Abstract:To solve the problems of slow hydration rate and low early strength of dredged soil solidified by steel slag，cement and steel slag were combined to improve the early strength of solidified soil.The influence of water content on the properties of soil solidified by cement-steel slag composite was studied through stress-strain curve，unconfined compressive strength，and elastic modulus. It is found that the strength of composite solidified soil increases with the decrease of dredged soil moisture content，and the properties of 1.25 times of liquid limit-soil are closer to those of 1.5 times liquid limit-soil. Based on the dredged soil strength of 100 kPa，the mixed ratio of cement and steel slag with different moisture content satisfying the strength standard was studied experimentally，which has important reference significance for the practical application of cement and steel slag composite curing agent. The microscopic analysis suggested that the mechanism of cement-slag composite action is that the reaction of cement hydration and slag pozzolan produce hydrated calcium silicate and orthorhombic，which can fill the pores，bond the soil particles and enhance the bearing capacity of the soil skeleton.

Abstract:Based on the simultaneous observation data of tidal current and sediment content at 12 stations in the Sanmen Bay during dry and flood seasons in 2013，the mechanism decomposition method was used to analyze the transport mechanism of suspended sediment in the dry and flood seasons，and to explore the contribution rate of different hydrodynamic factors. Results show that：1）Whether it is the flood season or the dry season，the Euler residual current and Stokes residual current increase gradually from neap tide to spring tide. The direction of Euler residual current is seaward，and the direction of Stokes residual current is landward in the study area. The size and direction of the single-width water delivery are mainly determined by the Euler residual current. 2）During the dry season，the advection transport term is the principal constituent of the suspended sediment transport in Sanmen Bay，and the largest contribution rate of T1 is 83% in the study area. The contribution rate of the tidal pumping transport term （T3+T4+T5）is the largest in the middle of the bay. During the flood season，the contribution rate of the advection transport item in Sanmen Bay decreases，while the contribution rate of the tidal pumping transport term increases. 3）Regardless of the flood season and the dry season，the net transport of sediment at individual stations （SM08 and SM11） in Sanmen Bay is in the opposite direction，and the laws of other stations are basically the same.

Abstract:As a typical multi-body dynamics system，the design of principle parameters for a soft yoke single point mooring system（SPM） is a tough problem for its so many principle parameters. We use the modified Morris filter method with the perturbation analysis technology（fixed step size 5%，and perturbation range ±25%） to study the maximum horizontal mooring force and displacement on which much attention is focused during the system design. Considering the steady force，high-frequency force and second-order wave drift force of moored body，we establish an ideal mechanism model of SPM to study the local sensitivity analysis on the parameters，so that can strengthen the identification of the model parameters and uncertainty，and provide some useful decision-making basis when determining the principles of SPM. The results show that for SPM with 13 DOFs and 8 principles，the descending order of sensitivity of parameters related to the maximum mooring force and displacement in the model is the length of the yoke，length of mooring leg，and ballast force，so these variables should be given corresponding priority in the design process.

Abstract:Water exchangeability is an indicator for evaluating the self-purification ability of estuary. To study the influence of shoreline changes and sea level rise on water exchange in the Pearl River Estuary，we establish a two-dimensional hydrodynamic-conservative mass transport model，compare the results of water level and flow direction simulated by the model with the measured data，and use the Euler method to calculate the water residence time variation of the Pearl River Estuary due to coastline changes and sea-level rise under the condition of wet and dry seasons and high and low tides. The results show that the impact of shoreline changes on water exchange in the Pearl River Estuary is different，for example from the 1970s to 2010，the average water residence time of the Lingding Bay first remains almost unchanged and then decreases slightly，while the water average water residence time of the Huangmao Bay and Modao Bay vary depending on the situation. Sea level rise is not conducive to water exchange，the water residence time increases with the rise of sea level，and the time increases in the dry season is longer than that in the wet season.

