Abstract:The Pinglu Canal is a landmark project for building a new land-sea corridor in the western region and accelerating the construction of a transportation powerhouse.Pinglu Canal starts from the Pingtang River estuary in Xijin reservoir area of Hengzhou City,Nanning,and ends at the east channel of Qinzhou Port in Beibu Gulf.It is built according to the standards of class I inland waterway and can accommodate 5,000-ton ships.The project will construct three cascade hubs,namely,the Madao,Qishi and Qingnian,from upstream to downstream,and each hub will be built with a double-line 5,000-ton ship lock at one time.The project development task is mainly focused on developing shipping,combined with water supply,irrigation,flood control,and improving the water ecological environment.The main construction contents include shipping hubs,waterways,river-crossing buildings and road projects,as well as supporting projects.The planning and design of the Pinglu Canal is always guided by systematic approach and ecological civilization thinking,adhering to the principles of technological empowerment and innovation leadership,and will construct the world’s largest inland river water saving ship lock with fastest opening and closing speed.

Abstract:The Pinglu Canal adopts multi-stage water-saving navigation lock technology,with a three-stage water-saving pond arranged at the Madao Junction lock,enabling a reduction of more than 60% in water consumption for navigation.Taking into account factors such as the development cycle of freight volume and the efficiency of ships passing through the locks,it is necessary to divert approximately 24 m3/s of water from the Yujiang River in the near term.Based on water resources assessment analysis,the Pinglu Canal,in conjunction with the water diversion project from Yujiang River to Qinzhou,and without compromising the current guaranteed minimum discharge rate of the Guigang Junction,can meet the near-term water demand for navigation by adjusting the power generation scheduling of the Baise Reservoir and unifying the scheduling of reservoirs such as Xijin and Yongning.

Abstract:Aiming at four typical permeable breakwater structures,a three-dimensional numerical model based on FLOW-3D is established to compare and analyze the wave dissipation performance and wave energy distribution characteristics of the structures under different wave periods.The numerical calculations indicate that:1)the curtain wall breakwater is suitable for short to medium waves,while the pile-supported permeable breakwater is only appropriate for short waves.The comb-type breakwater and double baffle pile-supported breakwater are applicable to waves ranging from short to long.2)The comb-type structure induces resonance under specific wave period,resulting in peaks and troughs in the transmittance and reflectance coefficients.3)Among the four perforated breakwaters,the double baffle pile-supported breakwater demonstrates superior wave attenuation under short waves,while the comb-type breakwater shows an edge in providing protection against medium to long waves.

Abstract:As ports and berths move deeper into the ocean,the problems of high cost and poor water permeability of traditional physical breakwaters become increasingly prominent.Combining the requirements of water permeability and wave dissipation in ports with large tidal range,a wave dissipation structure combining submerged breakwaters and baffle-type permeable breakwaters is proposed to achieve both high and low water level wave dissipation efficiency.There have been studies on the interaction between waves and individual submerged breakwaters or baffle-type permeable breakwaters,but there has been no precedent for their combined use at home and abroad,and there is a relative lack of research in this area.Through physical model experiments,this paper first studies the changes in energy spectrum caused by nonlinear effects when waves pass through submerged breakwater,and compares the wave dissipation performance of individual submerged breakwater,individual baffle-type permeable breakwaters,and combined breakwaters to further verify the rationality of the combined breakwater.Then,the wave dissipation characteristics of submerged breakwaters and baffle-type permeable breakwaters under different conditions are studied,and suggestions for selecting the spacing of combined breakwaters are proposed based on numerical calculations.The relevant conclusions can provide a basis for the design and application of such projects.

Abstract:：There are wave and current penetrating phenomena in riprap breakwater,the vertical wall of breakwater with slope prism shield is subjected to the wave force in the open sea,but there is no mature calculation method for the magnitude of wave force.This paper studies the influence law of slope prism shield on the wave force of vertical wall through the physical model test of the breakwater section.The following conclusions are drawn by analyzing the experimental results.The wave force of the vertical wall with sloping prism is obviously reduced.With the increase of the top width of the slope structure,the wave force of the vertical wall decreases and the reduction coefficient decreases,However,when the width exceeds a certain value,the amplitude of the wave force reduction slows down.It is suggested that the most economical scheme should be demonstrated in combination with the model test in the design stage.The reduction coefficient of wave force in Goda formula is too large.In the preliminary scheme research stage,when the conditions for model test are not available,it is recommended to take 0.5 as the reduction coefficient of shielded vertical wall.

