断层与隧道相对距离对围岩稳定性影响的试验研究

Experimental Study on the Relative Distance Between a Tunnel and a Fault and Subsequent Effects on the Stability of the Surrounding Rock

目前关于断层破碎带破坏围岩完整性方面的研究已取得不少成果,但断层对隧道围岩稳定性的影响程度及其机理仍是一个模糊问题。文章以石吉高速五峰山一号隧道为背景,采用室内模型试验对有无断层、断层与隧道距离变化情况下的围岩破坏特性进行了研究。结果表明,断层与隧道距离在一倍洞径以内时,围岩不能形成完整的压力拱,断层的存在对围岩的稳定性影响较大;隧道开挖对隧道周线两侧围岩稳定性的影响具有不对称性。

The imegrity of surrounding rock is commonly destroyed by the existenee of a fractured fault zone. In order to understand the effects of distance variation between a tunnel and a fault on the stability of surrounding rock, the failure be- havior of surrounding rock was studied by laboratory model experiments based on the Shijiazhuang-Jilin expressway tun- nel and examining the conditions with/without fauhs as well as the varying distances between tunnels and faults. The re- sults indicate that the stability of the surrounding rock is greatly affected by the existence of a fault since an integrated pres- sure arch cannot be formed when the distance between the tunnel and fault is less than one times the tunnel diameter, and the excavation has an asymmetrical influence on the stability of the surrounding rock on both sides of the tunnel contour.