The causes of the problem such as collapse encountered during Liuyanghe tunnel construction in the weathered slot were analyzed. Based on geology condition, the original design was modified and some countermeasures were put forward, such as reinforcement geology forecast and preliminary support, setting vertical temporary steel support.Construction safety was adjusted using simulation software and in-site monitoring. The tunnel stability was analyzed by strength reduction method. The results show that vertical steel support can effectively reduce crown displacement. Tunnel safety factor is 1.8 based on strength reduce method, and the main indicators of rock failure is crown displacement. The research can give a reference for similar tunnel projects.%针对浏阳河隧道过风化槽地段施工过程中遇到的易坍塌等问题,分析其主要原因,据现场情况修正原方案,提出施工应对措施,如加强超前地质预报和初期支护,采用"台阶法+竖向钢支撑"的开挖方法,进而应用数值模拟和现场监测分析其安全性,并基于强度折减法研究隧道整体稳定性.研究结果表明:竖向支撑可以很好地减少拱项沉降;隧道安全系数为1.8,且应以拱项沉降作为围岩失稳的主要指标.其研究成果可为同类隧道工程过风化槽等地段施工提供参考.
展开▼
