Dynamic Response Analysis Of Embedded Large-diameter Cylindrical Structure Breakwater Under Seismic Loading

The embedded large-diameter cylinder structure breakwater has a good adaptability to the foundation of soft soil,and it has a wide application prospect in port engineering.At present,the researches about it focus more on its stability and other static behaviors,while the results of dynamic researches are less.This paper mainly researches the dynamic response of the structure under seismic loading.The seismic action has short duration but great destructive power.When the seism acts,phenomenon of contact,detachment and slip and so on continue appear between the structure and soil,the interaction mechanism between the structure and soil is very complex.Seismic wave energy will spread to infinity,so it’s difficult to simulate the boundary conditions.In this paper,the three-dimensional model of the embedded large-diameter cylinder structure is firstly established.The contact between the structure and the soil adopts the Coulomb friction law in the tangential direction and penalty function in the normal.The foundation soil is simulated by finite-infinite element coupling method,which nicely solves the radiation problem of the seismic wave at the boundary.After analyzing the response of the large-diameter cylinder structure under seismic loading,Adopt a single factor analysis method to discuss the influence that cylinder height,diameter and shell thickness bring to the response.A coefficient was introduced to quantify the sensitivity of response indicators to different factor.According to the researches in this paper,horizontal displacement and vertical settlement are the main patterns of large-cylindrical structure under horizontal unidirectional seism while the rotation angle can be ignored.The impact degree of the three influencing factors from strong to weak to the horizontal displacement is: the diameter of cylinder body,cylinder height and cylinder wall thickness,while the vertical settlement is more affected by the cylinder height and cylinder diameter,and the sensitivity of the wall thickness is weak.The results of this paper can provide reference for seismic design of the embedded large-cylinder structure in practical engineering.