Research On Seismic Reinforcement Technology Of A Single-strap-frame Structure

The earthquake damage shows that if the single-span frame structure of primary and secondary schools is not designed properly,it is easy to produce weak floors,the structural safety redundancy is low,and the seismic performance of the structure is poor.At present,there are many single-span frame structures designed according to the requirements of class B fortification in China,which do not meet the requirements of the code.At present,the design method of building seismic reinforcement is mature and widely used in engineering practice.It is of great practical significance to choose a reasonable reinforcement scheme of single-span frame structure in primary and middle schools according to the comparison of seismic performance and seismic response of different seismic reinforcement schemes.This paper introduces the main forms of single-span frame structures in primary and secondary schools,and summarizes the main failure modes of single-span frame structures under earthquake action and analyzes the causes of earthquake damage in combination with the earthquake damage of single-span frame structures in previous earthquakes in China.The response spectrum analysis and elastoplastic dynamic time history analysis of single span frame structure with cantilevered gallery are carried out.The safety redundancy of single span frame structure with cantilevered outer corridor is low under the action of earthquake,and the structural deformation is large under the action of rare earthquake,and the local weak layer is easy to appear,and the vertical load-bearing members are easy to hinge out and collapse.In a belt cantilever verandah the weak link of single span frame structure,considering the construction is convenient,save cost and ensure normal use function etc,put forward additional shear wall reinforcement and adding support reinforcement buckling constraints and isolation bearing strengthening three kinds of solutions,based on different scheme for modal analysis,response spectrum analysis and dynamic elastic-plastic time history analysis,comparing its damping effect and the seismic performance of the structure.The analysis results show that the three reinforcement schemes can improve the seismic performance and enhance the anti-collapse ability.The shear wall scheme can significantly reduce the deformation of the first floor structure under earthquake action,while the isolation bearing scheme has the best effect on the reduction of the whole deformation.In addition,the feasibility and rationality of the structural reinforcement scheme are demonstrated by a practical reinforcement case of a single-span school building in Beijing,which can provide reference for the subsequent seismic reinforcement design of buildings.