城市浅埋大断面隧道穿越不良地质施工技术探讨

Discussion on Construction Technology of Urban Shallow-buried Large-section Tunnel through Poor Geology

拖龙山隧道属浅埋、大断面、小净距市政短隧道。为保证施工安全,在洞口浅埋段采用超前大管棚预支护、在隧道穿越不良地质段采用超前小导管注浆预加固,提高了围岩的自稳能力。施工过程中加强监控和超前地质预报,监测结果表明,隧道施工过程中的拱顶下沉、净空收敛及地表沉降值均在规范允许范围内,施工技术措施可行,质量得到有效控制。

The Tuolong Mountain Tunnel belongs to a short shallow-buried large-section and small-clearance municipal tunnel. In order to guarantee the construction safety, the advanced large pipe shed pre support is used at the shallow buried section of tunnel portal and the advanced small catheter grouting pre reinforcement is used at the poor geological section where the tunnel goes through in order to improve theself-stabilization capacity of the surrounding rock. It is to strengthen the monitoring and the advanced geological forecast in the construction process. The monitoring result shows that the crown settlement,clearance convergence and ground surface settlement values are all within the allowance range of the standard in the construction process of tunnel, the construction technical measures are feasible and the quality can be effectively controlled.