水力耦合条件下近距离煤层采动裂隙动态演化规律探究

Dynamic evolution law of mining-induced fracture in contiguous coal seams under hydraulic coupling

为了研究水力耦合条件下近距离煤层下覆岩破断特征及采动裂隙演化规律,以沙曲一号煤矿为研究对象,采用理论分析、相似模拟及数值模拟研究相结合的研究手段,分析了受水力条件影响下伏煤层回采过程中覆岩裂隙动态演化规律,指出了水力条件对于覆岩垮落及采动裂隙发育的影响。结果表明:工作面回采过程中上覆岩层的垮落形态及采动裂隙的演化规律不受水力条件的影响,然而受到水力条件的影响覆岩初次来压步距减小10m,其周期来压步距减小3m,且工作面回采相同的距离受水力条件影响的工作面覆岩垮落强度较为剧烈,其位移量及来压强度也相对较大,因此在对工作面覆岩进行支护时应加大支护强度或增加支护密度。

In order to study the fracture characteristics of overlying rock and the evolution law of mining induced fractures under the condition of hydraulic coupling, taking Shaqu No.1 Coal Mine as the research object, the dynamic evolution law of overlying rock fractures in the mining process of underlying coal seams affected by hydraulic conditions were analyzed by the theoretical analysis, similar simulation and numerical simulation, and the influence of hydraulic conditions on overlying rock collapse and mining induced fractures was pointed out. The results showed that, during the mining, the form of upper strata fall and evolution law of mining-induced fractures is not affected by hydraulic conditions;but under the influence of hydraulic conditions first weighting interval of overburden decreases 10 m, the periodic weighting interval decreases 3 m;and the overburden caving in the mining face influenced by hydraulic conditions is more severe under the same advance distance, its displacement and weighting strength are also larger, so the support strength or density should be increased when supporting the overburden of working face.