Sr. No.

RMR values

Q values

Estimated support by RMR

Estimated support by Q

1

41 - 60

1 - 4

Systematic bolts 4.0 m long, 1.5 - 2.0 m spaced in crown and walls with wire mesh in the crown. 50 - 100 mm shotcrete in crown and 30 mm.

Systematic bolting with 40 - 100 mm unreinforced shotcrete.

2

61 - 80

4 - 10

Locally, bolts in crown 3 m long, spaced 2.5 m with occasional wire mesh. Shotcrete 50 mm in crown where required.

Systematic bolting