Numerical Assesment of Support and Reinforcing Techniques of Alborz Tunnel

Document Type : Original Article

Authors

1 Faculty of mining, petroleum and geophysics, Shahrood university of technology

2 Faculty of Mining, Petroleum & Geophysics Engineering, Shahrood university of technology

3 Faculty of Mining, petroleum and Geophysics engineering, Shahrood university of tehchnology,, Shahrood,Iran

Abstract

Despite the development of numerous excavation methods and reinforcement of tunnels, finding a proper method for stabilization of underground structures is a challenging task. The use of pre-reinforcement systems is an appropriate method to improve the status of the ground. In this study, the performance of umbrella system in Alborz tunnel in north of Iran has been investigated. Rock mechanics studies of tunnel running area have shown that parts of this tunnel have unstable capacity due to being located in weak zones. Therefore, the tunneling operation running is not possible in these areas. On this basis, umbrella pre-reinforcement system that can be used for loose and running ground are modeled numerically by Flac3D software. In this research, in addition to investigating the performance of umbrella system, the effect of geometrical parameters such as the angle of placement of pipes relative to the horizon and the distance between the umbrella system pipes was investigated. The criterion of investigating is the displacement occurred at the crown of the tunnel. The results of this study indicate that increasing the angle and decreasing the distance between pipes, cause an increase in stability and by using umbrella system, the vertical displacement of crown of the tunnel has decreased by 70 %.

Keywords

References

باقرزاده، پریسا؛ گشتاسبی، کامران؛ 1393. مدل‌سازی و بررسی عملکرد روش چتری در تونل راه‌آهن قزوین-رشت-انزلی، نشریه علمی پژوهشی مهندسی معدن، دوره 9، شماره 24، 56-45.
جنرال مکانیک -مهندسین مشاور لانیز، 1393. گزارش­های زمین شناسی مهندسی و مهندسی تونل البرز، تهران، ایران.
Aksoy, C. O. and Onargan, T., 2010. The role of umbrella arch and face bolt as deformation preventing support system in preventing building damages. Tunnelling and underground space technology. Elsevier, 25(5), pp. 553–559.
Elyasi, A., Javadi, M., Moradi, T., Moharrami, J., Parnian, S. and Amrac, M., 2016. Numerical modeling of an umbrella arch as a pre-support system in difficult geological conditions: a case study. Bulletin of Engineering Geology and the Environment, 75(1), pp.211-221.
Hefney, A. M., W. L. Tan, P. Ranjith, J. Sharma, and J. Zhao., 2004. Numerical analysis for umbrella arch method in shallow large scale excavation in weak rock. In TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY. PROCEEDINGS OF THE 30TH ITA-AITES WORLD TUNNEL CONGRESS SINGAPORE, 22-27 MAY, vol. 19, no. 4-5.
Muraki, Y., 1997. The umbrella method in tunnelling. PhD Thesis, Massachusetts Institute of Technology. See also URL https://dspace.mit.edu.
Ocak, I., 2008. Control of surface settlements with umbrella arch method in second stage excavations of Istanbul Metro. Tunnelling and Underground Space Technology. Elsevier, 23(6), pp. 674–681.
Oke, J., Vlachopoulos, N. and Diederichs, M. S., 2014. “Numerical analyses in the design of umbrella arch systems”. Journal of Rock Mechanics and Geotechnical Engineering. Elsevier, 6(6), pp. 546–564.
Schumacher, F. P., 2012. Numerical Investigation of Pipe Umbrella Roof Support Systems in Underground Coal Mining. A Thesis for Degree of Master of Science, Department of Mining Engineering, University of Utah. See also URL collections.lib.utah.edu.
Shin, J.H., Choi, Y.K., Kwon, O.Y. and Lee, S.D., 2008. Model testing for pipe-reinforced tunnel heading in a granular soil. Tunnelling and Underground Space Technology, 23(3), pp.241-250.
Sakurai, S, 1997. Strength parameters of rocks determined from back analysis of measured displacements, Proceedings of the First Asian Rock Mechanics Symposium, International Society for Rock Mechanics, Lisbon.
Sakurai, S., Kawashima, I. and Otani, T., 1993. A criterion for assessing the stability of tunnels, in ISRM International Symposium-EUROCK 93. International Society for Rock Mechanics and Rock Engineering.
Volkmann, Gu., Button, E. and Schubert, W., 2006. A contribution to the design of tunnels supported by a pipe roof, The 41st US Symposium on Rock Mechanics (USRMS). American Rock Mechanics Association.
Volkmann, G. M. and Schubert, W., 2007. Geotechnical model for pipe roof supports in tunneling. Conference Underground Space–the 4th Dimension of Metropolises, Barták, Hrdina, Romancov & Zlámal (eds), Taylor & Francis Group, London.
Volkmann, G. M. and Schubert, W., 2006. Contribution to the design of tunnels with pipe roof support. Asian Rock Mechanics Symposium. World Scientific Publishing Co. Pte. Ltd., p. 125.
Zarei, H., Moarefvand, P. and Salmi, E. F., 2019. Numerical modeling of umbrella arch technique to reduce tunnelling induced ground movements. Environmental Earth Sciences. Springer, 78(10), p. 291.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Volume 15, Issue 4
March 2023
Pages 1-17

Files

History

  • Receive Date: 26 December 2020
  • Revise Date: 01 February 2022
  • Accept Date: 10 April 2022

Share

How to cite

Statistics