浅埋大跨地铁隧道双层叠合初支拱盖法施工力学机理及关键施工步骤分析  

Analysis of Mechanical Mechanism of Construction and Key Construction Steps of Shallow-buried Metro Tunnel with Large-span by Double-layer Superimposed Shotcrete Arch-cover Method

作　　者：尹学鑫 王忠钊 王强元 舒文韬 李毅[2] Yin Xuexin;Wang Zhongzhao;Wang Qiangyuan;Shu Wentao;Li Yi(China Railway No.3 Engineering Group Guangdong Construction Engineering Co.,Ltd.,Guangzhou 510000,China;Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiao tong University,Chengdu 610031,China)

机构地区：[1]中铁三局集团广东建设工程有限公司,广东广州510000 [2]西南交通大学交通隧道工程教育部重点实验室,四川成都610031

出　　处：《市政技术》2022年第11期59-65,共7页Journal of Municipal Technology

摘　　要：广州市轨道交通11号线华景路站—华师站间浅埋大跨段,因地质条件较差、周边环境复杂,所以为保证该浅埋大跨段的施工效率和施工的安全性,创新性地采用了双层叠合初支拱盖法进行施工,但该施工方法与其他拱盖法相比,也存在工序更加复杂、对施工水平要求更高等问题。基于此,为了定量分析该工法施工的力学机理及关键施工步骤,利用有限差分软件FLAC3D建立三维数值模型对施工全过程进行模拟,研究了大跨隧道施工过程中地表、拱顶沉降及支护结构应力随施工步骤的演变规律。研究结果表明:中部导洞的开挖与临时支撑的拆除将导致围岩位移和支护结构受力大幅增加,是双层叠合初支拱盖法的关键施工步骤,在实际施工中应当重点关注。Due to poor geological conditions and complex surrounding environment,the double-layer superimposed shotcrete arch-cover method is applied innovative in the shallow-buried long-span section between Huajinglu station-Huashi station of Guangzhou Rail Transit Line 11 to ensure the construction efficiency and safety.However,compared with other arch-cover methods,this construction method has more complex procedures and higher requirements for construction level.In order to quantitatively analyze the mechanical mechanism and key construction steps of this method,a 3D numerical model is established by the finite difference software FLAC3D to simulate the whole construction process to study the evolution rules of ground surface,vault settlement and supporting structure stress during the construction process of large-span tunnel.The results show that the excavation of the middle pilot tunnel and the removal of the temporary support will cause a significant increase in the displacement of the surrounding rock and the stress of the supporting structure,which are the key construction steps of double-layer superimposed shotcrete arch-cover method and should be focused on in practice.

关 键 词：浅埋大跨地铁隧道 双层叠合初支拱盖法 关键施工步骤 三维数值模拟 地表沉降 支护结构受力 

分 类 号：U215.7[交通运输工程—道路与铁道工程]