地铁线路穿越急倾斜煤层采空塌陷区相似模型试验

地铁线路穿越煤矿采空塌陷区问题为中国首例,因此进行急倾斜煤层开采岩移基本规律和地铁荷载作用下塌陷区及侧壁围岩稳定性研究具有重要意义。运用相似模型试验方法,模拟开采两组急倾斜特厚煤层,并用数码相机记录开采及加载过程中岩层破断及移动形态。试验反映了急倾斜煤层开采中垮落带形态、裂隙带形成与发展和地表移动特征等共性;此外,分别以顶底板移动角、边界角,表土层移动角、边界角参数计算煤层开采覆岩破坏边界范围,并以此划分不稳定区、基本稳定区和稳定区;考虑地铁及建筑荷载下,塌陷区破断岩体有闭合压实现象,地表最大下沉量为4~5 cm,顶板侧壁不稳定围岩最大离层量2 cm。所得结果对指导现场地铁线路穿越煤层采空塌陷区具有一定的参考意义。

Similarity Model of Subway Line Passing Steeply Inclined Mined - out Subsidence Area

Subway lines through the coal mined-out area for China"s first case, therefore, the research on the the basic law of rock movement in steep coal seam mining and stability of surrounding rock in subsidence area under subway load is of great significance. The similar model test method was used to simulate the mining of two groups of steeply inclined and extremely thick coal seams. The fracture and movement patterns of the rock strata during mining and loading were recorded by a digital camera. The test reflects the common features of the collapse zone morphology, the development of the fracture zone and the characteristics of surface movement in the mining of steeply inclined coal seams. In addition, the failure range of the overlying strata in coal mining is calculated by the parameters of the boundary angle, the movement angle of the the top and bottom corners, the boundary angle, the movement angle of the topsoil. Considering the subway and building loads, the broken rock mass in the subsidence area has a closed pressure, the maximum surface subsidence is 4~5cm, and the maximum thickness of the surrounding rock on the top wall is 2cm. The results provide reference for guiding the subway line passing through the subsidence area of coal seam.