Abstract:Aiming at the problem that the structural stability calculation for ecological landscape embankment with a wide platform breaks through the applicable scope of the codes，the physical model test is carried out. Firstly，we determine the main functions of embankment design according to the use requirements；secondly，we preliminarily determine the design section of embankment through the theoretical calculation of the stability and wave pressure of wave wall and armor block；finally，we verify the design section based on the wave model，compare and analyze the theoretical calculation and test data. The results show that：the distance between the seawall and the toe of the embankment with a wide platform should be greater than 1.5 times of the wavelength. Under this condition，the wave overtopping is small，and the greening can be planted back to the sea，so the effect of wave force can be ignored in the stability verification for the seawall. At the position 1 times the wavelength from the embankment toe，the stable and reliable type of armor block should be selected，and the wave dissipation effect is obvious. The research results provide experimental verification and reasonable suggestions for the design of ecological embankment with a wide platform.

Abstract:To study the influence of backfilling to the pile of the bridge near the shore side，we analyze the interaction of the Yushan reclamation and the pile foundation of the Yushan Bridge combining with the actual project，use the three-dimensional consolidation finite element method by ABAQUS to carry out the solid-liquid coupling analysis considering the soil seepage and the interaction of foundation，bridge pier pile foundation，and soil，simulate the process of backfilling and its influence to the bridge approach，foundation and bridge pile of the Yushan Bridge，and obtain the influence of land backfill on the Yushan Bridge under the interaction of soft foundation seawall and bridge.The results show that land backfillcan increase the settlement and displacement of the Yushan Bridge.

Abstract:For large-scale reclamation projects，the closure earthwork of the land boundary is an important design content to ensure stable penetration of the embankment and isolate internal and external water systems to meet high environmental protection requirements. However，the traditional closure earthwork by grabbing mudflats and backfilling in layers has the characteristics of low construction efficiency，weak soil strength，and difficulty to use land in closure earthwork areas，which often become a key issue that restricts the progress of the project. Based on the design and construction of the closure earthwork of the Zhoushan Green Petrochemical Base Reclamation Project，we have realized large-scale closure earthwork fast backfilling and hardening through the application of soil solidification technology. At the same time，combined with engineering practice，we summarize the main points of the application of the key technical issues when solidified soil is used as closure earthwork and the existing problems.

Abstract:Aiming at the problem that the reliability index calculated by the traditional reliability design method in the foundation reliability analysis is undersized and the failure probability is oversized，we apply the random field theory to the foundation reliability analysis. Combining with a large number of geological exploration data obtained in the process of building the green petrochemical base in the Yushan area，we discuss the rationality of determining the correlation distance of soil layer by improved recursive space method based on random field theory，count the correlation distance and variance reduction function value of the typical soil layer in this area，and apply it to the reliability analysis of slope stability. The results show that the application of random field theory to the analysis of foundation reliability has an important promotional value. The improved recursive space method is easier to determine the correlation distance value of soil property indexes，and the reliability index obtained by variance reduction of foundation soil strength indexes cohesive force and friction angle is more in line with the safety degree of engineering practice.

Abstract:Aiming at the complex conditions of the connection embankment between blasting compaction and plastic drainage plate，we study the site selection and treatment method of the connection position. Based on the analysis of the geological conditions within the scope of the embankment foundation，we combine with the factors such as the construction sequence，overall stability，differential settlement，and project investment of the sea embankment，select the embankment section with thin soft soil layer，thick sand layer and axis corner as the connecting position. Based on the influence of blasting vibration，we reduce the blasting compaction advance progress in connection position，reserve the safety distance of drainage plate，implement the blasting compaction first，then implement the drainage plate，use the simplified Bishop method to check the stability of the embankment in the connecting section，add counter pressure platform to make a smooth transition with the adjacent embankment，and verify the effect on the site. The results show that selecting the reasonable connection position can effectively reduce the project investment，and ensure the safety and reliability of the sea embankment as well as the smooth connection of the plane.

Abstract:Aiming at the characteristics of a large-scale reclamation project of offshore islands and reefs，such as large scale，heavy wind and waves，complex geological conditions，and urgent land demands，the key technologies of reclamation engineering are studied. Based on the reclamation project of the Zhoushan green petrochemical base，and the analysis of project scale，hydrological characteristics，geological conditions，and construction period requirements，we summarize the key technical problems of diking，seepage control，cutting mountains，reclamation，and foundation treatment，and propose the solutions to the key technical problems such as blasting silting，foundation seepage control，rapid land formation，and settlement control，then verify the treatment effect of key technical problems combined with the implemented projects. The research guides for the design of large-scale reclamation of offshore islands and reefs.

