Finite element-based direct coupling approach for dynamic analysis of dam-reservoir system

This paper deals with the dynamic analysis of dam-reservoir coupled system for different excitation. Both dam and reservoir are discretized by eight-node isoparametric element, and direct coupling approach has been used to simulate dam-reservoir coupled system. In this numerical approach, both dam and reservoir are analyzed simultaneously to get the effect of fluid-structure interaction. Pressure for reservoir and displacement for gravity dam are considered as nodal variable. Reservoir is truncated at a suitable distance, and a suitable non-reflecting boundary condition is applied at this truncation surface of reservoir to reduce the computational time. The effects of reservoir bed slope, inclined length and the reservoir bottom absorption on the responses of reservoir, such as, hydrodynamic pressure and responses of dam, such as displacement, major and minor stresses are thoroughly observed against harmonic and seismic excitations. Viscosity of fluid is neglected, and fluid is assumed as compressible. The outcomes of the analysis show that the variation of absorption coefficient at reservoir bottom influences the hydrodynamic pressure on gravity dam. This study also shows that the effect of bed slope angle and inclined length has significant effect on hydrodynamic pressure as well as responses of gravity dam for dynamic excitations.