Parameter

Description

Value

RQD

37 - 43

37 - 43

Jn

Three joint sets with random to four joint sets

12

Jr

Smooth to planar

1

Ja

Softening or low friction clay mineral coatings

4

Jw

Dry to medium inflow or pressure

1 - 0.66

SRF

Medium stress, favorable stress condition

1

Q

0.51 - 0.89

Class No.

Very poor rock