Analysis of the Pacoima dam accelerogram—San Fernando, California, earthquake of 1971
Analysis of the Pacoima dam accelerogram—San Fernando, California, earthquake of 1971
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DOI：
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发表时间：
1971-10
影响因子：
3
通讯作者：
M. Trifunac;D. E. Hudson
中科院分区：
文献类型：
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作者：
M. Trifunac;D. E. Hudson
根据Pacoima坝址记录的加速度图计算的综合地面速度和位移表明，强烈的地面运动主要在垂直方向和南北向方向，与余震研究推断的断层机制和现场观察到的断层位移基本一致。在两个水平方向上记录到1.25 g的高频峰值加速度，这是迄今为止地震记录的最高地面加速度。根据加速度曲线计算的响应谱曲线没有表现出异常特征，数值与以往经验一致。与最高峰值加速度相关的高频、高振幅脉冲地面运动对总体响应谱值没有显著贡献。在记录的加速度图中出现高频运动可能是由于记录地点离断层位错很近。
Integrated ground velocities and displacements calculated from the accelerogram recorded at the Pacoima dam site indicate that the strong ground motion was predominately in the vertical and NS direction, in general agreement with the mechanism of faulting as inferred from aftershock studies, and with fault displacements observed in the field. High-frequency peak accelerations of 1.25 g were recorded in two horizontal directions, these being the highest ground accelerations so far recorded for earthquakes. Response spectrum curves calculated from the accelerograms do not show unusual features, and the numerical values are consistent with past experience. The high-frequency, high-amplitude impulsive ground motion associated with the highest peak accelerations did not contribute significantly to the over-all response spectrum values. The presence of the high-frequency motions in the recorded accelerograms is presumably the consequence of the proximity of the recording site to the fault dislocation.