3-D Discontinuum Numerical Modeling of Rock Mass Stability Investigations Due to Ore Extraction and Backfilling, and Subsidence Estimation for an Underground Mine

摘要

Subsidence prediction due to ore extraction and backfilling during open sloping operations for an underground iron mine in China is reported in this paper. Geologic complexities including faults and interfaces between different lithologies, and the stoping and backfilling sequence adopted from the mine plans are incorporated in building a 3-D discontinuum numerical model. The stoping was simulated in two vertically stacked horizontal layers (Fig. 6), with a total of 16 stopes. Large displacements of up to 50 cm were predicted by the model along the roof of the stopes. and a maximum surface subsidence of 22.5 cm was predicted by the model. Backfilling was found to control subsequent deformation and subsidence. The extraction of the upper orebody led to relatively higher deformations in extracting the lower orebody. Finally, the predicted subsidences at all locations along a subsidence profile on the surface are shown.