Abstract:The determination of the layout plan for the hub cascade is an important prerequisite for cross water system connectivity development projects.By conducting a comprehensive comparison and selection of different cascade layout schemes for navigation hubs,taking into account factors such as navigation efficiency,water supply,irrigation,flood control,ecology,and land acquisition and resettlement,a differential economic analysis of engineering investment and operation costs is conducted to further improve the technical and economic efficiency of the project and the comprehensive utilization of water resources.The research case proposes a comparative method for the demonstration and selection of cascade layout schemes for water system connectivity engineering hubs mainly based on shipping,which can provide reference for similar projects.

Abstract:Curving cutoff is one of the important measures in the regulation of inland waterways.However,while it facilitates the navigation of ships,it also has a certain impact on the aquatic ecological environment of the original river channel and oxbow lake.This article focuses on the ecological impact and restoration issues of the curving cutoff project.By analyzing the quantity of the Pinglu curving cutoff project and combining existing research results,it is proposed that the curving cutoff project will cause damage to the biological habitats in the main river channel and oxbow lake,as well as varying degrees of population reduction.Restoration and mitigation measures for the ecological impact of the curving cutoff project are proposed from three aspects:formulating ecological protection plans,constructing biological habitats,and carrying out construction of river sections for breeding and releasing,the selection and construction methods of biological habitats are analyzed in detail.These measures can provide reference for the green and orderly development of the Pinglu Canal.

Abstract:To adapt to the development of marine engineering to deep water,a combination of tension mooring and combined stiffness mooring system is proposed and applied to floating breakwater.A numerical model of the floating breakwater with tensioned combined stiffness mooring is established based on the high-order boundary element method under the potential flow theory,and the accuracy of the numerical model is proved by comparing the bypassing wave force with the classical literature.Setting the incident wave as a second-order Stokes wave,the hydrodynamic characteristics of the floating breakwater under the influence of combined mooring stiffness and cable length factors are analyzed and the mooring tension safety factor is calculated.The results showed that the heave motion curves of the floating breakwater under each wave period exhibit obvious irregular phenomena,and the nonlinear influence of mooring geometry is significant.Different mooring stiffness schemes have different degrees of geometric nonlinearity and large differences in breakwater motion amplitude,and the statistics of breakwater motion displacements for different cable lengths are close to each other with similar motion characteristics.Finally,by comparing the safety factors of mooring tension,the parameters of the tensioned combined stiffness mooring system suitable for the designed wave conditions are derived.

Abstract:The arc plate permeable breakwater has gradually attracted attention and research due to its advantages of simple structure,low cost,short construction period and strong ability to adapt to the external environment.Opening on an arc plate permeable breakwater is beneficial to further improve its wave dissipation performance.The wave dissipation performance of an arc plate breakwater under different opening methods is studied through physical model tests.According to the opening position and opening shape,opening methods can be divided into circular openings on the wave-facing side,square openings on the wave-facing side,circular openings on the wave-back side,and square openings on the wave-back side.Physical model tests are carried out under different diving depths (-0.03 m,0 m,0.03 m),wave periods (1.2 s,1.4 s,1.6 s,1.8 s,2.0 s) and wave heights (0.06 m,0.10 m) to study the transmittance and reflection coefficients of arc plate permeable breakwaters with different opening methods,and to analyze their wave dissipation performance.The results show that when the submergence depth of the arc plate permeable breakwater is -0.03 m,the square hole is conducive to improving the wave dissipation performance of the arc plate permeable breakwater.When the submergence depth of the arc plate permeable breakwater is 0.03 m,compared with other opening methods,the square hole on the wave-facing side can significantly improve the wave dissipation performance of the arc plate permeable breakwater.

Abstract:Harbor oscillations is the most common form of wave disaster,which is very harmful.Accurate and efficient prediction of waves in the port is helpful to reduce economic losses and avoid casualties.The numerical simulation based on Boussinesq equation is an important method to study the harbor oscillation,and the calculation cost is high.To cope with the business oriented prediction of harbor oscillations,this paper proposes a parametric model of harbor oscillation and achieves rapid prediction of wave heights in the port,taking the Hambantota Port in Sri Lanka as an example.Based on the measured data of Hambantota port,the wave spectrum is divided into independent wave systems,each wave system is parameterized,the maximum difference selection algorithm (MDA) is used to select the calculation conditions,and the FUNWAVE-TVD numerical model is input to simulate the response of waves in the port under different incident wave parameter combinations,and the dataset is generated.The dataset is divided into generalization set and test set.The former is used to train and select the convolutional neural network (CNN),while the latter is utilized to measure the network performance on unknown cases.The output of the network is significant wave height and low-frequency wave height over the whole computing domain within the port.The results show that the model performs well on the test set and can accurately estimate the full-field wave height under unknown conditions.Then,the model is successfully verified according to the field measurement data,which proves the reliability of the wave numerical model and CNN.Once the wave parameters outside the port are obtained,the wave conditions inside the port can be quickly estimated.

