急倾斜走向分段充填倾向覆岩破坏特性及移动规律

Damage characteristics and movement of inclined strata with sublevel filling along the strike in the steep seam

为了研究急倾斜煤层综采走向分段胶结充填覆层变形破断特性及移动规律,建立了倾向岩梁的力学模型,推导了倾向方向上覆岩梁的挠曲方程,利用方程求出了充填区域和未充填区域的最大挠度位置。并以湘永煤矿2463工作面为原型,进行了相似模拟实验研究。结果显示:(1)充填区域的倾斜岩梁在胶结充填体柱的支撑作用下,顶板下沉较小。而未充填区域的顶板则变形较大,直接顶出现垮落现象,垮落后充填下部采空区,对下部的顶底板起到了支撑约束作用。(2)未充填区域结果显示,倾向岩梁上部为直接拉伸断裂,而中部层间岩层为倾斜砌体梁断裂形式,且断裂线位于工作面的中部偏上部位置,下部为岩层间张开形式,岩层断裂整体呈现了"F"型断裂,形成了下部裂隙发育支撑区、中部顶板自承弯曲下沉区和上端部支撑区组成的二次平衡结构。相似模拟实验结果与理论推理结论基本一致。

In order to study the damage characteristics and movement of inclined strata in the steep seam fully mechanized mining with sublevel filling along the strike,the mechanical model of inclined strata beam has been built,and the deflection equation of inclined strata beam has been derived.Based on the deflection equation,the maximum deflection positions in the filled area and unfilled area have been work out. Field simulation experiment has been done with the prototype of Xiangyong Coal Mine geological conditions,the result shows that（1） by the support effect of filling,the inclined strata subsidence in filled area is smaller,and the inclined strata subsidence in unfilled area is larger,where the strata is caved.The caved rock fill the GOB bottom and support the lower roof and floor.（2） the results of the experiment about the unfilled area show that the upper part of inclined strata is tensile failure; the middle part failure form is inclined voussoir beam,the fracture position is above the middle of working face; and the lower part failure form is pulling damage,the failure shape is ＂F＂.The secondary balance structure is formed of the lower fractured support area,the middle subsidence area by self-supporting of roof and the upper support area.The field simulation experiment result is conform to the conclusions of theoretical reasoning.