Abstract:In view of the present situation and development demand planning of coal transportation in Hunan Province,in order to give full play to the capacity of Haoji Railway,effectively enhance the energy security capacity of Hunan Province,and establish ways to reduce the cost of coal logistics and improve efficiency in Hunan Province,this paper studies the layout of coal rail-water intermodal storage and distribution base in Hunan Province with the functional goal of realizing coal emergency reserve and efficient operation.By analyzing the coal production,supply,storage and transportation system,coal supply-demand balance,and the construction of coal transportation channels in Hunan Province,this paper summarizes the influencing factors of base logistics volume,calculates the transportation cost of different transportation modes,and predicts the base logistics volume in combination with the logistics operation organization mode.Following the principles of optimal base function,minimum resource occupation,minimum environmental impact,best operation benefit and most scientific use of the Yangtze River coastline,this paper demonstrates the function,scale,site selection and construction scheme of the base,and obtains the construction recommendation scheme of arranging Huarong Base (supporting Hongshantou Coal Terminal) and Yueyang Base (supporting Nanyang Island Coal Terminal) at the same time,which provides decision-making basis for promoting the construction of Hunan Province’s coal rail-water intermodal transport reserve base.

Abstract:This paper implements the requirements of ecological civilization construction,scientifically utilize China’s territorial space resources,and explores the scientific protection and rational use of China’s scarce and precious port shoreline resources in port planning to better support the implementation of national and regional major strategies under the clear requirements of the state’s “comprehensive prohibition of reclamation except for major national projects”.Then,it systematically summarizes the spatial distribution pattern of China’s coastal ports,the status quo of utilization of port shoreline resources,and the connotation and application practice of the concept of “strategic blank space”,analyzes the temporal and spatial changes of China’s coastal ports reclamation,and the problems concerning “reclamation” in the current port planning.Combined with actual cases,this paper takes Beibu Gulf Port,an international hub port,as an example,proposes the application paradigm and implementation path of “strategic blank” in port planning to provide important reference for other port general planning and environmental impact assessment review,and provide effective support for the major strategic projects of port resource protection and reserve.

Abstract:The overall characterization method of waves using a single set of wave parameters has limitations when representing mixed waves accurately.By using multimodal characterization method to partition the wave spectrum into independent wave systems and representing each system in a parameterized form,mixed waves can be more accurately characterized.We investigate the influence of mixed waves condition characterization methods on water agitation in harbor through numerical simulation.We select three measured wave spectra of Chancay Harbor in Peru to theoretically reconstructed under different characterization methods,serving as input spectra for numerical models,and examine the typical errors introduced by the overall characterization method in describing mixed waves.The results show that wave conditions within the harbor are significantly impacted by the long swell system,and overestimation or underestimation of its energy levels leads to corresponding errors.Compared to the multimodal characterization method,the overall characterization method often yields average wave directions that do not align with reality,resulting in a misjudgment of the protective effect of breakwaters.

Abstract:Excavating channels for entering and leaving harbor and harbor basin can change the original riverbed topography and elevation,thereby altering its hydrodynamic conditions and sediment erosion and deposition,and affecting its navigation conditions.In response to this issue,we take Xiaogu Wharf in Qianwei as a basis,use Mike21 to build a two-dimensional numerical model of water and sediment,and analyze the water flow pattern and sediment accumulation before and after excavation of channels for entering and leaving harbor and harbor basin engineering,as well as after changing the depth,width,angle,etc.of the channel for entering harbor.The results show that excavation of channels for entering and leaving harbor and harbor basin has a relatively small impact on the overall water flow and sediment conditions of the original main channel,and a relatively small impact on the navigation conditions for ships entering and leaving harbor.Different excavation conditions have different impacts on the water and sediment conditions of channels for entering and leaving harbor and harbor basin.Different excavation angle conditions have a greater impact on the water and sediment conditions of Xiaogu Wharf,and the 30° layout can better meet the navigation flow conditions of Xiaogu Wharf.