Abstract:Feasibility study on steel slag substitution for offshore hydraulic concrete aggregates is conducted for the resource utilization of steel slag. The steel slag concrete ratio design is carried out by partially replacing natural coarse and fine aggregates with Baosteel roller slag，and various properties of steel slag concrete are studied through indoor tests and pilot project applications. The results indicate that with the increase of the portion of steel slag，concrete slump decreases gradually，the compressive strength，impermeability grade，and abrasion index increase，the electric flux and diffusion coefficient increase slightly，and the chloride resistance deteriorates slightly，and it can meet the quality requirements for the concrete applied in offshore hydraulic structure. The surface quality of the concrete applied in the pilot project is the same as that of the ordinary concrete，and the structural strength meets the design requirements，which provides a new way for the disposal and utilization of steel slag in coastal areas.

Abstract:The damage analyses of breakwaters have an important guiding role for its rehabilitation or reconstruction. During the past 45 years of construction and operation，a rubble mound breakwater armored with Tetrapod units in the Mediterranean has damaged successively under strong wave conditions. Although it has been repaired many times，it still suffered local damage. In this paper，by field investigation，theoretical formula verification，and 2D physical model test，the damage reasons of Tetrapod blocks are analyzed. Results show that：1）The Mediterranean area has strong waves，high wave height，long period，long duration，and great destructive power. 2）The main reason for the breakwater damage is that the slope of the protective surface is too steep. 3）The unit placement quality also has a significant effect on the stability of the Tetrapod units. The stability of the Tetrapod units with randomly placed is much worse than that of the Tetrapod units with regular well placed. 4）For the breakwater projects in the Mediterranean，the factors of amour slope，block installation quality and unit placement density should be considered in the design.

Abstract:For the navigable water flow conditions at the front of the wharf in the backwater area of the reservoir under the influence of large stage fluctuations，we take Baishitan wharf being built in downstream of the Baihetan Hydropower Station as an example to study the navigable flow conditions of the Baishitan wharf by grading the water levels for the large stage fluctuation and adopting the method of two-dimensional hydrodynamic numerical simulation. As a result，the linear relationship between the highest navigable flow of the wharf and the graded water level is obtained：the higher the water level in the front of the wharf，the better the navigable flow conditions. When the water level of the wharf reaches 585 m or more，the water flow conditions at all discharges of the navigable water area in the front of the wharf meet the requirements for safe docking and navigation of ships. The results indicate that the design plan of the wharf to operate during the higher water level after completion is feasible.

Abstract:For the ecological port construction measures in the overall planning of Taipingwan port area of Dalian Port，we carry out qualitative and quantitative analyses and mathematical model experiments to demonstrate two aspects. It is proposed that in terms of the marine ecological protection around the port area，we may take the measure of optimizing the planning of the port boundary and navigation channels and carrying out boundary demonstration for the protection of the agricultural and fishery areas，tourism and recreation areas，harbor seals，and national-level aquatic germplasm resources；in terms of the marine ecological protection inside the port area，we may take measures such as protection of water bodies，tidal channel and sluice gate arrangement，ecological shore protection and greening rate control，receding to wetness，and construction of permeable structures. It provides support for the optimization and implementation of the overall planning and provides references for marine environmental protection measures in similar planning.

Abstract:Aiming at the problem of structural detection and evaluation of the in-service high-piled wharf without engineering construction data，we combine with the engineering examples，use the method of combining the routine test items with the non-routine test items such as the integrity test of foundation piles and the structural load test to find out the current structural performance of wharf and assess the structural safety grade of the wharf，and achieve the purpose of the detection and evaluation. The results show that the combination of routine and non-routine inspection items can achieve the good results in the structural detection and evaluation of the in-service high-piled wharf. It is suggested that the static load test should be added in the construction detection，completion detection，and regular detection of the high-piled wharf，and the integrity of foundation piles should be checked for the in-service high-piled wharf.

Abstract:There is no unified calculation standard for dust emission and pollution tax paid in various domestic coal ports.In response to this problem，by analyzing the key factors affecting coal dust emission，this paper summarizes and analyzes the main calculation formulas for dust emission at home and abroad. Based on the recommended formula for the environmental impact assessment of port construction projects，the formula dimension is defined，the wind speed parameters are revised，the concept of source strength of a dust-raising event is introduced，and the operation of the dumper is included in the calculation of unorganized emissions. Finally the calculation formula of total emission which accords with the current situation of coal port operation is constructed. The formula is used to calculate the dust emission in Huanghua port of the national energy group，and the corresponding relationship between the water spraying operation and the dust emission is obtained. The formula has an important guiding significance for government departments to calculate the amount of dust emission from ports and to collect reasonable discharge tax.

