Abstract:Focusing on five major types of cargo transport ships，such as oil tankers，this paper investigates the overall development status of international transport ships and the characteristics of the changes in such ships in recent years to adapt to the new requirements of the development of ship types in the new development stage on the planning and construction of ports in China.Considering the conditions of international waterways，the conditions of China’s port waterways and waters，the transportation economy of various types of cargoes，and the development trends of China’s energy and industries，this paper analyzes the future development trends of major types of cargo transport ships on the global scene and explores the impact of the development trends on the port construction and planning in China.The research results show that the major types of cargo transport ships differ greatly from each other in their enlargement trends and the development trends of their main ship type，ultimately necessitating the close tracking and adjustment or advanced scheming of terminal planning and layout for corresponding cargo types.

Abstract:Among the top 100 ports in throughput around the world，83 are located in coastal areas.As an important transportation infrastructure in China，coastal ports are playing an important and irreplaceable role.Due to the resource endowment conditions of China’s coastal areas，natural excellent shoreline resources suitable for port construction are scarce.Consequently，most ports have to make up for the weaknesses involving water depth，sediment deposition，and wind and wave sheltering by engineering means.The fostering of deep-water shoreline resources through normal sea use and necessary sea reclamation is a basic rule and an inevitable requirement to ensure the construction and development of coastal ports.However，the implementation of port reclamation has been in a “one size fits all” manner after the issuance of the Circular of the State Council on Better Protecting Coastal Wetlands and Having Land Reclamation Under Stringent Control.This directly leads to a series of problems.For example，the strategic environmental assessment of port plans requires that all new reclamation works be canceled.Other problems include the slow handling of the longstanding problems in reclamation and the virtual stagnation of new coastal port projects.Port construction and development have already shown signs of a “standstill”，which necessitates urgent special attention and research for corresponding countermeasures.

Abstract:Taking the development of an overall plan for Beibu Gulf Port as an example，this paper discusses the ideas and methods of integrating the concept of green development into all aspects and the whole process of the overall planning of ports.Shoreline utilization planning should give due consideration to avoiding and keeping away from environmentally sensitive areas.The proposition of a hierarchical port area layout system should follow green development and other principles.Ecological and environmental factors deserve more attention in the layout of transportation systems for important cargo types.The optimization of plane layout schemes for ports should be in compliance with various principles，such as mitigating environmental impact and improving resource utilization efficiency.The planning of collection and distribution schemes should lay emphasis on coordinating port and urban traffic organization and adjusting transportation structure.The chapter on environmental protection should reinforce the guidance on green port development.The research idea of this paper can serve as a reference for the development of an overall plan for a port under the new development concept in the new development stage.

Abstract:Storm surge is a kind of serious natural disaster that occurring along the ocean coast，which is usually accompanied by large waves. The coupling of storm surges and waves is a great threat to the security of coastal areas. The previous researches on marine dynamic disasters of offshore disaster-bearing bodies are mostly focused on the influence of a single disaster-causing factor，and constant water levels and wave elements are mostly used. The research on the coupling effect of storm surges and waves and its dynamic response to seawall disaster-bearing body is still insufficient. In this paper，the storm surge tide level and wave process caused by typhoon 9711 in Beilun sea area of Ningbo are used to simulate the real dynamic tide level process by superimposing the continuous storm surge water level variation process with the wave process. The dynamic coupling simulation of storm surge and wave is realized in the three-dimensional wave basin，which provides a reference for the development of related model tests.

Abstract:To address the problem that open ore storage yards are highly likely to cause particle dust pollution under the action of external forces，this paper investigates the wind velocity reduction effect of the windproof and dust suppression net on different incoming flows. Specifically，the paper numerically simulates the flow field behind the dust suppression net with the renormalization group（RNG）k-ε model provided by Fluent. Then，it builds a three-dimensional model based on measured data to calculate the velocity distribution on the stockpile surface under different incoming flows. The simulation results suggest the following conclusions：1）After the airflow is combed by the pores of the dust suppression net，an obvious vortex backflow area emerges behind the dust suppression net. It changes the airflow structure on the stockpile surface，thereby effectively reducing the velocity on the stockpile surface. 2）The comprehensive velocity reduction rate is 23.52%. The area of the storage yard covered by the vortex backflow area varies with the direction of the incoming flow. The comprehensive velocity reduction rate differs significantly，and the difference range is 7.69%-50.87%. The attenuation of north-northwest and north-northeast incoming flows is particularly prominent.

