Investigation into Mechanism of Floor Dynamic Rupture by Evolution Characteristics of Stress and Mine Tremors: A Case Study in Guojiahe Coal Mine, China

Abstract

In order to explore the mechanism of floor dynamic rupture, the current study adopts a thin plate model to further investigate the condition of floor failure. One of the possible explanations could be floor buckling due to high horizontal stress and dynamic disturbance ultimately leading to rapid and massive release of elastic energy thus inducing dynamic rupture. Seismic computed tomography and 3D location were employed to explore the evolution characteristics of floor stress distribution and positions of mine tremors. In the regions of floor dynamic rupture, higher P-wave velocity was recorded prior to the dynamic rupture. On the contrary, relatively lower reading was observed after the dynamic rupture thus depicting a high stress concentration condition. Meanwhile, evolution of mine tremors revealed the accumulation and subsequent release of energy during the dynamic rupture process. It was further revealed that dynamic rupture was induced due to the superposition of static and dynamic stresses: (i) the high static stress concentration due to frontal and lateral abutment stress from coal pillar and (ii) dynamic stress from the fracture and caving of coal pillar, hard roof, and key stratum. In the later part of this study, the floor dynamic rupture occurrence process would be reproduced through numerical simulations within a 0.6 sec time frame. The above-mentioned findings would be used to propose a feasible mechanism for prewarning and prevention of floor dynamic rupture using seismic computed tomography and mine tremors 3D location.

Investigations of Coal‐Rock Parting‐Coal Structure (CRCS) Slip and Instability by Excavation

“…From Figure 16, the high P-wave velocity is significantly located in the rock parting zone, demonstrating static high stress concentration based on the relationship between P-wave velocity and the imposed stress of coal and rock [40,41]. e stress concentration in the zone was caused by bifurcation of the 3# coal generated by the rock parting layer, whereas the fault F7109 and FX6 did not cause static stress concentration, which may be associated with the fracturing of coal and rock.…”

Numerical Study on the Impact Instability Characteristics Induced by Mine Earthquake and the Support Scheme of Roadway

“…Zhu et al [18] believed that the dynamic disturbance triggering the rockburst is closely dependent on the static geostress condition. Liu et al [19] explained that the rapid and massive release of elastic energy induced the dynamic rupture in the floor. Liu et al [20,21] studied the failure evolution and instability mechanism of surrounding rock.…”