Abstract:Based on the bathymetric and topographic data of five years from 1960 to 2021 in the Dayushan Sea area of Zhoushan，we discuss the influence of the Dayushan reclamation project on the changes of surrounding seabed erosion and siltation.We adopt the digital quantitative erosion and siltation calculation and the method of characteristic isobath superposition based on GIS technology to study the changes in surface erosion and siltation and surface morphology of typical underwater terrains near the project.The results show that the whole study area is in a slight erosion state in natural conditions.After reclamation，the south trough silts near shore，while the outer and northern deep troughs continue to erode，and the shoals on the east and west show significant siltation.The Dayushan reclamation project has greatly changed the original shoreline distribution and the surrounding hydrodynamic sediment environment.This eventually leads to sea-bed erosion and siltation changes near the reclamation area，but the seabed tidal flat distribution is unchanged.

Abstract:Based on field data in half a month during flood and dry seasons by four observation stations deployed in the inner Lingdingyang bay，the temporal and spatial variation characteristics of residual currents and net flux are analyzed，and the action laws of the main dynamic factors are discussed.The study shows that depth-averaged residual velocities in half a month are less than 10 cm/s during flood season and 5 cm/s during dry season with directions generally pointed the offshore.Net flux in the bay head waters is transported from west to east in both flood and dry season，and is strongly positively correlated with runoff dynamics.After receiving the water and sand from the shoals on the east and west sides of the main trough，the water and sand are always transported to the southwest sea.However，the directions of net flux transportation would change from pointing offshore during flood season to upstream during dry season，and both are positively correlated with the runoff dynamics.The north waters of Qi′ao island in the west beach would be in a siltation state all along for continuous input of net flux in both flood and dry season.The multiple linear regression method is used to fit water surface residual currents and main dynamic factors in the main channel waters.The results show that water and sediment in surface layers would be drove to move upstream by tidal power，and downstream during flood season and upstream during dry season by runoff power，while wind power drive surface water and sand to keep consistent with its own direction.The constants in the fitting formula reflect the southwestward transportation law of surface water and sediment in the inner Lingdingyang bay under the comprehensive action of geostrophic Coriolis force and so on with more obvious in dry season.

Abstract:Pinglu Canal connects Beibu Gulf Port outward and the Pearl River inward，which is a new waterway that connects the sea and the river.The construction of Pinglu Canal will have a profound impact on the transportation pattern of access to the sea in southwest China.This paper comprehensively analyzes the overall pattern of the current freight transportation corridors to the sea in Southwest China.Then，the comprehensive transportation cost comparison between Pinglu Canal-Beibu Gulf Port river-sea combined transport corridor and the existing southeastward，eastward and southward corridors to the sea is made.It is proposed that Pinglu Canal will mainly have impact on Guangxi，Yunnan and Guizhou Province and affect Chongqing and Sichuan Province indirectly.The construction of Pinglu Canal will bring about the optimization of the freight transport mode and the flow direction to the sea in the southwest China，increase the proportion of southward corridor and enhance the comprehensive competitiveness of the port group around Beibu Gulf.The results can provide decision-making reference for the southwest region to improve the logistics system in advance around the construction of Pinglu Canal

Abstract:In this study，the transmission coefficient of a new type of pile-supported permeable breakwater is analyzed by a sectional method.The transmission coefficient of the whole breakwater can be expressed by multiplying the calculation results of the following three parts，including the upper retaining wall and the porous plates，the horizontal platform，and the piles.At the same time，this study establishes the wave numerical flume using the FLOW-3D software.The analytical results are compared with the numerical results，which have good agreement.In addition，this paper also carries out the expand analysis of the influence of the porosity and the length of the horizontal platform on the transmission coefficient by using the proposed calculation method.The results show that the transmission coefficient is apparently influenced by the increasing length of the horizontal platform，and the effect of porosity ε changes not obviously when ε＞20%.

Abstract:After the sand pillow is thrown from the water surface，it will have a drift distance in the direction of the water flow during the sinking process under the action of gravity and water flow.The sand pillow will still have a certain speed after falling into the river bottom，if the speed is greater than the stopping velocity of the sand pillow，the sand pillow will continue to move，and the movement distance after the sand pillow touching the bed surface is a stable displacement (secondary drift distance).According to the drift rule of sand pillow in dynamic water，combined with the vertical velocity distribution rule，the drift distance calculation formula of sand pillow in the whole process from underwater drift to landing stability is obtained through three drift distance calculation methods，and the comparative analysis is carried out.The results show that when the vertical velocity of the river is exponential velocity distribution，the drift distance formulas derived by using the inertial force method and the comprehensive coefficient method have good applicability.

