A tunnel is to be driven through a slightly weathered granite with a dominant joint set dipping $60$ against the direction of the drive. Index testing and logging of diamond drilled core give typical point load strength index value of $8$MPa and average RQD values of $70\%.$ The joints, which are slightly rough and slightly weathered with a separation of less than $1mm,$ are spaced at almost $300mm.$ Tunnelling conditions are anticipated to be wet.

Required:

Evaluate the RMR value of the rock mass

Provide an excavation method $($sequence$)$ and support system for the tunnel

Estimate the in situ modulus deformation of the rock mass.