大断面小净距隧道围岩压力的数值模拟研究  

The ground pressure of neighbor tunnel with large section based on numerical simulations

作　　者：唐勇三 TANG Yong-san(Pingtan Comprehensive Experimental Area Transport Investment Group Co.,Ltd.,Fuzhou 350400,China)

机构地区：[1]平潭综合实验区交通投资集团有限公司,福建福州350400

出　　处：《交通科学与工程》2020年第4期69-75,共7页Journal of Transport Science and Engineering

摘　　要：以龙兴岭隧道为工程背景,采用FLAC3D软件对四洞小净距隧道的分步开挖进行了数值模拟,分析了初期支护上的围岩压力分布。研究结果表明:主洞或辅洞开挖时,其围岩压力分布受开挖方式的影响很大。开挖辅洞采用单侧壁导坑法,临时支撑使作用在初支上的竖向围岩压力和水平围岩压力均呈“单峰折线型”分布;开挖主洞采用双侧壁导坑法,临时支撑使作用在初支上的竖向围岩压力和水平围岩压力均呈“双峰折线型”分布。同时,与常规分离式隧道相比,左、右主洞开挖使得临近隧洞初支的围岩压力显著增长,尤其是邻洞小净距侧的增幅最高可达50%。研究成果可为多孔大断面小净距隧道的设计和施工提供借鉴和参考。Based on the Longxinling tunnel project,the sequenced excavation of quadruple neighbor tunnel is carefully simulated on the FLAC3D platform,and the distribution of ground pressure carried by the first lining is well focused.The numerical simulation results show that:The distribution of ground pressure is influenced by the excavation sequence significantly when the main and auxiliary tunnels are excavated.The vertical and horizontal pressures carried by the first lining take the form of"single peak",due to the existence of vertical and horizontal supports in the unilateral pilot tunneling method.On the scenario of main tunnel excavation,the vertical and horizontal pressures carried by the first lining take the form of"double peaks",due to the existence of two vertical supports and one horizontal support in the bilateral pilot tunneling method.Comparing to the regular separated tunnels,the excavation of two main tunnels leads to the increasing of ground pressure upon its neighbor tunnels.Especially,the increment of maximum ground pressure may reach 50%upon its neighbor side.These researches could provide some reference for the design and the construction of large section neighbor tunnels.

关 键 词：隧道工程 大断面隧道 小净距隧道 围岩压力 数值模拟 

分 类 号：U452.12[建筑科学—桥梁与隧道工程]