Study On Anti-Seismic Performance Of R. C. Frame Structure With Special-Shaped Columns

The R. C. frame structure with special-shaped columns is easy to form a weak floor at the bottom of the structure. So two solutions were proposed in this paper to solve this problem. One is increasing the limb length of the special-shaped columns in the bottom; another is using the rectangular columns in the bottom. Studies on the anti-seismic performances of the structure as a whole were carried out for both the two solutions.This paper introduces the basic concepts and design principles of the R. C. frame with special-shaped columns. Internal force calculation and reinforcement were carried out with structural design software PKPM for both the two solutions. Then the two solutions is studied via the the finite element model build by a finite element software SAP2000. The basic dynamic characteristics of the two models have been analysed. Two sets of actual seismic waves and a set of artificial seismic waves were selected for the two models. Based on the modal-superposition response spectrum method and elastic time-history analysis separately, the elastic seismic behavior analysis of the structures which acted by horizontal seismic has been made. The result shows that elastic seismic behavior is consistent for the two models. The anti-seismic performance and failure mechanism of the structure under rare earthquake are studied using the nonlinear time history analysis. Finally, change the height of the bottom storey, research the effect of the storey height on the anti-seismic performance of the structure under rare earthquake.The result shows:The two solutions both effectively overcome the problem of the R. C. frame structure with special-shaped columns at the bottom; the elastic seismic behavior is similar for the two models; in the elastic-plastic stage, the model with the larger special-shaped columns in the bottom controls the underlying displacement more effectively; When storey height of the bottom is in the appropriate range, the elastoplastic anti-seismic performance of the R. C. frame structure with special-shaped columns using the rectangular columns in the bottom is better than the R. C. frame structure with special-shaped columns using large special-shaped columns in the bottom obviously. The good failure mechanism was presented.