Investigations of Backfill-Rock Mass Interface Failure Mechanisms

摘要

In underhand cut and fill mining, the stability of pastefill support can be achieved through various special techniques. However, the most important factor for the stability of pastefill is the developed friction between the rock wall and the pastefill itself. Yet, the contribution of rock wall roughness on backfill behaviour has not yet been quantified, and as a result, this important contributing factor is often disregarded in design studies. This paper presents a unique study developed to quantify, with acceptable accuracy, the contribution of wall roughness to the strength behaviour of pastefill-rock interfaces. An indirect procedure for correlating pastefill/rock interface strength with roughness, cure time and cement content has been developed and a new criterion, a revised Barton equation, has been introduced. The developed methodology provides the mine engineer with an important tool for the safe and efficient design of pastefill systems in undercut mining.