Abstract:In the nearshore construction,the crane vessel and the transportation vessel are normally under the ship to ship condition with a T-shaped berthing during the lightering operation at sea.The vessel motion response under such condition is studied.Two common construction ships in the field of offshore wind power construction in China are selected,and the frequency domain analysis method is carried out to calculate significant valves of the transportation vessel motion response with the consideration of interactions between two ships.The results reveal that when the transportation vessel faces the waves,the transportation vessel motions are significantly greater than the its motions when the crane vessel faces the sea.However,the disturbance on the crane vessel by the transportation vessel is subtle.In the meanwhile,the clearance between the two ships are ignorable to the motion response of the transportation vessel.For the cargo with different lifting point heights,different wave-facing strategies can be applied when the crane vessel and the transportation vessel are under the ship to ship condition with a T-shape configuration during the lightering and linking operation.For the higher lifting point case,the relative motion between the hook and the lifting point can be effectively curtailed when the crane vessel faces waves.When the lifting point is located near the deck of the transportation vessel,the transportation vessel facing waves may be preferable for short period wave conditions,the transportation vessel is a floating breakwater for the crane vessel in such a condition,effectively curtailing wave energy transmitted to the crane and relative motions between the hook and the lifting point.

Abstract:Beam-slab pile-supported wharf is an important wharf structural type in China.The wharf is inclined to be unusable in wartime by enemy strikes.For the rapid restoration of wharf functions,we analyze possible air and underwater explosions during war and terrorist attacks,and summarize damage modes of surface layer,longitudinal and transverse beams and pile based on research results from home and abroad.Then we analyze the damage characteristics of pile-supported wharf under air and underwater explosions,and propose suggestions for emergency repair methods for typical damage forms of various parts of wharf considering existing emergency repair methods and engineering application cases.The results show that surface layer,longitudinal and transverse beams and pile have different damage modes subjected to air and underwater explosion.The local damage includes cracks,spalling,craters,break,deformation.The overall damage includes the topside and pile foundation of the wharf have penetration failure.For different damaged parts and damage degrees of wharf,existing engineering technologies can basically repair the local damage in surface layer,longitudinal and transverse beams and pile.Prefabricated components can improve construction efficiency.Emergency repair for pile under water is of high technical requirements in design and more difficulty in construction.Pile repair is a key factor which restricts the construction speed and quality.Considering complex damage conditions and working during wartime,existing repair techniques still need be verified by practice.

Abstract:With the development of the domestic shipping industry,a large number of high-pile wharf urgently require maintenance.Establishing a scientific and reasonable performance evaluation method for high-pile wharf components is the prerequisite for accurately determining their maintenance needs.In order to find a method that can comprehensively evaluate the maintenance requirements of high-pile wharf components in all aspects,this paper conducts an in-depth study on the service performance of high-pile wharf components.It proposes a performance indicator system for high-pile wharf components and uses an improved analytic hierarchy process (AHP) to determine the weights of each indicator.Based on the fuzziness and randomness in the performance evaluation of high-pile wharf components,a performance evaluation method based on a cloud model is established.This method is applied to a structural evaluation of a container terminal in Tianjin,using the evaluation results of panels from section 29 to section 30 to determine the service performance status and provide repair recommendations for the panel.This approach offers a basis for maintenance decision-making of high-pile wharf.

Abstract:With the advancement of China's “Belt and Road” initiative,the scale and number of ships and ports have been increasing,and the study of mooring stability conditions is becoming increasingly important.This paper analyzes the impact of mooring stability conditions on ship mooring systems based on ship simulation experiments.By establishing ship motion and environmental load models,the stress response of cables with different materials and diameters under complex environmental conditions is simulated,verifying the accuracy and feasibility of the ship handling simulator.The results show that the roll motion of the moored vessel is a key factor affecting the stress of the mooring line.Increasing the pre tension of the cable within a certain range or using cables with higher elongation can effectively reduce cable stress.Wave height significantly affect rope stress,especially when the coupled wave period is close to the ship's roll period.The research provides scientific basis for port design and ship mooring,and proposes suggestions for improving the stability of mooring systems.

