深埋陡倾薄层小夹角隧道大变形时空演化规律及支护效果评价

Large Deformation Spatiotemporal Evolution Law and Support Effect Evaluation of aDeep Buried Steep Inclined Thin Layered Small-angle Tunnel

为探明某深埋陡倾薄层小夹角隧道大变形时空演化规律、评估不同支护方式抑制围岩大变形的效果,对该隧道一、二级大变形洞段设置了四个不同支护方式的试验段,并在每个支护试验段的拱顶和边墙等位置设置了7个测点用于进行断面收敛变形的长期监测。变形监测结果表明:不同支护方式的试验段中隧道边墙位置的收敛变形均较大。阐述了采用指数函数对变形演化监测结果进行拟合的过程,分析了不同支护条件下断面不同位置变形拟合参数a,b值的大小;最后,通过拟合参数值定量分析了断面不同位置的时效变形特征以及采取不同支护方式取得的效果。所取得的研究结果对于深部高应力隧道层状围岩变形破坏机制及支护方法的认识具有一定的启示意义[1]。

In order to explore the spatiotemporal evolution law of the large deformation of a deep-buried steeply inclined thin-layer small-angle tunnel,and to evaluate the effect of different support methods on inhibiting the large deformation of the surrounding rock,four test sections with different support modes were set up for the first and second level large deformation tunnel sections of the tunnel,and seven measuring points were set up at the vault and side wall of each support test section for long-term monitoring of cross-section convergence deformation.The deformation monitoring results show that the convergence deformation of the tunnel side wall position in different tunnel sections is large.The exponential function was used to fit the deformation evolution monitoring results,and the values of deformation fitting parameters a and b at different positions of the section under different support conditions were analyzed.Finally,the aging deformation characteristics of different positions of the section and the effects of different support modes were quantitatively analyzed by fitting the parameter values.The results of this study have certain enlightening significance for the understanding of the deformation and failure mechanism and support methods of layered surrounding rock in deep high-stress tunnels[1].