Some aspects of mining under aquifers in China

A number of case studies of mining-induced permeability enhancement are documented. The extent of strata failure around active underground mines is determined through use of a borehole discharge test. The test delimits zones and the severity of extraction induced fracturing. From these data, empirical relationships are developed to determine the vertical and horizontal extents of the caving and fracture zones induced by mining. These relationships are developed for a variety of strata types and strengths and give quantitative recommendations applicable to similar mining conditions elsewhere. These recommendations are particularly important for sub-sea or sub-aquifer mining to ensure hazard-free operation.