高地应力软岩隧道衬砌裂损重新施作段结构安全性分析

Structural Safety Analysis of Reconstruction Section of Lining Cracking in High Geo-stress Soft Rock Tunnel

为研究高地应力软岩隧道衬砌裂损重新施作段结构的安全性,依托木寨岭隧道衬砌裂损段,通过现场监测和数值模拟的方法,分析高地应力软岩隧道衬砌裂损重新施作段结构变形受力特征,进而分析结构的安全性。现场监测结果表明:衬砌裂损重新施作后,前3层支护几乎承担了所有的围岩压力和变形,通过层层支护、分层抵抗的方法来逐渐降低衬砌受力,保证衬砌结构的安全。通过数值计算对比分析衬砌重新施作前后的隧道受力变形状态,其中重新施作后衬砌各位置混凝土应力和钢筋应力增长趋势均不明显,计算得到衬砌裂损重新施作段结构安全系数均处于3. 3~8. 1,各位置安全系数均大于规范中的要求值,说明结构处于安全状态。

The safety of the reconstruction section of lining cracking in high geo-stress soft rock tunnel is important.Hence,the deformation and force characteristics of structure of the lining cracking section of Muzhailing Tunnel with high geo-stress soft rock are analyzed by field monitoring and numerical simulation.And then the safety of the structure is analyzed.The monitoring results show that most of the surrounding rock pressure and deformation is borne by the first three layers of support after reconstruction of lining cracking,and the lining stress is gradually reduced by layers of support,which can ensure the safety of the lining structure.The force and displacement states of tunnel before and after the reconstruction of lining cracking are analyzed by numerical calculation and comparison.The analytical results show that the growth trend of concrete stress and reinforcement stress in each position of lining after reconstruction are not obvious;it is calculated that the structural safety factors of the reconstruction section of lining cracking is in the range of 3.3-8.1,and the safety factors of each position is greater than those in the standard,which indicates that the structure is safe.