高地应力软岩隧道台阶参数对变形的影响分析

以某铁路隧道台阶法施工为例,通过建立数值分析模型,分析高地应力软岩环境下铁路单线隧道台阶法开挖时台阶高度和长度变化对变形的影响,并结合现场变形监测数据进行了验证。分析结果表明:台阶参数对控制隧道变形有重要作用;台阶高度均应控制在3~4 m,且在满足施工机械作业空间要求的情况下,应尽量减小上台阶开挖高度;开挖台阶长度为4~6 m较为合适。

Analysis on Influence of Bench Method Parameters on Deformation in Soft Rock Tunnel with High Ground Stress

Taking the construction of a railway tunnel by bench method as an example, this paper, through a numerical analysis model established, studied how the change of bench height and length affects the deformation in excavation of single-track railway tunnel by bench method in soft rock environment with high ground stress, and then did the verification in combination with the data from field deformation monitoring. The result of analysis shows that the bench method parameters play an important role in control of tunnel deformation; the bench height should be controlled in the range of 3~4 m and, when meeting the spatial requirement for operation of construction machine, the excavation height of upper bench should be reduced with every reasonable effort; the length of excavated bench prefers to be 4~6 m.