Seismically induced, non-stationary hydrodynamic pressure in a dam-reservoir system

Stochastic seismic analysis of hydrodynamic pressure in a dam-reservoir system is presented in this paper. The analysis is conducted assuming infinite reservoir compressible fluid and modeling seismic acceleration as a normal zero-mean stochastic process obtained by Penzien filter. The non-homogeneous boundary conditions associated to the problem have been incorporated into the equation of pressure wave scattering in the form of a forcing function turning the non-homogeneous boundary value problem into an homogeneous one. Solution obtained via modal analysis in time-domain is coupled with the use of classical Itô stochastic differential calculus to characterize the stochastic hydrodynamic pressure field. Both cases of hydrodynamic pressure acting along the upstream face of the dam in presence of stationary and non-stationary seismic accelerations have been considered.