Research On Caculation Method Of Horizontal Seismic Reduction Factor And Design Technology Of Pier In Isolated Structure

The earthquake not only causes structural damage, property loss on internal equipment as well as a large number of casualties, but also brings harm to the human spirit. Isolation technology can significantly reduce the seismic action of upper structure as a quite effective new method to defend and reduce horizontal earthquake disaster. In order to promote popularization and application of this high-tech in the field of earthquake engineering, this paper is according to the design and calculation of20isolated buildings in jining city xingtang guochui washington as engineering background,the theoretical analysis and practical project are used.based on the existed research achievements of isolation technology, and combined with the division of design method in latest code for seismic design buildings (GB50011-2010), the determination of horizontal seismic reduction factor is systematically analyzed, at the same time calculation program of pier is compiled, which providing reference for designer proficient in design context and method.Firstly, according to the characteristic of isolated structure, combined with the base shear method, the simplified calculation formula of shear ratio and overturning moment ratio is launched for isolation and non-isolated structure, moreover, comparative analysis of size relationship between the two is made by using matlab software. The study shows that:(1) the maximum of shear ratio locates in one layer in the case of both isolation and non-isolated structure, in other words shear ratio and ratio of overturning moment in one layer of structure can be compared directly for low multi-storey building, and the maximum of two is taken as determination of horizontal seismic reduction factor.(2) ratio of overturning moment is increasing obviously with the rising of total height in isolated building.Secondly, this paper is based on the design information of jining engineering example, through making the comprehensive summary and analysis of shear ratio and ratio of overturning moment data, the conclution is drown that:(1) since ratio of overturning moment increases in the mid-tall architecture with14-19floors, the determination of horizontal seismic reduction factor should be considered to calculate overturning moment ratio, and compare the maximum between shear ratio and story ratio of overturning moment.(2) when the number of floor in the isolated building is elevated to20or above, the story ratio of overturning moment is larger than shear ratio, the calculation of horizontal seismic reduction factor can be directly taken the maximum of overturning moment, this is consistent with theoretical conclusion.Finally, according to force transference mechanism of isolation bearing and the stress characteristics of pier, the design principle of pier in isolated structure is elaborated, the design procedure of short column and long column which are two different pier forms is developed by using the visual basic programming tool. Using this program can improve the design efficiency, which has deeper reference value for the further development of isolation technology in engineering application.