Abstract:Under a certain condition where in the incident angle of waves is smaller than a critical angle，there appears a stem wave propagation along the wall.There are few researches on stem waves and they remain in the theoretical research stage at present.Based on the physical model test results of vertical breakwater typhoon damage restimulations and combined with existing domestic and foreign research results，the generation，characteristic and engineering impact of stem waves are analyzed initially.The results show that：1) The wave height and width of stem waves increase gradually along the wall，and the wave-height ratio increases fast and then slower.2) Different incident wave heights and directions have great impact on stem wave characteristics，and detailed rules need further study.3) Serpentine damage to vertical breakwater or damage to sloping breakwater that connected with vertical breakwater could be caused by stem waves.Similar arrangement should be avoided in project planning and design，and three-dimensional physical model tests should be used to verify the structure safety under stem waves.Related items for stem waves are not included in present specifications，and the research results can be used as reference for engineering design.

Abstract:The breakwater has poor protection against long-period waves，which can easily invade the harbor directly and worsen the operating conditions in the harbor.This paper relies on the physical model test results and the BW numerical model to study the generation mechanism of long-period waves in the harbor pool under the action of two-color waves.The BW numerical model is verified，and the model agrees well with the test results.Under the action of two-color waves with frequencies f1 and f2 respectively，nonlinear interactions occur between waves to produce waves with frequencies such as Δf，2f1-f2，2f2-f1，2f1，f1+f2，and 2f2.When the wave frequency Δf equals to the harbour natural frequency，the wave height of such wave frequency will amplify.The nonlinear interaction of waves is positively associated with the increment of wave height and tenability，which results in the increase of long-period wave height.

Abstract:According to the deficiency of wide support calculation methods for crane girder of big pile cap in Design and Construction Code for Open Type Wharf on Piles (JTS 167-1—2018)，this paper puts forward a calculation model of the continuous beam with wide supports considering rotational restraint and derives a formula for rotational stiffness coefficient of wide supports.It programs the finite element program of the model by using Fortran language，establishes the space finite element model of the longitudinal bent through ANSYS software for comparative analysis，and obtains the internal force of the continuous beam under different calculation models.The calculation results show that under the condition of uniformly distributed load，ignoring rotational restraint to a continuous beam with wide supports will produce larger errors in the maximum positive moment，and the maximum positive moment obtained by the model of the continuous beam with wide supports considering rotational restraint agrees well with the space model.The maximum negative moments calculated by the method in the code and the proposed model in this paper both have a larger difference from the space model.Therefore，this paper analyzes the reasons and puts forward suggestions for improvement，so as to provide a reference for similar wharf structure design.

Abstract:In the current Chinese code，design methods are lacking in spring anchorage structures for marinas.We briefly introduce the style and principle of the spring anchorage structures and analyze their advantages and disadvantages.Based on the operating requirements of marinas，we propose a layout pattern of spring anchorage systems and raise the requirements for spring length calculation.Due to the complex structural calculation of the systems，it is difficult to simplify the calculation into a two-dimensional problem and draw conclusions by hand calculation.The 3D finite element method is appropriate.A simplified calculation method is proposed，which can realize the self-balance of vertical load calculation for spring anchorage systems.

Abstract:The service level and efficiency requirements of modern coal cargo terminals for overall port scheduling are constantly improving.The unloading solution of the coal cargo yard in Huanghua Port has problems of long manual decision-making time，operation conflict，and long train time in port.Therefore，this paper studies the automatic decision-making method for unloading in the coal cargo yard in Huanghua Port.Considering the characteristics of equipment flow uniqueness and train splitting，the paper proposes an innovative solution with a neighborhood searching strategy to minimize the train waiting time，maximize the matching score，and improve the searching efficiency of the algorithm.The results show that the innovative solution can make decisions within one minute and performs better than manual decision-making.

