Analysis on Dynamic Failure of Steel Cable-Stayed Double-Layer Grids under Strong Earthquake

Abstract

In this paper, the analysis on dynamic failure behaviors of steel cable-stayed double-layer grids used in a gymnasium with the function of earthquake victim shelter 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. The plastic development level of the rod, the deformed shape and the failure type and the ductility are estimated. The results show that the failure model of the structure under the earthquake wave action is the complicated combination of strength failure and elasto-plastic dynamic local buckling in deferent areas of the structure; When the structure reached its failure critical limit, the development of the plastic hinges is sufficient and 59.5%of the rods enter into their plastic stage; The ratio of its maximal failure node vertical displacement and its plane diameter is 1/115; Its critical failure peak acceleration of EL earthquake wave when applied in the combination of three directions is 3655gal, which is 8 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 5.54,which shows the structure owns good energy dissipation capacity.