Model Test and Numerical Simulation for Support Time of Tunnel in Loess

Abstract:

The work presented in this paper focuses on support time for tunnel, which has much effect on stability of tunnel. Based on loess tunnel of Zhengzhou-Xi’an high-speed passenger rail line in China, large scale model test with geometric proportion 1: 20 was applied to study on different support time. Supplemental numerical analysis was carried out to investigate the effect of release ratio of stress which cannot be covered by model test. It is revealed that it is asynchronous change for deformation, strain and stress of surround rock. If the supporting constructs prematurely, internal force of support would be excessive greatly and if the supporting constructs too late, it will bring excessive slack pressure which leads to the plastic zone unfavorable, even tunnel collapse. The reasonable support time can improve self-bearing capability of surrounding rock and reduce the cost. The limited displacements about 17.8 cm for crown and 12.9 for horizontal convergence are gained. The research results can act as reference for similar materials tunnel and underground engineering construction.

• Periodical: Advanced Materials Research (Volumes 243-249)
• Pages: 3696-3700
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.243-249.3696
• Online since: May 2011
• Authors: Chao Liang Ye, Yong Quan Zhu, Ben Guo He
• Keywords: Loess tunnel, Model Test, Release Ratio of Stress, Support Time

References

[1] Yong-Joo Lee. Investigation of subsurface deformations associated with model tunnels in a granular mass [J]. Tunnelling and Underground Space Technology, 2009, 24(6): 654-664.

DOI: 10.1016/j.tust.2009.07.001

[2] T. Y. Chen, Y. T. Lee, C. C. Hsu. Investigations of piston-effect and jet fan-effect in model vehicle tunnels [J]. Journal of Wind Engineering and Industrial Aerodynamics, 1998, 73(2): 99-110.

DOI: 10.1016/s0167-6105(97)00281-x

[3] Jong-Ho Shin, Yong-Ki Choi, Oh-Yeob Kwon, et al. Model testing for pipe-reinforced tunnel heading in a granular soil [J]. Tunnelling and Underground Space Technology, 2008, 23(2): 241-250.

DOI: 10.1016/j.tust.2007.04.012

[4] Liu Piede. Model test study on double lining of tunnels [J]. Tunnelling and Underground Space Technology, 1986, 1(1): 53-58.

DOI: 10.1016/0886-7798(86)90128-8

[5] Bin-Lin Chu, Sung-Chi Hsu, Yi-Long Chang, et al. Mechanical behavior of a twin-tunnel in multi-layered formations[J]. Tunnelling and Underground Space Technology, 2007, 22(3): 351-362.

DOI: 10.1016/j.tust.2006.06.003

[6] Yanshun Yu, Shaofan Zhang, Xianting Li. An improved model and the thermodynamic calculation method for tailrace tunnel ventilating system in hydropower station [J]. Energy Conversion and Management, 2009, 50(8): 2060-2066.

DOI: 10.1016/j.enconman.2009.04.002