盾构法施工深埋斜井的围岩应力变形分析

Stress and deformation analysis of the surrounding rock of deep buried inclined shaft constructed with shield method

以采用盾构法施工的神华新街台格庙矿区主斜井为研究对象,对该斜井穿越2种典型地层的施工过程进行数值分析,得到了施工过程中围岩的应力分布及变形规律.研究结果表明:随开挖的推进,围岩中的应力释放区和塑性区的分布及隧道拱顶、拱底的位移变化规律与水平隧道基本相同;开挖影响范围内,围岩的最大主应力与位移等值线均近似平行于斜井轴线,平行程度随距离斜井轴线由近至远而逐渐变弱;斜井埋深越大,表面沉降越小,且沿着斜井开挖方向成非线性分布;围岩力学性质越差,斜井开挖面的空间影响范围越大;开挖面前方影响范围大于后方,本文斜井的开挖面影响范围为其前方3倍洞径,后方4倍洞径,大于水平隧道.

It takes the main inclined shaft of Shenhua Xinjie coal mine which is constructed with shield method as the object of study in this paper,numerical analyses of the construction process of inclined shafts passing through 2kinds of typical rocks are conducted,and the stress distribution and deformation rules of surrounding rocks during construction are obtained.The results show that the distribution of stress releasing zones and plastic zones,the displacement changing rules of crown and invert of surrounding rocks in inclined shafts during excavation are basically the same with that in horizontal tunnels.The contours of the maximum principal stress and displacement of surrounding rocks within the influence scope of excavation are approximately parallel to the axis of inclined shaft,and the parallel degree is gradually decreased as the distance from the contours to the axis increases.The surface settlement varies nonlinearly with the depth of inclined shaft,and the larger the buried depth is,the smaller the surface settlement is.The spatial influence areas of the excavation face of inclined shaft get greater as the mechanical properties of surrounding rock get worse.The spatial influence area ahead the excavation face is larger than that behind the excavation face,and the spatial influence area ahead the excavation face is 3times of diameter,the spatial influence area behind the excavation face is 4times of diameter of the inclined shaft in this paper,which is larger than that of horizontal shield tunnels.