高速铁路隧道分修过渡结构的施工力学特性研究

Study on Construction Mechanical Characteristics of Transition Structure of Separated Repair in High Speed Railway Tunnel

高速铁路隧道的分修过渡结构是合分修隧道中连接大跨隧道和小间距隧道的过渡段,该区段的横向与纵向结构变化大,是隧道施工的重点和难点。以壁板坡隧道工程为背景,分析了大跨段A断面的力学特征;通过数值建模分析小间距段岩柱变形以及围岩应力,认为分修过渡结构的最优施工顺序为"大跨段左侧开挖→左线开挖→大跨段右侧开挖→右线开挖"的开挖顺序。现场监测大跨段A断面拱顶、边墙的实测值与计算值基本一致,验证了数值模型的正确性。

In the transition structure of separated repair, namely the transition section connecting the large span tunnel and the small spacing tunnel in high-speed railway tunnels, both transverse and longitudinal structure vary greatly, which forms the key and difficult point in tunnel construction. Based on the engineering background of Wainscot Slope Tunnel, this paper analyzed the mechanical characteristics of the large span section A. The numerical modeling analysis of the surrounding rock deformation and the surrounding rock stress in the small spacing section shows that the optimal construction sequence of the separated repair transition structure is ＂the left side of the large span, the left line excavation, the right side excavation of the large span and the excavation of the right line＂. The measured values of the arch and side wall of the large span section A are basically consistent with the calculated values, and the correctness of the numerical model is verified.