Abstract:The mixed wave of long-period surge and wind wave has the characteristics of long-period and large wave energy，and the design of slope breakwater structure in such environment cannot be carried out by simply referring to current codes. Based on a built project，we carry out the calculation and theoretical analysis to compare and analyze the design process and physical model test verification process of the project，and obtain the key points of structural design for sloping breakwater under long-period mixed wave in the open sea. The results show that the experience coefficient in the design should be considered such as the selection of block for outer slope protection and determination of the height of the top of the wave wall. The top of the breakwater behind the wall and the slope behind the breakwater need to be strengthened especially，and the appropriate structure type of the wave break wall should be selected as far as possible on the top of the breakwater. The calculation formula of rock protection bottom in the current code is inappropriate under the condition of shallow water.

Abstract:The Yangshan Phase IV automated terminal is currently the world’s largest single-scale automated container terminal with the highest degree of automation integration. The design throughput of the initial stage is 4 million TEU，and it can eventually reach 6.3 million TEU. The water-to-water transfer ratio of the Yangshan Phase IV container terminal is as high as 50%. To meet the efficiency of loading and unloading operations on the seaside of the yard and to ensure the truck transportation on the land side，mixed operations of no cantilever，single cantilever，and double cantilever ARMG were designed in the initial layout design. The AGV not only interacts with the ARMG in the seaside interactive zone but also can go deep into the side of the yard to interact with the single cantilever ARMG，which improves the efficiency of loading and unloading operations at the waterside of the yard. Based on this operating condition，relevant design scheme research was carried out. Based on the layout design of the cantilever yard，the AGV path rules，and related technical difficulties in the operation process，this paper systematically analyzes and elaborates the scheme.

Abstract:In view of the adjustment of the general layout of Taipingwan port area of Dalian Port，we optimize the scheme by qualitative and quantitative analysis and comparative study method according to the macro environment change and the development requirements in the new period. The total area，sea area，occupied natural shoreline，and number of berths are reduced，while the capacity，greening rate，and the wharf shoreline are increased，which significantly reduces the impact on the ecological environment and improves the degree of wharf specialization.

Abstract:The hollow block mound breakwater is quite different from the traditional slope dike in section and block shape. It is difficult to calculate the stable mass of the block using the formula in the specification.To solve this problem，the stability of the hollow block under the conditions of different water levels，different wave heights，and different wave periods under the action of regular waves and irregular waves has been studied through physical models. The test results show that dimensionless stable mass Wr shows a linear increasing trend with the increase of the Irribbarren number. Finally，combined with the research results，a calculation formula for the stable mass of the block considering the influence of wave steepness under the action of regular and irregular waves is fitted. The recommended stability factor is 9.1，and the formula provides a reference for the structural design of the hollow block mound breakwater.

Abstract:Haifa Bayport container terminal is a key project in Israel. The design requirements are very strict. The fire protection design of Haifa Bayport is based on the local codes of Israel. At the same time，the values of various parameters and calculation methods refer to the relevant NFPA standards. In view of Israel’s design style of paying attention to seawater utilization，two independent fire water supply systems，i.e.seawater firefighting，and freshwater firefighting，are adopted in the fire water supply design. The water consumption of each fire scenario is analyzed by the international scenario analysis method，and firewater consumption for the Bayport is determined. In addition，specialiatity of design for the types of the local outdoor fire hydrant，indoor fire hydrant，sprinkler system，and water curtain are explained.

Abstract:The contradiction between port and city becomes more and more obvious，Shijiu port area of Rizhao Port promotes the southward movement of bulk cargo operation area，divide the east，west，and north area for clean cargo handling service，and extends the length of container terminal shoreline. Taking the reconstruction project of the automatic container of the general terminal in Shijiu port area of Rizhao Port as an example，we compare the two general layouts including the direction of stockyard parallel and vertical to the shoreline，determine the general layout of the stockyard parallel to the shoreline considering the automated level，capital input，and the handling efficiency. This general layout can effectively improve the operational capacity of the stockyard，reduce the construction investment. It has good application value，and reserve the development space for the long-term application of unmanned container truck technology.

