Surge pool EL (m) | Required Support | Grouting | Drainage Arrangement | ||
Rock Bolts | Rock bolt spacing | Shotcrete | |||
Crown | 6 m long, 25 mm diameter resin end anchored cement grouted rock bolts (Fe415) | 1500 mm c/c (staggered) | 150 mm thick steel fibre reinforced shotcrete | Up to 6.5 m and spacing should be decided on the trial basis | 6.5 m long 50 mm diameter drain hole @ 6000 mm c/c |
Side walls | 7 m long, 25 mm diameter resin end anchored cement grouted rock bolts (Fe415) | 2000 mm c/c (staggered) | 200 mm thick steel fibre reinforced shotcrete | Up to 7.5 m and spacing should be decided on the trial basis | 7.5 m long 50 mm diameter drain hole @ 6000 mm c/c up to maximum surge level |