SGER: Sensitivity Analysis of Concrete Gravity Dams Subjected to Non-Uniform Seismic Excitations

摘要：混凝土重力坝的地震响应评价需要特别关注，因为这些大型结构的独特特点：(1)它们是位于复杂场地的长结构，因此地震地面运动的空间变异性起着重要作用；（ii）坝-库基础（岩）相互作用是结构响应的重要组成部分；（iii）由于混凝土中存在相当大的断裂过程区，特别是这些结构中使用的大骨料混凝土，其非线性本构建模尚未完全量化。虽然人们已经清楚地认识到，在大坝的地震反应分析中，地震地震动的空间变化是不可忽视的，但还没有对混凝土重力坝的地震反应进行评价。本探索性SGER方案首次提出了将地震地震动空间变化纳入混凝土重力坝响应评价的问题，并对空间变化对混凝土重力坝响应的影响进行敏感性分析。在评估混凝土重力坝在大范围非均匀地震激励下的反应和量化空间变异性的影响的初步尝试中，它提出了精确建模和计算努力之间的折衷。建模近似将考虑在更简单的地形设置中更复杂的结构或在更复杂的地形设置中更简单的结构。地震的地面运动将被记录在深度（代表震级高达8.0的地震记录），作为“参考”地面运动，从中产生空间可变的地面运动。这项工作的结果可以作为未来研究的“种子”，用于选择关键的非均匀输入运动特征，以评估复杂环境下混凝土重力坝详细模型的响应。

Abstract:The seismic response evaluation of concrete gravity dams requires special attention due to the unique characteristics of these massive structures: (i) they are long structures located at complex sites, and hence, the spatial variability of seismic ground motions plays a significant role; (ii) dam-reservoir foundation (rock) interaction is an important component of the structural response; and (iii) due to the sizable fracture process zone in concrete, and, especially, the large aggregate concrete used in the construction of these structures, their non-linear constitutive modeling is not yet fully quantified. Even though it has been clearly recognized that the spatial variation of seismic ground motions cannot be neglected in the seismic response analysis of dams, no evaluation of this effect on concrete gravity dams has been conducted. This exploratory SGER proposal addresses, for the first time, the issue of incorporating the spatial variation of seismic ground motions in the response evaluation of concrete gravity dams, and conducting sensitivity analyses of the effect of spatial variability on the response of these massive structures. It proposes a compromise between accurate modeling and computational effort in an initial attempt to evaluate the response of concrete gravity dams subjected to a wide range of non-uniform seismic excitations and to quantify the effect of spatial variability. The modeling approximations will consider either a more complex structure in a simpler topographic setting or a simpler structure in a more complex topographic setting. The seismic ground motions will be recorded data at depth (representative of recordings of earthquakes with magnitudes up to 8.0) that will serve as the "reference" ground motions, from which spatially variable ones will be generated. The results of this effort can then be used as "seed" in future studies for the selection of critical non-uniform input motion features for the response evaluation of detailed models of concrete gravity dams in complex settings.