深部石门硐室底臌形成机制与返修加固对策

Formation Mechanism and Repair Reinforcement Method of Floor Heave in Deep Crosscut Chamber

在西部高应力软岩中进行大断面硐室施工,极易引起快速、持续、严重的底板隆起事故,造成底板挠曲褶皱破坏,给矿井开拓和采矿运输带来极大的挑战。针对麦垛山煤矿18-2~#大巷水平石门硐室实际情况及西部软岩的典型地质特征,研究了深部软岩硐室的底臌形成机理,并根据主、被动支护相协调的理念,提出了"一次砌筑+锚梁、锚杆+二次砌筑"的软岩硐室底臌综合控制方案。数值模拟和现场监测表明:采用该支护措施能够显著改善底板的受力状态,有效提升巷道的整体稳定性,底部塑性破坏区域明显减小;硐室结构短期内即进入稳定状态,底板隆起量仅60.5~74.5mm,且没有出现明显的流变现象,变形抑制效果显著。

The construction of large-section chamber in the high-stress soft rock in the west was very easy to cause the rapid,continuous and serious floor heave accident,leading to the floor flexure and fold damage and bringing great challenges to the mine development and mining transportation.Combined with the actual situation of horizontal crosscut chamber in No.18-2 roadway of Maiduoshan Coal Mine and the typical geological characteristics of soft rock in the west,the formation mechanism of the floor heave in the deep soft rock chamber was studied.At the same time,according to the concept of coordination between active and passive support,a comprehensive control scheme of "primary masonry+anchor beam,anchor rod+secondary masonry" was proposed for the floor heave of soft rock chamber.Numerical simulation and field monitoring showed that the support measure can significantly improve the stress state of the floor,effectively improve the overall stability of the roadway,and significantly reduce the plastic failure area at the floor.The chamber structure would keep a stable state in a short time,and the displacement of floor heaven was only 60.5~74.5 mm.There was no obvious rheological phenomenon,and the deformation inhibition effect was significant.