Abstract:China’s dependence on crude oil is high.Since the conflict between Russia and Ukraine，the energy security problem has attracted great attention.The large coastal crude oil terminals play an important role in the national crude oil supply guarantee system.Based on the situation of crude oil supply，demand and transportation in foreign trade，the layout and capacity adaptability of large coastal crude oil terminals are analyzed，and the large crude oil terminals are put forward to meet the needs of Chinese petrochemical industry development and crude oil reserves in general，but the characteristics of regional imbalance are prominent，including Liaoning coastal capacity is sufficient，Shandong coastal capacity is tight，the capacity of the Tianjin-Hebei coastal area，the Yangtze River Delta，the southeast coastal area and the Southwest coastal area is moderately advanced.Considering the changes of crude oil supply and demand and the situation of the“14 th Five-Year Plan”large-scale crude oil terminal project，it is predicted that the capacity of large-scale coastal crude oil terminals in the future will be fully guaranteed.

Abstract:After decades of development，China has formed a relatively perfect container transport system，which has strongly supported the development of China’s economy and society and the implementation of opening-up strategy.In recent years，with the integration of port resources，the continuous fermentation of the new crown pneumonia epidemic and the in-depth adjustment of the global economic and trade pattern，and the “dual circulation” new development pattern，China’s container transport system also presents some new changes and new requirements.This paper composes the current situation of China’s container transport system，combines the new challenges and requirements in the new era，puts forward the future directions and priorities for improving and optimizing the container transport system.The results will better support the future preparation of China’s ports and other related planning and the high-quality development of the container transport system.

Abstract:With the rapid development of social economy and the industrial restructuring，the flexibility demands in the process of port overall plan compilation，implementation and management are increased.It is necessary to define the rigidity and flexible contents，and promote the overall plan thought implementation-oriented，management-oriented and “combination of rigidity and flexible”.Based on the analysis of the causes of the “rigidity-flexible imbalance” in the port overall plan，the paper classifies the plan indicators based on the current port overall plan formulation and management system，then the rigidity and flexibility contents of the port overall are clarified.And further，taking the “Ningbo Zhoushan Port overall plan” as an example，the paper verifies and explores the plan formulation concept of “combination of rigidity and flexibility” to enlighten the relevant plans.

Abstract:Estuarine areas are vulnerable to the compound effect of flood and storm surges.This paper investigates the response of storm surges at the Yangtze River Estuary to the runoff by analyzing the long-period runoff time-series of Datong Station on the Yangtze River and constructing a three-dimensional (3D) model of storm surges at an estuary with the finite-volume community ocean model (FVCOM).The results suggest the following conclusions：1) The high astronomical (or storm) tide level at the Yangtze River Estuary rises as the runoff increases.They are in a highly linear relationship and can serve as a reference for the forecast of flood and storm surges at estuaries.2) In a given astronomical tide (storm surge) scenario，the water level growth rate only depends on the station’s location.The water level growth rate is higher further in the upstream.3) The storm surge elevation reaches its maximum in the Jiangyin reach，decreases as the runoff increases in the upstream tidal reach from the Jiangyin reach，and undergoes no evident changes in the downstream estuary reach from the Jiangyin reach.

Abstract:Under the influences of rainfall infiltration and underground runoff，the rock foundation of inland port undergoes the dry-wet cycle，and the bearing capacity of the foundation gradually decreases with time.Taking siltstone as the research object，we carry out nuclear magnetic resonance (NMR) and uniaxial compression tests under five dry-wet cycle conditions.Based on the geometric damage and energy damage，we build two damage evolution equations combining with the change law of rock pore volume and elastic modulus，and analyze the dry-wet cycle damage evolution mechanism of siltstone.The results show that the T2 spectrum of siltstone shows three peaks，corresponding to smaller，small and large pores respectively，and the structural pores of siltstone are smaller and small pores.With the strengthening of dry-wet cycle，the total area of T2 spectrum peak and porosity show a power function increasing law，and the number of rock pores increases gradually.The dry-wet cycle promotes the attenuation of the peak strength and elastic modulus.When the number of cycles reaches 16，the attenuation amplitude gradually flattens.

