Abstract Due to the heterogeneity of massive concrete and unevenness of pouring process, concrete strengths in gravity dams show obvious spatial variability. In addition, since the evolution of damage states for gravity dams is a gradually transitional process, the threshold between adjacent damage states is ambiguous. A mathematical model for describing the fuzziness of damage states threshold is presented. And a methodology for fuzzy seismic fragility analysis of gravity dams considering spatial variability of material parameters is proposed by combining nonlinear dynamic analysis of dam-reservoir-foundation system, Hariri-Ardebili's damage quantification method and an approach for simulation of random field of material parameters. The seismic fragility of gravity dams was investigated to illustrate the proposed methodology. It is found that the spatial variability of concrete tensile strength leads the seismic damage of the dam to be spatially varying as well. The damage of dam body intensifies and the probability of exceeding for each damage state increases. The fuzzy seismic fragility curves are insensitive to the types of membership function (linear, mountain and polynomial). Due to the influence of frequency distribution of damage index, the effects of variation in the size of the fuzzy interval of threshold on seismic fragility curves are different. The probability of exceeding of each damage state for gravity dams obviously increases when the spatial variability of tensile strength and fuzziness of damage states threshold are considered simultaneously.

中文翻译：

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考虑材料参数空间变异性的重力坝模糊地震脆性分析

摘要 由于大体积混凝土的非均质性和浇筑过程的不均匀性，重力坝混凝土强度呈现明显的空间变异性。此外，由于重力坝损伤状态的演化是一个逐渐过渡的过程，相邻损伤状态之间的阈值是不明确的。提出了一种描述损伤状态阈值模糊性的数学模型。并结合大坝-水库-地基系统非线性动力分析、Hariri-Ardebili损伤量化方法和材料参数随机场模拟方法，提出了一种考虑材料参数空间变异性的重力坝模糊地震易损性分析方法。对重力坝的地震脆弱性进行了研究，以说明所提出的方法。研究发现，混凝土抗拉强度的空间变异性导致大坝的地震破坏也在空间上发生变化。坝体损伤加剧，每种损伤状态超标的概率增加。模糊地震脆性曲线对隶属函数的类型（线性、山峰和多项式）不敏感。由于损伤指数频率分布的影响，阈值模糊区间大小的变化对地震脆性曲线的影响不同。同时考虑抗拉强度的空间变异性和损伤状态阈值的模糊性时，重力坝超过每种损伤状态的概率明显增加。