Abstract:To calculate the designed depth of large open harbor basin and channel waters，this paper takes a project in Ningbo as an example and analyzes the ridable tide duration acquired according to the influence of tidal level and current relationship and berthing and unberthing time.The paper calculates the designed depth using the specification formula and applies the safe surplus water depth stipulated by navigation practice to supplement the analysis rationality.The paper suggests that the ridable tide duration of large open harbor basin and channel waters can be determined according to the tidal level and current relationship，berthing and unberthing time，navigation requirements，and navigation organization scheme of the local marine area.The research method can provide ideas for similar port designs.

Abstract:The nature and concentration of sewage produced are different according to different cargo types in the cargo terminal.The sewage produced by bagged cargo terminals and storage yards is mainly initial rainwater，while that produced by unpacked cargo storage yards such as wood and stone is mainly runoff rainwater.The initial rainwater and the later clean rainwater can be divided by electric gate or natural switching.This paper collects the initial rainwater in the initial rainwater tank and discharges the later clean rainwater into the rainwater system.The runoff rainwater sewage is collected in a regulating sedimentation tank.According to the nature of sewage，the initial rainwater and runoff rainwater sewage should be treated by air flotation and coagulant sedimentation respectively.If there are reuse requirements，the treatment process of filtration and disinfection shall be added.

Abstract:After adjustment of the sea use policy，the traditional contiguous scheme with caisson structure + rear backfilling/dredger filling makes it difficult to obtain approval for sea use.Combined with engineering examples，through the comparison of theoretical calculation and physical model test，this paper optimizes the structure force，structure，and construction and proposes the caisson pier + composite slab structure scheme，which has the characteristics of shallow bedrock surface，high wave，and large load.The scheme has been successfully applied in Lanshan Port Area of Rizhao Port.The operation of the wharf is in good condition，and good economic benefits have been achieved，which provides a reference for the design and construction of the wharf under similar conditions.

Abstract:The existing ecological revetment focuses mainly on stability and less on ecology.To improve the ecology of the bank slope，we propose a ring interlocking ecological revetment structure.To investigate the stability and protective effect of this structure at the initial construction stage (without vegetation)，we compare the bank slope stability under different protective measures and study the effect of flow velocity on the stability and protective effect of the revetment structure by dynamic bed experiments.The results are as follows.1) The proposed structure can reduce the scour area and depth of the bank slope and enhance the stability of the bank slope.2）There are two instability forms，including slump instability due to slope footing deformation and sag instability due to bank slope hollowing.3) The scour area and maximum scour depth increase with rising flow velocity，and their growth rate decreases with increasing flow velocity.

Abstract:Pinglu Canal is a new inland waterway channel from scratch，and the traditional inland waterway project freight volume prediction method is difficult to apply.Based on the perspective of building comprehensive transport network，we analyze the position of Pinglu Canal in the regional comprehensive transportation system，construct a method system suitable for forecasting the freight volume of new inland waterway transportation channel considering both diversion and inducement freight demand，and analyze the freight volume of Pinglu Canal.It is predicted that in 2035 and 2050，the freight volume of the Pinglu Canal will be 95.5 million tons and 120 million tons respectively，mainly from the traffic transfer of the three existing channels of the Beibu Gulf Port Group's sea-rail intermodal transportation，Beibu Gulf Port's sea-highway intermodal transportation，and the Pearl River Delta Port Group to Xijiang main river river-ocean combined transportation.In the long term，considering the development of the Pinglu Canal Economic Belt and the land cities within the impacted region，it is expected that under the optimistic scenario，the freight volume will reach 150 million tons to 180 million tons by 2050.

Abstract:To explore the water depth resources of the channel in Chenglingji to Wuhan reach，the study section is divided according to the river phase relationship parameters of each channel.The maximum stable channel depths of the channels in different sections are calculated by the stable channel depth estimation method to determine the maximum water depth of the channel in the study section.The results show that the study section is based on the change rule of the river phase relationship parameters of the channel，it can be divided into three sections from upstream to downstream，such as Xianfeng waterway to Xindi waterway，Shitouguan waterway to Paizhou waterway，and Shuihongkou waterway to Baishazhou waterway.The maximum stable water depths of the channels under 98% design navigation guarantee rate and 200 m navigation width of the three sections are 6.133 m，11.268 m and 6.433 m respectively from upstream to downstream，so the maximum stable channel depth of Chenglingji to Wuhan reach under 200m planned channel width is 6.1m.

