ASSESSMENT OF PERMANENT DISPLACEMENT OF ROCK-FILL DAMS

Abstract

The main criterion for stability analysis of an embankment dam is the factor of safety. If the dam body is subjected to strong earthquake motion, the factor of safety falls below unity and the dam body experience deformations far beyond elasticity. In such a case instead of factor of safety permanent displacements become the measure for estimation of the overall stability of the dam. In this study the seismic stability analysis of a tailings dam and a rock-fill dam is carried out. Pseudo-static method is used for the tailings dam and the effect of liquefaction of tailings material in seismic stability analysis is studied in detail. For the rock-fill dam permanent displacement analysis is carried out using the method as proposed by Paskalov (1985). The effect of pore pressure in permanent displacement is studied. Also the effect of vertical component of ground motion in the permanent displacement is studied in detail. Due to the effect of combined ground motion permanent displacement increases considerably. There is no significant change in permanent displacement due to the change in pore pressure.