In this paper the effect of nonlinear behaviour of concrete is investigated on seismic performance of a double curvature concrete dam. The Morrow Point concrete dam has been selected as the case study and dam-reservoir-foundation interaction considered in the model. Finite element method has been used for modelling and analysis of case study by applying the El Centro earthquake components considering nonlinear behaviour of concrete. The obtained results of nonlinear dynamic analysis illustrate the increasing of displacement of dam crest along the river and decreasing of maximum principle stresses in critical points. The results demonstrate the importance of consideration of nonlinear behaviour of material in seismic performance of arch dams to achieve the optimal design of models.

One of the major factors in an economic project of new concrete dams and safety valuation of available dams in seismic areas is the control and dissipation of the induced hydrodynamic pressure induced by dam and reservoir interaction. As one of the main control functions, dissipating the induced hydrodynamic pressure on the upstream face of the dam is considered in the evaluations. In this paper, the effects of a rubber damper as an isolation layer on the dam's seismic control have been investigated. For optimization of the rubber damper thickness and height, the Monte Carlo probabilistic analysis is used. The ANSYS program on the basis of finite element technique is applied for modeling and analysis. The Pine Flat dam in California, due to components of El Centro, San Fernando and North Ridge earthquake is modeled as a case study to evaluate the effect of upstream isolation layer on seismic control and optimization. The effect of the thickness and height of the rubber damper on reducing the responses is investigated and the optimum thickness and height are selected using sensitivity analysis for safe and economic design. The obtained results show the capability of the rubber damper in the seismic and hydrodynamic control of the sample model.

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In this research, the effect of bedrock stiffness on seismic performance of roller compacted concrete (RCC) dam is evaluated using probabilistic analysis. Due to the geometry and behavior of RCC dams, a two-dimensional modeling was selected for system. Ansys software is used for modeling and analysis of dam-reservoir- foundation system. Newmark implicit time integration scheme is developed to solve the time-discretized equations which are an unconditionally stable method. The Watana dam, due to San Fernando earthquake has been selected as a case study. In order to propagate the parametric sensitivity to the seismic performance of the system, Monte Carlo simulation with Latin hypercube sampling (LHS) method is used as a probabilistic method and uncertainty analysis. The sensitivity of responses under seismic loading is reliably examined utilizing different values of ratio of bedrock stiffness to body concrete stiffness as random inputs. Consider to obtained results, it is revealed that the bedrock stiffness how can effect on seismic behavior of concrete gravity dams due to earthquake. Regarding the safety of dams due to compressive stresses, various ways have been assessed to investigate the induced tensile stress in the heel and the results have been investigated. Finally, appropriate range of the ratio of bedrock stiffness to concrete stiffness of dam body is presented to assess the safety design.