China-based researchers have conducted a study examining the impact of disturbance stress and roof abscission layer monitoring in areas affected by fault activation during coal mining. Through their research, the scientists discovered a zigzag wave pattern on the relationship curve between coal mining and roof displacement near the fault. The objective of the study, outlined in a paper published in the Rock Mechanics Bulletin, was to establish a theoretical foundation for effective infrastructure support.
The researchers highlight that fault activation is a common occurrence in underground geological structures during coal mining processes. These geological structures have significantly compromised the continuity and integrity of rock strata in various parts of the world, making fault activation a crucial factor influencing the safety of coal mining operations.
Utilizing the discrete element 3DEC numerical analysis method, the team constructed a model to simulate the unstable fracture of surrounding rock resulting from fault activation. The focus was specifically on the excavation of the upper and lower side walls of the faults and examining the characteristics of unstable fracture and stress variations induced by fault activation in the surrounding rock.
Lead author Jie Chen explained that the pattern they discovered indicates a combination of static and dynamic loads experienced by the surrounding rock in the fault activation-affected zone. Co-corresponding author Yuanyuan Pu added that simulation results demonstrate an increase in stress and displacement of the surrounding rock near the fault as the coal mining face advances. The recommended safe distance when approaching the fault is 30 meters, as indicated by the numerical tests. However, a slightly shorter safe distance of 26 meters is suggested when approaching the fault.
Chen, Pu, and their team aim to utilize these findings to enhance safety standards in coal mines, contributing to improved practices and protocols within the industry.