摘要
针对软弱围岩浅埋偏压隧道围岩的稳定性和开挖方案选取问题,以湖南省安慈高速公路的樟树垭连拱隧道为工程背景,采用Midas GTS NX有限元软件,分别对其采用中导洞-单侧导坑法和三导洞法的施工过程进行数值模拟,分析和对比在这两种开挖方案下围岩应力与变形、支护结构应力及中隔墙应力的分布情况。研究结果表明:这两种开挖方案均能满足施工的安全要求。综合该隧道的实际情况,三导洞法能较好地控制隧道的拱顶沉降变形;采用中导洞-单侧导坑法进行开挖的围岩应力情况则更好,该法不仅能更好地保证隧道收敛,还能更有效地减少在浅埋侧开挖过程中深埋侧中隔墙墙腰开裂现象的发生,且其浅埋侧无需内支撑施工,可加速支护结构闭合,加快施工进度。因此,中导洞-单侧导坑法是更适合该隧道的施工方案。该研究结果可为其他类似工程提供参考。
Aiming at the stability of surrounding rock and the selection of excavation scheme of shallow buried eccentric pressure tunnel in soft surrounding rock,Midas GTS NX was used to numerically simulate the construction process of Zhangshuya tunnel of Hunan Anci Expressway by middle pilot tunnel single side pilot tunnel method and three pilot tunnel method respectively.The stress and deformation of surrounding rock,the stress distribution of supporting structure and the stress of middle partition wall under different excavation schemes are analyzed.The results show that the two excavation schemes can meet the construction safety requirements.According to the actual situation of the tunnel,although the three pilot tunnel method can better control the settlement and deformation of the tunnel vault,the middle pilot tunnel single side pilot pit method is suitable for the construction scheme and its surrounding rock stress is excellent,which can better ensure the tunnel convergence and can effectively reduce the cracking of the middle partition wall waist on the deep buried side during the excavation of the shallow buried side.Moreover,the shallow buried side does not need internal support,which can accelerate the closure of the support structure and speed up the construction progress.Therefore,the method of middle guide tunnel and single side guide tunnel is a more suitable construction scheme for the tunnel.The research results can provide reference for other similar projects.
作者
张妞
刘昶
刘辉
ZHANG Niu;LIU Chang;LIU Hui(College of Civil Engineering,Changsha University of Sciences&Technology,Changsha 410114,China;China Oil HBP Group,Changsha 410114,China;Shenzhen Hongyeji Geotechnical Science&Technology Co.,Ltd.,Shenzhen 518057,China)
出处
《交通科学与工程》
2023年第4期88-97,104,共11页
Journal of Transport Science and Engineering
关键词
地层偏压
连拱隧道
开挖方案
数值模拟
geological eccentric compression
double-arch tunnel
excavation scheme
numerical simulation