Abstract:The southeastern coast of Hainan Island presents harsh conditions for harbor construction,with the stability of breakwaters posing a critical challenge.How to ensure the safety of breakwater structures in high-wave areas is pivotal for the success of the project.Based on the Wanning Emergency Salvage and Comprehensive Base Project in Hainan,this paper utilizes three methods—normative formulas,wave section model tests,and overall wave physical model tests to determine the stable weight of T-shaped blocks on a sloping breakwater and validate the breakwater’s stability.The research findings reveal that the stable weight of the T-shaped blocks determined by normative formulas and wave section model tests is significantly lower than that determined by overall wave physical model tests.The main reason is that the overall wave physical model tests effectively reverse the locally concentrated wave energy effects along the embankment,causing a localized increase in wave height which necessitates a 79% increase in the stable weight of the T-shaped blocks on the breakwater’s protective face.Therefore,for regions experiencing the impact of oblique waves in strong wave areas,it is of great significance to conduct overall wave physical model tests to verify breakwater stability for ensuring design safety. The research results can provide reference for the design of breakwater engineering subjected to oblique strong wave action.

Abstract:In the construction of overseas rubble mound breakwaters by domestic design firms,the commonly used design codes mainly include the Chinese JTS 154—2018 Code for Design of Breakwater and Revetment and the British code BS 6349-7.Due to the differences between the two design methods,there are certain limitations in the international application of domestic codes.Combining with the two design codes,we use the comparative analysis method to discuss the design methods of wave,section structures,breast wall,slope,protective surface block,cushion block stone,riprap prism,bottom protection and submerged dike of rubble mound breakwater.The results show that the differences between the two codes are mainly reflected in the design concept,calculation formula and parameters,and structural requirements.These differences reflect the different development levels and engineering practice characteristics of the two countries in the field of breakwater design.Through the results of comparative study,we can better understand and apply these differences,and provide more scientific and reasonable suggestions for the design of breakwaters at home and abroad.

Abstract:The navigation and water flow conditions at the entrance of the inland river estuary are complex.Taking the east extension channel regulation project of the Dalu Line as an example,we use the two-dimensional tidal current sediment mathematical model to simulate the layout scheme,and analyze the influence of different diversion dikes on navigation conditions in complex waters.The results show that the scheme of parallel diversion dike outside the entrance has a certain effect on weakening the cross flow of the outer channel,but the scheme has the problems of increasing the cross flow at the head of the dike,increasing the local cross flow and increasing the amount of siltation,which is not conducive to ship navigation and channel maintenance,and cannot completely improve the navigation conditions outside the entrance,so this scheme is not recommended for the project conditions.The straight curved diversion dikes are arranged at the current siltation-promoting dikes on the south and north sides,which can weaken the cross-flow of some waters at the entrance and the outer channel,optimize circulation flow patterns,and improve the navigation conditions at the entrance,so this scheme is recommended for further study.Considering the effect of the comprehensive scheme and economic factors,it is recommended to set up a straight curved diversion dike with a length of 930 m on the south side and a length of 1 500 m on the north side of the current siltation dike in the south and north of the Dalu Line entrance.

Abstract:To the problems of water flow turbulence,cross-flow,backflow intensity exceeding the standard in the entrance area after the upgrade and renovation of the Yantan ship lift.This paper uses a two-dimensional mathematical model to focus on the influence of different arrangements of diversion piers on the navigational flow conditions in the entrance area,and analyzes the flow pattern under different shapes,number and relative spacing of diversion piers.By comparing the hydraulic parameters such as transverse flow velocity,longitudinal flow velocity and backflow velocity,the layout law of diversion pier is further explored and the layout mode of diversion pier is optimized.The results show that diversion piers have obvious improvement effect on the navigational flow conditions in the entrance area.The recommended arrangement is 7-8 octagonal diversion piers in the entrance area downstream of the Yantan ship lift,with a spacing-to-length ratio between 0.50 and 1.00.This arrangement effectively improves the navigational flow conditions in the entrance area downstream of the ship lift,meeting the requirements for navigation.

Abstract:In response to the issue of poor mooring conditions in the chamber under the original plan of the Mujing 34-meter wide ship lock,we use numerical simulation method to conduct mathematical model tests on the water filling and emptying system,study the water flow conditions and mooring conditions in the ship lock chamber under various energy dissipater configurations,and reveal the water conveyance characteristics of such filling and emptying system in the chamber.The results indicate that throughout the entire water conveyance process,compared to the original design with a single dissipating sill,the optimized configuration of “open ditch+dissipating sill” results in slower water flow velocity,weaker turbulence intensity on the water surface,and a smaller longitudinal slope of water surface in the chamber.This optimization enhances the stability of mooring conditions in the chamber.

