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

文摘：混凝土重力坝的地震反应评价需要特别注意，这是由于这些大型结构的独特特点：（i）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的作用;（ii）大坝-库基（岩石）相互作用是结构反应的重要组成部分;以及（iii）由于混凝土中相当大的断裂过程区，特别是用于这些结构的建造中的大骨料混凝土，它们的非线性本构模型尚未完全量化。尽管人们已经清楚地认识到，在大坝的地震反应分析中，地震地面运动的空间变化是不可忽略的，但还没有对混凝土重力坝的这种影响进行评估。 这一探索性的SGER提案首次提出了将地震地面运动的空间变化纳入混凝土重力坝响应评估的问题，并对这些大型结构的响应进行了空间变化效应的敏感性分析。它提出了一个准确的建模和计算工作之间的妥协，初步尝试评估混凝土重力坝的反应进行了广泛的非均匀地震激励和量化的空间变异性的影响。建模近似将考虑在更简单的地形设置中的更复杂的结构或在更复杂的地形设置中的更简单的结构。地震地面运动将是在深度记录的数据（代表震级高达8.0的地震记录），将作为“参考”地面运动，从中将产生空间可变的地面运动。这项工作的结果，然后可以作为“种子”在未来的研究中选择的关键非均匀输入运动的功能，在复杂的设置混凝土重力坝的详细模型的响应评估。

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.