Topographical Effects on Stress Distribution in Partially Mined Sites in Mountainous Areas

Partial mining, including room-and-pillar mining and strip pillar mining, is a widely accepted method for mining coal because it can effectively control ground subsidence and reduce damage to surface structures. Because coal mines can be in mountainous area, terrain profile can have a significant effect on the stress distribution in the mine roof–pillar–floor system. This paper reports an investigation of the terrestrial effect using numerical simulation. The results showed that the horizontal stress concentration at positions beneath the slope bottom [defined as bottom abrupt stress (BAS)] is influenced by the slope angle and the depth of mine. The BAS value can vary significantly compared with the maximum horizontal stress for a lateral ground surface, and the BAS is responsible for the mine roof instability in mountainous areas. The results were validated by comparison with a physical model and field measurements.