大倾角伪俯斜采场顶板运移规律实验研究

为研究大倾角伪俯斜采场顶板垮落运移及其与支架相互作用关系。采用大比例三维物理相似模拟实验和数值计算相结合的研究手段,深入分析了伪俯斜采场初采阶段和正常回采阶段顶板应力演化与变形破坏规律,垮落顶板充填特征以及"支架-顶板"相互作用规律。结果表明,大倾角伪俯斜采场顶板应力分布与位移具有非对称性,顶板具有非对称"O-X"破断特征,且具有明显的时序特征,其中"O"破断顺序为:采空区侧边界—采煤工作面侧边界—上部边界—下部边界;"X"破断顺序为:工作面倾斜上方基本顶先发生破坏,随后基本顶沿顺时针方向依次破断。顶板周期性来压与垮落均具有分区特性与时序性,沿走向工作面各个区域顶板的垮落位置与支架相对位置不同,其中,工作面倾斜中部支架直接受到垮落顶板的作用,具体为"砸—压—推",而倾斜上部与下部垮落顶板仅在下滑过程中对支架产生倾向向下的推力,未出现明显的砸、压现象,上部作用最弱,破断顶板使支架发生不同程度的"倒"、"扭"现象;垮落顶板对采空区的充填可分为4个阶段,各个阶段交替转化的过程对工作面中、下部支架的稳定性产生了影响,矸石堆积区最终沿走向形成充填稳定区域与动态运移区域。为大倾角煤层伪俯斜采场岩层控制提供科学依据,也丰富了大倾角煤层采场岩层控制理论。

Experimental study on the movement law of roof in pitching oblique mining area of steeply dipping seam

In order to study the movement of the roof and its interaction with the support in pitching oblique mining area of steeply dipping seam,the large scale three dimensional physical similarity simulation experiment and numerical simulation are combined to analyze the stress evolution,deformation and failure law of the roof,the filling characteristics of the caving roof and its interaction with the support in pitching oblique mining area.The results indicate that the pressure distribution and displacement of the roof show an asymmetric characteristic.Also,it has an “O-X” asymmetric breaking feature,and obvious timing characteristics,in which the order of “O” breaking is:the boundary of the goaf direction the boundary of the mining face direction the upper boundary the lower boundary.The order of “X” breaking is:the upper main roof of the working face is destroyed first,and then the main roof is broken in a clockwise direction.The periodic weighting and the caving of the roof have the zoned characteristic and timing characteristic.The falling position at each area of the roof along the strike of the working face is relatively different from the position of support.The support in the inclined middle part of the working face is directly affected by the falling roof.The specific performance is shocking pressing pushing,while tilting the upper and lower falling roofs only produces a downward thrust to the bracket during the descent process,and no obvious shocking and pressing phenomenon occurs.The upper part is the weakest,and the broken roof causes the varying degrees of “twisting hybridization” to supports.The filling process of the caving roof to the goaf can be divided into four stages.The process of alternating transformation of each stage has an effect on the stability of the support in the middle and lower parts of the working face.The gangue filling area finally forms a stable filling area and a dynamic migration area along the strike.The study provides a scientific basis for the ground control in pitching oblique mining area of steeply dipping seam,and also enriches the ground control theory of steeply dipping seam.