Abstract:This paper conducts research on the optimization of the plane design of channels within the port area in response to the problem that there is no planned waiting anchorage or emergency anchorage in the coastal port area,and the current water area in the port is limited,making it difficult to separately arrange the emergency anchorage area for dangerous cargo vessels.Based on risk analysis,the requirements for emergency berthing and emergency evacuation of vessels,relevant regulations and the current conditions of the port water area,through site selection analysis,demonstration of different anchoring methods,and comparison and selection of several plane schemes,the rationality and feasibility of emergency berthing and evacuation of dangerous cargo vessels in the port area are studied.An optimization plane design scheme of the channel within the port area that meets the requirements of the regulations and is feasible,using the water area of the channel within the port as the emergency berthing area,is proposed.Through comprehensive analysis of actual cases,the optimized channel has a “general” navigation risk level.It meets the emergency berthing and evacuation requirements of the designed vessel type.The channel has good stability.It has a relatively small impact on the surrounding water area,and certain economic and social benefits.This provides certain reference value for the plane design and scale optimization of using the water area of the channels within the port area as the emergency berthing area.

Abstract:Aiming at the key joint connection problem between precast beam and pile foundation of fully prefabricated pile-supported wharf,we carry out a joint model test of the grouting connection method,and analyze and compare with the conventional cast-in-place joints to study the reliability of different connection methods.Relying on an actual project,we carry out the structural design of a fully prefabricated wharf,and at the same time,for the installation of large-volume prefabricated beam components on site,we adopt the corresponding design of supporting piles to meet construction requirements.The results show that the joint design scheme of fully prefabricated pile-supported wharf is safe and feasible.Under complex natural conditions,the overall safety of the fully prefabricated wharf can be ensured by adopting joint strengthening measures such as channel steel and corrugated pipe,as well as supporting piles during the construction process.

Abstract:In view of the problem that the old wharf can not meet the use demand,the upgrading technology of the old wharf is systematically analyzed and summarized.Taking a general wharf in Nantong as an example,this paper analyzes the characteristics of upgrading and reconstruction,and discusses the service life and function of the wharf after the reconstruction from the demonstration of the design scheme.Based on the analysis of the test results of the old wharf structure,the reconstruction scheme is determined on the premise of realizing the functional objectives,and the necessary technical demonstration is carried out from the aspects of structural safety,usability and durability.In addition,the key construction schemes for wharf reconstruction are summarized.The research results can provide reference for the upgrading of similar wharves.

Abstract:A numerical calculation method is studied to determine the environmental conditions for emergency anchorage design of liquefied natural gas terminals.The calculation methods for LNG carrier environmental loads and anchorage loads are systematically analyzed using relevant regulations in international standards.The external environmental loads of large LNG ships anchored in the anchorage are obtained under different levels of wind speed,wave height,and current speed combinations,as well as anchorage loads under different bottom environments.The main influencing factors for determining the environmental conditions of LNG emergency anchorage design and the limit environmental standards for emergency anchorage for large LNG ships under different bottom conditions are preliminarily determined.The important influence of ship anchor parameters,anchorage bottom,and water depth on the limit environmental standards for emergency anchorage is demonstrated,and the wind speed limit standard and recommended measures for LNG emergency anchorage are proposed.The research methods can be applied to the early site selection of LNG emergency anchorage,saving experimental research time and costs.

Abstract:In view of the problem that the protection standards of the existing breakwater can not meet the operational standards in the port after the changes in the functions of the port area,it is analyzed that the wave in harbor is mainly caused by the secondary wave overtopping of the breakwater,the incident wave from the entrance and its diffraction.Based on the verified hydrologic wave data,the structural stability of the original breakwater is checked,and the elevation of the top of the breast wall is checked,and the technical reconstruction measures such as increasing the elevation of the top of the breast wall and optimizing the layout of the breakwater are adopted to improve the berth conditions in the port and realize the improvement of the port functions.The top elevation of the breast wall is calculated according to the water level and wave climbing height,and determined synthetically according to the protection standard,reconstruction conditions and feasibility,while the optimal layout of the breakwater is adjusting the direction of the entrance and the length of the breakwater according to the hydrologic wave and water depth conditions at the entrance.After many times of comparison and demonstration,combined with the results of model test,this paper puts forward a more targeted technical transformation scheme,which has a certain reference significance for similar projects.