Abstract:The reinforcing scheme of the seawall is studied because of the complex and changeable geological conditions of the foundation in the north levee of Da-xiao-yushan. 1）The characteristics of seawall foundation with deep soft soil and deep groove are analyzed，and the geological characteristics are summarized. 2）The stability of typical sections with different geological characteristics，especially deep groove sections are analyzed by the arc sliding method. 3）The optimization suggestions for structural schemes are proposed. The research results show that it is reasonable to use the blasting compaction foundation reinforcement scheme，and the range and elevation of the rock platforms have an important influence on structural optimization. The optimization scheme can effectively reduce the amount of rock and the cost.

Abstract:Relying on the Yushan Bridge connection area project，it is determined that the permanent embankment shall be reinforced with the sunken tube and gravel columns composite foundation based on basic design information. The Slide and Lizheng software are used for the analysis of the stability and settlement of the dike，thus the corresponding inspection requirements are proposed. The test tube inspection data and theoretical calculations are rechecked，and the recommended values of related parameters in the design of foundations similar to sunken tube and gravel columns composite foundation are provided.

Abstract:To maintain the natural ecological environment of the seas and islands，it is necessary to build a sea-linking structure on the dike. However，the construction of the structure is often affected and restricted by the geological and surrounding complex environmental conditions，leading to technical problems such as difficulties in structure selection and seepage prevention. Taking the remediation project of a sea island for the green petrochemical base in Zhoushan as an example，we study key technologies including structure selection，seepage prevention，structural calculation，and construction technology aiming at the complex conditions of the riprap foundation and the restricted sea environment，and propose an empty box structure plan for seepage prevention of punched plastic concrete piles and a construction plan for a temporary water-stop cofferdam with high-pressure jet grouting piles on a rock dump，which better solves related technical problems and may serve as reference for similar projects.

Abstract:Aiming at the problems of difficult hole forming and serious slurry leakage in riprap foundation，we analyze the successful cases of seepage control of other projects under the condition of riprap foundation based on the geological investigation of the riprap foundation of petrochemical base，compare the similarities and differences between the geological characteristics and successful cases in the riprap foundation. Combining with the hole forming technology of pneumatic down the hole（DTH）hammer，we propose the anti-seepage measures of using pneumatic DTH hammer combined with plastic concrete occluded pile in deep riprap foundation. In the process of drilling with a pneumatic DTH hammer，casing wall protection technology can effectively solve the problems of hole collapse and slurry leakage in the process of pile forming，and ensure the construction quality of impervious core. The admixtures added into the ordinary concrete for the plastic concrete occluded pile can improve the impermeability of the occluded pile and adaptability to the deformation of the foundation. The results show that the pneumatic DTH hammer combined with plastic concrete occluded pile is an effective and reliable anti-seepage measure in a deep riprap foundation.

Abstract:How to predict the partially penetrated settlement of soft soil under plastic drain plate is a difficult problem in the design of large area thick soft soil foundation treatment process. Based on the foundation treatment process of the Yushan reclamation project，we combine with observation data of settlement from the beginning of construction to the end of construction，analyze the settlement and settlement history of typical areas，compare the final settlement calculated by the measured settlement data with that calculated by the theory，and analyze the reinforcement effect of deep plastic drainage plate. The results show that the drainage efficiency of the plastic drain plate below a certain depth rapidly attenuates，resulting in the consolidation rate falling behind the theoretical calculation rate. The settlement under the plate should be corrected when the final settlement is calculated by the hyperbolic method combined with the measured data.

Abstract:To solve the problem of the large-scale earthwork construction organization management with difficulty and high intensity，we carry out the management overall the technology，quality，progress，and cost control in the construction process. Relying on the reclamation project of Daxiaoyushan，we analyze the key points and difficulties in each stage and aspect in the construction process of the super-large scale earthwork project and make a targeted solution. Through the whole process control of planning，paying attention to details，strengthening the pre-planning，in-process control，and post-analysis，we propose the new management methods in quality，progress，safety，contract cost，measurement，etc.，finally achieve the balance of stone supply and demand.

