风化花岗岩地层隧道变形与施工技术研究

Research on Deformation Characteristics and Construction Technology of Weathered Granite Formation Tunnel

摘要: 依托甬台温高速公路渔寮隧道工程，基于监控量测数据与数值模拟分析结果，对风化花岗岩地层中的隧道围岩变形特征进行了研究。总结出隧道围岩变形规律，渔寮隧道出口段左、右洞围岩变形差异以及采用双侧壁导坑开挖工法对隧道围岩变形产生的影响。现场监控量测数据显示：隧道出口段围岩变形量较小，左、右洞呈现出的围岩变形规律有较大差异，IV、V级围岩变形也有不同。并分析了隧洞开挖引起的地表沉降规律。对隧道出口段的施工过程进行了数值模拟，结果显示在V级围岩区段，采用长管棚联合注浆锚杆的超前支护体系以及双侧壁导坑开挖工法，能够有效控制隧道围岩变形。根据实测数据以及数值计算结果分析总结了控制隧道围岩变形的有效施工措施。

Abstract: Based on the measured surrounding rock stress, deformation and support structure stress in the weathered rock formation, combined with analytical formula calculation and numerical simulation, from the surrounding rock loose circle radius, support structure deformation and force, this paper evaluated surrounding rock stability and support effect. The results show that the surrounding rock conditions of the exit section of the Yuliao tunnel are better, the maximum deformation is 7.71 mm, and the thickness of the loose roof of the arch is 3.1 m. The thickness of the loose circle at the arch waist and the arch shoulder is more than 4.0 m. The analysis reflects that the bolts in the loose area of the surrounding rock are subjected to large forces. The stress characteristics of the supporting structure indicate that the additional load transmitted to the supporting structure due to the large deformation of the surrounding rock at the vault and the arch causes the force increase. The numerical calculation results show that there is a significant difference in the deformation of the bolts installed in different processes. Based on the deformation law and the force analysis results of supporting structure, the construction measures and support structure optimization suggestions are proposed.