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 barricades 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 considers the influence of the barricade position within the drift on the stress state. Comparisons are made between the proposed 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).