Abstract:To solve the problem that a large number of silt bulges at the head of the deep soft foundation and affects the bottom falling effect at the embankment gap，we carry out an analysis and research on the closure method of the embankment gap. Based on the Yushan south embankment project，we firstly analyze the charging technology of blasting compaction and measure the thickness of silt bulge，and then determine the width of the embankment gap according to the flow velocity. Finally，the embankment structure at the gap is formed by setting a temporary dam and blasting several times to both sides of the dam. The drilling test results show that the quality of blasting compaction and bottom falling at the embankment gap is good，and the closure method can meet the requirements of the design section.

Abstract:On the premise of the land demand of the green petrochemical base in Zhoushan，aiming at the layout of reclamation for Da-XiaoYushan sea area with high sediment concentration and current velocity，based on the full understanding of natural environmental conditions，and combining with the research results of the current and sediment model，we analyze the different reclamation layout schemes for Zhoushan green petrochemical base. It is proposed that the shallow waters in the island flow shadow area should be fully utilized in conjunction with land use requirements，and the reclamation layout should comply with the main direction of tide current，and an ecological priority concept shall be adhered to. It may serve as a reference for reclamation projects in offshore island areas.

Abstract:Due to multiple factors such as environmental protection，safety，and shoreline resources，more and more large-scale petrochemical projects will be constructed on offshore islands in the future，and port shoreline utilization is becoming a key technical problem to be considered in such projects. Zhoushan green petrochemical base is the largest typical petrochemical project on offshore islands，with no land transportation connecting to the mainland. Based on the characteristics of offshore islands and petrochemical projects，this paper classifies and arranges the port shoreline through the study of natural conditions，public utilities，and project construction and operation requirements，puts forward the port shoreline utilization scheme for the large-scale petrochemical base of offshore islands，and summarizes key issues needing attention in similar projects.

Abstract:We employ the 2D tidal current numerical model （MIKE21-HD） to build a current model in the Da-xiao-yushan water area，which is validated by observed data. In view of the complex tidal current conditions between islands in Da-xiao-yushan water area，the influence of the reclamation project on the surrounding hydrodynamic conditions is simulated by using the numerical simulation of the tidal current based on this model. The simulation results show：1）The influence scope of the reclamation project is mainly concentrated in the vicinity of the reclamation area，without affecting the hydrodynamic conditions of the large-scale sea area. The average tidal velocity change is basically within 0.5 m/s. 2）1.5～2 m/a siltation occurs in the weak current areas on the east and west sides of the reclamation area，and the seabed erosion and siltation rate in the remaining waters is basically below 1m/a. The reclamation project is feasible.

Abstract:The existing Yushan Islands reclamation has caused the hydrodynamic change and reformed the surrounding seabed. By comparison of the bathymetry before and after the construction，and referring to the numerical model results，we know that the south and north deep water channels of the islands area further grow，and siltation occurrs in part of the nearshore area. The bathymetric evolution leads to a positive influence on the port water depth maintenance in the deepwater area，improves the water depth condition in front of the coastline，and contributes to the future construction of large quay berths. However，it increases the difficulty of the water depth maintenance in the nearshore berth area and the further reclamation on the west area at the same time.

Abstract:Typhoons and heavy rain are the main causes of the flood disaster in Zhejiang island areas. Petrochemical bases in island enclosures have special requirements and characteristics on the site pattern，drainage water level，and drainage water quality. Taking the Zhoushan petrochemical base as a research object，this paper establishes the one-dimensional hydrodynamic model in the study area which combined with island region typhoon rainstorm characteristics，petrochemical base site layout requirements，and drainage conditions. Not exceeding the river target level of the river is the control requirment. Through the simulation analysis of different working conditions，a better drainage system and engineering scale are determined to ensure the safety of petrochemical base drainage.

Abstract:Aiming at the water area layout of large bulk cargo terminal under the complex water conditions in offshore islands and reefs area，based on the preliminary research and design work of the supporting terminal project of the Zhejiang petrochemical refining-chemical integration project （phase I dry bulk），we analyze the key factors that need to be considered in the layout of terminals in offshore islands and reefs area. We have carried out hydrological tests and research on tidal current and sediment mathematical models，and proposed a comprehensive utilization plan for the F-shaped layout of the first-line and second-line terminals. Since the operation of the project，the design parameters of the terminals water areas can adapt to the complex current conditions，and can meet the requirements of navigating and berthing （un-berthing） of ships，thus the layout of the terminals is reasonable.

