挤压性围岩隧道变形特征分析

Deformation Characteristics Analysis of Extrusion Rock Tunnel

乌鞘岭隧道是兰新线重点控制工程,是国内最长的单线铁路隧道。该隧道岭脊地段穿越四条区域性大断层,地应力高,围岩软弱、破碎,属挤压性围岩大变形隧道。隧道施工过程中,出现较为严重的支护变形、支护开裂、钢架扭曲,甚至变形侵限及坍塌事故。针对该隧道特点,开展以变形为主的施工监控量测,进行了变形分布规律、累计变形与最大变形速率的关系、变形与围岩条件的关系以及变形与施工方法的关系等综合分析。提出挤压性围岩隧道具有变形量大、变形速率高、变形持续时间长的变形特征。

Wushaoling railway tunnel is a key project of Lanxin railway line. It is the longest single -track railway tunnel in china, and is a tunnel with large deformation of extrusion rock, going through four regional faults with high ground stress and soft and fractured rock. Serious support deformation and craze as well as steel liner plate contorting happened during construction, which even went beyond the limit value and caused collapse. According to the characteristics of this tunnel, the comprehensive monitoring was executed during the construction. The deformation pattern, the relationship between total deformation and maximum deformation speed, and relationship between deformation and the condition of surrounding rock and method of construction, etc. are analyzed. The characteristics of extrusion rock tunnel are summarized as large deformation, high deformation speed and long deformation duration.