Seismic Behavior of a Bituminous-Faced Rock-Fill Dam: The Menta Dam

Abstract

In the analysis of the dynamic response of the bituminous-faced rockfill dam (BFRD) Menta, is applied non-linear model, where the rock material is approximated by variable sliding modulus, and the asphaltic facing with thickness of 32 cm is applied by joint elements with linear elastic constitutive law. Permanent displacements during the seismic excitation are determined by Dynamic deformation analysis, where the incremental forces are calculated by the difference of the effective stresses in two successive time steps, resulting in adequate deformations. For the state of reservoir rapid filling, as pre-earthquake state by normal water elevation in the reservoir, is used elastoplastic model by variable modulus of elasticity for the rock material. By the dynamic analysis is verified the seismic resistance of the fill dam at action of design earthquakes by PGA of 0.26 g, without disruption of the water impermeability of the asphaltic facing and without danger for rapid and uncontrolled emptying of the reservoir, because the settlements in the dam crest caused by dynamic inertial forces for the earthquake duration amounts 40 cm, i.e. they are much lower than the height above normal elevation in the reservoir till the dam crest, with value of 7.25 m.