炭质页岩隧道变形特征研究与稳定性分析

Research on Deformation Features and Stability Analysis of Tunnels in Carbonaceous Shale

大丽铁路松桂1号隧道在施工过程中围岩变形较大,出现了喷射混凝土开裂、净空侵限、钢架变形等施工难题,造成施工进展极其缓慢的现状。通过试验对炭质页岩的膨胀性、崩解性、风化性等物理特性进行研究,并分析层理产状对隧道稳定性的影响,指出垂直节理最不利于隧道的稳定。在隧道施工过程中对围岩变形进行现场测试,根据现场监测结果得出炭质页岩隧道的最大累计变形量和变形速度都发生在边墙位置,水平地应力为最大主应力。

In construction process of Songgui No.1 tunnel,Dali railway,the deformation of surrounding rock was quite big,which caused many construction difficulties,such as the cracking of shotcrete,the over-break of clean cross-section and the deformation of steel frames,etc.,leading to the very slow progress of construction.Through the study of physical properties of carbonaceous shale,such as dilatability,disintegration and weathering,etc.by experiment and the influence of bedding occurrence on the tunnel stability,it showed that the vertical joints were most harmful to the stability of tunnels.In tunnel construction process the field test of the surrounding rock deformation was carried out,and according to the above results the deformation law is that the maximum accumulative total deformation and maximum deformation velocity all occurred in sidewalls and the horizontal ground stress is the maximum principal stress.