复杂软弱岩层大巷的稳定性与支护方式研究

Study on Stability of Complex Soft Rock Tunnel and Its Support Ways

复杂软弱岩层大巷具有变形量大、难支护、围岩持续变形破坏的工程特征,实践表明,现有支护难以控制。通过对不同支护方式的数值分析,提出了全封闭支架+全断面松动卸压以及二次锚杆支护的支护方式,数值分析结果表明,新支护方式下应力集中程度减小,高应力区向围岩深部转移,有效控制了围岩的剧烈变形。现场试验证明,新支护方式通过适度让压和锚杆支护强化围岩的作用,充分发挥了锚杆与围岩的整体力学效应,使围岩变形达到稳定的时间明显缩短,保证了巷道的稳定,具有显著的技术经济效益。

The complex soft rock tunnel has engineering characteristic of large deformation, difficult to support and continuous distort destroys, practice indicates that it is difficult to control with existing support. By analyzing different support way numerically, proposed the way of fully enclosed support coupled with full face loose relieving, as well as bolt supporting for second time. The results of numerical analysis show no stress concentration occurred, and the high stress regions are converted into the deep areas after applying new support way, which efficiently control the severe deformation of surrounding rocks. It has been carried out in situ that the stability of rock can be achieved through fully exerting the mutual action between the bolt with wire mesh and the surrounding rock with new way, and the interval of reaching stability state of entry surrounding rock is obviously reduced, which possess remarkable technology and economic benefit.