基于注浆加固工况的隧道下穿既有通道相互力学作用分析

Analysis of Mutual Mechanical Effect of Tunnel Underpassing Existing Channels Based on Grouting Reinforcement Condition

以徐州地铁某盾构施工区间隧道工程为背景,针对隧道在上软下硬地层下穿地下通道的开挖问题,利用有限差分软件FLAC 3D,开展基于注浆加固工况下的盾构隧道开挖对地下通道稳定性与安全性的影响分析,研究不同工况下地下通道与隧道的位移场、应力场分布规律。结果表明:隧道在下穿地下通道过程中存在相互的力学扰动,穿越过程中采取壁后注浆加固措施能有效减小地下通道与隧道的沉降,提高施工安全性。隧道开挖会引起周围环境的应力场发生变化,使地下通道主体结构产生更大的集中应力。研究结果可以为类似隧道下穿工程提供参考。

Taking a shield tunnel project in Xuzhou metro as the background, aiming at the problem of tunnel excavation in upper-soft and lower-hard strata, the finite difference software FLAC3 D is used to analyze the influence of shield tunnel excavation on the stability and safety of underground tunnels based on grouting reinforcement. The displacement field and stress field distribution of underground tunnel and tunnel under different working conditions are studied. The results show that there are mutual mechanical disturbances in the process of tunnel passing through the underground passage. The post-wall grouting reinforcement measures can effectively reduce the settlement of the underground passage and the tunnel, and improve the construction safety. Tunnel excavation will cause changes in the stress field of the surrounding environment, resulting in greater concentrated stress in the main structure of the underground channel. The research results can provide reference for similar tunnel undercrossing projects.