Abstract:The reaches of the Yangtze River below Nanjing are mainly the branch river type. The movement of water and sediment，and riverbed erosion and deposition are complex by the combined action of runoff and tide. Taking the Yizheng waterway of key navigation obstructing shoal in 12.5 m deep water channel below Nanjing as an example，we analyze the evolution characteristics of this waterway before and after impoundment of the Three Gorges Reservoir according to the existing research results and the recently measured hydrological，sediment and topographic data，and discuss the influence of water and sediment changes on riverbed erosion and deposition after the impoundment of Three Gorges Project. The results show that after the impoundment of the Three Gorges Reservoir，the riverbed erosion and deposition are different from those before impoundment. Before the impoundment，the Shiyezhou left branch scours，and the right less deposition；after storage，both of them as scouring. Before the impoundment，the flood has a great influence on the pattern of the channel beach. After the water storage，the flood water is affected by the reservoir，and the flood decreases，the influence of the water and sand on the evolution of the beach is weakened.

Abstract:By the physical model test，we research the influence of cushion layer mass on the stability of sloping dike. We choose 1/20~1/10，1/40~1/30，1/60~1/50，1/100~1/90 of the stable mass of the twist Wang block as the cushion layer mass，research the influence of irregular wave on the stability of sloping dike （including effluent dike and submerged dike） under the same experimental conditions，and record the test process by video recording and shooting. The results show that effluent dike and submerged dike with the cushion layer mass of 1/20~1/10 and 1/40~1/30 have the similar stability of the sloping dike，and the stability of the two dikes can maintain under the calculated stable wave height，only slight instability occurs under the extreme wave conditions. And in the other two cases，the structural stability of the dike body is poor，resulting in the deformation of the dike body，the subsidence of the embankment top，the run-out of the cushion layer，the instability of the twist Wang block and other forms of damage. Compared with the sloping dike of two elevations，the stability of submerged dike is much better than that of the effluent dike with the same mass of cushion layer.

Abstract:To improve the development level of inland river shipping in China and explore the new method of integrating the concept of green ecological development into the construction and management of inland river shipping，we introduced the development characteristics and direction of German inland shipping from the aspects of infrastructure，ship capacity，information construction，collection，and distribution system，etc，and summarize the achievements and experience of Germany’s green shipping and green port development. Based on comprehensive consideration of the development status of our inland river shipping，the enlightenments for the development of inland river shipping in China are proposed. These enlightenments include：learning from Germany’s experience in the circulation of trunks and branches，and the construction of communication between water systems；creating a smooth and interconnected information system and improving the coordinated application level of information；developing the rail-water inter-model transportation and improving comprehensive transportation service capabilities，promoting the concept of green ecology and intensifying the research and application of green shipping technology and so on.

Abstract:While traditional dike projects exert social and economic benefits，they also have some impact on the original ecological system. With the development of society and economy，the awareness of ecological environment protection has been gradually strengthened during the construction of dike projects. Hollow hump ecological slope protection is a new type of slope protection structure proposed for the needs of ecological dike construction and has good wave-eliminating performance and ecological effects. This paper uses wave section physical model tests to research the design method of hollow hump ecological slope protection. The research result shows that：1）Under the action of regular waves or irregular waves，the thickness D required for the slope protection to meet its stability is related to the breaking parameter ξp of the incident wave. 2）The value of D/H increases linearly with the increase of ξ0.5p，and calculation formula of the stable thickness of the hollow hump ecological slope protection is proposed. This structure has been applied in the channel regulation project in Chaohu Lake of the Yangtze-to-Huaihe Water Diversion.

Abstract:There has been no effective method to monitor the slope instability and collapse of the muddy submarine channels so far. To predict and warn the instability and collapse of muddy submarine channel slope，the four features extracted by gray level co-occurrence matrix are used as recognition features，and the distance similarity is used for voiceprint feature matching，a voiceprint recognition system is designed and completed for the detection of instability and slumping of channel slopes. After inputting the sub-bottom profile images of the side slope of the channel to be detected into the system，it can quickly locate and display the image similar to the slope instability and collapse image. The test results show that the system has a high recognition rate，which is helpful for channel management and engineering technical personnel to detect the stability of channel slopes.

