传统的Pushover方法未考虑竖向地震效应对结构水平位移需求的影响,当地面运动中竖向分量所占比例相对较高时,该方法很难对结构最大位移需求作出精确估计。通过对其进行改进,提出首先对结构按一定方式施加竖向地震引起的惯性力,随后进行结构水平向的多模态推覆分析,并按SRSS方法计算其最大位移需求。最后采用一多层混凝土框架结构对其进行验证,结果表明,该方法所得的楼层位移及层间位移角与非线性时程分析结果十分接近,具有较高的精度。
In the traditional Pushover method, the vertical earthquake effect, which has an impact on horizontal displacement, is not taken into consideration. When the seismic intensity in vertical direction takes a high ratio, it is hard to accurately estimate the maximum displacement demands on structure by the traditional Pushover method. Hence, the paper aims at making improvement on the traditional one. Firstly, the inertial force caused by vertical earthquake is enforced on structure according to certain means. Then, the multi-mode Pushover analysis procedures are applied in the horizontal direction of structure, and the maximum displacement demand is calculated on the ground of SRSS method. A multistory concrete frame is applied to testify this theory. The data shows that, using the improved method, the numerical results of floor displacement and story drift ratio are well agreed with the results from nonlinear time-history analysis, which demonstrated that the improved method is of high accuracy.