Jinneng Group Co., Ltd.

针对晋城矿区3号煤层残留煤复采工作面存在顶板冒落问题,首先采用煤柱应力计对残留煤柱垂直应力进行了实测,然后建立3号煤层残留煤顶板矩形厚板模型,对残留煤顶板的挠曲变形进行了理论分析,得到了残留煤顶板的下沉规律。研究结果表明:在残留煤柱和巷道交叉点处发生拱形或椭圆形冒落,在残留煤柱区残留煤柱出现应力集中现象,煤柱压入底板,发生层状或拱形冒落;残留煤柱中心部位的垂直应力最大,约为13.7 MPa,残留煤柱采空区为应力降低区,在2个煤柱之间垂直应力最小;残留煤顶板下沉量以残留煤柱为中心向四边增加,呈椭圆状分布,残留煤柱两侧顶板下沉量较小,而煤柱采空区与巷道交叉点、交岔点等位置顶板下沉量较大,研究结果可为预防残留煤顶板冒落的难题提供了理论支撑。

According to the roof flling problems existed in the secondary mining face in the residual seam of No.3 seam in Jincheng Mining Area, a coal pillar stre ss gauge was firstly applied to measure the vertical stress of the residual coal pillar, then a rectangle thick plate model of the residual seam roof in No.3 seam was est ablished, a theoretical analysis was conducted on the flexure deformation of the residual seam roof and the subsidence law of the residual seam roof was obtained. The study results showed that the arch or oval roof falling was occurred at the residual coal pillar and the gateway cross point, a stress concentration phenomenon was occ urred in the residual coal pillar of the residual coal pillar area, the coal pillar was pressed in to the floor and a layer or arch roof falling was occurred. The vertical stress in the central location of the residual coal pillar was the max and was about 13.7 MPa. The goaf of the residual coal pillars would be a stress reduced area. The vertical stress between the two coal pillars was mini. The subsidence value of the residual seam roof was increased along the four sides based on the residual coal pillar as the center. The subsidence was distributed in oval, the subsidence value of the two side roof of the residual coal pillar was the min, but the subsidence value of the coal pill ar goaf and gateway cross point, the intersection and other location roof was high.The study results could provide the theoretical support to prevent the roof falling difficf ulty of the residual coal.