地震动强度指标与高拱坝响应的相关性

Correlation between ground motion intensity measures and seismic response of high arch dam

为了在高拱坝动力时程分析中采用合适的地震动强度指标选择和调整地震记录,将12种地震动强度指标进行分类,并对其中3种提出改进.以某300m级高拱坝为例,通过一系列非线性动力时程分析研究这15种地震动强度指标与高拱坝响应的相关性.结果表明,融合结构特征得到的地震动强度指标的相关性明显好于直接由地震动本身得到的指标;考虑一定周期范围的指标的相关性更优于只考虑结构基本周期的指标.改进后的3个强度指标能够更好地反映与结构响应的相关性和地震动表征的准确性,为高拱坝抗震设计中地震动的重构提供理论依据.

In the dynamic time-history analysis of high arch dams proper ground motion intensity measures are required for the selection and modification of earthquake records. 12 intensity measures were classified and three of them were revised for the application of a 300-meter-level arch dam. The correlations between 15 intensity measures and arch dam responses were presented by a series of nonlinear dynamic time-history analyses. Results show that the intensity measures obtained based on the structural features perform better than those obtained from the ground motion immediately. The intensity measures which covered a proper period range are more efficient than those only corresponding to the fundamental period. The revised intensity measures are relatively sufficient and reasonable to the correlation between this high arch dam and the ground motions, which provide theoretical basis for the reconstruction of earthquake records in seismic design of high arch dams.