复杂地质条件下隧道三维变形规律分析

对乌鞘岭隧道岭脊F7断层和志留系地层的三维位移进行现场测试,并与三维数值计算结果进行对比分析;采用均值比较方法分析F7断层和板岩地段的三维变形规律,并与地应力场反演结果进行印证分析。结果表明,F7断层和千枚岩地段软岩隧道三维位移十分明显,具有隧道大变形特性,其纵向位移背离开挖面方向发展并在相距开挖面约2.0倍洞径时趋于稳定状态;F7断层地段隧道三维位移呈不均匀对称地发展变化,而板岩地段三维位移变化的一致性较好;隧道三维变形规律与隧道区域地应力场的分布存在相互印证关系。因此,在复杂地质条件下开展隧道三维位移测试并掌握其三维变形规律,对隧道工程的修建具有较大的指导作用。

Analysis of 3D deformation of tunnels under complex geological conditions

Field tests on 3D displacement at F7 fault and Silurian system strata at the ridge of Wushaoling tunnel were carried out and the test results were analyzed and compared with the 3D numerical results.By comparison of the average values,the 3D deformations at F7 fault and slate section were compared and analyzed,and were verified with the results of back-calculation of ground stress fields.It was shown that the 3D deformation in the tunnel at soft rock was obvious at F7 fault and phyllite section,with the characteristics of large deformation and longitudinal displacement developing in the opposite direction of work face and being stable at a distance about 2.0 times of tunnel diameter from the work face.And the 3D displacement of tunnels at F7 fault zone developed in an uneven symmetrical way,while there was good consistency for 3D deformation at slate section.Furthermore,there was a mutally verifying relationship between 3D deformation and ground stress distribution of tunnel region.Therefore it was necessary to carry out 3D displacement tests to detect the development of its deformation,and it would play a positive role in tunnel construction.