Abstract:According to the latest industrial planning and overall layout of Zhoushan Green Petrochemical Base，we carry out the planning adjustment of the Yushan Port. Through analyzing the effect of the implementation of the Yushan Port planning，we carry out the analysis of the transport demand and the prediction of the design ship type，propose the scope and the key points of the planning adjustment，and summarize the principles of the planning adjustment. The principles concluded are as follows：according to the miniaturization characteristics of a chemical tanker，a rational arrangement of the berth is carried out；specialized container terminals can effectively provide loading and unloading and save coastline resources；the dock form reasonably can be arranged according to berth grade demonstration. The results show that the adjusted planning scheme can save the engineering investment，improve the loading and unloading efficiency，and save the resource of the port shoreline.

Abstract:To study the influence of different construction schemes on the landing trestle of the pipeline，we combine with the actual engineering case of 40 million t/a refinery integration project，compare the two schemes of the upper structure including the pre-stressed concrete box girder structure and the large-span steel pipe tie-bar arch bridge + prefabricated small box girder structure，carry out the comprehensive consideration from the aspects of economy，the quantity of work，the structural durability，and the late maintenance，and propose the recommended scheme and key points of construction technology. The results show that generally it is convenient to use the pre-stressed concrete box girder structure for construction，and the number of pile foundations is more and safer. Moreover，this structure has a good self-corrosion protection effect and less maintenance in the later period. Considering comprehensively，when the product pipeline needs to land on the trestle，the pre-stressed concrete box girder structure should be preferred for the upper structure design of the trestle scheme. When designing the structure of the pre-stressed concrete box girder，it is necessary to reasonably control the pre-stress tension time，accurately analyze the stress characteristics of the structure and adopt appropriate pre-stress technology to ensure the suitability of construction work and the actual environment.

Abstract:The Yushan Green Petrochemical Base has formed the land area through the large-scale reclamation. Compared with the original natural reef terrain，the boundary conditions such as wave，tidal current，and bottom topography in the harbor area have changed after reclamation. To reasonably design the wharf structure and meet the normal use after completion，we analyze the design conditions including ship type，cargo type，use load，wave，tidal current，seabed scouring and silting，port construction status，and marine environment corrosion，and solve the key problems including the selection of position and azimuth of wharf apron，selection of hydraulic structure and assurance measures of structural durability in Yushan Phase I project. The results show that the wharf structure is safe and reliable and in good use since it is fully completed and put into operation in 2019.Various structural design parameters have been well verified. The construction of Yushan Phase I project plays a huge economic benefit and social benefit.

Abstract:The internal force of piled wharf transverse bent is usually simplified as a plane structure to calculate，but the end bent of the wharf as the stressed bent of the bow and stern cables，is affected by the adjacent structures. The pile foundation layout of end bent is different from other bents，and the simplified plane calculation cannot accurately reflect the force and deformation of the end bent. Based on the example of pile foundation layout design of Yushan ash loading wharf，we use the plane calculation method and space calculation method to compare and analyze different pile foundation layout schemes of the end bent of wharf structure under horizontal load，and obtain the differences of calculation results of internal force and deformation of each pile foundation under different calculation methods and pile foundation layout schemes. The results show that for the symmetric horizontal load，the axial force of pile foundation calculated by the plane calculation method is equivalent to that of pile foundation of end bent with the free end of wharf structure. For the asymmetric horizontal load，the axial force of pile foundation calculated by the plane calculation method is generally larger than that calculated by the space calculation method. The displacement of the wharf structure is reduced to a certain extent after the end bent is strengthened with double row piles.

Abstract:Aiming at the fire protection design issues of the first phase reconstruction project and the second phase of the Zhejiang petroleum chemical liquid bulk terminal，the existing fire protection facilities of the terminal are compared with the relevant regulations of JTS 158—2019 Code for fire protection design of oil and gas chemical terminals. Contradictions between the fire protection design of the Zhejiang petroleum chemical first phase project and the current fire protection codes are obtained，and what needs to be improved is pointed out. In the future，improvements can be made in the fire protection design of the first phase reconstruction project and the second phase.

Abstract:To save the project investment of oil terminal，reduce the construction difficulty and shorten the construction period，in view of the typical island near-shore geological conditions with large rock surface undulation and varying thickness of overburden layer，we compare comprehensively the traditional rock embedded pile structure，anchor rock pile structure and new combined pile structures with steel pipe pile core filled with concrete，and recommend the combined pile scheme with steel pipe pile core filled with concrete. The construction technology，technical innovation，and economic effect of this solution are introduced，which may serve as reference for the design of piled quay structures under similar complex geological conditions.

