为考察pushover侧向力模式对桥墩地震反应的影响,以圆形双柱墩模型为例,进行了6个地震动作用下的非线性时程分析和4种常用侧向力加载模式的pushover分析,并以时程分析结果的平均值作为对比基准。研究表明,不同侧向力加载模式计算结果存在一定差异,静力法计算结果误差最大;给定振型下的模态法误差较小,在不同轴压比下的计算结果分布规律与时程法的吻合最好;常量加速度法的误差基本介于前述两种模式之间;M-phi曲线法的误差随着轴压比的增大而变大;与时程法相比,模态法的计算结果比其它方法更为合理。
A circular double-column piers model was chosen as an example to investigate the effects of lateral loading pattern in pushover analysis of the seismic responses. The nonlinear time history analyses under six earthquake ground motions and pushover analyses with four common lateral load patterns were performed respectively. And the average value of six time history analyses was used as the benchmark for comparison. The results indicated that there were some variances among the different lateral loading patterns. The error of the static loading method was the greatest. The modal method, which was based on the specified modal shape had the minimal error, and the values of this method were most closely coincident with the time history method under various axial compression ratios. The error of the constant acceleration method was between the two patterns above. The error of the M-phi curves method increased with the increase of axial compression ratio. Compared with the time history method, the modal method can get more reasonable results.