Abstract:With the advancement of the water transportation industry,instances of ships colliding with miter gates occur repeatedly.In order to investigate the extent of damage inflicted on gates when ships under various operational conditions navigate through ship locks,we use ANSYS/LS-DYNA software to build a finite element model encompassing a miter gate and a 5 000-ton class ship,and analyze gate damage in terms of impact depth and stress distribution.Then we vary various parameters such as impact velocity,angle,ship tonnage,and gate thickness to conduct comprehensive collision simulations,and analyze the influence of different factors.The results show that during the collision process,the ship undergoes three distinct stages:contact,compression,and detachment.The ship’s kinetic energy is transformed into the deformation energy of the gate,primarily resulting in plastic deformation at the impact site and excitation phenomena.An increase in impact speed,angle,and ship tonnage leads to a significant rise in impact force,whereas miter gate thickness exhibits a nearly linear reduction in impact force.The finite element model presented herein accurately replicates real-world collision scenarios.

Abstract:In view of the problem that the Huoyanqi Beach in the upper reach of the Yangtze River is prone to being shallow and obstructs navigation,and the water depth in the navigation channel does not meet the planning requirements,we propose two different regulation plans.We use the unstructured grid to build a planar two-dimensional flow mathematical model of the engineering river section,apply the measured hydrological data of the prototype to verify the reliability of the model,and calculate the main parameters such as water level,flow field,and beach dissipation criterion of the two plans under different working conditions.The results show that the two plans can achieve the expected regulation goals.However,the regulation building layout plan of extending the Huoyanqi dam and building three new spur dams requires a large amount of work and blocks the possible of subsequent adjustment of the navigation channel in the beach section.By extending the plan of connecting the dam head to the shore,the amount of engineering work is greatly reduced,and it also leaves space for subsequent adjustments to the channel in the beach section.

Abstract:During the suspended shipping period of a domestic ship lock,corrosion situations of its miter gates are fully detected.The corrosion level evaluation and the reasons analyses of coating blistering and steel gate corrosion are conducted corresponding to the region divided on basis of the position of anti-corrosion coating on the miter gate,namely atmosphere zone,water level fluctuation zone and submerged zone,respectively.The results show that coating blistering is commonly presented on the miter gate of this ship lock and the corrosion below blistering layer became gradually prominent as the coating effective life approaches.The total area of coating damage regions is in the proportion of 6.5%-12.7% of the miter gates.In general,the damage and failure process of protection coating on the miter gate can be separated into three stages:blistering of organic coating,corrosion development of thermal spraying aluminum layer,consumption of aluminum layer acted as sacrificial anode to suppress local corrosion of steel substrate.Moreover,it is pointed out that a long-term anti-corrosion effect is difficult to be achieved with piecemeal coating repair.An alternative method with respect to prolonging the service life of miter gates,including overall maintenance of anti-corrosion coating and the application of cathodic protection is proposed in present work.

Abstract:Abstract：In the north bank of the north branch channel of the Yangtze River Estuary,Yinyang port area of Qihai operating district has been planned.The port construction promotes the development of local marine ship industry,but it also faces problems such as the lack of anchorage layout planning and insufficient typhoon prevention capacity.This paper focuses the necessity of typhoon prevention anchorage layout in the northern branch from the aspects of the typhoon prevention requirements,anchorage layout and safety hazards of typhoon prevention measures,and analyzes the construction conditions of the anchorage in downstream of north branch channel from the aspects of tidal sediment,river regime,water depth,planning and engineering coordination.Then a site selection plan for typhoon prevention anchorage is proposed.The research results show that the area on south side of the red float from BZ3# to BZ2# is a suitable location for arranging typhoon protection anchorage,which has relatively advantageous water depth conditions,and it is close to the Yinyang port area,showing a slight siltation trend but in a state of siltation shrinkage.This research can provide reference for port planning adjustments in the future.

Abstract:The renovation and expansion of the double-line ship lock project on the existing hub of the first-line ship lock face difficulties in being limited by existing buildings and structures,as well as difficulties in effectively utilizing the structure scheme of the first-line ship lock.Combined with the double-line ship lock project of Fengguang hub of Dongjiang waterway,two existing ship lock utilization ideas and corresponding layout schemes are put forward:Plan 1 using the old ship lock structure as the new ship lock approach channel and plan 2 using the old ship lock as the cofferdam during the construction period.Comparison is conducted on the advantages and disadvantages of the two schemes in the current structure utilization,construction difficulty,land acquisition area and so on.In view of the problem of large land acquisition area in Plan 2,the optimization measures are put forward that the main lock is arranged on the river side and the small lock is arranged on the bank side,so as to make full use of the water and land space of the current lock and effectively reduce the land acquisition area.

