Seismic evaluation of existing arch dams and massed foundation effects

In the present paper, the effects of a massed foundation on the nonlinear seismic response of an existing arch dam are investigated. A co-axial rotating smeared crack approach was used to model the nonlinear behavior of the mass concrete in a 3D space which is able to model cracking/crushing under static and dynamic conditions. The analysis also considered the opening/slipping of joints. The reservoir was assumed to be compressible and was modeled using the finite element method with the appropriate boundary conditions. The Dez arch dam was selected for the case study and excited by a maximum credible earthquake. It was found that assuming a massless foundation leads to the overestimation of the stresses within the dam body and causes many more crack profiles than the massed foundation model. As a result, in the case of a massed foundation, no numerical instability was found to exist during the analysis.