Abstract:Baoying junction is located at the end of the connecting section of the S-shaped bend in the upper reaches of the main stream of the Baihe River.The river section has the characteristics of small flow in non rainy season and sharp rise in rainstorm season.The upstream approach channel of the ship lock is affected by the topographic conditions of the bend and the river section,and the flow conditions in the entrance area are very disordered,which is difficult to meet the navigation requirements.In view of the complex flow regime in the upstream entrance area of the ship lock,combined with the characteristics of the dam site and the navigation requirements of the ship lock,this study conducts a numerical simulation of the overall flow conditions in the upstream channel of the junction.By analyzing the causes of the adverse flow conditions,this study proposes the treatment measures of “horn” inlet+permeable breakwater and carries out comparison and optimization.The results show that adjusting the shoreline shape and adding a suitable permeable breakwater project can significantly improve the complex flow regime in the entrance area and ensure the navigation safety of ships passing through the ship lock.The research results can provide technical reference for similar projects.

Abstract:To solve the problem of rapid growth of ship flow and insufficient channel capacity in Xiaomiaohong Channel,which is navigable by tidal channel in the radial sandbar sea area of northern Jiangsu province,and then the compound channel design is studied.Combined with the water depth conditions and the surrounding wading structures,it is determined that the section type of the compound channel adopts“the middle main channel and the small ship channel on both sides”.According to the prediction results of ship flow and the needs of maritime departments,the comprehensive comparison and recommendation of the construction scale,plane layout and navigation mark distribution schemes of multiple complex channels are carried out.The research results can provide scientific reference for the construction of radial sandbar sea area and other similar compound channels.

Abstract:Weishan three-line ship lock is the largest ship lock on the Beijing-Hangzhou Canal with an effective scale of 280 m×34 m×5.5 m (length×width×threshold depth) and a designed maximum water head of 4.0m.It is determined that the ship lock is adopt the form of end filling and emptying system according to the general layout of the ship lock and requirements of the code.On the basis of Weishan three-line ship lock project,a physical model test with geometric scale of 1:30 is established to study the hydraulic characteristics of the filling and emptying system.There are some bad hydraulic phenomena in the original scheme,such as the local formation of the funnel vortex,the uneven distribution of the flow velocity in the sluice chamber and the visible suction vortex in the intake of the drainage gallery.Some optimization measures are proposed to solve above problems,such as adding a permeable vortex eliminator at the water inlet,optimizing the arrangement of energy dissipation grid and adjusting the buried depth of drainage gallery.The results show that after optimizing the layout of the filling and emptying system,all hydraulic characteristics meet requirements of the code.

Abstract:To study the water and sediment characteristics of the completed Sheyang Port waterway,on-site hydrological tests are conducted.According to the hydrological test results,the flow velocity outside the entrance of the Sheyang Port waterway is greater than that inside the entrance.At the inner channel of the double guide embankment,the rapid flow velocity is higher in the surface layer and lower in the bottom layer,while the rapid flow velocity in the water layer is higher than that in the 0.4H-0.8H range.The surface layer is the smallest,and the residual flow direction in the middle and upper layers of water is falling tide,while the middle and lower layers of water is rising tide.The sediment concentration outside the entrance of the waterway is significantly higher than inside.In the channel,during the low tide period,the average sediment concentration of the upper and middle water bodies of the falling tide is greater than that of the rising tide,while the middle and lower water bodies of the rising tide is greater.and during the high tide period,the average sediment concentration of the falling tide is mostly greater than that of the rising tide.The single width sediment transport rate at both high and low tide levels in the channel is greater than that at low tide,and the net sediment transport is from the channel entrance towards the harbor.The net sediment transport rate during the low tide period is greater than that during the high tide period.It takes about 4.5 to 6.5 hours for the bottom water flow to move from the entrance of the waterway to the harbor.Within a tidal cycle,the sediment from the outer sea can be transported from the entrance of the waterway to the harbor,providing a source of sediment for the sedimentation of the waterway and harbor.

Abstract:With the continuous development of the water transportation industry,low-grade channels are gradually upgraded,and in recent years,large-scale ships has developed rapidly,and the main dimensions of actual navigable ships often exceed the channel design standards.The navigation clearance scale of some bridges is not compatible with the navigation standard of the upgraded channel.However,due to the limitation of engineering investment and other reasons,it is impossible to dismantle and rebuild in time,which has certain restrictions on the navigation of the channel.This article takes the Wuxuan Bridge as an example to analyze the navigation clearance scale of the bridge,the hydrological conditions of the river section where it is located,and the navigation ship type.Numerical simulation methods are used to simulate and analyze the navigation flow conditions and collision resistance performance of the bridge.From the perspective of navigable clear width,navigation clearance height,bridge anti-collision ability and meteorological factors ,etc.,the limiting conditions and safety guarantee measures for the safe passage of various types of ships through old bridges are proposed,which can provide reference for the navigation and management of similar old bridges.