Abstract:Aiming at the energy dissipation problem of the single open ditch of the ship lock bottom long-culvert，we combine with the Shanxiu second lock in Zuojiang River in Guangxi province，establish the three-dimensional turbulent mathematical model of the filling and emptying system with side branch hole in the ship lock bottom long-culvert，carry out the three-dimensional simulation for the filling operation period of the chamber，and compare and analyze the internal flow field distribution，velocity distribution uniformity，residual specific flow energy and other parameters of the original design scheme and three optimization schemes. The results show that the energy dissipation performance of the system is significantly enhanced by laying a longitudinal sill for the open ditch. The values of the corresponding flow velocity distribution and specific residual flow energy of the optimization schemes increase slightly beyond a critical value （1.2 m） of the height. The results can indicate that the space for enhancing energy dissipation is limited after the height reaches 1.2 m.

Abstract:Underwater reef blasting，as an important link in waterway construction，expansion，and dredging engineering，is also the main factor affecting the efficiency and safety of the whole project. To analyze the influence of blasting effect factors on the safety discrimination，we carry out the study on the field monitoring，adopt double factors of velocity-frequency and blasting vibration speed-frequency-duration of blasting with triple factors in research methods to compare and analyze the results of the field monitoring and obtain the fitting formula and the corresponding fitting accuracy. The results show that the formula of triple factors has a higher fitting precision. The duration of blasting should be considered as the important effect factor when underwater blasting induces vibration. Formula （5） is the optimal criterion method suitable for the safety of underwater blasting engineering.

Abstract:The structure of water flow around the submerged dike with variable slope is complex and changeable. Based on the Hechangzhou submersible dike project，this paper analyzes the reasons of topographic scour and soft bank damage for the submersible dike. Based on data collection and model analysis，this paper summarizes the correlation between the elevation of the dike top and water level and flood season at the scour site，and analyzes the hydrodynamic characteristics. The following influential factors are obtained：strong combined flow over the dike and around the dike，large flow and rapid retreat of the Yangtze River，and poor stability of the riverbed of the binary soil layer structure. The scour development can be restrained by using the sandbag and stone.

Abstract:A large number of existing bridges have insufficient navigation clearance in China’s high-grade inland waterways. How to scientifically and rationally determine the standard of step-by-step reconstruction is a universal and key technical problem to be solved urgently in the construction of the high-grade waterway. Taking the Beijiang and Dongjiang waterway in Guangdong province as examples，we analyze the clearance dimension of the existing bridges in the study area. Combining with the prediction of representative ship types，we put forward the requirement of bridge clearance dimension for ship navigation and analyze the adaptability of the flood standard of the designed maximum navigable water level. It is recommended that the clearance dimension of the bridge should meet the requirements of 8.3 m clear height （ the flood recurrence period of the design maximum navigable water level is 2 years），and 86 m clear width of two-way navigation with single holes，or 44 m clear width of one-way navigation with double holes in the Beijiang and Dongjiang kiloton waterway projects. On this basis，taking into account the experience of other waterway constructions，suggestions are put forward to adapt to the reconstruction standard of the kiloton mountain waterway bridge. The conclusion may serve as a reference for the construction of the high-grade inland waterway.

Abstract:To design a more reasonable layout scheme of ship lock，we carry out the experimental research on the navigation safety of the original design scheme and the modified scheme of the first ship lock of the Jinweizhou hub expansion project in Xiangjiang River.Based on the hydraulic model test，we apply the small-scale ship model technology to observe and analyze navigation parameters，such as rudder angle and speed. The results show that the modified scheme layout is more reasonable than the original design scheme layout，and the navigable flow conditions are optimized. When Q≤5，210 m3/s，the navigation parameters of the upstream and downstream channel of the first ship lock do not exceed the corresponding limits，which can generally meet the navigation requirements of 1，000 t self-propelled vessel （still water speed：18 km/h）. From the comprehensive analysis of the study results，we suggest that the maximum restricted navigable flow of the first ship lock should be 5，210 m3/s.

Abstract:In view of the increasingly prominent contradiction between navigation demand and deep-water channel width resources brought by the increase of large-scale ships’ rendezvous demand in the Yangtze Estuary deep-water channel，we study the utilization standard of the natural water depth of the deep-water channel slope. Based on the principle of minimizing the impact on channel maintenance and utilizing the natural water depth，we propose the width，depth and，section of the slope’s natural water depth utilization by using the method of statistical analysis of the measured data and theoretical calculation. It provides a basis for relevant departments to carry out ship tests and research on support measures，and is fully applied to the overall scheme for the utilization of the slope’s natural water depth.

