An improved method to assess the required strength of cemented backfill in underground stopes with an open face  

作　　者：Li Li Michel Aubertin 

机构地区：[1]Department of Civil, Geological and Mining Engineering, Ecole Polytechnique de Montréal,Montreal H3C 3A7, Canada

出　　处：《International Journal of Mining Science and Technology》2014年第4期549-558,共10页矿业科学技术学报（英文版）

基　　金：financial support of the Natural Sciences and Engineering Research Council (NSERC) of Canada and the partners of Research Institute on Mines and the Environment (RIME UQAT-Polytechnique; http://rime-irme.ca)

摘　　要：Backfill is increasingly used in underground mines to reduce the surface impact from the wastes produced by the mining operations. But the main objectives of backfilling are to improve ground stability and reduce ore dilution. To this end, the backfill in a stope must possess a minimum strength to remain self-standing during mining of an adjacent stope. This required strength is often estimated using a solution proposed by Mitchell and co-workers, which was based on a limit equilibrium analysis of a wedge exposed by the open face. In this paper, three dimensional numerical simulations have been performed to assess the behavior of the wedge model. A new limit equilibrium solution is proposed, based on the backfill displacements obtained from the simulations. Comparisons are made between the proposed solution and experimental and numerical modeling results. Compared with the previous solution, a better agreement is obtained between the new solution and experimental results for the required cohesion and factor of safety. For large scale(field) conditions, the results also show that the required strength obtained from the proposed solution corresponds quite well to the simulated backfill response.Backfill is increasingly used in underground mines to reduce the surface impact from the wastes produced by the mining operations. But the main objectives of backfilling are to improve ground stability and reduce ore dilution. To this end, the backfill in a stope must possess a minimum strength to remain self-standing during mining of an adjacent stope. This required strength is often estimated using a solution proposed by Mitchell and co-workers, which was based on a limit equilibrium analysis of a wedge exposed by the open face. In this paper, three dimensional numerical simulations have been per- formed to assess the behavior of the wedge model. A new limit equilibrium solution is proposed, based on the backfill displacements obtained from the simulations. Comparisons are made between the proposed solution and experimental and numerical modeling results. Compared with the previous solution, a bet- ter agreement is obtained between the new solution and experimental results for the required cohesion and factor of safety. For large scale （field） conditions, the results also show that the required strength obtained from the proposed solution corresponds quite well to the simulated backfill response.

关 键 词：Underground mines Backfill Required strength Analytical solutions Numerical modeling Mitchell＇s solution 

分 类 号：TD80[矿业工程—矿山开采]