Chapter 3 – Grouted Cable

The major influencing factors of fully grouted cable bolts have been studied including embedment length, cable surface geometry, and confinement of surrounding rock under axial-loading conditions. The basic deducing process of several analytical models were presented for different performances of standard and modified cable bolts together with two different bond failure modes. The diameter effect of the rock sample, which was used to confine the grouted cable bolt, was studied since the traditional test in the British Standard is only limited to a relatively small diameter being approximately only three times the diameter of some of the larger cable bolts. The results showed that with the borehole diameter increasing in weak test material, the failure modes were from grout/rock interface to cable/grout interface, and the performance in terms of both peak and residual capacity were improved.