Abstract:In the investigation of waterway engineering，the consolidation test is commonly used in laboratories to test the deformation characteristics of soil，and it is also an important means to study the relationship between strength and structure of soil.A consolidation instrument is the main equipment for laboratory geotechnical consolidation tests.Upon the analysis of the performance of existing equipment both at home and abroad，this paper develops a new intelligent shipboard consolidation instrument，which has obtained the utility model patent.This instrument aims to solve the problems of existing consolidation instruments，such as large volume，loud noise，poor sloshing resistance，low intelligence，and inapplicability for laboratory shipboard use in waterway engineering.Experiments verify that the instrument has stable performance and high measuring accuracy and features a simple structure，simple operation，high intelligence，and superior shipboard performance.The new intelligent shipboard consolidation instrument for waterway engineering has a broad market application prospect，especially for use in mobile geotechnical laboratories.

Abstract:The study is focused on the minimization of dredged mud produced by construction and maintenance of port and waterway engineering.By adding polyacrylamide (APAM) and polyaluminum chloride (PAC) to dredged mud，the composite flocculation test of rapid separation of solid particles from dredged mud was studied.The effects of composite flocculation on the sedimentation time of mud，sediment moisture content and sediment permeability were investigated.The results show as follows：1) Compound flocculation effect of APAM and PAC is better than that of single APAM or PAC.Among the test，the APAM plays a key role in the mud sedimentation time while the PAC plays a key role in the clarity of the upper liquid of mud.2) Compound flocculation of APAM and PAC can reduce sediment moisture content effectively.While with the increase of the addition of APAM or PAC，the sediment moisture content maintains an upward trend.Namely，small amount of APAM and PAC is more beneficial to the reduction of sediment moisture content.3) Compound flocculation of APAM and PAC can enhance sediment permeability，and there exists an optimal addition amount of APAM.4) APAM is superior to PAC in reducing mud sedimentation time，decreasing sediment moisture content and increasing sediment permeability.For 2.4 ratio of silt to clay content of dredged mud，the suitable addition amounts of compound flocculation is 1 600 gt PAC and 240 gt APAM.The research results can provide reference for engineering.

Abstract:To improve the positioning ability of shipborne underwater acoustic equipment in complex operating environments of port and waterway engineering，this paper investigates the components of the shipborne position and orientation system for marine vessels (POS MV) and the basic principle of integrated global navigation satellite systeminertial navigation system (GNSSINS) positioning by the onboard Applanix IN-Fusion.Specifically，it develops four kinds of mode selection strategies for POS data post-processing and the procedures of corresponding methods on the basis of POSPac MMS and fosters the core technology system for shipborne POS data acquisition and processing.Then，relying on the scanning survey project of the Wenling Waterway dredging project，the paper presents the engineering practice of POS MV WaveMaster data acquisition and processing conducted 35 km offshore for 2.17 h.The results suggest the following conclusions：1) In the case of non-satellite difference，the real-time plane and elevation positioning accuracy of POS MV are both at meter level，and its average roll，pitch，and heading positioning accuracy are 0.026°，0.026°，and 0.029°，respectively.2) In the Post-processing Real Time eXtended (PP-RTX) and SingleBase post-processing modes of POSPac MMS，the plane and elevation positioning accuracy increase to 2-3 cm，and the average roll and heading positioning accuracy rise to 0.012° and 0.015°，respectively，with a stable mean square error in true heave data of 0.01 m.3) POS MV can obtain stable and effective inertial navigation data in real time，and auxiliary post-processing technology can provide accurate position and attitude information for port and waterway engineering.

Abstract:Regarding at the calculation of mooring force of windproof single point mooring system in harbour engineering，the equilibrium position of the ship under wind，wave and current loads is obtained according to Load Code for Harbour Engineering and Daidola formula.On this basis，the instantaneous wave impact force is superimposed，and the force model of the mooring system is established.Considering that the mooring ship will produce sway motion under the combined action of wind，wave and current，referring to the relevant formula form in the military standard Anti-typhoon mooring buoy system，and comparing the results of physical model test，the combined correction coefficient of wind，wave and current forces is proposed，which provides a solution for engineering application.The method in this paper can be used for the engineering under similar conditions to preliminarily determine the parameters of windproof buoy，and provide a necessary basis for subsequent physical model tests.

