Page 56 - Engineering Rock Mass Classification_ Tunnelling, Foundations and Landslides

ameter Tunnels in Rock

Rock bolt Conventional shotcrete

Total thickness (cm) Additional
supports
Additional Crown Sides
requirements None
Rare None to None
occasional None None
Rare None
None to None None
r Occasional mesh occasional None
and straps None
Occasional mesh Local application
and straps 5 to 7.5 cm Rock bolts
Mesh and straps
as required Local application Rock bolts
Mesh and straps 5 to 7.5 cm
as required
5 to 10 cm

10 cm or 10 cm
more or more