Abstract:A physical model of Xingzi-Hushan section of the North Lake of Poyang Lake is established，to study whether the navigable flow condition of Poyang Lake Water Control Project meets the navigable safety，including the experimental study on navigable flow condition of the current channel of the first stage cofferdam，the design channel of the second stage cofferdam and the operation period of Poyang Lake water control project under different conditions.Firstly，physical model tests are conducted to verify whether there are bad flow patterns in the channel.Secondly，the corresponding optimization measures are studied for the bad flow patterns.Finally，the navigable flow condition in the optimized channel is tested to ensure the safe navigation.The conclusions are as follows：The navigable flow condition of the design channel of the second cofferdam and the the operation period has some problems under the condition of large flow rate，such as the transverse velocity of the upstream entrance area exceeds the limit and large scale backflow is generated in the downstream anchorage.The flow conditions of the designed channel can meet the navigation safety requirements under all conditions by adjusting the form of upstream separation levee，excavating the shoal on the right side of the channel，and moving down the downstream anchorage，etc.

Abstract:Hunan Lishui Wushenggong beach is located in the 53 km channel of Songhu route，which is an important part of the waterway transportation system of Hunan province，and the waterway is rerouted improve its navigation standards and improve its shipping value.The paper focuses on the comprehensive analysis of the evolution trend and navigation characteristics of the study river section，and proposes the diversion scheme of Lishui Wushenggong beach waterway.After the implementation of the channel diversion，the paper studies the changes of navigation conditions of the river section，the changes of relevant parameters under different flow conditions and the lowest navigable water level，analyses the stability of the excavated channel by numerical simulation model test.The model test results show that after the implementation of the scheme，the water flow conditions and channel stability of the excavation area of Lishui Wushenggong beach meet the needs，and it is technically feasible to study the channel diversion of the river section，which can provide a reliably theoretical basis for the treatment of similar dangerous beaches.

Abstract:The general layout of the new Jianghaihe ship lock is restricted by external construction conditions.To this end，we summarize the general layout principles of ship lock.Meanwhile，we study various factors such as the construction conditions around the lock site，river channel conditions，ship navigation conditions，influence on the external environment，construction conditions，and project investment.In addition，we adopt the method of combining quantitative and qualitative analysis.As a result，the optimal lock site scheme is obtained.We also obtain the optimized layout scheme by analyzing the maximum navigable diversion flow and annual operating hours of the ship lock in the upstream entrance area and adopting methods to reduce the maximum navigation flow and sacrifice a small amount of navigation time.The results show that the general layout of ship lock should be determined by comprehensive comparison and analysis in combination with various factors.The layout can be optimized by reducing the maximum navigable flow to provide references for similar projects.

Abstract:Since the 175m experimental impoundment of the Three Gorges Reservoir，the problem of pebble and gravel siltation has continued to exist in the local key obstruction shoal in the upper section of fluctuating backwater area under new water and sediment conditions，which has adversely affected the channel conditions of backwater surface profile and there are certain hidden dangers in the safety of ship navigation.Since the catastrophic flood season in 2020，the shallow moraine in Yudong waterway(Zhongdui/Diaoyuzui)in the upper section of fluctuating backwater area has been silting up year by year.Based on the background of the key beach hazards in this section，this paper analyzes the characteristics of scouring and silting in key obstruction shoals and the causes of navigation obstruction，puts forward targeted maintenance and dredging schemes，and analyzes the dredging effect.From the perspective of the effect of maintenance dredging after completion and the channel conditions of the river section，the channel width，water depth and bending radius of the key obstruction shoal in Yudong waterway (Zhongdui/Diaoyuzui) have been improved，and the channel conditions have improved significantly.

Abstract:In the long river section between the two dams of Shihutang junction and Xiajiang junction in Ganjiang River，due to the protection of the reservoir area of Xiajiang junction，the actual operating water level on the dam of the junction is far lower than the designed operating water level in recent years，resulting in the overall reduction of the water level in the river section between the two dams and leading to many problems，such as the failure of normal use of most wading projects between the two dams due to the deviation of the designed water level selection at the design stage.Using the one-dimensional numerical simulation method of the long river section，this paper calculates the river water surface profile under the combination of the multi-level characteristic flow in the flood and dry season and the actual operating water level in front of the dam corresponding to Xiajiang junction according to the actual operation scheme of Xiajiang junction.Then，it calculates and analyzes the water level along the river section between the two dams and the channel gradient and selects the upper and lower envelope lines of each group of backwater curves as the reference water level for the design of the river section at this stage.The research results of this project can provide hydrological characteristics reference data for the design of wading projects in the studied river section.

