高原浅埋隧道不同施工方法力学行为分析

Mechanical Behavior Analysis of Shallow Buried Tunnels in Plateau Constructed with Different Methods

为了分析不同施工方法对高原浅埋隧道施工过程中稳定性的影响规律,以某隧道工程实例为背景,采用有限差分软件FLAC3D对双侧壁导坑法和三台阶预留核心土法进行数值模拟,并分析对比高原浅埋隧道在2种施工方法中的围岩变形、支护应力和围岩塑性区分布规律。数值模拟结果表明:双侧壁导坑法在控制围岩变形和地表沉降方面优于三台阶预留核心土法;支护拉压应力更小,围岩塑性区分布范围也更加均匀合理。因此,对于高原浅埋隧道,采用双侧壁导坑法施工具有更大优势。

In order to analyze the influence of different construction methods on the stability of the construction process of the shallow buried tunnel in the plateau, the finite difference software FLAC3 D was used to simulate the double-sided pilot tunnel method and the three-step method with reserved core soil based on a tunnel project, and the deformation of the surrounding rock,the supporting stress and the distribution law of the plastic zone of the surrounding rock were analyzed and compared between these construction methods. The numerical simulation results show that the double-sided pilot tunnel method is better than the three-step method with reserved core soil in controlling the deformation and surface subsidence of the surrounding rock; the stress of the support is smaller, and the distribution of the plastic zone is more uniform and reasonable.Therefore, for the shallow buried tunnel in plateau, the application of double-sided pilot tunnel method has a greater advantage.