Ndakaini is a 70m earth fill embankment, but at the bottom is a
grout curtain built during the construction to contain possible seepage and spills.
Right abutment of Shahid Abbaspour Dam (Iran) was modeled in layers considering actual soil profile and consolidation grouting, a high pressure
grout curtain, a drainage curtain along with concrete cutoff wall to prevent seepage thr ough a clay-filled fracture zone in the right abutment of dam was proposed by (Ghobadi et al.
The project originally called for sealing 440 manholes by creating a
grout curtain around each structure.
To secure the dam to the surrounding foundation, a
grout curtain reaches to a depth of 200m beneath the dam and extends 100m into the rock on either side of the valley.
grout curtain is more than 450,000 meters in length, and the main rock for grouting is granite.
Sometimes normally adopted treatments to control seepage such as
grout curtain, dental treatment and impervious blanket do not work; then again geological investigations are scrutinized.
The first step was to isolate the shaft from groundwater by grouting the rock fissures around it and creating a
grout curtain to reduce ingress, minimising potential contamination.
Drain holes in diversion tunnel and downstream of right saddle and strengthening of
grout curtain of left abutment of main dam were also carried out.
If Obama signs the bill, the corps would receive the $44 million to help extend a
grout curtain as a temporary fix for the next several years as engineers design and construct a permanent fix to stop a leak through a damaged abutment next to the Hanson Dam.
If you are tunnelling and drilling holes for grouting then the quality of the
grout curtain and the safety in the tunnel is depending on the pattern of the holes.