Abstract:The elliptic pier-type wharf is a relatively new type of wharf structure.At present，the relevant standards of water transportation engineering are not fully applicable to the wave force calculation of large elliptic pier-type wharfs.Based on the calculation theory of wave force on pier and pile in the water transportation engineering code，a comparative study is carried out with engineering cases and test data.The results show that：1) For large-scale elliptic pier，the measured values of small-scale pile transverse wave force are less than the calculated values，and the measured values of large-scale pier longitudinal wave force are greater than the calculated values.2) For small-scale piles，the difference of wave forces between the side pier and the middle pier cannot be reflected by the calculation method of water transport code，and the measured value of the lateral wave forces of the side pier is slightly smaller than that of the middle pier.For large-scale piers，the difference of longitudinal wave forces between side pier and middle pier cannot be fully reflected in the calculation of code.3) For important engineering，it is suggested that the wave force should be determined by the results of physical model test.

Abstract:Coastal ports are the transportation field with the highest degree of marketization in China，and the port capacity level is closely related to the operation of the market economy.At present，the actual cargo throughput of some berths in coastal ports far exceeds the statistical value of berth passing capacity，presenting the phenomenon of “overload” operation.It reflects the inadaptability of the existing statistical method of berth capacity.It is also worth noting whether the “overload” operation would bring production safety problems.Given the requirements of ensuring the stability and safety of the shipping supply chain of important strategic materials，supporting the construction of strategic reserve bases for bulk cargoes，and improving the emergency deployment capacity of civilian materials，this paper combs through the normative design algorithms and current statistical rules for berth passing capacity in detail.Regarding the “overload” operation phenomenon of berths，this study mainly analyzes the reasons for the statistical distortion of berth passing capacity and suggests using the “berth utilization rate” index to characterize the berth capacity.The research provides a technical reference for reasonably understanding and judging the wharf passing capacity，grasping the real-time development and real dynamics of coastal ports in China，and realizing reasonable decision-making and scientific management.

Abstract:Due to the construction of the Three Gorges Dam impoundment project and the Baihetan Hydropower Station in China，the water level of the upstream of the dam varies more dramatically.As a result，the frame height of the high-pile framed wharf increases，and the size of the structural section of the wharf increases accordingly，which further leads to a larger influence of temperature on the structure.By investigating the Gele Tourist Center wharf project，which is a first-phase project of the Dongchuan Port construction project in Yunnan Province，this paper develops a concrete high-pile framed wharf model under temperature stress by the finite-element software ANSYS.Furthermore，it examines the adverse effect of temperature change on the structure and the influence of horizontal braces on the temperature effect on the structure.The results show that after seasonal warming，the most unfavorable position in the structure is at the lower part of the upper beam and the roof in the sense that the tensile stress in this area is large，which may lead to the tensile cracking failure of the concrete.The most unfavorable position in the structure is in the bottom beam after seasonal cooling.Placing horizontal braces in the structure can effectively reduce its temperature stress.

Abstract:By analyzing the characteristics of the collection and distribution system，it is found that Xiamen Port has shortcomings and advantages in the supply side of the collection and distribution system and the demand side of cargo transportation.The supply side of the collection and distribution system lacks inland river support and backward railway facilities，but the coastal water-to-water transfer conditions are advantageous.The cargo source is mainly distributed in the coastal urban belt，and the nature of cargoes has high loyalty to sea transportation.It is proposed that Xiamen Port should rely on sea transportation to develop container transshipment in the future.On the one hand，Xiamen Port should take advantage of the dense ports brought by coastal cities to promote coastal water-to-water transfer.On the other hand，Xiamen should attach great importance to the expansion of the sea to the hinterland，and rely on the advantages of Southeast Asia and Taiwan to expand and strengthen the international transit function.The significance of railways to Xiamen is to consolidate the landward hinterland without losing，its competitiveness against the hinterland is limited.

