Analysis on the Effect of Stair for Aseismic Performance of Base-Isolated Structure under Near-fault Ground Motions

摘要

In order to study the aseismic performance of base-isolated structures considering stair under near-fault ground motions, two base-isolated structure models were established in this paper, which one considered the effect of stair and another didn't. four near-fault ground motions and four far-fault ground motions from the Chi-Chi earthquake of Taiwan were selected as input excitation, two models are done the time history analysis by numerical analysis software Matlab2010. By contrast with the calculation results of two models each other, the effect of stair on aseismic performance of base-isolated structure under two kinds of ground motions was studied, the change trend of aseismic performance of two base-isolated structure models under near-fault ground motions was discussed. The results show that the deformation of upper structure of base-isolated structures is reduced obviously considering the effect of stair under near-fault ground motions and far-fault ground motions, the story shear force ratio of base-isolated structure is decreased significantly, the aseismic effect is better, the aseismic performance of base-isolated structures improves well. The effect of stair for the aseismic performance of base-isolated structures is low under near-fault ground motions, but it has significance in safety and reliability of base-isolated structures.