Elasto-plastic earthquake response of arch dams including fluid–structure interaction by the Lagrangian approach

Elasto-plastic earthquake response of arch dams including fluid–structure interaction by the Lagrangian approach is mainly investigated in this study. To this aim, three-dimensional eight-noded version of Lagrangian fluid finite element including the effects of compressible wave propagation and surface sloshing motion, and three-dimensional version of Drucker–Prager model based on associated flow rule assumption were programmed in FORTRAN language by authors and incorporated into the program NONSAP. Two new components added into the NONSAP were tested on a simple fluid tank and a simple fluid–structure system and obtained very reasonable results.Elasto-plastic earthquake analysis of an arch dam including fluid–structure interaction by the Lagrangian approach was performed using Wilson-θ method. The El Centro N–S component of Imperial Valley earthquake in 1940 was chosen as a ground motion. The component considered was applied in upstream–downstream direction.Displacements at various nodes on dam body, hydrodynamic pressures at three fluid elements near the dam–reservoir interface and yield functions at two elements predicted cracks in dam body were obtained. The elasto-plastic response of the arch dam was also compared to its linear response. It is seen that Drucker–Prager model in the representing elasto-plastic behaviour of arch dams and in estimating location of cracks in dam body is a fast tool.