地铁大跨隧道开挖支护及临时支撑拆除方案研究  

Study on the Scheme of Excavation Support and Temporary Support Demolition of Large Span Metro Tunnel

作　　者：刘亮 刘振汉 郭昊 姚明明 Liu Liang;Liu Zhenhan;Guo Hao;Yao Mingming(The Third Construction Co.,Ltd.,China Railway Fourth Bureau Group,Beijing 100016,China;School of Civil&Architecture Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]中铁四局集团第三建设有限公司,北京100016 [2]北京交通大学土木建筑工程学院,北京100044

出　　处：《市政技术》2022年第2期102-106,157,共6页Journal of Municipal Technology

摘　　要：北京地铁12号线三元桥站—芳园里站区间停车线隧道沿城市主干道下方敷设,具有隧道断面类型多、隧道跨度大、上方道路沉降控制标准高的特点。为此,对该大跨停车线隧道进行了超前深孔注浆、导洞开挖、临时支撑拆除等方案的研究。研究结果表明:随着超前深孔注浆厚度的增大,地表沉降逐渐减小,但当注浆厚度达到2 m以后,增大注浆厚度对控制地表沉降的效果逐渐降低,因此,提出了最优注浆厚度的概念;导洞开挖应采用先上导洞、后下导洞,先边导洞、后中导洞的开挖顺序;二衬施工应采用跳仓拆除临时支撑的方案,且跳仓长度8 m较适宜。The tunnel of the parking line between Sanyuanqiao Station and Fangyuanli Station of Beijing Metro Line12 is laid below the urban main road, which has the characteristics of many types of tunnel sections, large tunnel span and high standard of settlement control of the above municipal road. In this paper, the schemes of advanced deep hole grouting, the pilot tunnel excavation and the temporary support dismantling of the tunnel are discussed in detail. The results show that the surface subsidence decreases gradually with the increase of the thickness of the grouting layer. However, when the thickness of the grouting layer reaches 2 m, the effect of the increasing the grouting layer thickness on controlling the surface subsidence gradually reduces. Therefore, the concept of optimal grouting thickness is proposed. The excavation sequence of firstly upper pilot tunnel, then lower pilot tunnel, firstly edge pilot tunnel, then middle pilot tunnel should be adopted. The temporary support structure should be removed at intervals during the construction of the second lining,and the interval length of 8 m is appropriate.

关 键 词：地铁大跨隧道 超前深孔注浆 开挖支护 临时支撑拆除 地表沉降 

分 类 号：U455.411[建筑科学—桥梁与隧道工程]