Abstract:The rock foundation of inland ports experiences different degrees of dry-wet cycles，and the bearing performance of the foundation decreases and deteriorates. The number of dry-wet cycles and confining pressure are taken as the working conditions for the conventional triaxial compression test of siltstone. The micro-element strength of siltstone is assumed to obey the improved Harris probability distribution，and then the damage variable is defined. The M-C strength criterion is selected to build a new statistical damage model that can reflect the dry-wet cycle in combination with the logarithmic attenuation law of the elastic modulus and internal friction angle in the test results. The parameter analysis method is given，and the damage development curve is obtained. After that，the new model is used to identify the test curves of siltstone and argillaceous dolomite and sandstone in the literature，and simulations are performed for comparisons. The results show that the elastic modulus，cohesion，and internal friction angle of siltstone decrease gradually with the increase in the number of dry-wet cycles. When the number of cycles reaches 16，the attenuation curve tends to be stable，and the attenuation law can be expressed by the logarithmic function. The dry-wet cycle promotes the attenuation and deterioration of the mechanical properties of rock，and the macroscopic performance is represented by the reduction in peak stress. The feasibility of the new model is verified.

Abstract:For the engineering geological environment in deep sea，a wave-current flume test scheme is designed for pile-supported wharf（PSW），and the experimental investigation on the dynamic response of PSW under wave-current action is carried out. The test really reproduces the operating condition of PSW，and the internal response difference of PSW is discussed，and the pore pressure and acceleration in the free field and soil layer around piles are analyzed. The results show that：1）The responses of each pile in PSW are obviously different，and hydrodynamic pressure on pile decreases gradually along the wave-current direction. The bending moment on the front pile is greater than that on the rear pile，and the bending moment on the middle pile is larger than that on the bilateral pile. 2）The displacement and acceleration of deck change periodically，and the torsion decreases with wave-current action. 3）The acceleration and pore pressure of soil layer gradually decrease with the wave-current propagation and increase of the burial depth，the pile group increases acceleration of soil layer and decreases its pore pressure. 4）In the design of PSW，the strength of middle pile should be appropriately increased and the reinforcement of surface seabed soil should be emphasized. The above research can provide a reference for the design and maintenance of PSW.

Abstract:With the vigorous development of intelligent water transportation，the monitoring of operation safety and health of high piled wharf structure based on life cycle has attracted more and more attention. Combining with a new wharf project of a port area，this paper carries out the research on the life-cycle health monitoring system of high piled wharf. Based on the structural load conditions，operating environment and monitoring instrument characteristics of high piled wharf，this paper carries out the life-cycle sensor and its durability design，line protection and replacement reservation design，develops the corresponding monitoring system，and analyzes the obtained monitoring data combining with data normalization，dynamic time warping and numerical modeling methods. The results show that the adopted data processing method can better quantify the similarity between data of different measuring points，and the real-time monitoring data can be used to evaluate the existing state of the wharf structure，which can provide a basis for the decision-making of the repair，maintenance and management of the wharf structure.

Abstract:The approach channel in the core area of Ningbo-Zhoushan Port has been saturated in stages. For the construction of terminals for very large vessels in the core port area，it is necessary to carefully analyze the carrying capacity of the channel and the inherent safety level of the berths. Taking the construction of three new terminals for the 300，000 DWT very large crude carrier（VLCC）in the Jintang port area as an example，this paper analyzes the carrying capacity of the channel for VLCCs in the core area of Ningbo-Zhoushan Port using the theory of tidal windows. Moreover，it explores the requirements for the net spacing between VLCC berths using ship maneuvering simulation. The study draws the following conclusions：1）The channel carrying capacity of Ningbo-Zhoushan Port could bear the traffic pressure brought by the addition of three 300，000 DWT VLCC terminals. 2）It is recommended that the net spacing between adjacent large berths should not be less than a ship’s length.

Abstract:With the increase of cargo load，the enlargement of ships and the requirement of high permeability in the sea area，slender high square caissons are becoming more and more common，but the floating stability of slenderer caissons is poorer. To study the floating stability of slender high square caissons，the length，width and height of regular and symmetrical caissons are transformed into 5 groups respectively，and the characteristics of floating stability parameters of square caissons with different shapes and sizes are summarized. The conclusions are that：1）The smaller the plane size of the slender rectangular caisson，the greater the relative draft required to meet the floating stability，and the worse the floating stability.2）The total width of the caisson is the most important parameter affecting the floating stability. The effect of the total length on the relative draft is far less than that of the total width. 3）When the caisson height is small，it has a greater impact on the relative draft. However，with the increase of the caisson height，the relative draft will tend to be constant.

