FINITE-ELEMENT ANALYSIS OF DAM-RESERVOIR SYSTEMS USING AN EXACT FAR-BOUNDARY CONDITION

This paper deals with finite element analyses of dam-reservoir systems where an effective and accurate far-boundary condition is used to mod el reservoirs with infinite extention. The far boundary condition is e xact in the sense that no spatial discretization is required to obtain modes of vibration. Analytical solutions for an infinite reservoir do main of constant depth and with flexible foundation are employed to co nstruct a nonlocal relation between the velocity potential and its der ivative on the far boundary. The symmetry of the finite element stiffn ess matrix is retained and only a small broadening of the band width i s required. Comparative studies show that the proposed far boundary is numerically efficient and accurate for undeformed and deformed dams.