STUDY ON THE COLLAPSE-RESISTANT CAPACITY OF RC FRAMES WITH DIFFERENT SEISMIC FORTIFICATION LEVELS
Collapse safety is the most important objective of performance-based aseismic design.Buildings should have an enough safety margin to avoid collapse subjected to a severe or mega earthquake.However,current Chinese seismic design code for building structures does not provide an explicit design or a quantitative evaluation method for collapse-resistant capacity.In this paper,the collapse-resistant capacities and safety margins against collapse of multi-story reinforced concrete(RC) frames with different seismic fortification levels are quantitatively evaluated,with a collapse fragility analysis based on an incremental dynamic analysis(IDA).The influences of the axial compression ratio and the failure mode to the collapse-resistant capacity are discussed,and suggestions are proposed to improve the current design.