摘要
文章依托内蒙古呼和浩特市窑沟隧道工程实例,对典型断面所在区段的节理特征参数进行了采集,得到了实际地层中存在的近水平、垂直发育节理的详细参数;通过综合运用现场监测、室内模型试验、数值模拟手段,分析了隧道开挖后的上覆岩层运动行为与结构受力特征,研究了该类地层中围岩的变形特征与失稳模式,为后续的支护设计及其优化提供了参考。研究结果表明,在窑沟隧道所处的典型地层,即近水平、垂直节理发育工况下:(1)无支护开挖时,地层稳定性极差,塌落区与松动区集中分布于拱顶上方,最大塌落高度为0.48倍洞宽,塌落面积为0.51倍断面面积,拱顶等效荷载为0.084 MPa,松动区延伸至地表,近似呈三角形分布;(2)按设计方案施作初期支护后,地层松动范围明显缩减,高度降为1.1倍洞宽,拱顶最大沉降为7.7 mm,边墙收敛为3.4 mm,结构安全储备足够。
In this paper, based on the construction of the Yaogou tunnel in Hohhot, the characteristic parameters of approximate horizontal and vertical developed joints are collected for areas of the typical section; additionally, the kinematic behaviors and force characteristics of the overlaying rock are analyzed and the deformation and in- stability patterns of the surrounding rock are studied by adopting field monitoring, a laboratory model test and nu- merical simulation. The results show that： 1） without support, the stability of the strata is very poor during con- struetion with the caving and loosening zones concentrated above the vault, of which the maximum caving height is 0.48 times the tunnel width, the caving area is 0.51 times the section area, the equivalent load of the vault is 0.084 MPa and the loosening zone extends to the ground surface in an almost triangular distribution; and 2） with a primary lining, the loosening range of the strata is significantly reduced, with a maximum caving height of 1.1 times the tunnel width, and the maximum settlement of the vault is reduced to 7.7 mm and the sidewall conver- gence becomes 3.4 ram.
出处
《现代隧道技术》
EI
CSCD
北大核心
2015年第2期67-71,共5页
Modern Tunnelling Technology
关键词
隧道
围岩变形
节理特征
稳定性
模型试验
Tunnel
Surrounding rock deformation
Joint characteristics
Stability
Model test
