In-stope measurements at two Western Australian mine sites

摘要

This paper presents the results of in situ pore pressure and total horizontal stress measurements taken during and after the backfilling of two stopes at two different mine sites in Western Australia. Both sites used cemented paste backfill (CPB) and a staged filling strategy. However, stope geometries and the CPB particle size distribution vary significantly between sites. Results are normalised by geostatic (overburden) stress to allow comparison between the stopes. Despite the faster fill rate, it was found that the narrow stope with coarser backfill (Raleigh) showed a noticeably lower stress ratio than the wider stope with finer particle size distribution (Lanfranchi). This indicates that consolidation and arching play a critical role in reducing pressures.