老东山隧道软弱围岩变形开裂控制技术研究

Study on deformation and crack control measures of weak surrounding rock of Lao Dongshan tunnel

老东山隧道地处区域性断层夹持的构造挤压带中,隧道在施工过程中多次出现初期支护变形开裂现象。通过对现场地质状况的调查,从围岩岩性、地质构造、地下水等方面,探讨了隧道产生大变形的原因和机制;结合围岩变形实测数据的分析,得到不同施工工序以及工序间隔时间和间距对隧道围岩变形量产生的影响,进一步通过五种不同支护参数的现场对比试验,获得了不同支护方案的不同抗变形能力,确定了老东山隧道不同围岩条件下控制围岩变形的具体支护参数和施工控制措施,确保了隧道变形开裂得到有效控制。

Lao Dongshan tunnel is located in compressed zone gripped in regional fault.There were a lot of deformation and crack conditions appear in the primary support during the progress of tunnel construction.Through checking into field geological condition,this paper discussed the causes and mechanism of tunnel large deformation with regard to the surrounding rock lithology,geological structure,groundwater,etc.Combined with the analysis of the practical data of surrounding rock mass deformation,the impact on surrounding rock deformation,generated by the different construction process,process time interval and spacing was got.Through the five on-site experiments with different supporting parameters,the paper got the ability of deformation resistance in the different support schemes,determined the specific supporting parameters and construction control measures for surrounding rock deformation of Lao Dongshan tunnel in different conditions.So the tunnel deformation and crack were effectively controlled.