Abstract:The water storage operation of the lower Jinsha River terrace reservoirs has an obvious impact on the water and sand conditions in the Three Gorges Reservoir area,which in turn causes changes in the navigation channel conditions.Based on the measured water and sand data,this paper analyzes the impact of the lower Jinsha River gradient reservoirs on the water and sand conditions of the Three Gorges reservoir during waning period.The results show that from January to May 2015,the discharge flow of Xiangjiaba increased by 37% on average,and the discharge at Zhutuo station and Cuntan station also increased by 34% and 26%.The sand transport amount at Xiangjiaba station has decreased by about 98%,from over 58% of the sand amount at Cuntan station to 1%-5%.The change of water and sediment conditions is conducive to improving the channel conditions in the Three Gorges Reservoir area.In particular,the minimum maintenance depth of the channel in the lower reaches of Chaotianmen reservoir increases from 2.7 m in January to April to 2.9 m in December,while the channel conditions in the lower reaches of Chaotianmen are less affected by the discharge flow rate of Xiangjiaba.

Abstract:To ensure the safe operation of the ship lock and improve the efficiency of ship passage,it is necessary to install collision prevention devices in front of the ship lock gate.In response to the problems of short braking distance,high demand for braking force,and high cost of traditional hydraulic buffering anti-collision devices,we design and manufacture a new type of gravity energy dissipation anti-collision device for ship lock gate,and conduct on-site anti-collision tests.Then we analyze the entire process of colliding with the blocking cable at the maximum allowable entry speed of 0.6 m/s for the design ship type of Changzhou fourth line ship lock under a full load of 3,000 t.The results show that the braking distance of the ship during the collision is 12.8 m,and the total height of the counterweight lifting is 2.23 m,both within the design allowable range.The pulling force of the blocking cable and the pulling force of the front drum do not exceed their ultimate tensile strength,which verify the effectiveness of the device in blocking the ship.This anti-collision device can effectively resist the impact of ships,protect the ship lock gates,and has the characteristics of meeting large water level fluctuations,simple mechanism,and easy maintenance.

Abstract:nfluenced by the unsteady flow under the power station,the 30 km downstream area of Xiluodu has complicated navigational current conditions,which threatens the safety of ship navigation.Through the prototype observation,the propagation law of unsteady flow and its main influencing factors are investigated.The results show that the change of the water level in each dock is consistent with the trend of the discharge flow,the phenomenon of franking along the propagation is obvious,the propagation speed is fast.The average wave speed of Dahewan to Shunhe section is 11.2 m/s,and the water level variation and change rate at the Dahewan dock during the flood season are as high as 4.38 m and 1.21 m/h.The unsteady flow characteristics of the river channel below Xiluodu dam are related to the variation of the discharged flow rate,the change duration,and the water level of the Xiangjiaba reservoir,with the greatest response to the flow rate variation.When the discharge flow increases (decreases),the larger the variation amplitude of the discharged flow at the power station,the shorter the change duration,the higher (lower) the water level of Xiangjiaba reservoir,the faster the propagation of unsteady flow,and the larger the variation amplitude of the water level and the change rate of the water level of the dock.

Abstract:This article proposes a new type of upright ecological waterway revetment and wave dissipation structure to address the existing problems in the current waterway revetment structure.This structure can effectively reduce the erosion of water flow and ship shaped waves on shoreline plants,while maintaining water connectivity and biological passage between aquatic plant areas and flood navigation areas,constructing natural habitats in the riparian zone,and improving the waterway ecosystem.Through experimental research on three types of vertical wall wave dissipation structures,namely flat grid type,flat hole type,and cylindrical grid type,the results show that the transmission coefficients of flat hole type,flat grid type,and cylindrical grid type wave absorption structures are in the range of 0.15-0.40,0.40-0.60,and 0.40-0.80,respectively.The wave absorption capacity from high to low is flat hole type,flat plate grid type,cylindrical grid type.The new upright ecological channel revetment and wave dissipation structure can provide reference basis for the design of channel revetments.

