Seismic Response Analysis Of Base-Isolated Structures With A Tower

In recent years, due to many earthquakes occurred in the western areas of China, people have higher and higher requirement for building safety. At the same time, building base-isolated technique has become a popular direction of research. Despite a great deal of theoretical research and experimental research, both domestically and abroad, have been done in the anti-seismic performances of structure, the number of researches on base-isolated structures with a tower is still rather limited.This paper first introduces the basic principle of the base-isolated structure, the mathematical model of lead rubber bearing and two frequently used dynamic analysis methods of base-isolated structures. Then, this thesis is based on the engineering background of a base isolated building in Shenyang, adopt software SAP2000 of finite element at the same time, set up a practical engineering and two comparison models, and compare the difference between the anti-seismic performances of three models. Finally, this paper discusses how the height and strength of the towe influence on its seismic response.This paper focuses on key factors show the anti-seismic effect of structure under rare event of earthquake, including the Acceleration response, the inter-storey displacement, the inter-storey displacement-angle and the inter-storey shear force. The main conclusions are as follows:1. Compared with the non-isolated structure, the natural vibration period of base-isolated structures is greatly extended. In addition, after the base isolation is adopted, the existence of the small tower will lengthen natural vibration period of the main structure, but the effectiveness is not very obvious.2. The base-isolated building has the great advantage of anti-seismic performance, the acceleration response, displacement response and stress response are obviously reduced. In addition,after the base isolation is adopted, the"whiplash effect"of structures does not eliminate,But it is better than the non-isolated case.3. After the base isolation is adopted, the existence of the small tower has inhibiting effect on the acceleration response of main structure, and it has a slight amplification effect on the inter-storey displacement-angle and the inter-storey shear force of the main structure.4. Nnder the prerequisite tosatisfy the function, reducing the height of the tower and choosing reasonable stiffness of the tower, it is the effective way to control the"whiplash effect"of the base isolation system with the tower.