浅埋煤层采动地表移动变形规律及电塔塔基稳定性研究

Study on Surface Movement and Deformation Law of Shallow Coal Seam and Stability of Electrical Tower Foundation

陕北矿区地表存在大量的高压电塔,煤层采动引起的地表移动变形,对高压输电线路安全造成威胁。基于概率积分地表移动变形预计理论,采用理论分析、理论计算和现场实测等研究方法,对浅埋煤层采动地表移动变形规律及电塔塔基稳定性展开研究。研究结果表明:(1)拟合了基采比JC和基载比JZ的概率积分参数计算式,地表下沉和水平移动均与基载比和基采比呈负相关,沉陷盆地的影响范围和拐点距离均与基载比呈正相关;(2)建立了采动高压电塔移动变形计算式,电塔塔身的倾斜变形量取决于地表倾斜变形和塔高,电塔基础的水平变形量取决于地表水平变形、电塔根开、基础性质和土体性质;(3)陕北锦界煤矿31104工作面开采过程中,电塔Z219预计产生的最大倾斜变形量为92 mm,小于450 mm,最大水平变形量为4.15 mm,小于4.55 mm,稳定性较高,倾斜变形理论预计值与实测值平均偏差为5.69%。

There are a large number of high-voltage electrical towers on the surface of the mining area in northern Shaanxi. The mining of coal seams will cause the movement and deformation of high-voltage electrical towers, posing a threat to the safety of high-voltage transmission lines. Based on the theory of prediction of surface movement and deformation by probability integral, the law of surface movement and deformation and the stability of tower foundation were studied by theoretical analysis, theoretical calculation and field measurement and other research methods. The research results are concluded as follows. Firstly, the calculation formulas of the probability integral parameters of the base mining ratio JCand the base load ratio JZare established. Both the surface subsidence and horizontal movement are negatively correlated with the base load ratio and the base mining ratio. The inflection point distance is positively correlated with the base load ratio. Secondly, the calculation formula for the movement deformation of the mining high-voltage electrical tower is established. The inclination deformation of the tower body depends on the surface inclination deformation and tower height, and the horizontal deformation of the tower foundation depends on the horizontal deformation of the surface and the root opening of the tower, foundation properties and soil properties. Thirdly, during the mining process of the 31104 working face of Jinjie Coal Mine in northern Shaanxi, the maximum inclined deformation expected by the tower Z219 is 92 mm, less than 450 mm, and the maximum horizontal deformation is 4.15 mm, less than 4.55 mm. The average deviation between the theoretical predicted value and the measured value is 5.69%.