木寨岭隧道大变形分级标准与支护时机研究

依托兰渝铁路木寨岭隧道工程,对建设过程中大量监控量测数据的统计分析,获得了木寨岭隧道最大水平收敛变形、沉降变形以及挤压大变形的分布规律。基于现场监控量测数据和现场施工过程调查,从有利于应力释放、支护变形可控及降低二衬挤压形变压力的角度,建立了炭质板岩隧道支护位移管理基准和挤压大变形分级标准,这些标准对于炭质板岩等挤压大变形地层中隧道的建设管理具有重要指导意义。最后,基于监控量测得到的初期支护收敛速率与大变形分级标准,开展了炭质板岩隧道二衬施作时机研究,结合工程经验类比,得到了大变形地层二衬施作时机的变形控制基准。这些基准在木寨岭隧道等其他隧道工程中得到了广泛的应用。

Classification Standard of Large Deformation and Construction Time of Second Lining in Muzhailing Tunnel

Based on the Muzhailing tunnel of the Lanzhou-Chongqing railway, a vast amount of monitoring and measuring data in the process of construction are analyzed statistically, and the maximum extrusion deformation, settlement deformation and the distribution of large deformation were obtained. According to the data of field monitoring measurement and field investigation in the process of construction, the management standard of support displacement and classification standard of large extrusion deformation were established from the perspectives of deformation and stress distribution, which had guiding significance for construction of tunnel in carbonaceous slate strata. Finally, based on the convergence rate of initial support and classification standard of large extrusion deformation, the timing of second lining construction in carbonaceous slate strata was investigated and the standard of deformation control for second lining construction time was obtained. The management standard of support displacement, classification standard of large extrusion deformation and standard of deformation control for second lining construction time had been widely used in Muzhailing tunnel and other tunnel projects in carbonaceous slate strata.