Analytical Method to Evaluate the Stress State Within Vertical Backfill
In mining industry, voids created during ore removal are generally backfilled with mill tailings that are left over from processing of mineral ore. Evaluating the stress state in backfill is a critical step for design of backfilled stopes. An analytical method to evaluate the stress is proposed in this paper. Nonuniform distribution of vertical stress is considered in this method. The trajectory of minor principle stress in the fill from the centreline to the wall is assumed as circular-arc. The stress state within vertical backfill can be obtained through the equilibrium consideration of differential flat element. Several examples carried out by analytical and numerical modeling are then presented and compared with existing analytical solutions. The proposed analytical method is also used to evaluate an in situ project from literature. The results by presented analytical method are in good agreement with numerical results and in situ data from literature. So the proposed analytical method can be used to evaluate the stress state in backfilled stopes.
The authors acknowledge the financial supports from the National Key Basic Research Program of China (973 Program) (No. 2015CB057801), National Natural Science Foundation of China (NSFC Grant No. 51278449, NSFC Grant No. 51238009 and NSFC Grant No. 51338009).
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