台阶法施工对隧道变形影响分析

Impact Analysis of Bench Method in Construction on Tunnel Distortion

介绍了乾山隧道的施工方法和隧道监控量测的内容、方法。通过对监测结果的分析,得出隧道在相应支护条件下不同围岩等级位移变形趋势基本一致的结论:位移变形在最初10 d左右增加较快随后趋缓,并在30 d左右基本达到稳定;采用台阶法开挖时,变形由大到小依次为上台阶、中台阶和下台阶,并且下台阶开挖对上台阶变形有明显影响。这可为合理确认二次衬砌的时间提供参考依据,也可为类似地质条件下的工程施工提供参考。

Introduced the construction method of Qianshan tunnel and the tunnel monitoring and measuring contents, and through the analysis of the monitoring results, concluded that the tunnel of different rock levels in the corresponding support conditions were basically identical in displacement deformation trends： the deformation in the initial 10 d increased rapidly and then slowed down, to around 30 d basically reached stable; the deformation of bench method from big to small is the upper stage, the middle stage and the lower stage, and the lower stage excavation has obvious impact on the upper stage deformation. Provides reference basis for reasonably confirming the time of secondary lining, and also provides reference for construction engineering under similar geological conditions.