Abstract:This study focuses on the professional transformation of the process system of a general berth in Jiangyin Port to tackle the problems of high energy consumption and pollution.According to the actual operation of the wharf，it reasonably determines the transformation design principles and proposes a professional transformation scheme from the aspects of ship unloading，ship loading，and yard operation.In terms of ship unloading，the research adds a receiving belt conveyor and a fixed hopper for continuous operation of the gantry crane and modifies the traveling mechanism of the gantry crane to satisfy the safety requirements of hydraulic structures.In terms of ship loading，it uses the mobile ship loader and places the tail truck behind to reduce the length of the tail truck and increase the scope of operation.In addition，it adopts a bucket wheel stacker reclaimer for yard operation.By analyzing the utilization rate of import and export operation lines，it optimizes the number of operation lines and sets an electric three-way valve to ensure that the entry and exit process covers all berths.The results show that after the transformation，the wharf enjoys a significantly improved carrying capacity，reduced dust pollution，and lower energy consumption of operation.

Abstract:To ensure the mooring safety of floating bollards in service，based on a representative ship lock of the Beijing-Hangzhou Grand Canal，according to the actual structural characteristics of floating bollards and the basic principles of mathematical mechanics，this paper deduces and constructs an expression that can reflect the quantitative relationship between the strain signal of floating bollards and the mooring force of ships.On this basis，a set of monitoring methods for the safety of mooring lines of floating bollards of ship locks are proposed.To verify the reliability of the safety monitoring method，field test is carried out on the representative floating bollards in the ship lock.By comparing the ship mooring force obtained by the safety monitoring method in this paper with the mooring force measured by the traditional load measurement method，it is found that the relative error between the two is less than 15%，which indicates that the safety monitoring method of the ship lock floating bollard mooring line proposed in this paper has high measurement accuracy.

Abstract:The classification of the navigation flow conditions at the confluence of a large-scale water drop project group on an artificial canal can pave the way for the selection of several typical water drop projects as the key research objects for numerical simulation or physical model tests and provide technical support for the subsequent comprehensive navigation safety evaluation of the water drop project group.The navigation flow conditions at the confluence of a water drop project mainly depend on quantitative influencing factors，such as the confluence ratio，confluence angle，flow，weir width，and water depth of the main channel，and the type of the confluence layout.The evaluation index for classifying the complexity of navigation flow conditions constructed on the basis of the quantitative influencing factors can quantitatively reflect the complexity of the navigation flow conditions at the confluence.Using the minimum-maximum standardization method and the K-means cluster analysis method，the paper classifies the water drop project group in the Yangtze-Huaihe communication section into four categories according to the evaluation index.Then，it selects 18 typical water drop projects with highly complex navigation flow conditions and highly representative types of confluence layouts from the 50 water drop projects as the key research objects.These typical water drop projects are in a relatively balanced distribution in various types of confluence layouts.

Abstract:The navigable flow conditions in the entrance area affect the navigation safety of ships.Hence，this study constructs a generalized numerical model according to the characteristics of the downstream entrance area of the sharp bend channel.It explores the influence of the number，the arrangement angle，and the relative spacing of diversion piers on the navigable flow conditions in the downstream entrance area of the ship lock.In addition，it builds a two-dimensional mathematical model on the basis of the navigation and power junction located in the sharp bend channel to verify the arrangement laws of diversion piers.The results show that reasonable arrangement of diversion piers can greatly improve the flow conditions in the entrance area.When the number of diversion piers is increased appropriately，and the spacing and length of diversion piers are equal，the improvement effect on navigable flow is more prominent.When the direction of diversion piers is parallel to the route，the flow conditions are better.

