Elasto-plastic Dynamic Analysis For The Structure With Base-isolation System

Seismic isolated structure system is a passive active control system, which is different from traditional anti-seismic structure system. Through setting isolation layer, earthquake energy is absorbed and dissipated and earthquake response of structure is reduced, so that the safe of structure is ensured. Isolated structure system changes the energy dissipation mechanism of traditional anti-seismic structure, i.e. the earthquake energy is absorbed and dissipated by energy dissipative device set in a isolation layer rather than by the structure and structure elements. This excellent energy dissipation characteristic can not be realized by traditional anti-seismic structure. After studying for thirty years, many research results of applied foundation theory and engineering application of isolation technique have been obtained. Up to now, near twenty countries and region in the world have constructed isolated buildings. The strong motion observation records of Northridge earthquake 1994 and Kobe earthquake 1995 have indicated that this isolated structure system is one of the effective and new type structure system for earthquake disaster reduction.In this paper, the seismic reduction effectiveness and earthquake response offrame structure building adopting base seismic isolation is studied. A finite elementANSYS program used to dynamic time history analysis was developed to analyze the character of the nonlinear structure. Beam-column elements modal and bilinear spring is used to describe the mechanic character frame structure. And a five stories frame structure with basement isolation, a same structure with basement isolation I and a same structure with basement isolation II are analyzed as a example in this paper. The El-centro earthquake wave was inputted on the structure. Some useful results are obtained through lots of comparative analysis.The research results illustrate that frame structure with basement isolation can reduce the horizontal earthquake response of superstructure effectively compared with traditional technique. This method is very effective, base shear, floor deformation, acceleration of isolation structure is less than no isolation structure. At the same time, because of superstructure seismic functionary decrease, seismic measure is less than no isolation structure distinctly. Accordingly obtain lowerbuilding price and improved house useful function.Because of particularity of basement isolation structure and current research is not perfect, So optimizing design is necessary, The contents and methods of optimizing design is studied. At the same time, According to the character of force and distortion, giving the construct desire.