Abstract:In view of the rare phenomenon of “anti-dry in flood season” in the Yangtze River Basin during the flood season of 2022,based on the measured water and sediment data and the water level observation data of the fluctuating backwater area of the Three Gorges Reservoir,combined with the water level in front of the Three Gorges Dam and the discharge data of Xiangjiaba,the characteristics of the channel conditions in the Three Gorges Reservoir area from 2022 to 2023 are analyzed.The results show that the water level in front of the Three Gorges Dam continues to be low (155-160 m) for a long time from the flood season of 2022 to the flood season of 2023.During the period of increasing the discharge of Xiangjiaba,the actual channel maintenance depth in the fluctuating backwater area is greater than the planned water depth,and the water depth decreases during the period of reducing the discharge.There are even cases where the planned maintenance scale is not reached.It is suggested to carry out in-depth research on the joint operation of river basin water projects in dry season.According to the real-time water and rainfall information and the operation of the Three Gorges Reservoir,when the water level in front of the Three Gorges Dam is low ( below 160 m ),the joint operation of river basin water projects should be scientifically refined to further give full play to the channel benefits of water conservancy projects to cope with the drought in the river basin.

Abstract:The demand coefficient method is usually used to calculate the total power load of a port.The installed capacity of handling equipment is relatively large in the total installed capacity of the port,and the selection of handling equipment demand coefficient will directly affect the total power load value of the port.However,the value of the demand coefficient mostly depends on experience,and there is no clear evaluation standard.To improve the method of load calculation,this paper proposes a load calculation method based on real-time simulation using PSCAD power system simulation software,it can simulate the real-time load curves of port equipment according to the technical parameters of handling equipment,and then accurately calculates the total power load of port equipment.The simulation results show that this method can further improve the accuracy of load calculation.

Abstract:Currently,the use of AI technology to improve the efficiency of personnel work has been commonly applied in various industries.However,due to the low standardization of ship types and poor installation conditions of monitoring equipment in inland waterways,which leads to a low level of application of video graphic algorithms and reduces the convenience of using related systems.This paper addresses the problem that the lack of view information makes information processing susceptible to interference.Multi-view clustering technology is used in the Jining smart harbor navigation graph processing algorithm,and a set of graph processing algorithm framework based on incomplete multi-view clustering is constructed.The construction of this algorithm effectively improves the application level of AI recognition of navigation video,and improves the accuracy and efficiency of recognition.Meanwhile,due to the excellent scalability and openness of the system architecture,it also provides a foundational technology development idea for solving more water transport regulatory business based on this framework.

Abstract:The pile core and cap of high pile wharf are the key structures of pile top connection,and the traditional cast-in-place construction on water usually faces operational difficulties and construction quality problems.The prefabricated pile core and cap structure is changed from cast-in-place to prefabricated in factory,and the pile top structure is formed by grouting material and steel pipe piles,which avoids the influence of hydrological conditions on its construction.In this paper,the failure mode and grouting material ratio of precast pile core and cap structure are studied by physical experimental.The results show that the interface between grouting material and precast pile core of pile top structure is immobile under vertical load,only the relative displacement between grouting material and steel pipe is generated,and the interface bond behavior between grouting material and inner wall of steel pipe is relatively weak.The bond strength between UHPC grouting material and steel pipe decreases with the incorporation of steel fiber and increases with the incorporation of expansion agent.The combination of 0.08% plastic expansion agent and 12% national standard II expansion agent is the optimal ratio.The interfacial bond strength shows an increasing trend within 28 days and tends to be stable after 28 days.

Abstract:Taking the proposed offshore large cylinder project in Guangdong as an example,in view of the problem of too small displacement in the structural design based on two-dimensional theory,we use Plaxis 3D software to build a three-dimensional model of the overall space between the reinforced concrete structure and the soil,and use the HSS model in the three-dimensional finite element simulation to simulate the foundation soil and the backfill material inside the cylinder.Then we calculate the displacement of the cylinder itself and the displacement generated by the soil under different working conditions,and obtain the motion trend of the deep buried large cylinder structure,and the influence of the strength of backfill soil inside the cylinder,the thickness of the cylinder wall,and the depth of penetration on structural stability.The results show that the motion of the soil inside the cylinder and the cylindrical structure is basically the same,and there is no fully developed active and passive area.Targeted suggestions are provided for the minimum height of construction backfill.The wall thickness has a relatively small impact on structural stability,while the strength of backfill soil inside the cylinder and the depth of penetration has a significant impact on structural stability.However,after reaching a certain limit,the growth trend of stability results gradually slows down and tends to stabilize.

