采场上覆岩层采动裂隙演化规律相似模拟研究
Similar Simulation of Mining Cracking Evolution Law for Overburden Strata Above Coal Mining Face
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摘要: 为得到薄基岩厚风积沙地区采场裂隙带发育高度及演化特征,基于采场覆岩"三带"的划分,对薄基岩地区厚风积沙煤层采动过程中裂隙发育特征进行相似材料模拟试验研究,得到开采过程中上覆岩层垮落破坏特征及运移规律,岩层内部压力分布规律,分析采动裂隙带发育高度及存在形态与工作面推进速度的关系。结果表明:补连塔煤矿12406工作面周期来压步距为22.5~30.0 m;上覆岩层的破断角在采空区侧为64°,在煤壁侧为61°;裂隙带高度为157.1 m,为工作面采高的26.18倍;工作面上覆岩层下沉趋势呈非线性曲线,移动形态具有非对称性。Abstract: In order to obtain a development height and evolution features of cracking zone above mining face in mine under thick aeolian sand area of thin bedrock, base on the three zones of the overburden strata divided above the coal mining face, the similar material simulation experiment was applied to study the cracking devel opment features in the seam mining process under thick aeolian sand area of the thin bedrock area.During the mining process, the falling failure features and movemen t law of the top overburden strata as well as the internal pressure distribution law of the strata were obtained .A relationship between the development height and existed shape of the mining cracking zone and the pushing forward speed of the coal mining face was analyzed. The results showed that the periodical roof weighting step of N 0.12406 coal mining face in Bulianta Mine was 22.5 ~ 30.0 m.A broken angle of the top overburden strata at the goaf side was64° and the broken angle at the coal wall side was 61°.The height of the cracking zone was 157.1 m and was 26.18 times of the coal mining height of the coal mining face.A subsidence tendency of the overburd en strata above the coal mining face was in nonlinear curve and the moving shape was in asymmetry.