Analysis On The Seismic Collapse Margin Of Multi-story Steel Frames

The problem of structural seismic collapse resistance has been highly valued by the engineering researchers. A large number of buildings were damaged by earthquakes in recent years. However the damage is different, such as minor damage, moderate destroyed and relatively serious even collapsed. How to reasonably evaluate the safety margin of structure under earthquake becomes an urgent question to be solved in the forefront of the seismic field.This paper summarizes the evaluation methods of the structural seismic collapse resistance, and introduces the collapsed criterion of judgment of the steel frame construction in the seismic collapsed simulation. Applying a new evaluation method—CMR (collapse margin ratio) method, this paper analyzes the seismic safety margin of multi-layer steel frame construction under the earthquakes.In order to evaluate the seismic safety margin of steel frames, this paper analyzes four steel frames with different section and different stories which are designed according to the"Code for Seismic Design of Building"(GB50011-2001) by the CMR method, and gets the corresponding collapse margin ratio, the system collapse overstrength factor and the collapse possibilities under the different ground intensities.