Horizontal pressure on barricades for backfilled stopes. Part I: Fully drained conditions

Stope backfilling is used in underground mines to provide a safer working space for personnel and machinery. To ensure a secure application of backfill, it is critical to accurately evaluate the pressures exerted on the walls and barri- cades placed near the base of the stope to retain the fill materials. In this paper, existing solutions for evaluating the stresses on barricades are reviewed. The authors then propose a new three-dimensional analytical solution that takes into account the stress transfer from the backfill to the walls in both the stope and access drift. In particular, the solution con- siders the influence of the barricade position within the drift on the stress state. Comparisons are made between the pro- posed solution, physical model test results, and numerical simulations. The good agreement between various results indicates that the proposed formulation provides a good estimate of the pressure on a barricade. The solution presented here is applicable to fully drained backfill (without water-pore pressure); the solution for saturated backfill is given in a companion paper (see Part II, this issue).