Explicit Directivity-Pulse Inclusion in Probabilistic Seismic Hazard Analysis
Explicit Directivity-Pulse Inclusion in Probabilistic Seismic Hazard Analysis
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DOI：
10.1193/1.2790487
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发表时间：
2007-11
影响因子：
5
通讯作者：
P. Tothong;C. Cornell;Jack W. Baker
中科院分区：
文献类型：
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作者：
P. Tothong;C. Cornell;Jack W. Baker
概率地震危险分析 (PSHA) 广泛用于估计评估结构性能时应考虑的地震动强度。 PSHA 分解通常用于根据震级和距离来识别代表性地面运动，以进行结构分析。正向方向性引起的速度脉冲可能发生在近断层（或近源）运动中，已知会在某些周期的结构中引起相对严重的弹性和非弹性响应。在这里，PSHA 的原理被扩展为包含在近断层地震动中可能出现的速度脉冲。对于每个幅度和位置源几何形状，考虑脉冲发生的概率以及脉冲确实发生的脉冲周期的概率分布。利用近源“窄带”衰减定律修正来预测地面运动谱加速度 (Sa) 幅度，该幅度利用了附加的脉冲周期信息。此外，分解结果提供了给定水平的地面运动强度由脉冲状地面运动引起的概率，以及与该地面运动相关的脉冲周期的条件概率分布。这些扩展提高了断层附近场地的 PSHA 精度，并为选择用于结构动态分析的适当近断层地震动提供了合理的基础。
Probabilistic seismic hazard analysis (PSHA) is widely used to estimate the ground motion intensity that should be considered when assessing a structure's performance. Disaggregation of PSHA is often used to identify representative ground motions in terms of magnitude and distance for structural analysis. Forward directivity–induced velocity pulses, which may occur in near-fault (or near-source) motions, are known to cause relatively severe elastic and inelastic response in structures of certain periods. Here, the principles of PSHA are extended to incorporate the possible occurrence of a velocity pulse in a near-fault ground motion. For each magnitude and site-source geometry, the probability of occurrence of a pulse is considered along with the probability distribution of the pulse period given that a pulse does occur. A near-source “narrowband” attenuation law modification to predict ground motion spectral acceleration ( Sa ) amplitude that takes advantage of this additional pulse period information is utilized. Further, disaggregation results provide the probability that a given level of ground motion intensity is caused by a pulse-like ground motion, as well as the conditional probability distribution of the pulse period associated with that ground motion. These extensions improve the accuracy of PSHA for sites located near faults, as well as provide a rational basis for selecting appropriate near-fault ground motions to be used in the dynamic analyses of a structure.