Abstract:With the construction of “the Belt and Road”，the coastal areas of West Africa，Mediterranean and Indian Ocean have obvious long-period wave components due to their specific natural conditions，which have a serious impact on port engineering construction. The example of a port in Africa in this paper has the characteristics of long wave period and large coastal sediment discharge，and long period wave and large sediment discharge are easy to cause problems such as poor mooring stability conditions in the port，heavy sediment deposition，and high construction risks of offshore ships. After studying the general layout scheme，we decide to adopt the layout scheme of excavated-in harbor basin，and verify the scheme by the research methods of wave-sediment mathematical model and physical model test.The results show that the excavated-in harbor basin scheme can better solve the above problems.

Abstract:The turnover time of outbound container trucks is one of the main indicators to measure the production and service capacity of a terminal. Aiming at the problem of low operation efficiency of the collection and distribution of the automated terminals，this paper studies the operation modes of the outboard container trucks and the factors affecting the turnover time of the outboard container trucks，and summarizes the factors affecting the average turnover time of outbound container trucks into ten categories，such as the number of containers in the collection and distribution，the inventory of the yard，the busyness of the seaside operation，the time arrangement of the collection port，and the collection and distribution capacity of the yard. The results show that coordination of port collection time can avoid centralized pressure at stations；balancing sea and land side production can reduce operational conflicts；strengthening the management and control of collection and distribution at surrounding stations can reduce traffic jams at gates；strengthening inter-departmental coordination can improve system and equipment stability and other measures to effectively reduce the turnover time of outbound container trucks.

Abstract:The bulk cargo ports in north China face many difficulties，such as the lack of freshwater resources，waterlogging in the storage yard during heavy rain seasons，dust pollution，and noise pollution. Considering this，this study focuses on green upgrading and transformation of bulk cargo ports. Guided by the environmental problems confronted by bulk cargo ports，this study summarizes the direction of green upgrading and transformation of bulk cargo ports on the basis of the green design concept. By referring to an engineering case，this paper proposes a specific scheme in this regard. Specifically，a new ecological reservoir can be constructed to establish the port water circulation system，which can realize the full collection，total processing，and full reuse of rainwater and sewage in the port area under the intensity of rainstorms once in two years. The whole-process pollution control can effectively reduce the dust concentration and noise value in the port area.

Abstract:This paper focuses on the reconstruction of the process scheme to solve the problems that the current process scheme of a port on the Yangtze River for bulk cargo loading causes environmental pollution，high energy consumption，and heavy yard and wharf surface wear. By designing a bucket-wheel stacker-reclaimer with a retractable tripper car and a discharging conveyor with an extension header，the paper enables material feeding and discharging and material sorting at the same side of the yard. It also achieves material feeding and loading at both sides of the yard by adopting a scheme of a mobile ship loader with a tripper car on both its left and right sides and a two-way conveyor. The flow-oriented reconstruction of the loading process and the utilization of the outer-rotor permanent-magnet direct-drive roller enables the project under discussion to achieve the expected effects of environmental protection and energy saving.

Abstract:The reconstruction and expansion project of liquid chemical wharf with continuous butterfly shaped multi loading and unloading area has complex boundary conditions，generally limited available shoreline length，multiple berthing ship types，complex and special mooring line layout，and high safety requirements. Although the Mooring Equipment Guidelines published by OCIMF has carried out certain study on the layout of the wharf based on the ship mooring，there are few studies focused on the layout for liquid chemical wharf reconstruction projects. Taking the reconstruction and expansion project of a wharf as an example，the plane layout principles of the reconstruction and expansion project are summarized by analyzing the utilization of the existing wharf.Based on the layout plan of ship mooring lines，the characteristics of ship mooring lines in multi loading dock and optimizing the layout of mooring points are studied. The OPTIMOOR mathematical model is used to verify the feasibility of the plane layout and the departure control conditions are proposed.

Abstract:Taking the rear rail foundation of a gravity wharf in Yangjiang as an engineering example，this paper analyzes the common rail foundation structure and puts forward a combined rail beam structure to solve the problem of difficult post-settlement adjustment of the elastic foundation beam during its service period under the action of a heavy-loaded rail crane. Then，the paper calculates and analyzes the foundation beams，steel rails，and sleepers with the finite-element software Midas Civil on the basis of the Winkler hypothesis. The results meet the requirements of engineering application. The design of the combined rail bearer structure is reasonable. Compared with the conventional scheme，it has better comprehensive performance and economic performance. The application research of the proposed combined rail beam structure can serve as a reference for similar projects.

