地下导控气化采煤地面变形实测研究

Study on surface deformation laws over underground gasification face

为华亭煤业集团安口矿地下导控气化试采工作面设计了地表变形观测站,设计倾向、走向测线各一条,在先期测量的基础上,于工作面点燃后,对所有测点进行x,y,z坐标的连续观测,共获得12组数据。为确定地下导控气化工作面地表变形的危险范围,计算各测点倾斜、曲率、水平变形3个变形量参数,发现不同于传统采煤工作面自开采后地表"下沉—稳定"的两阶段变形规律,气化工作面的地表变形过程可明显划分为"上升—下沉—上升—下沉—稳定"5个阶段,对各阶段变形原因进行了分析,认为工作面燃烧热量使岩层热胀冷缩,从而使上覆岩层产生"塑性—弹性—断裂"的变化过程,反映在地面变形上即是:第1阶段,热胀使岩层塑性增强,地面上升;第2阶段,燃空使上覆岩层塑性弯曲下沉;第3阶段,冷却使岩层弹性增强,收缩过程中岩层之间产生离层,地表表现为上升;第4阶段和第5阶段,完全冷却后顶板岩层断裂,引起地面下沉并趋于稳定。

Devised a deformation observation station for undergroud coal gasification face in Ankou Mine Huating Coal Group.Analysied the 12 sets data of the measure points and calculated the boundary angles of ground subsidence basin in both trend and oblique direction,calculated the tilt,curvature and horizontal deformation parameters of all the points.Based on the monthly observation data ploted the subsidence process after igniting the gasification face of all of the points,found that the surface deformation of gasification face follows a five-stage pattern（rising→sinking→rising→sinking→stable）,which was different from the traditional coalface mining pattern（sinking→stable）.Concluded that the overlying rocks expanding and contracting is the main cause：The first stage,the rocks thermal expansion resulted in the surface rising.The seccond stage,overlying rocks with thermoplasticity curving to the burn-out area resulted in the surface sinking.The third stage,overlying rocks cooled and shrinked,abscission zone occurred,shallow rocks rising resulted in the surface rising.The fourth and fifth stages,roof rocks fractured after cooling completely,resulted in the ground sinking and tending stable state.