偏压连拱隧道二衬开裂加固措施及实施效果分析

Reinforcement measures and implementation effect analysis of secondary lining cracking in unsymmetrical multi-arch tunnel

某偏压连拱隧道在施工过程中二衬出现开裂,且随着后行洞掌子面的持续推进,裂缝的宽度、长度、深度和数量有进一步增加的趋势,研究裂缝的分布规律和发育特点及产生原因,进而确定合理的加固措施对于保证隧道安全具有重要的意义。通过埋设应力、位移监测设备对裂缝段进行监测,结合现场地形地质条件、施工工艺、裂缝分布规律确定了联合加固处理措施,并对加固处理区域进行联合监测。监测结果表明,隧道处于安全状态,该措施对于保证隧道结构安全和加快施工进度具有良好的效果,可为类似工程提供参考。

When cracks are found during construction in the second lining of an eccentrically loaded multi-arch tunnel,with the continuous tunneling advance,the width,length,depth and quantity of crack have a further increasing trend. It is significant to study the distribution law,development characteristics and cause of cracks,and then to take reasonable reinforcement measures to ensure the tunnel safety. The combined reinforcement measures are taken considering the on-site topographic and geological conditions,construction technique and crack distribution,meanwhile the stress and displacement of the crack section in the reinforcing area is being monitored. The monitoring results show that the tunnel is in a safe state,and the measures have a good effect to ensure the safety of the tunnel structure and speeding up the construction progress. The measures could be referred by the similar projects.