Assessment the Stability of Tunnels in Y Shaped Intersections with Regard to the Intersection Angles, Case Study: Penstock Tunnels of Rudbar Dam

Document Type : Research Article

Authors

1 Assistant professor, School of Railway Engineering, Iran University of Science and Technology

2 MSc Student, School of Railway Engineering, Iran University of Science and Technology

Abstract

Stress analysis and stability control in tunnel intersections is a very complicated issue due to stress concentration and three-dimensional situation. During tunnel construction, increase in load on support, extra tunnel deformations and disordering in rock around of intersection zone is unique and instability may be occur in this sections. In order to control extra deformation and stress, these sections need stronger support system than other sections. Extra deformations and stress values in Y shaped intersections influenced by tunnel intersection angle. The effect of intersection angle on length of extra support has been studied in this paper by three-dimensional modeling of penstock tunnel intersection of Rudbar Dam in FLAC3D. Numerical analysis results for three intersection angles of 60, 75 and 90 show an increase in length of extra support by decreasing in intersection angle.

Keywords

References

[1] شرکت آب و نیرو، طرح سد و نیروگاه رودبار لرستان، گزارش زمی نشناسی مهندسی، مطالعات مرحله دوم، فروردین 1386 .
[2] Hsiao, F. Y.; Wang, C. L.; and Chern, J. C.; "Numerical Simulation of Rock Deformation for Support Design in Tunnel Intersection Area", Tunneling and Underground Space Technology, Vol. 24, pp. 14-21,2009.
[3] Tsuchiyama, S.; Hayakawa, M.; Shinokawa, T.;and Konno, H.; "Deformation Behavior of the Tunnel under the Excavation of Crossingtunnel",In: Numerical Methods of Geomechanics. Balkema, Rotterdam, pp. 1591-1596, 1988.
[4] Pottler, R.; "Three Dimensional Modeling of Junctions at the Channel Tunnel Project", International Journal for Numerical and Analytical Methods in Geomechanics, Vol. 16, pp. 683-695, 1992.
[5] Nonomura, S.; Kimura, H.; Nakamura, J.; and Tamura, S.; "Design and Construction of a Tunnel Intersection Area with Special Structure", Tunnelling and Underground Space Technology, WTC 2004,G13, pp. 1-7, 2004.
[6] Hsiao, F. Y.; Yu, C. W.; and Chern, J. C.; "Modeling the Behavior of the Tunnel Intersection Area Adjacent
to the Ventilation Shaft in the Hsuehshan Tunnel",World Long Tunnel, pp. 81-90, 2005.
[7] Hoek, E.; and Brown, E. T.; "Underground Excavations in Rock", London, The Institute of Mining and Metallurgy, 1980.
[8] Itasca Consulting Group Inc, "FLAC3D Fast Lagrangian Analysis of Continua in 3 Dimensions",Ver 3.1, User's Manual, 2002.
[9] Sakurai, S.; "Direct Strain Evaluation Technique in Construction of Underground Opening", In Proc. 22,
U.S. Symp. Rock Mech. Boston. M. A. (Edit by: H. H.Enistein), pp. 278-282, 1993.
[10] Sakurai, S.; "Back Analysis in Rock Engineering", Comprehensive Rock Engineering, Chap. 19, 1993.
Amirkabir Journal of Civil Engineering
Volume 48, Issue 2
September 2016
Pages 191-198

Files

Share

How to cite

Statistics