Pushover方法的准确性和适用性研究

Study on the Accuracy and Applicability of the Pushover Analysis

Pushover方法作为一种建筑结构弹塑性地震响应的简化近似计算方法和抗震性能评价方法已得到广泛应用。但由于其理论基础不严密,其准确性需要给予必要确认,同时其适用性也应受到一定的限制。本文以逐步增量弹塑性时程方法的结果为基准,分别以一个普通6层RC框架结构和一个18层RC框架-剪力墙结构为例,对Pushover方法的准确性和适用性进行了分析研究。结果表明,Pushover方法仅适用于以第一振型为主的高度不大的结构,且应采用两种以上的侧力模式;对于高阶振型影响较大的结构,该方法的准确性较差,承载力预测显著偏低。

The nonlinear static pushover analysis procedure is now widely used as a simple method to estimate the inelastic seismic response for building structures. However, the accuracy of the method still needs to be validated because of the inherent limitations in its theory. Besides, there are some limitations on the application of this method. In this paper, the accuracy and the applicability of the pushover analysis procedure are verified based on the incremental dynamical analysis method with a 6-storey RC frame and an 18-storey RC frame-wall structure. The comparison between the results of the two methods shows that the pushover method can be used only for low-rise building structures that their responses are controlled by the first modal. It is also shown that for the high-rise building structures which are much influenced by the higher modal, pushover analysis always gives the much lower capacity results.