Analysis on dynamic failure behaviors of steel double-layer grids supported by circumjacent steel columns used in a gymnasium with the function of earthquake victims shelter under disaster earthquake

摘要

In this paper, the elasto-plastic dynamic analysis on dynamic failure behaviors of steel double-layer grids supported by circumjacent steel columns used in a gymnasium with the function of earthquake victims shelter under disaster earthquake is carried out under EL-centro wave with SAP2000, and the appraisal results on their anti-failure performances are presented under strong earthquake action based on the plastic-hinge theory. In the analyses, the geometric and material nonlinear effects are considered simultaneously based on the plastic-hinge theory. The plastic development level of the rod, the deformed shape and the failure type and the ductility are estimated by plastic hinge principle. The results show that: Along with the growth of the seismic wave peak acceleration (shorted as PGA), structure developed from elastic into the elastic-plastic. The failure model of the structure under the earthquake wave action is due to overall elasto-plastic instability of double-layer grids. When the structure reached its failure critical limit, the development of the plastic hinges is sufficient and 24.5% of the rods enter into their plastic stage; The ratio of its maximal failure node vertical displacement and its short span is 1/51, The ratio of its maximal failure node horizontal displacement and its columns is 1/49; Its critical failure PGA is 771 gal, which is 1.9 times more than the official seismic fortification level of 8 degree (major earthquake, 0.2g) and can be served as earthquake victims shelter in the area of 8 degree seismic fortification; Its displacement ductility coefficient is 7.6,which shows the structure owns good energy dissipation capacity.