Abstract:The implementation of bulk cargo transportation through ship-to-ship transfer system can effectively reduce the construction costs of ports and waterways.The operation of ship-to-ship transfer system is affected by factors such as the ability of transfer operations,channel conditions,number of transfer ships,navigation and avoidance of transfer ships.Therefore,the reasonable number of transfer ships cannot be determined only by the calculation of standardized formulas.Based on practical engineering cases,the production operation process of the transfer system is analyzed,a simulation model for the transfer system is established,its operation process is simulated,and sensitivity research on the configuration scale of transfer ships is conducted.The results show that as the number of transfer ships increases,the average waiting time per ship increases and the average operating time decreases.In addition,the minimum number of barge configurations for different periods is determined based on meeting the demand for transportation volume.The system simulation analysis method can provide certain support for the design and subsequent operation of the transshipment system.

Abstract:The construction of offshore artificial islands lacks high-precision geographical information spatio-temporal benchmarks and effective communication methods.At the same time,there are also issues such as overall settlement monitoring technology and a unified engineering application comprehensive management platform.In view of these problems,digital and intelligent technology for offshore construction of artificial islands is studied.Using BDS-based construction ship maritime positioning communication,digital construction machinery automatic control and BDS high-precision safety monitoring technology methods,the overall architecture and microservice functional architecture of the artificial island digital intelligent construction management platform are designed and developed.The platform is deployed and applied on-site in the Pasay Blow-Fill-Seal Project.The results show that the comprehensive utilization of BDS technology can realize the unified dispatching and command of ships,machinery,and personnel at the construction site,reliable communication guarantee,and artificial island safety monitoring services,and improves the work efficiency and digital intelligence level of artificial island construction.

Abstract:In view of problems of low efficiency,low level of intelligence,and relatively backward management and maintenance modes in the operation and maintenance of ship lock,we conduct research on key technologies for smart management and maintenance of ship lock,including building information modeling(BIM) data governance and integration,intelligent control of ship lock operation,real-time perception of ship lock health status,intelligent monitoring of channel siltation,and digital inspection of ship lock.We use internet of things(IoT),BIM,geographic information system(GIS),big data and other technologies to build a smart ship lock management and maintenance system,and apply it in Babao ship lock project in Hangzhou.The results show that compared with the traditional ship lock management and maintenance mode,key technologies of smart ship lock management and maintenance can effectively improve the level of ship lock operation and maintenance,increase the maintenance efficiency of ship lock facilities and equipment,and realize the digital management,visual display,and intelligent application of ship lock maintenance information.

Abstract:To the problem of BIM model can not be directly applied to the finite element structural analysis calculation,this paper carries out the research of extracting BIM model data and transforming it into finite element calculation model data.By formulating the modeling rules for BIM model of high-piled wharf and developing data interface software based on the specific structural calculation software,the extracted data from the BIM model is converted into the calculation data for the structural calculation software.The finite element structure calculation model is created through the calculation software for internal force calculation,achieving data transfer from BIM model to finite element calculation model.Engineering practice shows that this technology can transmit data accurately and improve design efficiency.

Abstract:Traditional photogrammetry and airborne LiDAR scanning for intertidal zone surveying face challenges such as difficulty in image control points layout,producing aerial triangulation and creating topographic map.Based on the analysis of the advantages and shortcomings of using these two technologies independently for tidal flat surveying and mapping,a method is proposed to fuse the photogrammetric aerial triangulation point cloud and the airborne LiDAR point cloud to construct a real-time 3D model based on the terrain features of intertidal zone.Experiments demonstrate that the method can give full play to the capability of photogrammetry in object identification and data extraction,overcome the numerical uncertainty caused by extracting elevation from LiDAR point cloud in traditional map drawing,make up the limitations of the two individual techniques,make them play their respective advantages,and provide a convenient and effective new method for tidal flat surveying and mapping.