Abstract:This paper focuses on the construction of anchorages for the Three Gorges Hydro-junction after its shipping capacity expansion.It draws on carrying capacity analysis，traffic volume prediction，planning of ship types passing through the ship locks，and other previous achievements and employs the empirical formula and the queuing theory to analyze and calculate the number of berths required at the anchorages in the upstream and downstream of the hydro-junction.Furthermore，the paper analyzes the capacity demand on the anchorages between the two dams.The anchorages in the upstream of the Three Gorges Dam and the downstream of the Gezhouba Dam need to meet the anchor demand of 96 ships.The upbound and downbound anchorages between the two dams both need to meet the anchor demand of 28 ships.The paper further proposes an anchorage planning and construction scheme according to the current anchorage deployment situation and future navigation traffic organization demand of the Three Gorges Hydro-junction reach.The purpose is to provide a reference for the planning and construction of anchorages for the Three Gorges Hydro-junction after its shipping capacity expansion so that the hydro-junction can better meet the anchor demand of ships and bring into full play its shipping benefits.

Abstract:Upon the analysis of the monitoring data on underwater topography and cross-sections after the trial excavated channel of the approach channel of Toumen Port in Taizhou，we obtain the siltation characteristics of the trial excavated channel and discuss the siltation mechanism.The results show that during the monitoring period of 13 months，the trial excavated channel experiences the development process of natural and slow back-silting to alternating sudden silting and scouring to natural and slow scouring，and finally reaches a dynamic equilibrium and remains stable.The average water depth of the trial excavated channel meets the design navigation water depth requirements of 11.7 m.Under normal weather conditions，suspended sediment deposition is the main form of siltation in the trial excavated channel.Under strong wind conditions，the sediment-lifting effect of typhoons causes sudden siltation in the trial excavated channel，and a floating mud layer develops in the channel；the cold-air outbreak has a weak effect.

Abstract:Based on the double distribution function shallow water Lattice Boltzmann Method，a transport model of supersaturated total dissolved gas (TDG) is established to study the influence of downstream channel regulation structures of a power station on the transport law of TDG in the river channel.The results show that the construction of regulation structures has little influence on the changes of flow pattern and TDG in the mainstream area.The influence of waterway regulation structures on the temporal and spatial distribution of supersaturated TDG is mainly characterized in the local area near the regulation structures.The flow velocity in the back-flow area of the dam field is reduced，and the mass transfer of the water body is weakened，resulting in the decrease of TDG concentration and the increase of the area of the low concentration area，which can provide a certain refuge space for fish.This study provides a new method for the study of TDG transport and diffusion in water bodies，and provides a scientific basis for improving the adverse effects of TDG supersaturation on fish caused by power station discharge and building ecological waterways.

Abstract:Due to the channel that a ship lock located is lack of water resources，and the water consumption of one filling and emptying process is large，the ship lock should have water-saving function.According to the maximum difference between water level and the topographic conditions of the lock site，we propose a short-culvert filling and emptying system with a water-saving pool.To solve the key hydraulic problems of the filling and emptying system layout during the design of water-saving ship lock，we test the hydraulic characteristics and berthing conditions during lock filling and emptying with non-water-saving and water-saving operations by lock physical model with a scale of 1：30.The results show that the layout of the filling and emptying system is reasonable and feasible，and the hydraulic characteristics meet the specifications and design requirements.

Abstract:Aiming at the problem of causes of the obstruction to navigation at the outlet of the Fubei waterway in the lower reaches of the Yangtze River，we study the recent bed evolution，channel maintenance and river type and hydrodynamic characteristics at the outlet section of the Fubei waterway at the river section of Fujiangsha by combining such research techniques as data analysis，channel evolution analysis and model calculation.The results show that the outlet section of the Fubei waterway is subject to such factors as upstream incomings of water and sediment，the weakening of the hydrodynamic force due to the natural relaxation of the river channel and the increase of the resistance to discharge caused by the lateral overbank flow at the tail of the Minzhu Sand，which sometimes leads to the phenomenon of the siltation of obstruction to navigation.It is suggested to take engineering measures to weaken the overbank flow at the tail of the Minzhu Sand in time to reduce the pressure on the maintenance of the Fubei waterway.