Abstract:In the design of dust-bearing sewage treatment plants for coal and ore terminals，the treatment duration of design runoff rainfall determines the treatment scale of sewage treatment plants，but the selection of this value is not specified in the current code. Given the statistics of rainfall in 15 typical port areas，this paper analyzes and compares the rainfall frequency and rainfall. The results show that the average occurrence ratio of rainfall over 2 mm for two consecutive days in each area is large，especially in the south where the ratio is over 50%. The average occurrence ratio of the sum of daily rainfall over 2 mm for two consecutive days exceeding the minimum value of annual maximum daily rainfall is less than 20%，and that exceeding biennial daily rainfall is less than 4%. To ensure that the sewage treatment plant can treat dust-bearing sewage in time and prevent sewage overflow，we put forward the following suggestions：1）The minimum value of the annual maximum daily rainfall，i.e.，H，should take the rainfall corresponding to the design return period not less than two years in the calculation of runoff rainfall. 2）The design treatment duration of sewage plants should not exceed 48 hours.

Abstract:Good regulation effects have been achieved for the Phase I and Phase II projects of the 12.5 m deepwater navigation channel from Nanjing. Regarding the problems that the Tongzhou shoal is not completely stable，and the Xinkai shoal is still being scoured and keeps retreating，this study focuses on the subsequent improvement engineering to stabilize the channel and adopts the test scheme of the fixed-bed physical model to study the flow field after the implementation of improvement engineering. The study shows that the hydrodynamic axis of the improvement engineering scheme has a certain degree of northeastward migration at the inlet of the Nantong waterway and eastern Tongzhou shoal waterway. The scheme can greatly reduce the overtopping rising-tide volume of the embankment line of the Tongzhou shoal and the overtopping ebb-tide volume of the erosion ditch between Xinkai shoal and Kuzigang shoal. The average ebb-tide flow velocity in the reach between Tianshenggang and Longzhaoyan generally increases due to the engineering，and the increased range generally covers the existing channel position. The ebb-tide dynamics and the capacity of sediment transport by ebb tides are enhanced. Therefore，the improvement engineering can achieve the desired goal of protecting shoals and improving waterway maintenance conditions.

Abstract:Focusing on the issue of reasonably determining the axial distance between two ship locks in a reconstruction and expansion project，this paper analyzes the relevant clauses in the current code and the research status. Then，the paper puts forward an analysis process of determining lock sites，deciding the initially proposed spacing，adjusting the spacing，and analyzing and reviewing the spacing to determine the axial distance between two ship locks. For this purpose，it adopts the method of combining theory with practice，takes into account factors influencing the axial distance between two ship locks，and combines engineering experience with the research results of existing projects. Furthermore，it proposes the corresponding calculation formula. Finally，the paper selects three representative ship lock projects and applies the above analysis process and corresponding calculation formula to them. The results show that the proposed technical route and calculation formula are reasonable and feasible.

Abstract:A systematic summary for canal route selection principles is conducted refer to the route selection practice of Xiong’an New Area and Shanxi Province’s sea corridor. The construction conditions such as river and reservoir conditions，topography and geology，water resources and short-term and long-term construction schemes are discussed，and the methods of qualitative analysis and quantitative comparison are adopted，it can be concluded that current status of the river and reservoir，transportation volume，ecology，obstructions shall be taken into consideration when selecting the canal route. It is feasible for Xiong’an New Area to connect to the sea with Duliujianhe River，and Shanxi Province to connect to the sea with multimodal way. Preliminary schemes are provided for Xiong’an New Area and Shanxi Province to connect to the sea，which can be references for canal route selection projects and waterway design codes updating.

Abstract:The filling and emptying system is one of the important parts of the ship lock. To avoid the influence of the model scale effect in the ship lock hydraulics and ensure the safe operation of Qianwei ship lock at water level of 335 m，the prototype observation and commissioning of the hydraulic characteristics of filling and emptying system are carried out. Through the arrangement of 19 water level indicators in lock chamber，valve wells（service valve wells），upper（lower）miter gate，the hydraulic characteristics of filling and emptying system during the commissioning are obtained. The results show that when the filling valve is opened and closed at the recommended speed tv=4 min，the overfilling（over emptying）phenomenon occurs in the lock chamber obviously，which can be 0.40m and 0.10 m respectively，and it has an adverse influence on the safety of the miter gate and the ships passing through the lock.By optimizing the operation mode of the lock and valve，the phenomenon of over-filling（discharge）in the lock room is effectively alleviated，and the inertia of bilateral water filling（discharge）is reduced to 0.15 m and 0.10 m respectively. The paper puts forward the operation mode of the ship lock adapted to the water level of 335 m，which provides guarantee for the safe operation of the ship lock and the efficient navigation of ships.

