Comprehensive 3-D Modeling of Mining-Induced Fault Slip: Impact of Panel Length, Panel Orientation and Far-Field Stress Orientation

We conducted a 3-D finite element analysis to explore the mining-induced faulting process, focusing on reverse fault reactivation triggered by mining operations. Specifically, we examined the effects of panel length (Wm) and far-field intermediate principal stress (sigma h) on fault slip behavior. Our findings reveal a positive correlation between sigma h and fault slip extent, while an increase in Wm leads to a linear expansion of the width of the mining-induced fault slip zone. The maximum slip approached a limit predicted by 2-D plane strain calculations. We further investigated the impact of far-field stress and panel orientation on fault slip, referring to realistic mining conditions. It was observed that sigma h significantly promotes the slip when the maximum principal stress deviated to the fault normal direction. The average slip and slip area becomes the smallest when the panel was perpendicular to the fault strike. We confirmed that the observation at the F16 fault zone in the Yuejin mine was consistent with our results, highlighting the physical mechanism of mining-induced rock-bursts on preexisting fault. Given the observed slip distribution and the assumed nucleation length, we proposed a modification of the panel layout strategy, in particular, a change in panel layout from nearly parallel to perpendicular to the fault strike. This adjustment reduces the potential for faulting and subsequent induced earthquakes. This modification will contribute to the overall mitigation of seismic hazards associated with mining-induced fault reactivation.