Abstract:To solve the problem of channel route selection for the project connecting the water systems and canals in Hunan Province and Guangxi Zhuang Autonomous Region，this paper systematically summarizes the project’s characteristics and route selection principles and proposes four feasible route schemes.By means of qualitative analysis and quantitative calculation，the paper systematically compares the factors of each route，such as navigation efficiency，water supply conditions in watershed sections，navigation-obstructing facilities，and ecologically sensitive targets.The results show that Route 1 can serve as a recommended route for the Hunan-Guangxi water transportation passage as it has many advantages，such as high navigation efficiency，low elevations in watershed sections，favorable water supply conditions，and no reconstruction of high-speed railway bridges.

Abstract:The adjustment of runoff by a hydro-junction after its construction destroys the inter-annual consistency among upstream and downstream water level samples，consequently complicating the determination of the designed navigable water level.Focusing on the problem of selecting the designed lowest navigable water level for a ship lock expansion project of a cascade hydro-junction，this paper discusses the double-line ship lock of the Guoyang Hydro-junction as an example.Specifically，it statistically analyzes the inconsistent water level sequence and selects the representative hydrological sequence for the calculation of the guaranteed water level.Then，the paper compares the guaranteed water level with the dead water level and the lowest navigable water level of the hydro-junction and discusses the rationality of the designed navigable water level selected according to factors such as project investment.The results show that using the dead water levels of the Guoyang and Mengcheng hydro-junctions as the designed lowest navigable water levels of the upstream and downstream can not only meet the navigation guarantee rate with favorable economy but also ensure the water level connection between the cascade hydro-junctions and the navigation safety of ships.

Abstract:As the Chengzihe ship lock needs to cross multiple water systems，its location selection is limited by many factors，and the navigable flow conditions of its approach channel are complex.To deal with these problems，this paper carries out the technical and economic comparison and selection for the layout of the ship lock from many aspects，such as water system connection，flood control planning，navigation safety，the impact on irrigation and drainage，ship lock operation management，land acquisition and demolition，and investment.Through numerical simulation research，we set the maximum safe navigable flow conditions of 300 m3s and 120 m3s at the intersections of the approach channel with the upstream and downstream rivers，respectively.In addition，we use dredging and excavation to increase the overflow section and set up a diversion wall to adjust the main flow direction，which improves the navigable flow conditions of the approach channel.This study can provide a reference for the location selection and layout of ship locks under complex water system conditions.

Abstract:Regarding the problems of compacting mechanism and construction parameter optimization of high-frequency hydraulic vibration compaction riprap foundation bed，a reasonable particle discrete element model is established based on the conditions and results of vibration compaction test.The rammed settlement，the void ratio and the vertical stress of the foundation bed are analyzed，and the influence of the vibration response of the foundation bed under different excitation forces and vibration frequencies is analyzed.The results show that：1) At the initial stage，the amount of rammed settlement increases rapidly，and then gradually tends to smooth.The vertical stress of riprap bed under vibro-ramming has a linear change along the depth.2) When the maximum exciting force is 150 kPa，the shallow subgrade of the foundation bed has a good compaction effect.But for the deep stone foundation bed，the greater the exciting force，the better the compaction effect，that is，the maximum exciting force is 200 kPa.3) For the stones in different depth of the foundation bed，the vibration frequency of 25 Hz can achieve a good vibration compaction effect.

Abstract:Based on the soft soil foundation treatment project of the multi-purpose transfer area in the second harbor basin of Xuwei Port in Lianyungang，we carry out the solidification，dry-wet and freeze-thaw cycle tests of marine soft soil，and study solidification characteristics and strength deterioration mechanism of the marine soft soil solidified by cement together with lime，fly ash and gypsum.The results show that the cement mixed lime has the best solidification effect and durability，followed by cement mixed fly ash，cement mixed gypsum.The unconfined compression strengths of marine soil solidified by cement and lime are about 2.3 to 2.9 times and 4.7 to 7.8 times respectively of soil solidified by cement together with fly ash and gypsum.When the solidified soil subjected to one and five dry-wet cycles，reductions in the strength of solidified soils are 25.0% to 51.7% and 37% to 59.5% respectively.It means that the first dry-wet cycle has the most significant effects on the strength of solidified soil.After five freeze-thaw cycles，reductions in the dynamic elastic modulus and mass of the solidified soil decrease are 56.3% to 60.3% and 10.9% to 14.0% respectively.Dry-wet and freeze-thaw cycles induced strength reduction or even failure of solidified soil is mainly due to damage of microstructure and increase of soil voids.

