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2018年35卷第4期《计算力学学报》473-479


摘要：开发了考虑圆弧场地水平多分层效应的地下多点地震动模拟程序，实现其可视化，验证其可靠性。首先，描述了给出的圆弧场地多分层效应的SH波动散射频域解，其本质是突破了传统“均匀介质”和“分层不穿越峡谷”前提的局限性；进而，利用从水平地表到峡谷表面再到地下土层的传递函数，从而得到了通过两次传递得到峡谷地下的目标功率谱和反应谱；然后，具体描述所导出的圆弧场地“平-凹”相关性的相干函数及其推导过程。最后，基于上述理论，开发了多层状的非均匀圆弧场地的多点地震动模拟程序，给出了模拟结果与目标功率谱、反应谱和相干函数的拟合对比，验证了合理性和可靠性，旨在便于将所发展理论和方法的实用化和推广。

关键词：相干函数；分层圆弧形峡谷;地形效应；传递函数; 地下多点地震动

中图分类号：P315.9;U442   文献标识码：A     文章编号：

Abstract： In this paper, a program for simulating spatially variable underground seismic motions in circular-arc canyons taking the multi-layer effect into account is developed, the visualization of the program is realized and the reliability of the program is verified. Firstly, the frequency-domain solution for the scattering of SH waves by a circular-arc arc considering multi-layer effect is obtained, which breaks through traditional theoretical limitations of homogeneous medium and canyons do not pass through multi-layer soil. Secondly, a two-step transferring method combining the transferring from flat-ground terrain to the canyon surface (step one) with the transferring from the canyon surface to underground location (step two) is adopted to derive the underground target PSD and response spectrum. And then, the coherence function taking account of the flat-concave correlation of circular-arc field and its derivation is described in detail. Finally, aiming to provide convenience for further development and application of the simulation theory above, a program for simulating underground seismic motions in circular-arc canyons taking account of multi-layer effect is developed and the comparison of fitting contrast between simulated and target result including PSD, response spectrum and coherence coefficient is given, which further verified the rationality and reliability of the result.