大断面隧道施工对洞口边坡稳定性的影响  

Influence of large-section tunnel construction on slope stability

作　　者：朱彦鹏[1,2] 张浩亮[1] 李忠[1] 陈思阳[1] 

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]兰州理工大学甘肃省土木工程防灾减灾重点实验室,甘肃兰州730050

出　　处：《兰州理工大学学报》2014年第3期120-125,共6页Journal of Lanzhou University of Technology

基　　金：国家支撑计划项目(2011BAK12B07)

摘　　要：以兰州市九州隧道为研究背景,以ADINA有限元软件建立前处理模型,采用FLAC3D有限差分程序进行后处理计算,对隧道进口段进行三维动态施工分析.基于全断面法及短台阶法开挖,探究不同开挖方式对洞口未支护及已支护边坡的位移、稳定性安全系数及塑性区域分布的影响.研究结果表明:隧道开挖对边坡竖向位移影响较水平位移强烈,水平位移波动较大的区域位于一、二级边坡的中下部;隧道开挖导致边坡稳定性安全系数降低,采用全断面法与采用短台阶法分别降低29.8%、19.8%;塑性区域分布集中于边坡的坡肩、坡趾及隧道的左拱肩、右拱脚附近区域,应对相关区域进行加固处理.Taking the Jiuzhou tunnel in Lanzhou as investigation background, the pre-processing model was established with finite element software ADINA, the post-processing computation was conducted by using finite difference program FLAC3D, and the three-dimensional dynamic construction analysis was performed for the tunnel entrance part. On the basis of tunnel excavation with full-section or short-bench method, the influence of excavation method on the displacement, stability safety factor, and plastic zone distribution of the slope at tunnel entrance with or without retaining support. It was shown by investigation that the tunnel excavation would have stronger influence on slope vertical displacement than its horizontal displacement. The zone with large fluctuation of horizontal displacement was located at the middle and lower part of first- and second-level slopes. The tunnel excavation made the slope stability safety factor decreased by 29. 8% and 19. 8% respectively for the tunnel excavation with full-section method and short bench method. The plastic zone was basically concentrated on the shoulder and toe of the slope as well as on the area of left arch shoulder and right arch foot of the tunnel, so that the relevant area should be reinforced.

关 键 词：边坡位移 大断面 边坡稳定性 塑性区 

分 类 号：TU311.2[建筑科学—结构工程]