Question: A certain coal mine has weak layer comprising of 10cm, 11cm, 9cm, 12cm, 15cm , and 19cm of inter laminated shales and mudstone. Design a full column resin bolt support system if the weak layer is overlain by 70cm of sandstone.

Given:

Hole diameter=28mm, bolt diameter=20mm, bolt tensile strength=500MPa, sandstone tensile strength=6MPa, bord width=6m, resin rock interface shear resistance=2.5MPa

Also determine the reasonable cut-out distance