The effects of strong motion duration on the dynamic response and accumulated damage of concrete gravity dams

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• 作者：Sherong Zhang ; Gaohui Wang ; ^{tjudam@126.com} ; Bohui Pang ; Chengbo Du
• 刊名：Soil Dynamics and Earthquake Engineering
• 出版年：2013
• 出版时间：February, 2013
• 年：2013
• 卷：45
• 期：Complete
• 页码：112-124
• 全文大小：2176 K

文摘

Strong motion duration is one of the challenging characteristics of ground motion, which affects the cumulative damage of structures significantly. Many researchers have conducted investigations related to the effects of strong motion duration on the response of building structures. However, the corresponding studies of concrete gravity dams are limited. In this paper, the effects of strong motion duration on the accumulated damage of concrete gravity dams are investigated. A Concrete Damaged Plasticity (CDP) model including the strain hardening or softening behavior is selected for the concrete material. This model is used to evaluate the nonlinear dynamic response and seismic damage process of Koyna dam during 1976 Koyna earthquake. Subsequently, the damage analyses of Koyna dam subjected to earthquake motions with different strong motion durations are performed. 20 as-recorded accelerograms, which are modified to match a 5 % damped target spectrum, are considered in this study. Strong motion durations are obtained based on the definition of significant duration. According to the characteristics of the cracking damage development, both local and global damage indices are established as the response parameters. The results show that strong motion duration is positively correlated to the accumulated damage for events with similar response spectrum, and has significant influence on the cumulative damage of the dam. Longer duration will lead to greater accumulation damage to which aseismic design of the dam should be given attention.