Dynamic Localized Failure of Soils via Nonlocal Poromechanics Model: A Case Study of the Lower San Fernando Dam Failure
Dynamic Localized Failure of Soils via Nonlocal Poromechanics Model: A Case Study of the Lower San Fernando Dam Failure
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通过非局部孔隙力学模型进行土壤动态局部破坏：圣费尔南多下游大坝溃决案例研究
DOI：
10.1061/9780784483701.002
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Song, Xiaoyu
中科院分区：
文献类型：
--
作者：
Menon, Shashank;Song, Xiaoyu
在这篇文章中，最近开发的非局部孔隙力学模型的岩土材料的动力响应分析的下圣费尔南多大坝在1971年圣费尔南多地震。地震期间，大坝上游边坡发生了严重的水流破坏。现场调查结果表明，圣费尔南多大坝上部边坡的水平移动是由于大坝某些区域的水力填充材料液化和弱化造成的。大坝上游部分的大块大部分完整的土壤进入水库，骑在液化的土壤上。现场分析表明，由于循环荷载，大坝中心区域出现了显著的压力累积，随后循环荷载迁移到上游“趾部”，引发了破坏，随后发生了滑动流。为了证明所提出的非局部孔隙力学是现实的，相关的大规模，非线性和耦合分析的解决方案，我们进行了两个阶段的下圣费尔南多大坝的地震分析。首先，在准静态条件下进行弹性分析，以确定初始有效应力和水压力分布。其次，进行了完全非线性动力分析与地震荷载建模为基础激励以下记录的加速度剖面。结果表明，所提出的非局部孔隙力学模型是强大的在地震荷载作用下，通过捕捉现场观察到的故障的位置和模式的岩土材料的局部故障建模。
In this article, a recently developed nonlocal poromechanics model for geomaterials is applied to analyze the dynamic response of the Lower San Fernando Dam during the 1971 San Fernando earthquake. During the earthquake, the dam experienced a major flow failure in the upstream slope. Field investigations in the immediate aftermath indicated that the horizontal movement in the upper slope of the San Fernando Dam was caused by the liquefaction and weakening of the hydraulic fill materials in certain zones in the dam. Large blocks of mostly intact soil from the upstream section of the dam moved into the reservoir, riding over on the liquefied soil. Field analysis suggested that a significant pressure buildup occurred in the central region of the dam due to cyclic loading that later migrated to the upstream “toe” where it triggered failure and subsequently a sliding flow. To demonstrate that the proposed nonlocal poromechanics is realistic and relevant to the solution of large-scale, nonlinear, and coupled analysis, we conduct a two-stage seismic analysis of the Lower San Fernando Dam. First, an elastic analysis under quasi-static condition was carried out to determine initial effective stress and water pressure distributions. Second, a fully nonlinear dynamic analysis was performed with the earthquake load modeled as a base excitation following recorded acceleration profiles. The results have demonstrated that the proposed nonlocal poromechanics model is robust in modeling the localized failure of geomaterials under seismic loading by capturing the location and mode of failure observed in the field.
影响因子：
5.7
作者：
Xiaoyu Song;Shashank Menon
通讯作者：
Xiaoyu Song;Shashank Menon