Author: C. Baisre
CDA, Canadian Dam Association, October 5 - 8, 2009
Abstract
To exploit the diamond pipes, at the Diavik Mine owned by Rio Tinto and located at NWT, it was required to build two
dikes into the Lac de Gras, dikes A154 and A418. During the construction of the curtain grouting of the A418 Dike, the
pressure grouting technique did not achieve the desired closure of a subhorizontal joint located at variable depth beneath the
dike foundation into the granitic rock mass at the South abutment. The joint, of stress relief origin, was filled mostly with
silt, sand and gravel. The following pages present a review of the challenge faced with the pressure grouting treatment
methodology, and the final decision of Nishi Kohn and SNC-Lavalin (NKSL), the designer and construction manager, to
treat the joint by jet grouting.
