临时支护对连拱隧道中隔墙施工力学行为影响

The Influence of Temporary Support on the Mechanical Behavior of Middle Wall Construction in a Continuous Arch Tunnel

采用中隔墙单侧临时支护可减轻非对称开挖对中隔墙受力和稳定性的影响。以粤西某双连拱隧道工程为依托,对Ⅳ级围岩区有无单侧临时支护、同一支护形式不同支护强度对调节中隔墙复杂应力状态分布的效果进行了对比研究,分析并得到了临时支护对中隔墙施工力学的影响规律,进而对中隔墙临时设计支护方案进行了优化。结果表明:临时支护应遵循中隔墙左右受力平衡的原则,对Ⅳ级围岩,与设计工况相比,工况三各监测点的位移、应力变化更为均衡,可作为临时支护的推荐方案。

The influence of asymmetric excavation on the force and stability of the middle partition wall can be alleviated by using the temporary support on one side of the middle partition wall. Based on a double-arch tunnel project in west Guangdong, this paper studies the effect of adjusting the complex stress state distribution of the middle partition wall for the temporary support of the Ⅳ surrounding rock areas and the different support strengths of the same support form. The influence rule of temporary support on the construction mechanics of the middle partition wall is analyzed and obtained, and then the temporary design support scheme of the middle partition wall is optimized. The results show that the temporary support should follow the principle of the left and right force balance of the middle wall, and the displacement and stress change of each monitoring point in the fourth grade surrounding rock is more balanced than that in the design condition, which can be recommended as the temporary support scheme.