摘要
针对钻爆法隧道开挖引起的上部既有隧道沉降问题,提出了一种新型门架桩加固方案。以惠盐高速公路隧道上行线盾构隧道建设工程下穿如意路嶂背隧道为背景,建立三维荷载结构模型和三维地层结构模型,使用ABAQUS有限元软件数值模拟钻爆法隧道的循环开挖施工过程,研究不采用门架桩保护措施和采用门架桩保护措施下上部既有隧道的沉降规律。结果表明:1)门架桩加固方案能有效降低既有隧道开挖导致的隧道沉降,采用门架桩保护措施后既有隧道最大沉降降低至2.49 mm,相较于无保护措施降幅达30%。2)采用门架桩保护措施会增大横梁与隧道连接位置隧道的剪力与纵向轴力,其中,峰值剪力增大了433.2 kN。采用该方案后,需要在连接处进行局部加固,防止隧道在该位置发生应力集中,导致局部剪坏。
A new gantry pile reinforcement scheme is proposed to handle the settlement issue of preexisting tunnel caused by drilling and blasting tunnel excavation in the top.Three-dimensional loading and stratum structure model are established for the shield tunnel of Huiyan Expressway under the Ruyi Road Zhangbei Tunnel.We performed finit element simulation using ABAQUS to model the cyclic excavation construction process of the tunnel.The settlement patterns of the pre-existing tunnels in the top with and without gantry pile protection are studied.The results show that:1)the gantry pile protection can effectively reduce the tunnel settlement caused by excavation in pre-existing tunnels.The maximum settlement of pre-existing tunnels is reduced by 2.49 mm when using gantry pile protection,which is 30%lower than that without protection.2)The use of gantry pile protection increases the shear force and longitudinal axial force in the tunnel at connection of the crossbeam and the tunnel.The peak shear stress increases by 433.2 kN.The use of this technique requires local reinforcement of the connection to prevent local shear damage due to stress concentration in the tunnel.
作者
罗驰恒
王泽军
汤善彪
曹翔鹏
LUO Chiheng;WANG Zejun;TANG Shanbiao;CAO Xiangpeng(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;National-Local Jonit Engineering Research Center of Underwater Tunnelling Technology,Wuhan 430063,China)
出处
《交通科学与工程》
2024年第2期47-54,共8页
Journal of Transport Science and Engineering
基金
国家重点研发计划(2021YFB2600400)。
关键词
下穿隧道
近接施工
数值分析
地层加固
钻爆法隧道
门架桩加固
undercrossed tunnel
close construction
numerical analysis
ground stabilization
drilling and blasting tunnel
reinforcement of gantry pile
