Risk assessment of rockburst based on geo-dynamic division method in suberect and extremely thick coal seam

The main influence factors and interaction relationship of rockburst in Wudong Coal Mine were identified by geo-dynamic method, and the geo-dynamic environment of Wudong Coal Mine was also evaluated. Northern of Bogda Fault zone is strongly compressed. Wudong mining area is located on Bogda Fault system, which is strongly influenced by tectonic activity. The characteristics of fault activities and structure form at Wudong Coal Mine were determined by geo-dynamic method respectively. The primary stress of suberect and extremely thick coal seam was analyzed, the risk assessment method of rockburst based on geo-dynamic division in suberect and extremely thick coal seam had been established, and the rockburst points in southern mining area at Wudong Coal Mine had been found by this method, which mainly occur in high stress area and stress gradient zone. At last, the relationship between mining effect and rockburst was built using FLAC3D numerical method. Subsequently, the areas with rockburst risk were divided and forecasted. Research results show that large strain compression will appear in surrounding rock at Wudong minefield, and high elastic potential energy will be accumulated under the influence of structural stress, which will provide an energy foundation for rockburst. The value of elastic potential energy will increase and will be closer to the critical condition from steady-state to non-steady-state under the action of mining, thus the risk of rockburst will be increased. To avoid the occurrence of rockburst, some monitoring and rescue measures should be taken in advance in two high risk zones. © 2015, China Coal Society. All right reserved.