Site amplification effects of a radially multi-layered semi-cylindrical canyon on seismic response of an earth and rockfill dam
Site amplification effects of a radially multi-layered semi-cylindrical canyon on seismic response of an earth and rockfill dam
复制标题
径向多层半圆柱形峡谷场地放大效应对土石坝地震响应的影响
DOI：
10.1016/j.soildyn.2018.09.014
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发表时间：
2019
影响因子：
4
通讯作者：
Yang Jun
中科院分区：
文献类型：
--
作者：
Zhang Ning;Zhang Yu;Gao Yufeng;Pak Ronald Y. S.;Yang Jun
本文介绍了半空间中径向非均匀多层半圆柱形峡谷中土石坝在斜入射平面SH波作用下的解析处理方法。采用径向波函数展开法和传递矩阵法，对变形峡谷的非均匀性及与之相关的波重定向、反射、透射、散射和集中等现象进行了严密的分析。在用均匀峡谷中大坝退化情况的过去精确解证实了其准确性之后，将多层解扩展到被表面带覆盖的峡谷中大坝的情况，并将幂律剪切波速模型作为光滑原位变化的广义类。通过数值算例说明了坝体响应对峡谷顶部非均匀剖面、地震波入射角和频率含量的敏感性。从频域和时域上可以看出，波集中是坝内位移放大较大的主要原因。
An analytical treatment of an earth and rockfill dam in a radially inhomogeneous multi-layered semi-cylindrical canyon in a half-space under obliquely incident plane SH waves is presented. In terms of a radial wave function expansion and a transfer matrix approach, a rigorous approach is formulated to consider inhomogeneity of the deformable canyon and associated phenomena of wave redirection, reflection, transmission, scattering and concentration. Upon confirmation of its accuracy with a past exact solution for the degenerated case of a dam in a homogeneous canyon, the multi-layer solution is extended to the case of a dam in a canyon covered by a surficial zone with a power-law shear-wave velocity model as a generalized class of smooth in-situ variations. A comprehensive set of numerical examples are presented to illustrate the sensitivity of the dam response to the inhomogeneity profile of the top canyon zone, the frequency content and the angle of the seismic wave incidence. As illustrated in both frequency and time domains, wave concentration is found to be the main reason for the high amplifications of the displacement within the dam.