Abstract:The Datengxia Water Conservancy Project has a large amount of construction with long period.It's necessary to take measures to guarantee the safety of channel navigation during the construction period of the hub.This paper establishes a physical model for the the layout plan of the first phase construction diversion cofferdam，and studies the water flow conditions and potential safety hazards of the open channel navigation under the engineering measures.The results show that the upstream head of the longitudinal cofferdam causes the slow flow area in the waist of the structure，and the open channel water body is narrow，which is not conducive to the navigation of ships during the construction period.After excavating the protruding part of the bottom of the main channel channel and adding a diversion structure at the front of the structure，the water flow in the open channel has been significantly improved.The velocity values of each measuring point are less than 5.00 m/s under the condition of maximum navigable flow rate.When the discharge flow rate is less than 12 000 m3/s，the velocity values of each measuring point are less than 3.00 m/s，which meets the requirements of self-navigation.The water surface along the diversion open channel with low gradient，and the maximum is -1.9‰.

Abstract:To study the contact stress distribution and contact surface abrasion of the pillow block for the miter gate，we build the calculation model of the contact stress and contact surface of the pillow block based on the empirical formula and the general formula of Archard abrasion calculation，taking the two-dimensional model of the pillow block as the research object.Then we obtain the magnitude and distribution of contact stress of the pillow block under different support reaction forces of main beams，and the change distribution of contact surface abrasion under different rotational speeds and interference conditions.The results show that the contact stress of the pillow block is approximately symmetrically distributed on both sides of the initial line contact position，and increases with the rising support reaction force of the main beam.The stress of the miter gate is mainly concentrated on the axis of the main beam and decreases sharply among the beams.The abrasion amount of the contact surface rises with the increase in the rotational speed of the gate and the fit interference of the pillow block，and the maximum abrasion depth shifts to the downstream side.

Abstract:The current JTS 144-1—2010 Port Engineering Load Code puts forward the calculation formula for the ultimate extrusion ice force of sea ice and river ice，but there is no calculation formula for large freshwater lake area in the code.Based on practical projects，this paper makes a comparative analysis of the calculation formulas of the ultimate extrusion ice force in relevant domestic industry codes，and combines with numerical model experiments to conclude that the ultimate extrusion ice force calculated by using the river ice formula of Port Engineering Load Code is small，but by the sea ice formula is large.According to the current JTG D60—2015 General Code for Design of Highway Bridges and Culverts，the ultimate extrusion ice force is basically consistent with the simulated value of the mathematical model.Therefore，the calculation formula in General Code for Design of Highway Bridges and Culverts can be referred to for the calculation of the ultimate extrusion ice force in large freshwater lakes.This study provides a basis for the calculation of the limit ice extrusion force in large freshwater lakes，and provides a reference for the revision of specifications.

Abstract:Linhuan ship lock is located in the south of Linhuan control lock，about 30.0 km away from Likouji，the provincial boundary，and 31.5 km away from Nanping lock.The connecting section of the downstream approach channel is located in the turning river section，with a turning angle of about 75°.Affected by the terrain，the main stream of the river flows into the downstream main channel close to the convex nozzle on the right bank，resulting in counterclockwise reflux between the connecting section of the approach channel and the concave bank.This exerts a compressive effect on the approach channel flow，with significantly narrowed width of the local mainstream.The physical model test shows that the mainstream of the river forms an obvious shear to the flow in the entrance area of the approach channel，resulting in a large reflux range in the entrance area with a length of nearly 350 m.As a result，multiple complex reverse reflux combined flow patterns are formed，and the flow conditions are very complex.Therefore，corresponding engineering measures should be put forward for improvement.By dredging the channel and increasing the separation submerged dike，we solve the poor flow pattern in the downstream approach channel，large cross-flow velocity exceeding the standard，large reflux intensity in the entrance area，and inability to meet the specification requirements.

