管道作用下急倾斜煤层稳定性分析  

Stability Analysis of Steeply Inclined Coal Seams under Pipeline Load

作　　者：徐帅陵[1] XU Shuailing(Sinopec Petroleum Engineering Corporation)

机构地区：[1]中石化石油工程设计有限公司

出　　处：《油气田地面工程》2024年第7期77-81,共5页Oil-Gas Field Surface Engineering

摘　　要：近地表荷载与急倾斜煤层老采空区的“活化”有着紧密的关联,采空区覆岩中裂隙带底部的岩块在荷载作用下极易发生回转失稳和滑落失稳,这些岩块对采空区的稳定性起到至关重要的作用,被称为关键岩块,当荷载作用使得关键岩块失稳时,采空区将发生“活化”。基于采空区覆岩“砌体梁”结构力学模型对关键岩块进行力学分析,构建荷载作用下采空区上覆岩土体失稳判断依据,进而对荷载作用下急倾斜煤层上覆岩体稳定性进行定量分析,研究发现:当作用于土体截面处最大摩擦力大于该土体所受最大剪切力时,该块体不会发生滑落失稳;只有关键岩块与岩块之间的平均挤压应力小于岩块在边角处的挤压强度,关键岩块才不会发生回转失稳。将推导结果应用于广东省某急倾斜煤矿,计算结果表明:在茶山煤矿4煤和6煤采空区上方铺设输气管道并不会引起采空区的“活化”;荷载作用下的关键岩块力学分析在急倾斜煤层上覆岩体稳定性中应用效果较好,对实际工程有一定指导作用。There is a close correlation between near surface loads and the“activation”of old goafs in steeply inclined coal seams.The rock blocks at the bottom of the fractured zone in the overlying rock of the goaf are prone to rotational instability and sliding instability under load.These rock blocks play a cru-cial role in the stability of the goaf and are known as key rock blocks.When the load causes key rock blocks to become unstable,goaf“activation”will occur.In this paper,based on the mechanical model of the“masonry beam”structure of the overlying rock in the goaf,the mechanical analysis of the key rock block is carried out,and the judgment basis of the instability of the overlying rock mass in the goaf under the load is constructed,and then the stability of the overlying rock mass in the steeply inclined coal seam under the load is quantitatively analyzed.The study shows that when the maximum friction force applied to the soil section is greater than the maximum shear force of the soil,the block will not slide and lose stability.Only when the average extrusion stress between the key rock block and the rock block is less than the extrusion strength of the rock block at the corner,the key rock block will not undergo rotational instability.The derived results are applied to a steeply inclined coal mine in Guangdong Province,the results show that the laying of gas pipelines above the goafs of 4 and 6 coal seams in Chashan Coal Mine will not cause the“activation”of the goafs.The mechanical analysis of key rock blocks under load has a good application effect in the stability of overlying rock mass in the steeply inclined coal seam,which has a certain guiding effect in practical engineering.

关 键 词：长输管道 急倾斜煤层采空区 砌体梁理论 覆岩稳定性 

分 类 号：TD823.212[矿业工程—煤矿开采]