中文摘要：

选取56条Ⅲ类场地近场地震波，采用IDA分析方法，对3个不同墩高的混凝土桥墩进行分析．以桥墩的墩顶位移响应为研究目标进概率特征统计，得出以下结论：对于低周期桥墩，墩顶位移响应及地震波峰值加速度在取双对数的情况下，对于每个地震波峰值加速度，位移响应的对数近似可以看成正态分布，且位移响应对数的均值与地震波峰值加速度的对数呈线性关系，其方差随着地震波峰值加速度的增加呈增大趋势，但并非线性关系．同时，墩的高度也是影响墩顶位移响应离散性的因素之一，墩的高度越大．墩顶位移的离散性也越大．

英文摘要：

Based on IDA （Incremental Dynamic Analysis）, three RC piers with different height are analyzed with 56 seismic waves which are belong to Ⅲ kind site and near field. Distance seismic response of top piers is analyzed statistically, and the results indicate that, for RC piers with low period, the Ln （D） which is the logarithm of distance response is regarded as Gaussian distribution approximately under each Ln（PGA） which is the logarithm of PGA. At the same time, the average of Ln（D） is linear relation with Ln（PGA）, and the variance also increases with Ln（PGA） but not linearly. It is also clear that the height of RC pier is also an influence factor of the variance of Ln（D） which raises with the increment height of RC pier.