单线铁路隧道水平岩层施工技术

Construction Techniques for a Single-Track Railway Tunnel in a Horizontal Stratum

南吕梁山隧道2#斜井进口围岩以水平层状泥岩、泥灰岩、灰岩为主,层理和节理裂隙发育,爆破后拱部极易出现平顶、落石、掉块、塌顶等现象,快速掘进、成本控制、安全风险等均难以得到保证。文章通过对开挖方法、超前加固、控制爆破、初期支护、监控量测等思考,提出了单线铁路隧道水平岩层施工中短台阶法开挖、超前小导管注浆、弱控制爆破、拱部中空注浆锚杆支护,以及地质超前预报、加强施工监测等主要施工方法和技术措施。

In the South Luliangshan tunnel, the surrounding rock at the entrance of the #2 inclined shaft is mainly composed of horizontally layered mudstone, marlstone, and limestone with developed bedding and joint fissures, which are inclined to result in rock falls, chipping, and rock collapse at the arch after blasting, causing difficulties in terms of rapid excavation, cost control, and safety risks. In this paper, considering the excavation method, advance reinforcement, controlled blasting, primary support, monitoring, and measurement, major construction methods, measures, and techniques are presented for the single-track railway tunnel in horizontal stratum, such as the short bench method, advance condulet grouting, slight controlled blasting, hollow grouting anchor support for the arch, geological advance prediction, and strengthened construction monitoring.