Author(s)

A. Rivera & N.R. Correa

Abstract

Numerical evaluation of the transient groundwater regime generated by a tunnel at the Grimsel Test Site A. Rivera," N.R. Correa* o CO^ETVCO Power CWWfm# IW, MeZ/wgeraZmase CH-5405 Baden, Switzerland ABSTRACT A series of numerical investigations of the transient effects on the groundwater regime caused by the presence of tunnels was performed in the rock body surrounding the underground rock laboratory at the Grimsel Test Site (GTS) in Switzerland. The simulations were done in a vertical two-dimensional section through the GTS, and with a full three- dimensional model at a sub-regional scale. The simulations were performed to evaluate the effects of different: (a) diffusivity ratios, (b) saturated and free-surface boundary conditions, and (c) time scales. Two different FE numerical codes were used for the same model in order to verify the results. This study demonstrated the dependence of the model results on the: (a) modeling approach, (b) adopted parameter values

Keywords