Abstract:The self-floating elevating navigation mark platform is a new type of water navigation mark platform device，and it can adapt to large water level changes through the sliding of the floating body on the guide column. The draft of the floating body platform is an important factor affecting the stability of the floating body. The relationship between the draft of the floating body and the center of mass and the center of buoyancy is derived by formulas.Through the hydraulic physical model test，the law of the stability change of the floating body caused by the changes of the draft is observed and analyzed，and the movement of the floating body is simulated by the finite element software. Finally，the response law between the draught of the navigation mark platform and the stability of the floating body is obtained.

Abstract:In view of the disadvantages of low efficiency，low precision，and difficulty in application of the 3D geological model in the port and waterway engineering design，we realize the quick establishment of geological layer model and 3D geological model according to the geological interpolation calculation by the secondary development of Civil 3D. We also realize the arbitrary cutting of the 3D geological model，the generation of the geological profile，and the application of the geological model in the calculation of pile foundation bearing capacity. The engineering practice verifies that this technical method is practical and feasible，which can provide reference for similar application of BIM technology in port and waterway projects.

Abstract:The vigorous development of BIM technology realizes the transition of engineering design from 2D drawing to 3D model，but there is a large amount of modeling work and the secondary development is a high threshold. Aiming at the problems of complex manual modeling and many repetitive components in the design modeling of water transportation engineering，we introduce Dynamo visual programming platform，apply the visual programming and parameterized modeling method，calculate the relative position relationship of model components by boundary conditions along the front of wharf and land terrain，use Dynamo node to call Revit family library to set up the model of wharf frontier frame and modify the model parameters，solve the problem of repeated work and error of 3D manual modeling，and improve the speed and precision of modeling. It provides references for the deep application of BIM technology in the 3D modeling of water transport engineering.

Abstract:In order to verify the application value of the Beidou satellite positioning system in water transportation engineering，and discuss the application prospect and development direction in the future，based on the application research status of Beidou satellite positioning system in the engineering field，we carry out a preliminary exploration on the application of Beidou satellite positioning system in water transportation engineering，including safety supervision of port personnel，safety supervision of vehicles，drivers and passengers in the port area. The characteristics of the application platform and method are summarized，and the improvement and development direction of the Beidou system in the future are prospected. The application shows that the Beidou positioning system has the advantages of safety and reliability，large coverage，and accuracy comparable to GPS，but there is still room for improvement in the application field，such as improving the positioning instability when the equipment is blocked，solving the cost problem of the equipment using short message communication in the open sea，and further expanding and improving the application scenarios.

Abstract:With the increasing attention of the country to environmental protection，the price of medium-coarse sand and other high-quality fillers have also risen rapidly，resulting in a large increase in the cost of many land backfill projects.Aiming at the problems of high price and shortage of medium-coarse sand in the land backfill project，we research the land backfill and reuse technology of engineering waste soil，and apply laboratory test and field test to analyze the engineering properties and environmental protection characteristics of engineering waste soil，so as the utilization effect of engineering waste soil after environmental protection landfill. The results show that it is feasible to replace medium-coarse sand with engineering waste soil for backfilling，which meets the requirements of environmental protection and has significant economic and social benefits.

Abstract:It is often necessary to excavate a deep foundation pit near the existing ship lock for the expansion of lock capacity，which may cause excessive additional displacement of the adjacent existing lock，and then affect the lock safety and normal operation. To study the multi-factor sensitivity of the newly built foundation pit to the adjacent ship lock，four main factors including the strut levels，the thickness of the diaphragm wall，the row spacing of diaphragm walls，and the distance between the excavation and the ship lock were selected to design 3 levels orthogonal test，based on which series of finite element models were established. The horizontal and vertical displacement of the ship lock was adopted as the evaluation indexes，and the above four factors were analyzed and ranked through range analysis. The results show that among the four factors，the distance between the foundation pit and the ship lock has the most significant influence，strut levels take second place，and the influence of diaphragm wall thickness and row spacing is relatively weak. The influence law of diaphragm wall row spacing on ship lock displacement is different from other factors. The trend of ship lock displacement changing with diaphragm wall row spacing is not monotonous，which is different from that of other factors，but there is an optimal value. Within the current factor level range，optimum results can be obtained when the row spacing of diaphragm walls takes the intermediate value of 15 m while the other three factors take the maximum values.

