Analysis On Progressive Collapse Vulnerability Of Shear Wall Structure With Some Supporting Frames Under Seismic Force

The safety,reliability and stability of structure design was always being the constant criterion of our engineering,but occasional emergencies were always constituting a threat to the buildings around us. Since the Ronan Point incident of England, study on progressive collapse gradually flourishes around the world. With the continuous efforts of all scholars for decades, more and more research has been received about progressive collapse. Our researchers on progressive collapse didn’t go as earlier as foreigners, and also contents involved in our standard were less. So study on progressive collapse is of great significance not only in science, but also to improve the standard of our Country.This paper goes from the introduction and research especially on vulnerability of progressive collapse. The collapse point of structure is decided by the law of collapse. By theoretical derivation of vulnerability formula, this paper mainly focuses on the vulnerability analysis of structures. Meanwhile the frame supported shear wall structures are suited by establishing finite element model in Midas. This paper employs incremental dynamic analysis method, analysis on progressive collapse vulnerability of structures are based on inter-storey displacement angle and Sa(T1,5%).Then fragility curves for each structures are obtained via analysis of numbers from Midas in various performance levels. As a result, which are designed in strict accordance with current specification can all hit the target "no collapses in big earthquake" The axial compression ratio becomes the dominant aspect in structural vulnerability. When converting layer position unchanged, with the increase of axial compression ratio, seismic resistance of structures decrease, it is difficult to achieve yield strong column weak beam mechanism. When the axial compression ratio is similar, the vulnerability of higher conversion layer is more obvious than lower conversion layer.So the design of structures should use low convert position as possible. The conversion layer’s position is also the weak storey, the column is easily destroyed as bending shear failure mode under seismic forces then leading to progressive collapse. High conversion layer structure can absorb more energy compare with the lower conversion layer structure. So we must control the axial compression ratio of the frame supported shear wall structure to provide more margin and ductility to make the structure more safe.