Effects of material properties and boundary conditions of discontinuous foundationonthe seismicperformance of archdams

This paper details the influence of material properties change of discontinuous rock foundation on the seismic behavior of arch dams. In this regard, proper modeling of far boundary conditions at far-end of rock foundation and reservoir fluid domain is important. Nonlinear seismic response of dam - reservoir - foundation system includes dam-canyon interaction, dam body contraction joint opening, discontinuities (sliding planes) of foundation rock and failure of the jointed rock and concrete materials. Therefore, a finite element program for nonlinear dynamic analysis of 3D dam - reservoir - foundation system was developed. Karun 4 Dam as a case study was analyzed the results revealed the essential role of modeling discontinuities and boundary conditions of rock foundation under seismic excitation.