涌水隧道支护对围岩力学性质的影响

Influences of support on mechanical property of rock in water-containing tunnel

以宜万铁路堡镇隧道为工程背景,首先对高地应力大变形段中所揭示的软弱围岩不同饱水状态下的单轴试验方案进行设计,进行单向应力状态下岩石力学性质测试,探讨饱水状态对软岩强度和峰后体积应变的影响规律;然后,根据试验结果和现场监测数据,对饱水时间1月的岩石试件进行了低围压(0.2,0.4,0.6,0.8和1.0MPa)条件下的三轴压缩试验,研究围压对软岩强度和体积应变的影响规律;最后,提出隧道二次衬砌的作用时机。研究结果表明:当堡镇隧道大变形段围岩变形量达到总变形量的70%时,适宜施作二衬。

To assure the design,construction,support and operation safety of tunnel,the change law of soft rock strength and volumetric strain under different saturated time was studied using XTR01-01 microcomputer electro-hydraulic servo controlling triaxial test instrument. The mechanical behaviors of black macker that was widely distributed in Baozhen tunnel were discussed by a series of compressive tests under different saturated conditions,and the effects of saturated time on mechanical properties were researched. According to test results and the measure data of Baozhen tunnel,a series of triaxial compress tests of the rock samples whose saturated time is 1 month were carried out; the variation laws of strength and volumetric strain under low confining pressures （0.2,0.4,0.6,0.8,1.0 MPa） were analyzed. Finally,the occasion of constructing the second liner was put forward. The results show that the second liner can be constructed when the surrounding rock deformation reaches 70% of the total deformation at large deformation section of Baozhen tunnel.