pit and the lock,and slope of the pit,we present the proposed value of the safe distance and excavation slope of the foundation pit near the lock.

Abstract:The outer channel of Huanghua port often confronts with sudden siltation induced by strong winds,and the study on the return values of sudden siltation volumes can be helpful to the treatment of sediment accumulation.The point estimations of return values given by diverse methods may produce large differences.The interval estimation can present some reference intervals of design return values under certain confidence levels,so it will provide corresponding instruction for the designers and constructors.Fitting the predicted sequences of the annual maximum sudden siltation of Huanghua port with the lognormal and maximum entropy distributions separately,we estimate the confidence intervals of the return values of sudden siltation volumes by the maximum likelihood method.With the increase of return periods,the scale of the confidence intervals becomes large.The results given by the maximum entropy distribution have higher precision,so they can be applied as reference for the treatment of sediment accumulation.

Abstract:Due to the bedrock and gravel bed of the upper reaches of the Yangtze River,the navigation-obstructing reaches are common with the diara,shoal and beach,which are of complicated boundaries.To meet the needs of the actual project and waterway regulation,there always exists a sandpit,excavation of navigation channel,the construction of the moraine dam and other ways to change the local river boundary.Taking Zhanqizi reach for example,we establish the mathematical model of the first moraine diversion dams which turn right to 0°,5°,10° respectively.The result show that the 0° moraine dam causes smaller stage rise and diversion ratio change,and it has less influence on shoals of moraine son;the 5° moraine dam has an obvious effect on the optimization of the main channel split ratio an water-ways navigable depth and flow rate,and the navigation effect is better ;and the 10° moraine dam has a remarkable effect on improving the navigation condition on the main channel,and it changes greatly the flow field,and thus causes significant river changes.The research result may serve as reference for providing a reference for the design and research of the regulation engineering of complicated navigable channel on the upper reaches of the Yangtze River.

Abstract:Based on the comparative analysis of dynamic characteristics of different types of spur dikes through moving bed scouring experiment，and combining with the riverbed scouring terrain contours,we find the relationship between the turbulence characteristics and bed scour.On this basis,we carry out an in-depth analysis of the impact of different types of dikes on the dynamic characteristics of turbulent flow,and optimize the structure of the new-type dam.Test results show that the erosion of terrain around the spur dike is associated with the intensity of turbulence flow,the depth of the scour pit increases first and decreases later along with the change of flow turbulence characteristics;the sand ridge is mainly composed of coarse sand,and the cross section is in the “streamlined” shape,the backflow zone appears fine sand layer,and the circular cross section and hook type of spur dike has a certain advantage in less flow turbulence.

Abstract:Ship navigation safety will be greatly influenced by the obstruction due to bridge group.Based on generalized meandering river with bridge group,the corresponding relationship between bridge span and distance is confirmed using the ship maneuvering motion simulation method.Considering the actual conditions of the river,the general coupling relationship between the distance and span is obtained.Taking Dengjiaba bridge group of Tuojiang river in Sichuan province for example,the feasibility of the proposed site and span layout scheme of Dengjiaba bridge is proved by the obtained general coupling relationship.Moreover,the navigation condition of Caiyuanba bridge group reach of the Yangtze River is evaluated.

Abstract:After the impoundment of the Three Gorges reservoir (TGR),the velocity of the left channel of Huanghuacheng reach in the permanent backwater region of TGR deposited badly.The depositions are fine sediments with median diameters of about 0.01 mm,thus it is controversial to apply the traditional waterway dredging theory.A diversion dam-based regulation scheme is proposed to improve the diversion ratio and enlarge the velocity of the left channel.Numerical simulation and model experiment of renovation plan show that the velocity of the left channel reaches the sediment transportation-velocity,indicating that the deposition area keeps no more scour or deposition.The regulation method which combines waterway dredging with diversion dam is proposed.

Abstract:To analyze the subsea-slope stability affect by the wave load,we use Visual C# software language platform to develop an application programming interface and realize the data transfer between the Gocad and Abaqus.With the basic contour map,the complex seabed topography could be 3-D modeled in Abaqus.We also develop a program to treat the mechanics field in Abaqus and realize the stability analysis of subsea-slope by the strength reduction method.Based on the analysis of the subsea slope stability of Zhujiajian island in Zhoushan,we adjust the the stability of the side slope.The calculation result shows that wave load will exert certain impact on the subsea-slope,and the subsea-slop near Zhujiajian island faces landslide risk.

