Pile-Soil-Structure Interaction Analysis Of Nonlinear Planar Structures Under Strong Earthquake

A large amount of test researches demonstrate that, the dynamic interaction of soil-foundation-structure system has a great influence on the dynamic characteristics of superstructure, and its seismic response may be remarkably changed. Moreover, for different soil composition and different types of superstructure, to some extent, the force and deformation characteristics of the interaction system are different. Compared with the traditional method of seismic design, this assumption that the foundation is rigid is reasonable in engineering accuracy range when the stiffness of foundation is very big and the stiffness of superstructure is very small. When the stiffness of superstructure is relatively close to that of foundation, the assumption will produce greater erroneous. Besides, because the pile is being widely used in the high-level structure, the study about seismic response analysis on pile-soil-structure interaction is very important.Based on previous researches, a new kind of the constitutive relationship about the soil was amended, and the finite element numerical simulation analysis of the seismic response for the pile-soil and pile-soil-structure interaction system was carried out using the ANSYS software. And the methods and laws of the seismic response were studied. The main achievements are as follows:(1) By carding the data and materials about the topic, the paper introduces firstly the research situation and development level about the interaction of soil-structure on home and abroad, and the analytical methods of dynamic pile-soil-superstructure interaction are summarized.(2)The finite element analytical methods of dynamic pile-soil-superstructure interaction are decision, including the establishment of movement equation, the solution of nonlinear dynamic equation, the selection of the unit, the input method about the earthquake, the division about the size of mesh, the simulation of soil border adopting sticky elasticity, the consideration about the damping and the gravity of the model.(3)Basing on previous research, Drucker-Prager constitutive relationship is amended by considering the influence of the principal stress, and which is applied in ANSYS. The feasibility of model has been validation.(4)The pillar-soil-superstructure interaction system analysis model of two-dimensional is established. The seismic responses of the pile-soil-structure interaction system underâ…¡andâ…¢sites were analyzed, when the superstructure, which was 5 stories and 10 stories or 20 stories, was frame structure, shear-wall structure, and frame-shear wall structure. By summarizing the reaction characteristics of its internal forces and deformation, some useful advice were derived.