Abstract:Foundation stability calculation is an important step to ensure the safety of the structure connecting shore of the high piled wharf，and the choice of foundation stability calculation method is crucial. To solve this problem，we choose the Swedish slices method and composite sliding surface method for the comparison of resistance division coefficient calculation and propose a treatment scheme for weak interlayer. At the same time，based on the original design，the sensitivity analysis of the key parameters of the weak interlayers，such as cohesion，internal friction angle，and thickness，and the correlation analysis of the coefficient of frictional resistance，are combined with the two methods. The results show that two methods should be used for the foundation stability calculations；under the same rate of change，the influence of the internal friction angle resistance component coefficient is significantly higher than the influence of the cohesion force；the minimum values of the fractional coefficients calculated by the two methods are highly correlated. The conclusion can provide a reference for the foundation stability calculations under similar conditions.

Abstract:A good design of the pile layout of a high-piled pier can make the structure more economical and reasonable. However，the design process of pile layout usually needs a lot of manpower. In this paper，the optimization algorithm is integrated into the calculation and post-processing through the APDL command flow of Ansys software，to realize automatic optimization of pile layout under specific load conditions. The optimization process of genetic algorithm and the influence of optimization parameters on the optimization process are introduced by taking an example of optimization of pile layout，to get an optimized pile layout with small internal force value in very few time.

Abstract:Aiming at the problem of the construction and application of dredging equipment parameter standardization for trailing suction hopper dredger，based on the characteristics of dredging equipment and engineering experience，we use the method of comparison，induction，and standardization analysis，establish the standard of dredging equipment parameters for trailing suction hopper dredger. Combining with the actual construction case，we compare and analyze the actual measurement and theoretical calculation. The results show that the standardization of main dredging equipment parameters is very important for the control of dredging equipment characteristics and the improvement of dredging efficiency，which needs to be supplemented and improved continuously combining with engineering application to provide the references for dredging operation of trailing suction hopper dredger.

Abstract:The bank above water is usually high at low water level，and the force state of dragging the soft mattress with concrete interlock blocks to the riverbank of high elevation has not been studied. Aiming at this problem，the contact state between the soft mattress and the external environment is divided into three types by using the method of segmentation：clinging，hanging，and enwinding. The calculation formula of the static model in the clinging state，the calculation formula of the catenary model in the hanging state，and the calculation formula of the cambered surface friction model in the enwinding state are derived. The maximum dragging force of the soft mattress is analyzed and calculated，and the calculation method is obtained. The method can be applied in the analysis of soft mattresses in similar conditions for project design and equipment selection.

Abstract:The non-invasive and visual characteristics of electrical resistance tomography （ERT） technology have unique advantages in pipe slurry concentration detection. As the core of ERT technology，the choice of imaging algorithm has a great impact on the detection level. LBP algorithm，Newton-Raphson iterative algorithm，and Landweber iterative algorithm are used to inversely image the three pipe slurry flow regimes，and the applicability of the three algorithms is quantitatively evaluated from three indicators including the imaging accuracy，imaging speed and anti-noise ability. The calculation results show that the LBP algorithm has the fastest imaging speed and the strongest anti-noise ability；the Newton-Raphson algorithm has the highest imaging accuracy. The real-time imaging requirements determine which algorithm shall be chosen.

Abstract:In view of the severe wear of the cutter teeth in the dredging project of the cutter suction dredger，the carbide material of reamer teeth is heat-treated，and the test of cutter teeth wear is carried out on the “Tianfeng”cutter suction dredger in Rizhao Port. The test soil is clay mixed with coarse sand，and the arrangement is 3 active cutter teeth and 3 new cutter teeth. Two indicators，the wear length and wear weight are used to determine the wear resistance of the cutter teeth，and a comprehensive cost-performance model for the wear resistance of the cutter teeth considering price factors is proposed. The test results show that the wear resistance of the new cutter teeth is about 87% of that of the original teeth under this soil.