Abstract:The laboratory test reveales that the excavated rock materials with high content of palygorskite has potential problems with swelling and dispersion in New Doha port project.Most of the filling materials do not comply with the accepted criteria in specification and shall be considered as unsuitable filling materials.As per specification,the general reclamation fill shall have fine contents of less than 15% with a liquid limit not exceeding 65% and a plasticity index not exceeding 35%.To make full use of these materials and reduce the amount of surplus soil,the EDC has provided new criteria for the unsuitable material based on the structural function on the reclamation surface,i.e.the air void content shall be less than 10% after ground improvement and the volume change shall be less than 1% of the filling thickness.A series of laboratory test comprising particle size distribution test,hydrometer liquid and plastic limits test,swelling test and X-ray diffraction test etc.were scheduled and carried out by local laboratory to verify whether this new criteria has been met for unsuitable filling material.And a correlation has been built between the swelling and fine content. The test result indicated that the unsuitable fill material with fine content less than 45% can be used as general fill material and has been demonstrated by a large scale flooded embankment test.However,the prevention from dispersion should be considered when the filling material with fine content between 20%～45% is used.The research may serve as reference for similar projects in the future.

Abstract:High-vacuum densification method is a new technology for rapid reinforcement of soft soil foundation,by which we are capable of reducing the water content of the soil,improving the compactness and bearing capacity and reducing the amount of settlement and differential settlement of the foundation after construction through several times of high-vacuum differential pressure drainage and several times of appropriate variable energy densification.To validate the applicability of this method in the project,we carry out typical tests in the car yard area.The test results reveal that the allowable bearing capacity,foundation settlement,foundation modulus of resilience and other indicators all meet the design requirements,and the treatment effect is obvious.It may serve as reference for similar projects at Dayaowan port area of Dalian

Abstract:During construction of the port engineering on the soft soil foundation,the loading of embankment has enormous influence on the construction time and structural safety of the lateral pile foundation of the approach bridge.Based on a fishing port engineering,we study the lateral displacement of soft soil foundation of loading embankment and the regression of follow-up tracing data of deep horizontal,and forecast the change law and trend of development of later horizontal displacement of the foundation with the loading of embankment.According the ANSYS three-dimensional modeling,we analyze the internal force and deformation of bored piles with the loading of the embankment,and determine the construction time of lateral bored piles foundation.The research result shows that the lateral deformation of soft soil is consistent with the deformation law of index function in the process of load;under the action of lateral deformation of the soft soil foundation lateral deformation,the effect on the lateral displacement of the bored piles is bigger than its internal force influence;when the soft soil occurs 150 mm maximum horizontal displacement in the upper,the safety degree of yield stress of the surface concrete of bored pile is still larger,and accordingly we may know the construction time of the lateral bored piles foundation of approach bridge.This research may serve as reference for the design and construction of similar projects.

Abstract:With the broad application of modern diaphragm wall engineering,problems including inaccurate depth of buried pipes control during pouring of underwater concrete and large-area exposure of the reinforced bar for the diaphragm wall after excavation of the foundation pit exposed gradually.For the purposes of strengthening the project process control and improving the quality of diaphragm wall,we put forward the concept of the membrane effect of underwater pouring concrete and its formation stages and nature for the first time taking the underwater pouring concrete as the investigation objective.At the same time we put forward the concept of taking the membrane thickness as the measurement standard and the membrane resistance as the characterization method.According to field tests and theoretical analyses,we get to know the influential factors of the membrane effect,and put forward main measures for controlling the depth of buried pipes.According to the characteristics of the membrane effect and large-area exposure of the reinforcement,we put forward the concept of edge-membrane stranding effect and the influential factors for the first time.Based on the cause analysis of large-area reinforcement exposure,we put forward main measures for reducing the large-area reinforcement exposure.

Abstract:Based on recent years’ construction experience on the Yangtze River estuary 12.5 m deepwater channel maintenance dredging engineering,we analyze its engineering characteristics.In view of the severe conflict between the dredging operation and channel safe traffic,high quality requirements,complicated external environment and the fact that the actual back-silting volume exceeds significantly the contractual volume,we propose key control points such as knowing well back-silting discipline,focusing on operation progress control,safety control and external coordination to meet project requirements.