Assessment of variations in shear strain energy induced by fault coseismic slip in deep longwall mining

Shear strain energy is a pivotal physical quantity in the occurrence of earthquakes and rockbursts during deep mining operations. This research is focused on understanding the changes in shear strain energy in the context of retreating longwall mining, which is essential for the optimized design and mitigation of rockbursts and seismic events. Through the application of innovative analytical models, this study expands its analytical range to include the variations in shear strain energy caused by fault coseismic slip. An integrated methodology is utilized, taking into account the changes in coseismic and fault friction parameters as well as enhancements in mining-induced stress and existing background stresses. Our numerical investigation highlights the significance of mining location and fault characteristics as key determinants of shear strain energy modifications. The analysis demonstrates significant spatial variability in shear strain energy, especially noting that fault slip near the mining face greatly increases the likelihood of rockburst. This finding emphasizes the need to integrate fault coseismic slip dynamics into the triggering factors of rock (coal) bursts, thus broadening the theoretical foundation for addressing geological hazards in deep mining operations. The results are further corroborated by observational data from the vicinity of the F16 fault zone, introducing the concept of mining-induced fault coseismic slip as an essential element in the theoretical framework for understanding rockburst triggers.