Abstract:There is a deep layer of volcanic ash deposited soft soil in the site of Project 7 in Java，Indonesia，the natural moisture content is 115.4%，the pore ratio is 3.21，and the plasticity index is 25.5.Combining with engineering practice，we analyze the effect of soft soil foundation treatment and the reasons for the slow growth of bearing capacity.Taking soft foundation treatment in wharf yard area as an example，we calculate the post-construction settlement and consolidation degree by three-point method，and verify the effectiveness of this method .Through the analysis of vane shear test and plate load test data，we verify the applicability of the calculation formula of bearing capacity eigenvalue.The results show that the measured ground settlement is 1 587 mm to 2 496 mm，with an average value of 2 307 mm，and the reinforcement effect is remarkable.The consolidation degree of the foundation reaches 90% and the shear strength of the vane is greater than 20 kPa，which can meet the design requirements.

Abstract:To solve the problem that the mismatch between the bottom elevation of Sanjiang approach channel and the threshold elevation of No.2 ship lock，it is necessary to implement the promotion construction project of Sanjiang downstream channel at Gezhouba Dam.The project can effectively improve the throughput of ship locks of Gezhouba Dam in dry season.Considering that ship locks of Gezhouba are currently in saturated operation，we propose three representative construction schemes on the basis of full investigation to reduce the possible negative influences of project construction on navigation，and proof in detail.The results show the all-cofferdam dryland construction scheme is the best one in no doubt if taking into account of various factors such as navigation safety and capacity，construction schedule and so on，while the wetland construction scheme is conversely the best one to uninterrupt the economic and social life along the Yangtze River.

Abstract:The selection of pile hammer specifications for power piling is an important and complicated link in pile foundation construction，and the ultimate bearing capacity of pile foundation design is the main factor to be considered.The common methods for hammer selection include formula calculation，empirical comprehensive analysis，and the wave equation method，which can select the hammering energy and ultimate bearing capacity of pile hammers.The analysis of hammer selection elements can lead to the minimum energy value of hammer selection，which extends from the traditional single hammering energy to a range.This simplifies the method of hammer selection and improves the piling efficiency.From the perspective of hammering energy efficiency and efficiency，this paper analyzes the reason why the hammer-to-pile mass ratio should not be less than 14，namely that the hammering energy efficiency would be significantly reduced.In this way，power piling and static pressure piling are related in theory.

Abstract:In recent years，super-long and large-diameter steel pipe piles have enjoyed increasingly wide application in port projects.However，the construction of this kind of pile foundations requires a large-scale piling barge and a large water area for construction operations.Drawing on an example of an additional piling project of a wharf，this paper addresses the difficulties involving the narrow space in the rear water area，the penetration of the riprap layer by the cast-in-place pile as needed，and the super-long steel pipe pile.For this purpose，the paper puts forward the methods of impacting a guide hole to penetrate the riprap layer and lifting and driving a steel pipe pile in a piecewise manner and describes the technological process of pile driving construction，the main construction technology，and the construction equipment.Owing to the employment of the proposed methods，the project achieves a satisfactory construction effect and meets the requirements of the design and specifications.

Abstract:During the subsea pipeline trench dredging for the newly-built offshore oil terminal at a port in East Africa，the hard rock layer is encountered.To solve this problem，this paper studies and contrasts the conventional processes such as rock hammer breaking，backhoe excavating，and underwater reef blasting.We apply a rotary drilling rig to assist the grab dredger in hard rock layer dredging，which does not need to deploy professional ships such as the cutter-suction dredger.The results show that the grab dredger can smoothly dredge the hard rock layer after the operation of the rotary drilling rig，and the working efficiency and cost are well controlled.The research can serve as a reference for similar projects.