高水平应力软岩巷道预留刚隙柔层支护技术

Support Technology of Reserved Rigid Gap Flexible Layer in High Horizontal Stress Soft Rock Roadway

为解决某矿运输巷大变形、强流变的工程难题,通过对巷道地应力、围岩松动范围、变形破坏特征及岩层力学状态进行分析,总结了其大变形失稳破坏的原因;基于"定量让压"支护理论,提出了"多级锚网索+预留刚隙柔层+U型钢强力支护"联合控制技术,并采用FLAC3D模拟确定了刚隙柔层最佳预留空间大小。工业性试验表明,采用该支护技术后围岩顶板下沉量、底鼓量及两帮移近量分别为37.8、97.8、105.3 mm,顶板及帮部锚杆轴力分别在80～112 kN和78～137kN范围内,有效解决了该运输巷蠕变大变形的工程难题。

In order to solve the engineering problem of large deformation and strong rheological behavior of a coal mine transportation roadway, the causes of large deformation instability and failure of roadway are summarized by the analysis of the ground stress test, the loose range of surrounding rock, the deformation and failure characteristics and the mechanical state of rock stratum. Based on the support theory of quantitative pressure, this paper proposes a joint support scheme of multi-stage anchor cable ＋ reserved rigid gap flexible layer ＋U beam strong support. The optimal reserved space of rigid gap flexible layer was determined by FLAC^3D simulation. The industrial test shows that the maximum subsidence, floor heave and two sides moving amount of roadway roof are respectively 37.8 mm, 97.8 mm and 105.3 mm; the bolt axial force are in the range of 80 kN to 112 kN at roof and 78 kN to 137 kN at two sides after adopting the supporting technology, which effectively solves the engineering problem of large creep deformation of the transportation lane.