Study On Seismic Performance Of Steel Structure Adding Layer In Reinforced Concrete Frame Structure

The adding stories of steel structure are promoted to be a form of building adding layer and transformation. It has the advantages of light weight, good anti-seismic performance and convenient construction. Compared with reinforced concrete structure, it has obvious advantages in technology, economy, safety and other aspects. The adding stories of steel structure have a widespread application in our country, but design method is not perfect now. Only the adding part of the completed adding stories of steel structure projects is calculated and designed, and the construction in the completed projects completely rely on experience, lack of a theoretical basis as a guide. The existing national standard cannot meet the need of design. Adding stories of steel structure to reinforced concrete structure forms a new hybrid structure, the periodic, damping ratio, stiffness, seismic performance in the hybrid structure have been changed, it is not scientific to only design the adding part. For the hybrid structure, it is necessary to have an integral calculation on the structure, also the seismic calculation.This paper studied the adding stories of steel structure Based on the reinforced concrete frame structure. It summarized the research status of the adding stories in steel structure, application of engineering in home and aboard, the related technology in the structure, the basic theory and method of static and dynamic analysis under seismic action and the finite element theory. PMSAP finite element analysis software is used to analyze the seismic performance of a four story reinforced concrete frame structure with adding two stories of steel structure in Tian ge-zhuang, fengtai district of Beijing. The analysis results show that: compared with the original structure, the hybrid structure has a lager internal force and displacement. A weak layer is formed in the adding stories. And the hybrid structure has a longer natural period of vibration, which can reduce seismic effect of the original frame structure.