Abstract:The smart channel is a new information-based research and construction direction of channels，which is derived from the development of smart shipping. Relevant research and engineering construction have developed rapidly throughout the country. This study is to clarify the historical position of the development of smart channels at this stage and promote the research and construction of smart channels in a scientific and effective manner. Specifically，this paper divides the development of smart channels into three stages through nationwide information-based research on channels，taking the national five-year plan as the main line. Then，it analyzes the main results of each stage and points out the existing problems such as the unclear concept of the smart channel，lack of intelligent navigation support，the non-unified standard of the electronic navigation chart（ENC），the lagging update mechanism，insufficient service capability，and the absence of the information sharing mechanism. On this basis，it puts forward relevant suggestions from four aspects：the construction of the smart channel evaluation system，intelligent navigation support，application of the S-100 standard，and construction of the operation monitoring mechanism for multi-level inland waterway networks.

Abstract:The non-stop construction at important sharp channel bends leads to many passing ships，frequent water level changes，and poor visibility. Therefore，ensuring traffic safety during construction has been a technical problem for the construction unit. For the waterway regulation project of Laokou Junction on the Guangxi Yujiang River，this study considers the natural geographical characteristics such as severe backflow in the downstream deep pool of the construction section and the traffic and transportation conditions during the construction period. It adopts the method of combining blasting in the strips and layers，with the medium- and deep-hole benches as the main and shallow holes as the auxiliary. Upstream dredging shall be before downstream dredging，and the design of the overburden layer and excavation slope shall take into account the excavation slope value designed for offshore reef cleaning. The excavation scope of the water area within the design bottom line of the channel shall meet the design requirements，and the excavation section shall not be less than the design excavation section. In addition，shallow spots are strictly prohibited in the water area within the design bottom line. The construction combination of land blasting and water slag removal can avoid comprehensive construction and the occupancy of the channel width and reduce the impact on passing ships.

Abstract:To solve the problem of ecological revetment under the action of traveling wave in restricted waterway，a new type of ecological revetment cavity structure is developed，and the model flume test of self-sailing ship is carried out to study the velocity distribution，turbulence characteristics and fish gathering effect in the cavity under the action of traveling wave. The results show that when the ship traveling wave is controlled by the complex structure of the cavity，the water flow changes from low frequency oscillation to high frequency boundary layer turbulence，the farther away from the edge wall，the greater the velocity is，and the energy tends to be evenly distributed in each frequency. The turbulence in the cavity shows a process of multiple peaks and gradual dissipating，and the maximum turbulent kinetic energy is 0.002 5 m2/s2 at the normal ship speed of 4.6 m/s. When the ship speed increases to 6.3 m/s，the maximum turbulent kinetic energy is 0.177 1 m2/s2，which exceeds the preferred kinetic energy range of crucian carp and is no longer conducive to fish habitat. Therefore，the speed limit should be set for ships sailing in key fish reserves.

Abstract:For the ship lock project with high water head，the dock structure has the disadvantages of insufficient anti-sliding stability and large structural stress. In this paper，three groups of optimization schemes for dock structure are proposed：increasing the section size，adding the cantilever，and replacing the backfill with foamed mixture lightweight soil. By defining the anti-sliding influence factor δ，the influence of three groups of optimization schemes on anti-sliding stability is analyzed. Using the finite element model and introducing the analytical algorithm of section size，the structural stress changes of three groups of optimization schemes are analyzed. The results show that the optimization effect of anti-sliding stability is the most obvious when the cantilever is added，the scheme of foamed mixture lightweight soil replacement is more economical and reasonable for improving the internal force of the structure.