Abstract:Tianxingzhou is a central bar of the lower reaches of the Yangtze River.The piers on the north side of the proposed Changtai Yangtze River Bridge are arranged adjacent to the tail of Tianxingzhou.We carry out physical model tests to study the influence of Changtai Yangtze River Bridge construction on Tianxingzhou tail evolution.The results show that after the construction of Changtai Yangtze River Bridge，the scouring range of Tianxingzhou tail is increased compared with that before the project.This is not conducive to the stability of Tianxingzhou slot，so it is necessary to protect the beach at Tianxingzhou tail.Compared with the beach protection scheme with higher submerged dike elevation，the low submerged dike scheme causes a slightly smaller increase (within 0.03 m/s) in velocity near the Tianxingzhou tail and a slightly smaller decrease (within 0.02 m/s) in velocity in the Tianxingzhou slot，which is more conducive to the stability of Tianxingzhou tail and the water depth maintenance of the temporary channel of Qiwei.The implementation of the project can protect Tianxingzhou tail，and there is slight scouring near the downstream of the bridge site of the temporary channel of Qiwei，which is conducive to the maintenance of the water depth of the channel.

Abstract:In view of the fact that there are few network RTK tests under different satellite combinations in the canyon reach，this paper tests the positioning performance and accuracy of the mobile station under the BDS/GPS/GLONASS combination between the Three Gorges Dam and the Gezhouba Dam.Six observation modes are adopted to test positioning service timeliness，spatial availability and positioning accuracy.The results show that the BDS network RTK of domestic GNSS equipment meets the specification requirements，the fixed solution ratio is 98.1%，and the positioning accuracy of 0.02 m level and 0.05 m elevation can be achieved，which are better than GPS to a certain extent.BDS and BDS/GLONASS dual-system network RTK can still provide high-precision positioning services when GPS signals are missing or not used.Combined positioning can make up for the shortcomings of a single system，and the fusion system has different degrees of improvement compared with each single system.BDS/GPS/GLONASS and BDS/GPS are optimal in terms of positioning service timeliness，spatial availability test and positioning accuracy.

Abstract:To further develop the navigation aid deployment plan and navigation route and method for key sections of the downstream of the Yangtze River，and improve the navigation environment，we explore a method to optimize the virtual navigation aid deployment by automatic identification system (AIS) based on big data analysis，and take the port side channel，deep-water composite channel and “last kilometer” channel from main channel to port as examples to conduct application analysis.The results show that based on the electronic nautical chart，the methods of ship trajectory playback，collision risk analysis，ship trajectory line analysis，channel gate line analysis and distance analysis between ship and buoy for ship traffic flow can effectively find the weak position of the navigation aid deployment scheme by visual means，and provide strong data support for the deployment and optimization of the virtual navigation aid by AIS.

Abstract:Aiming at the shortage of 3D visualization technology of ice flow evolution in the visual simulation of frozen rivers，we propose a visualization method based on the numerical simulation results of ice flow evolution by combining with MIKE21 and ArcGIS software.Meanwhile，we conduct numerical simulation and analysis of the ice flow evolution by model building，grid division，and boundary condition determination.Then we propose an extraction method of numerical simulation results for the visualization of the ice flow evolution，which can realize the fusion of the 3D visualization simulation scene and numerical simulation results of the ice flow evolution.The built simulation system of the flow evolution based on the spatial database and the attribute database can comprehensively display the simulation results such as the terrain，water flow，and embankment structure during the ice flow evolution.

Abstract:Compared with conventional dredging projects，ecological dredging construction has the requirements of high dredging accuracy，less sediment disturbance，and high excavation concentration.For this production demand，this paper develops an environmentally friendly spiral dredging tool.The theoretical excavation concentration of the dredging tool is more than 60%，which meets the construction requirements.According to the design requirements，the strength and stiffness of the key structures of the dredging tool should meet all working conditions，but it cannot be directly verified by mathematical calculation.The paper uses the finite element method to analyze the complex structures and utilizes the overall modeling method to construct the simulation model.In addition，it analyzes forces by the enumeration method and simulates the stress and deformation of the dredging tool under different working conditions，so as to evaluate the strength and stiffness of the dredging tool.The results show that the strength and stiffness of each structure of the dredging tool meet the needs of the operation.At the same time，the paper finds that there is a displacement difference between the upper and the lower hinge point of the depth cylinder and the direction adjustment cylinder，and the deformation of the far-motor side and near-motor side of the spiral knife group shaft is different.Finally，the paper proposes that the hydraulic cylinder deformation compensation can be realized by designing universal joints to prevent the hydraulic cylinder structure from damage.