Abstract:The Yushan wharf not only has the function of container transportation but also provides transportation services such as sand，steel，and heavy cargo during the construction of the rear green petrochemical base. For this characteristic，it is proposed to integrate the construction of the multi-purpose wharf and heavy cargo wharf. Due to the rational layout of the wharf，and adopting the structure of the combination of longitudinal beam slab and pier adopted in the section of mast crane，the construction quality and safety are ensured，and the construction progress is speeded up.The implementation effect is quite satisfactory.

Abstract:Aiming at the problem of vapor recovery and treatment of large terminals with multiple liquid bulk products，large flow rate，and high emission standard，combining with the 40 million t/a refining integrated project （phase I） oil and liquid chemical jetty design of Zhejiang Petroleum Chemical Co.，Ltd.，we analyze the principle，characteristic and applicable products of each vapor recovery process，summarize the combined process flow of vapor recovery and treatment，and draw the conclusion that under the requirements of high emission standard，the catalytic oxidation process should be added to the vapor recovery treatment process to ensure that the exhaust gas meets the emission standard. Separate pretreatment of vapor should be based on various factors such as melting point，vapor partial pressure，polymerization，and treatment capacity.

Abstract:To evaluate the characteristics of soft soil in the Yushan Island sea area，we research the physical and mechanical property indices and spatial distribution development characteristics of soft clay layer based on the analysis of a large number of investigation data from the drilling，vane shear test and geotechnical test data in the sea area near Yushan Island，and conclude that soft soils in the Yushan Island sea area are mainly silty，powdery clay layers interspersed with thin layers of more chalky sand，and its thickness and depth of burial gradually increase from the pre-hill alluvial zone to the coastal zone. Meanwhile，we propose the soft ground treatment method in the Yushan area.

Abstract:Based on engineering examples offshore in the Yushan area and geotechnical engineering investigation results，in view of the variability of the vertical and horizontal engineering geological characteristics of the thick soft soil layer widely developed in the shallow part of the Yushan offshore，we carry out segmented analysis and comparison by the method of mathematical statistics，probe into the variability of the physical and mechanical properties under different buried depths and reveals its variation law with the buried depth，to provide technical reference for identification of the engineering geological characteristics of thick soft soil and determination of the scope and depth of foundation treatment，and foundation reinforcement technology. The analysis results show that with the change of the buried depth，the engineering geological property of thick soft soils changes，and the engineering geological property at the bottom are better than that at the top.

Abstract:The sea condition of the Yushan reclamation project is complex and the soft soil is very developed. The in-situ undrained shear strength of saturated soft clay is an important geotechnical index for foundation design and foundation treatment. Therefore，the accuracy of the vane shear test is greatly improved by using the electrical vane shear instrument，selecting the appropriate operation platform and the key technology of the self-developed shipborne“static”platform，which greatly improves the accuracy of the marine vane shear test，and solves the problems of large dispersion and data distortion in the conventional offshore vane test. The technical achievements provide strong technical support for the engineering design while providing a reference for similar projects.

Abstract:In view of the problem that soft soil in the Yushan sea area is very developed and has a great influence on the engineering construction，we analyze the results of the soft soil geotechnical test in this sea area，including the influential factors such as physical and mechanical indices of the ③2 silty powder clay layer. Using mathematical-statistical methods and fitting the main indicators for correlation，we obtain the results which show that the layer has poor engineering properties and dispersion of conventional physical test indicators is small；the natural moisture content and pore ratio，liquid limit and plastic limit，plasticity index have obvious linear correlation characteristics；shear strength increases with depth，showing the rule of cross-slab in-situ test （in-situ）＞ straight shear fast shear＞ consolidation fast shear.

Abstract:GPS RTK（real-time kinematic ） survey is affected by the satellite signals and transmission of RTK radio stations，the mobile station cannot obtain the fixed solution. For solving this problem，the working principle，field operations，and data processing methods of GPS PPK （post-processed kinematic）are studied. In the survey of Yushan marine，the method of known point check and elevation comparison between the RTK inspection line and the PPK main survey line is used to statistically analyze its measurement accuracy. The results show that when the application of RTK is limited，the survey accuracy of PPK is consistent with that of RTK.The combined application of PPK and RTK can improve operational efficiency and data reliability，which not only saves the survey costs but also shortens the construction period，therefore PPK technology is worthy of promotion in the marine survey.