Abstract:Board insert machine is the main equipment of drainage board.In this paper,CEL numerical method is used to study the penetration resistance curve with depth when the pipe-pile of board insert machine penetrating layered soil.The influence parameters of pipe-pile penetration resistance are discussed by using Pearson model,and the magnitude of the penetration resistance is predicted and analyzed.The results show that the penetration resistance increases linearly with the increase of depth when the pipe-pile penetrating dredged soil layer,and the influence of different parameters on the slope is different.There is an obvious turning point in the penetration resistance curve of pipe-pile,and the position of the extreme resistance value is near the soil layer boundary,and the influence of parameter change on the extreme value is different.When the pipe-pile penetrates into the silt soil layer from the dredged soil layer,the penetration resistance decreases sharply and then basically remains unchanged.The correlation between the friction angle and the extreme value of penetration resistance is the greatest,and the correlation coefficient is 0.88.Finally,the analysis model is used to predict the value of penetration resistance under different parameter conditions,and the accuracy of the model is 0.91.

Abstract:The project of Berth 11 in Shimen'ao operation area of Xiuyu port area in Meizhou Bay Port,is a project constructing a 100,000 DWT bulk and general cargo wharf with relevant supporting facilities.The wharf is a high-piled beam-slab structure,which requires high foundation bearing capacity.In response to the geological condition of the lower part of the wharf foundation which is extremely soft rock,post-grouting technology is adopted at the pile toe of large-diameter cast-in-place piles,the static load test results of non-grouting and post-grouting cast-in-place piles is compared.The results show that the post-grouting pile can effectively improve the vertical bearing capacity of single pile,control the settlement of wharf,reduce the depth of foundation pile,shorten the project construction period,save the project cost,and has significant economic and social benefits.

Abstract:The construction of offshore platform structure has long period and high cost in the construction of diaphragm wall in sea.To solve the problem,the combined cofferdam of locking steel pipe pile and I-shaped sheet pile is used to built islands in the sea,and the parallel steel wire cable is set outside the cofferdam for flexible restraint,forming a flexible composite cofferdam structure of “lock steel pipe pile+I-shaped sheet pile+parallel steel wire cable” in the sea.Compared with traditional rigid hoop and the non-hoop composite cofferdam structure,based on field monitoring data,stress and deformation characteristics of the proposed flexible hoop composite cofferdam structure are analyzed.The results show that compared with the conventional rigid hoop structure,the maximum bending moment of the pile in the flexible hoop structure is reduced by about 50% under the same dredger fill pressure load.The maximum horizontal displacement of the pile top is too large without the hoop structure.Under the action of uneven loading,the stress of the rigid hoop will change abruptly,while the flexible hoop is always tensioned and the stress is evenly distributed.The monitoring results show that the measured stress and deformation of the flexible composite cofferdam structure are in good agreement with the calculation.

Abstract:Regarding the problem that how to set jet target distance to improve scouring capacity and reduce energy consumption in engineering practice,we carry out a numerical simulation study.Taking fine sand with a median particle size of 0.13 mm as the research object,we build a moving jet scouring model,and verify the reliability of some parameters chosen by comparing with physical test outcome.Then we use this model to simulate vertical submerged jet scouring on fine sand,and analyze effects of target distance on scour depth,productivity and specific energy of jet.The results show that with the increase of moving jet target distance,scour depth first increases and then decreases.Sour capacity first increases and then decreases,while scour specific energy first decreases and then increases.An optimal target distance exists with limited energy consumption but high scour capacity.

Abstract:The transverse,longitudinal beams and panels of high-pile wharf are gradually being designed and constructed in assembled structure.However,the pile core and pile cap structure in the water level fluctuation area are still mainly cast-in-place,which has a great impact on the overall construction period,quality and safety of the project.The bearing capacity and installation process of the prefabricated integrated pile core cap are studied by model experiment.The results show that the bearing capacity of the prefabricated pile core and cap structure mainly depends on the bonding performance between the grouting material and the steel pipe interface,and the average bonding strength of the new structure is higher than that of the traditional cast-in-place concrete and steel pipe bonding strength and its corresponding standard values,indicating good bearing performance.The developed airbag sealing device at pile bottom can meet the requirements of bearing and sealing performance,and the slurry has good fluidity during the embedded grouting process.The structure and installation process of prefabricated pile core and pile cap have good application effects in engineering projects.

