强风化砂岩地区浅埋偏压隧道病害分析及整治

Analysis and Improvement of Bias Shallow Tunnel in Heavily Weathered Sandstone Area

浅埋偏压隧道在铁路建设中较为常见,偏压荷载是形成隧道病害隐患的根本原因。为解决强风化砂岩地区浅埋偏压对隧道结构稳定造成的不利影响,以某隧道为研究背景,通过现场观察和分析监测结果,探讨隧道受力机理,归纳总结出地形因素是偏压荷载产生的根本原因,施工干扰及水的因素恶化了隧道不平衡的条件。隧道成功的施工,验证了反压回填能够平衡隧道承受的偏压荷载、注浆加固能够提高破碎围岩的整体稳定性,双侧壁导坑法对施工干扰少,在开挖中应优先选用。

The bias shallow tunnel is very common in railway construction. The bias load is the root cause of potential tunnel defects. This paper addresses tunnel stress mechanism and the root cause of the bias load based on site observation and analysis of monitoring data collected from a tunnel as to mitigate the adverse effects on the stability of tunnel structure in heavily weathered sandstone area. It is geological conditions that generate bias load, and the construction activities and water that deteriorate tunnel unbalanced conditions. The success of tunnel construction verifies that the back pressure backfill can balance the tunnel under bias load, grouting reinforcement can improve the overall stability of broken surrounding rock, and the double side heading method has less interference on the construction and should be prioritized in excavation.