Numerical analysis and field monitoring tests onshallow tunnels under weak surrounding rock
来源期刊：中南大学学报(英文版)2015年第10期
论文作者：LIU Jian-hua LIU Xiao-ming ZHANG Yong-jie XIAO Ting
文章页码：4056 - 4063
Key words：tunnel engineering; shallow tunnel; weak surrounding rock; numerical analysis; field monitoring tests
Abstract: The Jianpudong No. 4 tunnel is a shallow tunnel, which belongs to Shaoshan County scenic highway in Hunan province, China and whose surrounding rock is weak. According to its characteristics, the field monitoring tests and numerical analysis were done. The mechanical characteristics of shallow tunnels under weak surrounding rock and the stress-strain rule of surrounding rock and support were analyzed. The numerical analysis results show that the settlement caused by upper bench excavating accounts for 44% of the total settlement, and the settlement caused by tunnel upper bench supporting accounts for 56% of the total settlement. The maximum axial force of shotcrete lining is 177.2 kN, which locates in hance under the secondary lining. The maximum moment of shotcrete lining is 5.08 kN·m, which locates in the arch foot. The stress curve of steel arch has three obvious stages during the tunnel construction. The maximum axial force of steel arch is 297.4 kN, which locates in tunnel vault. The axial forces of steel arch are respectively 23.5 kN and -21.8 kN, which is influenced by eccentric compression of shallow tunnel and locates in hance. The results show that there is larger earth pressure in tunnel vault which is most unfavorable position of steel arch. Therefore, the advance support should be strengthened in tunnel vault during construction process.
LIU Jian-hua(刘建华)1, LIU Xiao-ming(刘晓明)2, ZHANG Yong-jie(张永杰)3, XIAO Ting(肖庭)1
(1. School of Traffic and Transportation Engineering, Changsha University of Science and Technology,
Changsha 410004, China;
2. College of Civil Engineering, Hunan University, Changsha 410082, China;
3. School of Civil Engineering and Architecture, Changsha University of Science and Technology,
Changsha 410004, China)
Abstract:The Jianpudong No. 4 tunnel is a shallow tunnel, which belongs to Shaoshan County scenic highway in Hunan province, China and whose surrounding rock is weak. According to its characteristics, the field monitoring tests and numerical analysis were done. The mechanical characteristics of shallow tunnels under weak surrounding rock and the stress-strain rule of surrounding rock and support were analyzed. The numerical analysis results show that the settlement caused by upper bench excavating accounts for 44% of the total settlement, and the settlement caused by tunnel upper bench supporting accounts for 56% of the total settlement. The maximum axial force of shotcrete lining is 177.2 kN, which locates in hance under the secondary lining. The maximum moment of shotcrete lining is 5.08 kN·m, which locates in the arch foot. The stress curve of steel arch has three obvious stages during the tunnel construction. The maximum axial force of steel arch is 297.4 kN, which locates in tunnel vault. The axial forces of steel arch are respectively 23.5 kN and -21.8 kN, which is influenced by eccentric compression of shallow tunnel and locates in hance. The results show that there is larger earth pressure in tunnel vault which is most unfavorable position of steel arch. Therefore, the advance support should be strengthened in tunnel vault during construction process.
Key words:tunnel engineering; shallow tunnel; weak surrounding rock; numerical analysis; field monitoring tests