Abstract:The traditional leveling measurement has the problems in actual long-distance control measurement，such as time-consuming and labor-intensive，as well as being greatly affected by terrain.A feasibility study on the GNSS elevation measurement method to replace fourth order leveling measurement is carried out.Based on a canal project and the control network data built by GNSS elevation measurement method，the provincial high-precision quasi geoid elevation model is used to transform the normal height of the control points.The 1985 national elevation results of the control points are obtained to compare them with the third-party leveling results，and the results precision of GNSS elevation measurement method is evaluated.The results show that the GNSS height measurement method in this project can achieve the precision of third and fourth class leveling.Under the precision requirements of fourth class leveling，the GNSS results measurement method can be used to replace traditional leveling measurement.

Abstract:The engineering geological properties of the rock mass change greatly because of the neodiagenesis，diagenesis difference，lithology weakness，low modulus，low strength and low bearing capacity of the Tertiary mudstone strata，which are susceptible to environmental conditions especially after unloading or excavation exposure，and the index obtained by conventional rock test methods is often lower than the true value.In this paper，according to the rock mass loading test，borehole acoustic wave velocity test and side pressure test carried out on site in Guangxi shipping hub project，the allowable bearing capacity of the foundation of the Negene mudstone in Guangxi is studied.SPSS data analysis software is used to analyze the correlation between the allowable bearing capacity of the foundation，the longitudinal wave velocity of the borehole and the rock mass integrity coefficient，and finally the relevant formula is obtained.The allowable bearing capacity of Neogene mudstone foundation can be obtained indirectly through borehole acoustic wave velocity test.The research can provide reference for similar projects.

Abstract:Based on the peat soil treatment project of cement mixing piles in the inner yard of a wharf on the east coast of Malaysia，we carry out the indoor mixing ratio test of cement pile，the final hole parameter analysis of the test pile，and the engineering efficiency analysis of test pile.Meanwhile，we systematically study the strength change and treatment effect of cement mixing pile composite foundation under various mixing ratios.The results show that due to the different soil layer distribution and engineering properties of the two test pile sites，the 28-day core unconfined compressive strength (UCS) of test pile site 1 is generally high with large strength surplus under the ratios of 16%，18%，and 20%.At test pile point 2，the strength at 7-9 m is lower than that at other depths when 18%，20%，and 22% are adopted，and thus 18% cement content is recommended.The surface humic soil section adopts other strengthening measures or excavation and replacement processes to ensure the construction quality.Finally，the utilization of cement mixing piles to strengthen the peat soil can yield good results.

Abstract:Under complex conditions，such as limited transportation conditions，continuous navigation during construction，and high voltage line height limit，the new respiratory-type prefabricated ecological revetment structure construction faces technical difficulties in terms of component lifting and installation，pile sinking accuracy control，connection between piles and prefabricated bottom plate，and flatness of prefabricated bottom plate installation.This paper carries out a comparative analysis of various complex conditions and puts forward the technical measures such as the lifting process of a self-balance lifting vessel，the positioning frame process of pile planting，the pile driving process of the reserved steel bars at the pile top and steel sleeve，and the technology of the cushion construction，which can better solve the technical problems of this new structure during construction under complex conditions.

Abstract:To study the mechanism of the influence of the plastic concrete anti-seepage system on the seepage gradient of the anti-seepage wall in the earth-rock cofferdam construction of the ship lock with high head difference，including its seepage gradient，stress，strain，cofferdam filling materials，and permeability coefficient of the formation，this paper calculates and analyzes the stress and strain of the plastic concrete anti-seepage wall by finite element method in combination with the monitoring results of the earth-rock cofferdam applied in the Wan'an second-line ship lock project.The calculation analysis simulates the filling materials in different filling areas of the earth-rock cofferdam with different constitutive models.The results show that the plastic anti-seepage wall plays a good role in seepage prevention and pressure reduction，and its effect is related to the permeability coefficient of the cofferdam filling materials and the formation.The strain monitoring results show that the anti-seepage wall is mainly subjected to compressive stress at the working stage，and the compressive strain value is -247.8×10-6-0，which falls into the allowable strain range of -750×10-6-100×10-6，ensuring the safety and reliability of the anti-seepage wall during the working stage.