浅埋煤层条带充填隔水岩组力学模型分析

Mechanical model of water resisting strata group in shallow seam strip-filling mining

我国西部浅埋煤层开采引起严重的地表塌陷和潜水流失,进行条带充填控制隔水岩组稳定性是保水开采的有效途径。基于"上行裂隙"和"下行裂隙"对隔水岩组稳定性的影响,建立了2个充填条带的非水平五跨连续梁力学模型,并给出了其放松结构,求出了岩梁的应力和弯矩表达式。考虑充填条带及其支撑岩柱的压缩变形,给出了条带充填隔水岩组的下沉曲线,提出了"上行裂隙"发育高度与"下行裂隙"发育深度和位置的计算方法。研究表明,上行裂隙发育高度随间隔宽度的增大而增大,下行裂隙发育深度随隔充比的增大而明显增大。充填位置、充填条带宽度、充填间隔宽度和隔充比是隔水岩组稳定性的主要影响因素。

Shallow coal seam mining caused serious surface subsidence and phreatic water loss in western China. Stripfilling aquiclude stability control is an effective way to water preserved mining. Based on the effect of 'upward crack'and 'downward crack'on the stability of the water resisting strata group,the un-horizontal five span continuous beam mechanical model of 2 filling strips was established,and its relaxed structure was set up,thus the expression of stress and bending moment expression of rock beam was put forward. Considering the compression deformation of filling strip and its supporting strata pillar,the subsidence curve of the water rock group with filling strip was obtained,so the calculating method of the 'upward crack'development height as well as the depth and location of 'downward crack'were proposed. Research results show that the development height of upward crack increases with increase of the width of filling interval,and the depth of downward crack increases with the increase of the ratio of filling width to filling interval significantly. The filling position,filling strip width,filling interval width,and the ratio of filling strip width to filling interval width are the key factors to the stability of water resisting rock group.