Abstract

The current study aims at seismic analysis of damaged concrete gravity dams subjected to aftershocks loading of earthquake. Dams’ sliding behaviour is also discussed to shed light on the issue. For the purpose of the study, a cracked concrete gravity dam was modelled, and zero thickness contact elements were used to model the contact between the main body and the separated damaged parts of the dam. The augmented Lagrangian method, considering frictional sliding and opening of contact joints, was used in non-linear analyses. Fluid-structure-interaction, considering fluid compressibility and absorptive boundary of reservoir, was also taken into account. The damage model of ‘Konya’ and ‘Manjil’ dams comprised our case study. Non-linear dynamic analyses were done based on both models. Stiffness and damping coefficients effect on the seismic response of dam were examined. Dam, foundation and reservoir interaction effects were also included. The results were compared to the results obtained from other methods, which showed adequate similarities. The differences between damages caused by aftershocks are discussed, and it is pinpointed that the stability of dam during aftershocks is not compromised. It is demonstrated that top block slides during each aftershock and finally incurs some permanent sliding which may destroy the dam.

摘要

本研究旨在对地震余震荷载作用下受损混凝土重力坝进行抗震分析。还讨论了大坝的滑动行为以阐明这个问题。出于研究的目的，对开裂混凝土重力坝进行了建模，并使用零厚度接触单元来模拟大坝主体与分离的损坏部分之间的接触。考虑到摩擦滑动和接触接头张开的增强拉格朗日方法用于非线性分析。还考虑了流体-结构-相互作用，考虑了流体可压缩性和储层的吸收边界。“Konya”和“Manjil”大坝的破坏模型构成了我们的案例研究。基于这两种模型进行非线性动态分析。研究了刚度和阻尼系数对大坝地震响应的影响。还包括大坝、地基和水库的相互作用效应。将结果与从其他方法获得的结果进行比较，显示出足够的相似性。讨论了余震造成的破坏之间的差异，指出余震期间大坝的稳定性不受影响。结果表明，在每次余震期间顶部块体滑动并最终导致一些可能破坏大坝的永久性滑动。并指出余震期间大坝的稳定性不受影响。结果表明，在每次余震期间顶部块体滑动并最终导致一些可能破坏大坝的永久性滑动。并指出余震期间大坝的稳定性不受影响。结果表明，在每次余震期间顶部块体滑动并最终导致一些可能破坏大坝的永久性滑动。