Abstract:The disintegration characteristics of soft rock under water immersion condition are closely associated with various geological hazards.To further investigate the disintegration properties of soft rock,this study focuses on the soft rock of the Pinglu Canal.Indoor soaking disintegration experiments are conducted to observe the disintegration behavior of soft rock at different soaking times and analyze its disintegration patterns.The study incorporated X-ray diffraction (XRD) and scanning electron microscopy (SEM) to examine the mineral composition and microstructure changes of the samples.Additionally,the discrete element method is utilized to simulate the disintegration process of the soft rock and explore its disintegration mechanism.The results indicate that soft rock undergoes significant disintegration in the initial stages of soaking,followed by a deceleration in the disintegration rate.As soaking time extends,the internal pores of the samples gradually enlarge,and changes in mineral composition exacerbate the disintegration.During the disintegration process,friction and collision between particles lead to a rapid increase in kinetic energy,while elastic potential energy also rises due to the deformation of the internal structure.This study reveals the disintegration patterns and microstructure changes of soft rock under water immersion condition.Combined with discrete element modeling,it analyzes the disintegration mechanism,providing some reference for engineering construction in the area.

Abstract:The large variability of soil parameter causes that the overall stability of dock slope often has large uncertainty.The reliability analysis of a dock slope is carried out considering the variability of the soil cohesive force and internal friction angle in order to analyze the overall stability of the dock slope more accurately and reduce the uncertainty in the stability analysis.The slope stability numerical simulation software Slide is used to obtain the deterministic safety factor on the basis of the rigid body limit equilibrium analysis.Then according to the measured soil parameter distribution of the dock slope,the response surface method and the first-order second moment method are used to calculate the reliability of the dock slope.The results show that the safety factor based on the deterministic analysis of the standard value of soil parameters is one-sided to the reliability evaluation of the dock slope,and the stability of slope based on the reliability analysis is closer to the actual situation.In the actual engineering design and construction,the safety factor and reliability of the slope should be considered comprehensively.

Abstract:The suction grille of cutter suction vessels often experiences stone blockage,and the cleaning of stones requires stopping the pump,which is time-consuming and labor-intensive.This article introduces a new type of retractable suction grille,in which each group of retractable suction grilles consists of a fixed inner grille and a movable outer grille.During normal construction of cutter suction vessels,the outer grille is in an upward pushing state under the action of high-speed water flow,and the spacing between the grilles is small.When the stones are blocked between the grilles,the flow rate is reduced to below the critical flow rate,the outer grille drops,the spacing between the grilles increases,and the stones fall off on their own.This article provides a design method for the overall dimensions of the grille,and provides a calculation method for the critical velocity of the upward push of the outer grille and the critical velocity of the detachment of the outer grille and the blocked stone through the theoretical force analysis of the grille and the blocked stone.Furthermore,typical case designs are carried out using theoretical calculations.The grille designed using this method can clean the cutter suction without stopping the pump,effectively improving the efficiency of the cutter suction dredger,and can be used for dredging multi stone soil.

Abstract:In response to difficulties,high risks,and low efficiency of the extra large cutterhead reversing operation,a design scheme for the cutterhead reversing device is built by three-dimensional software.Hinge positions at both ends of the hydraulic cylinder are reasonably selected according to the requirements of the deck space,and appropriate hydraulic cylinder shape parameters are selected on the basis of this.Force states of the reversing device at five angles are analyzed by the enumeration method,and hydraulic cylinder parameters are calculated to meet the force requirements.The structural strength and stiffness of the cutterhead bracket and base are verified by finite analysis software.The results show that the developed cutterhead reversing device can improve the efficiency of cutterhead reversing and reduce labor safety risks of crew members.

Abstract:In recent years,with the realization of aerial photogrammetry by unmanned aerial vehicle(UAV) carrying a variety of sensors and the development of computer science and technology,aerial photogrammetry technology and products have become more and more widely used to serve a variety of industries.Several drones from DJI are used to carry out aerial survey equipment in Minjiang,Jinsha,Tuojiang,and Jialing Rivers in Sichuan Province for the application of water transportation engineering survey projects.The principle and process of the drone aerial surveying production operation are pointed out.The quality and accuracy of aerial survey products are evaluated,such as photographs,videos,digital orthophotographs(DOM),digital surface models (DSM),point cloud,etc.Their new applications in water transportation engineering survey scenarios are analyzed,such as land topographic map survey,water topographic map survey,hydrological data acquisition,and power line overhang height capture.The future development of UAV aerial survey technology is looked forward to.The UAV aerial survey technology product is more advanced than traditional operation methods,and can better serve the cause of water transportation engineering survey.