Numerical modelling and in situ monitoring of drift support performance with respect to mining sequence

Haulage drifts in deep hard rock mines require special attention in ensuring their long-term stability and safety, as these drifts must remain functional during the life of a mine plan. The stability of a haulage drift is influenced by many factors, most notably nearby stoping activities and the distance between the drift and production stopes. Thus, the evaluation of drift support performance before and during nearby stope extraction is important. In this study, numerical modelling is performed to evaluate the support performance in the drift. In order to calibrate the numerical model, selected bolts were instrumented with load cells to measure the axial load acting on the bolts as mining progresses. The load distribution along the rockbolt is computed after each mining step. The peak load is found to be consistently at the bolt head in both the fully grouted rebar and the modified cone bolt. It is found that same-level mining of nearby stopes has a more severe effect on the drift support system than low...