Li Hao, Long Sichun, Lai Xiangen, Kuang Lijun, Zhou Jian, Liao Mengguang, Zeng Chaofeng
School of Earth Sciences and Spatial Information Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
China Construction Fifth Engineering Bureau Civil Engineering Co., Ltd, Changsha, 410011, China.
Sci Rep. 2025 Mar 11;15(1):8415. doi: 10.1038/s41598-024-81128-0.
Understanding the deformation mechanism and behaviour of adjacent tunnels subjected to dynamic train loads provides vital technical insights for engineering design. This study conducted a detailed analysis and revealed that tunnel excavation significantly affects the stability of adjacent existing tunnels under dynamic loads. First, we developed a dynamic load simulation approach and derived a calculation formula for shield-soil friction. A methodology for analyzing the stress in the surrounding rock of the tunnel was established. Subsequently, the impact of dynamic loads on the stability of existing tunnels was assessed through numerical simulations. Finally, the numerical results were compared with field-measured data to validate the reliability of the research findings. The results indicated that, compared to the condition without train load, the maximum vertical and lateral displacements at the vault of the existing tunnel under dynamic load condition increased by 2.9 mm and 1 mm, respectively, leading to an overall safety and stability coefficient reduction of approximately 0.1. Furthermore, the influence of dynamic loads on the stability of the existing tunnel intensified with increasing train speeds under various load conditions. For train speeds of ≤ 40 km/h, the dynamic load could effectively be considered as a static load. Notably, the surrounding soft rock exhibited a higher degree of stress release compared to the surrounding hard rock. The stresses at the soft-hard rock interface were found to potentially induce damage to the tunnel. In scenarios where new and existing tunnels were in proximity, the dynamic load was incorporated into the entire simulation process, yielding results that closely aligned with actual measurements.
了解相邻隧道在列车动荷载作用下的变形机制和行为，可为工程设计提供重要的技术见解。本研究进行了详细分析，结果表明，隧道开挖显著影响既有相邻隧道在动荷载作用下的稳定性。首先，我们开发了一种动荷载模拟方法，并推导了盾构与土体摩擦力的计算公式。建立了一种分析隧道围岩应力的方法。随后，通过数值模拟评估了动荷载对既有隧道稳定性的影响。最后，将数值结果与现场实测数据进行比较，以验证研究结果的可靠性。结果表明，与无列车荷载工况相比，既有隧道拱顶在动荷载工况下的最大竖向位移和横向位移分别增加了2.9毫米和1毫米，导致整体安全稳定系数降低约0.1。此外，在各种荷载工况下，动荷载对既有隧道稳定性的影响随列车速度的增加而加剧。当列车速度≤40公里/小时时，动荷载可有效视为静荷载。值得注意的是，与周围硬岩相比，周围软岩的应力释放程度更高。软硬岩界面处的应力可能会对隧道造成破坏。在新建隧道与既有隧道相邻的情况下，将动荷载纳入整个模拟过程，得到的结果与实际测量结果非常吻合。
