The materials varied onsite from fresh and weathered Siltstone and Sandstone.
Menard was chosen as a specialised grouting contractor to carry out the grouting as part of the upgrade works.
A 120m long grout curtain was installed which required a series of Primary, Secondary and Tertiary holes to be
drilled to depths of up to 25m BGL. Downstage permeation grouting was carried out for the purposes of the
installation of a Grout Cut Off wall. After the completion of the grouting works, Menard installed 381 number 3m
long anchors. The purpose of the anchors were to tie down the precast concrete cut-off wall on surface to the
rock formation. The works were safely and successfully carried out over a 7-week process.