Dynamic Response Analysis Of Group Piles In Earthquake Based On ANSYS

Pile-soil interaction is a hot research topic in the field of geotechnical earthquake engineering. Due to complexity of the problems such as the dynamic behavior of soil, pile-soil interface of the dynamic contact behavior and piles-piles interactions, pile-soil interaction is a very complex phenomenon in practice. With the rapid development of social economy and the reduction of land resources, more and more heavy plants and high-rise buildings are putting up. Pile foundations appear more frequently and complex in the project, which require the better design of the pile foundation, particularly in the design of the dynamic loading pile put forward higher requirements. Based on the shaking table, this paper studies the earthquake pile-soil interaction phenomenon by the finite element method.The dissertation firstly designs the pile-soil-structure interaction system by shaking table tests, including the adoption of similar relations, soil box model selection, and test loading system and etc. Then the author explores the foundation calculation model established by finite element software ANSYS, and researches some key issues, such as soil constitutive model selection , treatment of pile-soil contact problems, the use of symmetry and the constraint settings and etc. After calculation, the numerical simulation results agree well with the shaking table test results, proving that the numerical simulation is effective. The author analyzes the results in the factor of the acceleration response, the displacement reaction and the internal forces change of the pile. And gets a series of results which the different frequency of earthquake with the same energy effects on the structure, such as acceleration response, additional stress produced by vibration of adjacent pile, distribution of the bending moment and etc. And has a new understanding for the loading mechanism of piles under earthquake. Finally, the article thoroughly discusses the group pier system changing with pile length, the effects that the soil layer work on the seismic performance. The analysis of the unit length maximum relative displacement and internal force of piles shows that pile length increases have positive effects on the seismic. The nonlinear effects that the soil layer produced should be considered in foundation design, especially near the soil interface.