高铁隧道穿越采空区段围岩变形受力规律分析

为研究高铁隧道过采空区段的围岩变形规律,本文以太焦高铁皇后岭隧道典型过采空区段工程为背景,通过对典型断面进行隧道围岩变形和拱架内力的持续监测,对比分析不同施工阶段下高铁隧道围岩变形受力规律。分析结果表明：上台阶开挖时是围岩变形发生的主要阶段,隧道最大沉降变形发生于拱顶,占总变形比值的50%以上,且隧道距离采空区底板距离越近,围岩受开挖和采空区扰动影响越大;钢拱架受力为全环压应力,整体分布呈现“上大下小”、“不均匀对称”的特点,受力最大位置出现在拱顶和右拱肩位置,并且拱架受力随着掌子面的远离,其轴力变化速率呈现出逐步减少的趋势。结合位移和应力监测数据分析结果,采空区对隧道的影响高度约为25.7m。研究成果可为类似隧道过采空区工程的设计、施工提供借鉴和参考。

Analysis of Surrounding Rock Deformation Law of High-speed Railway Tunnel passing through Mined-out Section

In order to study the deformation law of the surrounding rock of the goaf section of high-speed railway tunnel, the typical goaf section of the Huanghouling tunnel of the Taijiao high-speed railway is taken as the background. The deformation law of the surrounding rock of high-speed railway tunnel under different construction stages is compared and analyzed through the continuous monitoring of the deformation of the surrounding rock of the tunnel and the internal force of the arch frame on the typical section. The analysis results show that the maximum settlement deformation of the tunnel occurs at the vault, accounting for more than 50% of the total deformation, and the closer the tunnel is to the goaf floor, the greater the influence of excavation and goaf disturbance on the surrounding rock. The stress of the steel arch is the whole ring compressive stress, and the overall distribution is characterized by "small on the top and small on the bottom" and "uneven symmetry". The maximum stress is at the vault and right arch shoulder. And with the distance of the face of the palm, the change rate of the axial force of the arch is decreasing. Combined with the analysis results of displacement and stress monitoring data, the influence height of goaf on the tunnel is about 25.7m. The research results can provide reference for the design and construction of similar tunnel goaf engineering.