291 / 2018-04-30 22:00:44

Investigation of sudden faults instability induced by coal mining

physical test; abrupt stress change; fault instability; overlying strata movement; strain energy

矿山动力灾害 > 岩爆冲击

In this paper, the sharp change of roof bolt loading, roof separation, roadway deformation and mining face support stress were observed during the routine field tests. According to the preliminary estimation, the reason for such a phenomenon was possibly relevant to the sudden instability of fault structures. To investigate the sudden faults instability, a physical test was carried out with two fault structures that were disturbed by mining activities. The modelling results suggest that the strain rate from relatively low to sharp increase may be identified as a precursor of fault slip. The overlying strata was severely damaged under the interactive effect of two faults. The depth of damaged strata between two faults was higher than that influenced by a single fault. Due to the severely damaged strata between two faults, the abrupt stress change could be induced during excavation of coal mining face, and thus, more attention should be paid to the influence of overlying strata movement above goaf between two faults. The sudden collapse of roof strata and abrupt stress change could release tremendous strain energy and induce coal bursts.