断层赋存条件下采场矿压显现规律研究

通过相似模拟研究了2条断层赋存条件下采场的矿压显现规律,并从应力与应变速率角度解释采动与断层相互作用规律。研究结果表明:工作面未进入断层影响范围时,上覆岩层垮落形态与无断层影响时基本相同。当覆岩裂隙与断层贯通之后,工作面进入断层影响范围,老顶周期垮落步距变小,断层处底板应力达到峰值。第1条断层的影响范围为150 m,且与工作面相距70 m时断层出现较大裂隙,相距40 m时断层整体大规模滑动,上盘悬空;第2条断层的影响范围为80 m,与工作面相距30 m时,断层出现明显滑动迹象,相距10 m时,断层整体滑移失稳。相似模拟结果揭示了动压影响下断层滑移与上覆岩层运移规律,断层影响区域内煤层上方100 m以内的覆岩受到较大扰动,位移明显。工作面过第2条断层时对第1条断层有明显扰动,在现场生产实践中,应当防范多断层赋存时的耦合致灾。

Study on Characteristics of Mining-induced Pressure under Existence of Faults

This paper presented the characteristics of mining-induced pressure under faults coupling by means of physical simulation.It was suggested from the simulation results that the collapse morphology under faults was basically the same as that without fault before the exploitation was influenced by faults.Working face entered impact area of faults after the overlying fracture through with faults.Then the periodic caving step distance of main roof was reduced,and the stress in the floor near fault reached the maximum.Large cracks appeared in the fault zones after a distance of 70 m in front of the mining face,and the fault slid largely when distance was 40 m.The second fault's impact area is 80 m.The fault slid obviously after a distance of 30 m in front of the mining face and the whole fault slid instability when distance was 10 m.It was revealed that the rule of fault slid and the overlying strata movement under the mining-induced pressure.Faults became the boundary of the overlying strata when the working face went into the impact area.And the overlying rock above 100 m is disturbed obviously.Research on the strain rate of floor shows that the first fault was disturbed obviously when the working face was passing through the second fault.So it is important to prevent the disaster with a number of faults.