An analytical solution for estimating the stresses in vertical backfilled stopes based on a circular arc distribution

Abstract

Backfilling of mine stopes with waste rocks or tailings is commonly done to enhance ground stability. It is also an alternative for mining wastes disposal. A successful application of underground backfilling requires an accurate evaluation of the stress distribution in stopes. Over the years, various analytical solutions have been proposed to assess these stresses. Most of them were based on the arching theory, considering uniform stresses across horizontal layer elements. The vertical and horizontal stresses in vertical stopes are principal stresses only along the vertical center line, but not close to the walls where there is rotation of the principal stresses. A few solutions use arc layer elements that follow the iso-contours of the minor principal stresses, based on numerical solutions. In this paper, a modified analytical solution is developed for the stresses in vertical backfilled stopes, considering a circular arc distribution. The proposed solution is calibrated with a few numerical modeling results and then validated by additional numerical simulations under different conditions.