Abstract:：Aiming at the problems of slow sand filling construction of steel cylinder cofferdam and high cost of purchased sand,this paper adopts blow filling technology of TSHD by the way in which multiple tubules disperse water flow filled steel cylinder cofferdam to form 4 steel cylinders in one day.The construction efficiency is 5 times higher than that of sand blowing ship,and the cost is only a quarter of that of sand blowing ship,which has good technical and economic value.At the same time,the construction process of loading barge is carried out by TSHD,which guarantees the supply of bagged sand and solves the problem of insufficient sand source and high cost of outsourcing.The application of blow filling technology at steel cylinder and barge loading of TSHD in M project can guarantee project progress and save cost,and provide reference for the multi-functional application of blow filling technology of TSHD.

Abstract:Pneumatic DTH(down the hole) hammer drilling has the characteristics of fast construction speed,high efficiency,reliable quality,high cost-effectiveness,small equipment footprint and green environmental protection without mud,especially suitable for drilling in areas with ultra-thick riprap layer,but it is less applied in the field of port engineering.The pipe rack foundation project on an embankment of a petrochemical terminal in a port project used the traditional punching and cast-in-situ pile scheme,which has very low construction efficiency and could not be completed as scheduled with quality.The construction process with long spiral pneumatic DTH hammer assisted PHC pile sinking is introduced innovatively,which greatly improves the efficiency of pile sinking,shortens the original 29 months construction time to 2.5 months,and ensures timely completion to meet the overall project schedule requirement.Simultaneously the technology reduces material and construction costs,and effectively solves engineering problems,ensuring smooth and timely completion of projects.

Abstract:Polymer sheet pile has been widely used in the treatment of inland waterways,but the problems existing in the construction process and corresponding measures have not been deeply studied.In this study,the application of polymer sheet pile construction technology is studied in combination with a waterway revealment project in Jiangsu Province,and the construction key points of polymer sheet pile are summarized.The causes of construction problems such as verticality deviation,pile sinking difficulty and axial tilt are analyzed,and specific treatment measures are given according to engineering practice.The results show that the appearance quality of sheet pile materials should be strictly controlled during storage,transportation and construction.During the construction process,the perpendicularity of sheet piles should be ensured within the permissible deviation range.The vibration pile driver should be selected with appropriate power to maintain the driving speed of sheet pile in a reasonable range.If necessary,a screw or water knife device is used to pilot holes to reduce friction resistance and ensure that the pile is in place.The research results can provide reference for the improvement and optimization of construction technology of inland waterway construction projects.

Abstract:When drilling blasting under deep water,a reasonable plugging length cannot only improve the blasting effect but also save construction cost.In order to study the reasonable value of plugging length for deep water drilling blasting under deep water conditions,we use a single variable method to only change the plugging length,and apply ANSYS/LS-DYN software to conduct numerical simulation research on underwater drilling blasting combining with waterway regulation project of Liantuo River between the Three Gorges Dam and Gezhouba Dam.The results show that as the water depth increases,the water pressure on the rock mass also increases accordingly.The water pressure can replace part of the blockage.As a result,the reasonable plugging length should decrease with the increase of the water depth.Under the four typical deep water conditions of 20 m,25 m,30 m,and 35 m,the corresponding reasonable plugging lengths are 140 cm,120 cm,100 cm and 80 cm.When the same charge structure of the explosive drilling blasts at different water depths,the reasonable plugging length and water depth are approximately linearly related.

Abstract:：Chancay Port project in Peru is located in a harsh sea area with long period waves and strong surging waves.There are a large number of steel pipe piles to be constructed without shielding,making it difficult to use traditional techniques for pile driving.A set of equipped automated mobile pile driving platform is developed based on the sea conditions and engineering characteristics.The main body of the platform is composed of horizontal and vertical steel box beams spliced with bolt flanges.The platform movement is driven by a track beam and an automated hydraulic cylinder pushing system.Multiple double layer pile holding frames are installed on the platform to stabilize and position the piles.A set of automated monitoring and control system is also developed for the intelligent operation of the platform.Based on the usage characteristics of the platform,the steel pipe pile driving technology of platform method is proposed.Practice proves that the platform and related technologies have successfully solved the multiple difficulties of steel pipe pile driving under harsh sea conditions,achieving good economic benefits,which can provide reference for similar projects.