近断层地震动的一种随机模型及其参数识别

A stochastic model of near-fault ground motion and parameter identification

近断层脉冲型地震动是一类特殊的破坏性地震动,但此类地震动记录数量匮乏,难以满足近场工程结构抗震分析需求。本文首先从PEER强震数据库中选取典型近断层脉冲型地震动记录,形成近断层脉冲型地震动数据库。然后,将基于小波包变换的随机地震动模型与速度脉冲模型相结合,建立了一种考虑竖向分量的脉冲型地震动随机模型。在此基础上,利用非线性规划方法进行了模型参数识别,并选取走滑断层和逆断层地震动记录各一条,将实际地震动与模拟结果进行对比,验证了模型有效性。结果表明:本文模型可对近断层区域的水平向及竖向地震动进行有效模拟,文中给出的模型参数识别方法可在时域上和频域上均获得与目标地震动相匹配的结果。

Near-fault pulse-like ground motion is a special kind of destructive ground motion,but the number of suchground motion records is scarce,which makes it difficult to meet the needs of seismic analysis of engineering structures in near-fault areas.In this paper,typical pulse-like ground motions are selected from the PEER strong earthquake database to form the near-fault pulse-like ground motion database.On this basis,model parameters are identified by nonlinear programming method.A strike-slip fault and a reverse-fault ground motion record are selected respectively,and the actual ground motion is compared with the simulation results to verify the efficiency of the model.The results show this method can effectively simulate the horizontal and vertical seismic records in the near-fault area.The parameter identification method adopted in this paper can effectively match the target ground motion in time domain and frequency domain.