Abstract:Essential differences in stress state and reinforcement mechanism exist between underwater vacuum preloading and preloading combining vacuum with overlying water on the membrane. Specifically，the total stress does not change during underwater vacuum preloading. In contrast，the total stress in soil increases with the thickness of the overlying water on the membrane in preloading combining vacuum with overlying water on the membrane. The reinforcement mechanism of underwater vacuum preloading is the same as that of onshore vacuum preloading，namely that on the premise of the same total stress，vacuum pumping reduces the pore water pressure and further increases the effective stress. The increasing amplitude between the effective stress before and after underwater vacuum preloading is independent of the water depth，with a theoretical maximum value of 100 kPa. The key construction process of underwater vacuum preloading mainly includes membrane laying and sealing and the selection and layout of the vacuum pump. A combination of sealing with an overlying sealing membrane and vacuum pumping with a jet pump similar to that adopted in the field test in Norway is advisable for the sake of a favorable reinforcement effect. However，factors influencing the construction site of underwater vacuum preloading are complex，demanding the selection of the scheme with the optimal cost performance according to the actual situation on site. Integrating the functions of the sealing device，filter pipes，and membrane outlet device，the patented technology of the sealing membrane laying device for underwater vacuum preloading is available for the sealing membrane laying and sealing in a completely underwater environment，and it reduces underwater operation，It is especially suitable for small-scale seabed soft clay reinforcement for suction bucket foundations in the field of offshore wind power.

Abstract:Due to the huge reclamation area of Hengsha Phase 8 project，the soil quality of the reclamation is diverse and the distribution is different. To study the change law of the soil quality of the blown fill in the super-large enclosed area，the distribution law of the horizontal and vertical blown fill at the mouth of the blown fill pipe is analyzed through borehole sampling of the actual blown fill site. The results show that the depth of about 3.0 m below the surface of the filling soil in the super-large enclosure area is basically silt，and the depth below is fine sand. Within the range of about 150.0 m from the mouth of the filling pipe，fine sand is the main component，and outside this range，silt is the main component. These results can provide a useful reference for pipeline layout and flatness control in the process of land reclamation.

Abstract:Ports and terminals in the Middle East are generally built by hydraulic fill. Due to the limitation of construction technology，fine grains are easy to form siltation in hydraulic reclamation，which results in excessive settlement. The current design calculation methods do not consider the fine-grain content，mineral type，and other factors in the calculation of post-construction settlement of sandy soil with a high content of fine grains. Thus，it is difficult to evaluate the influence of the fine-grain content on post-construction settlement. To solve this engineering problem，this study proposes a calculation method for the long-term settlement of hydraulic-fill sandy soil based on creep characteristics and compares it with traditional and in-situ test methods to verify the feasibility of the proposed method.

Abstract:About the problem of total uplift force on platform in front of straight wall，this paper studies the spatial and temporal distribution characteristics and the statistical distribution of total uplift peak value under the action of irregular waves by using physical model test，and analyzes the relationship of the factors of wave height，relative wavelength，relative platform width，relative superelevation with total uplift force. The results show that，when Δh/Hs＞-0.5，the maximum total uplift force and the maximum impact pressure occur at the same time.The statistical distribution of total uplift peak value conforms to the three parameters Weibull distribution. The change of total uplift force with relative superelevation is approximately normal distribution，and extreme value occurs near Δh/Hs=0.2. It is suggested that in engineering design，the bottom of the platform should be arranged in the position of half wave height below the water surface rather than near the static water surface.

Abstract:As port construction，waterway maintenance，island reclamation and other projects continue to move towards the direction of longer blowing distance，harder bottom，larger digging depth and other complex conditions，higher requirements are put forward for dredging equipment selection，technical scheme design and construction organization.Regarding the complex site conditions of Dongying Port approach channel，poor sea conditions，scattered dredging area，long transport distance of dredged soil，difficult cost control and other problems，the comparison and selection of dredging equipment，pipeline redundancy design，transportation capacity calculation and construction combination optimization are carried out for the construction scheme of ultra-long distance multi-point dredging. A set of special combined construction scheme of extra-long distance multi-point dredging for cutter suction vessel is designed，which is technically feasible，safe，environmentally friendly，convenient and economical，and can provide reference for similar dredging and filling projects.

Abstract:In the design of cofferdam section，the stability of the cofferdam body is usually considered as only the internal filling sand，which will lead to the design of the cofferdam section is not economical and extend the construction period. At present，there is no relevant code in China to guide the stability calculation of geotextile cofferdam considering the effect of bag reinforcement. In view of this problem，by analyzing the reinforcement effect of geotextile and using the method of calculating the geotextile reinforcement effect of reinforced structures abroad for reference，a calculation method is proposed to consider the reinforcement effect of the bag cloth by checking whether the maximum resistance provided by the bag cloth satisfies its allowable tensile strength. The practice shows that this method can optimize the section of cofferdam body，shorten the construction period and save the investment.