Analysis On Ovetrurning Resistant Property Of Base-isolated Structures Subject To Near-fault Ground Motion

Base-isolation structure is a kind of system whose isolation layer is composed withrubber bearings setting between the upper structure and foundation. Layered rubber bearingswork through reducing stiffness of solation layer, extend of the natural vibration period ofstructure, increasing damping and reducing the seismic energy passed to the upper structure toachieve the effect of isolation.Base isolation technology has got accepted by the domestic and foreign academic andengineering circles because of its good shock effect,economy,durability and applicability.According to statistics, China’s base-isolation building area has been more than2millionsquare meters. The application and development of base isolation technology is closelyrelated to mechanical properties of base isolation and the process of earthquake responseanalysis theory of the isolation structure.In recent years, many large earthquakes have happened in our country. Huge damage caused bynear-field earthquake has increased remarkable, which caused the attention of engineer officials and experts.In all previous major near earthquake, the influence of near-field earthquakes to the structure have beenobvious, such as the Northridge earthquake in the USA, Kobe earthquake in Japan, Chichi earthquake inTaiwan and Wenchuan earthquake in China, etc. Studies have shown that, fierce response of the structureoften caused by the pulse effect of near-field earthquake have great influence on the isolation structure withlong cycle, by increasing the structural displacement and ductility demand of the structure. With the rapiddevelopment of modern architecture, many high-rise buildings emerged and base-isolated structure alsodevelop gradually from low-rise building to high-rise buildings. In this process, many design problems hasarouse, and one of the most important problem is the overturning resistance performance of thebase-isolated structure.In order to further study the influence of parameters of base isolation structure action on its overturningresistant, and to provide basic theoretical basis and the reference design for engineering application, siteconditions, earthquake intensity, Isolation period, natural vibration period and height-to-width ratio ofupper structure and velocity pulse in near field ground is analysed through SAP2000in this article.