Horizontal Bearing Capacity Analysis Of Embedded Large-Diameter Cylindrical Structure Under Wave Loading

With the expansion and development of the urban area in China,tensions of construction land in the coastal areas have prompted the construction of the project to gradually develop into the deep water area of the outer sea.However,the foundation conditions of the deep-water area are complex,mostly silt soft clay,which has low bearing capacity and can not meet the bearing capacity requirements of the traditional gravity-based foundation.In recent years,the new structure introduced-embedded large-diameter cylinder structure can be directly applied to the soft clay foundation,especially suitable for the construction of deep-water wharf and other offshore structures in weak seas,but also to meet the needs of rapidly building the island.For example,Dubai's Palm Island,Japan's Kansai Airport,artificial islands of the China's Hong Kong-Zhuhai-Macao Bridge and artificial islands of the Shenzhen to Zhongshan cross-sea channel.Although scholars have done a lot of research on the experimental research of embedded large-diameter cylinder structures,the research on the bearing capacity and deformation of structures,the calculation methods of stability and the stability deformation of soft clay under cyclic loading,considering the strain softening effect of soft clay,the research on the stability of embedded large-diameter cylinder structure and the reinforcement measures to be taken when the bearing capacity of the soft clay foundation does not meet the engineering requirements are relatively few.Therefore,with reference to a project example in this paper,taking into account the strain softening effect of soft clay,carrying out a series of analysis on the bearing capacity of embedded large-diameter cylinder structures on soft clay foundation under the action of wave loads,and put forward the reference value for practical engineering Suggestions,the main contents and conclusions are as follows:1.Combining with a practical engineering case in China,using the finite element software ABAQUS,through the secondary development,a embedded large-diameter cylinder structure model under cyclic loading is established.The horizontal ultimate bearing capacity of the large cylinder structure is compared and analyzed without considering and considering the strain softening effect,the results show that under this condition,the ultimate bearing capacity of the structure is reduced obviously when the strain softening effect is taken into account.2.By calling the user subroutine to realize the secondary development,taking into account the strain softening effect of soft clay caused by the cyclic loading of the wave,the model is simulated by finite element method.The depth L of the large cylinder structure,the height of the wave loading point Li,the initial undrained shear strength su0,the sensitivity of soft soil St,the relative ductility of saturated clay ?95 and other parameters were changed parameters analysis to further clarify the above parameters on the horizontal cylinder ultimate bearing capacity.The results show that the variation of bearing capacity of three parameters of structure depth L,initial undrained shear strength su0,relative ductility ?95 of saturated clay is the same as that of large diameter cylinder structure.The larger the parameter value is,the higher the bearing capacity of the structure will be,the initial undrained shear strength su0 in the three parameters has a more significant effect on the bearing capacity of the structure;while the changing law of the bearing capacity of the two parameters of the height of the wave load Li and the sensitivity of the soft soil St is opposite,That is the parameter value increases,but the bearing capacity of the structure decreases.3.Considering the strain softening effect of soft clay,the finite element numerical analysis is carried out in the case of embedded large-diameter cylinder structure in deep clay foundations.When the large cylindrical structure on soft clay foundation does not meet the requirements of the upper structure,discussed three different reinforced conditions(that is,the soft clay inside the cylinder foundation,outside the cylinder soft clay foundation as well as inside and outside the soft clay foundation plug plastic drainage board),through the calculation and analysis,the results show that inserting and draining the soft clay foundation in the cylinder has no significant effect on improving the bearing capacity of the structure,and outside the tube outside the soft plastic foundation plugged plastic drainage board reinforcement with the same time on the inside and outside the soft clay foundation plugged plastic drainage board reinforcement on the structure to enhance the carrying capacity of the same,are more significant,so from the perspective of engineering economy,It is recommended to adopt the method of reinforcing the plastic drainage board on the soft clay foundation only outside.