On the selection of an appropriate excavation pattern for urban tunnels with big cross-section: A case study

Bolghonabai, Roohallah; Hossaini, Mohammad Farouq; Mohammadi, Mohammad; Nazem, Ali

doi:10.22059/ijmge.2015.56116

On the selection of an appropriate excavation pattern for urban tunnels with big cross-section: A case study

Document Type : Research Paper

Authors

¹ The Alborz Tunnel site, General Mechanic Contracting Co., Alborz, Iran

² School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran

³ PhD candidate, Colorado School of Mines, USA

10.22059/ijmge.2015.56116

Abstract

Among various practical measures used for restriction of the ground surface settlement in such tunnels driven in soft ground, selection of an appropriate excavation method plays a significant role. In this paper, employing suggested diagram by Yu & Chern, corresponding values of Niayesh tunnel has been inserted into the diagram. Later, two excavation methods namely: central diaphragm and side drift methods have been suggested and numerically modeled using Finite Difference Method. Side drift excavation pattern has finally been selected since it causes less settlement. To reach an optimized selection of excavation sequence through side drift method, seven excavation patterns have thus been recommended and numerically modeled. Results have revealed that the first pattern causes the least amount of settlement. Consequently, the aforementioned excavation pattern has finally been considered as an appropriate excavation pattern encompassing optimum excavation sequence for Niayesh tunnel.

Keywords

References

[1] Malekzadeh, B. SH., Shahriar, K., & Khoshrou, S.H. (2012). Designing a Drainage well-channel system to decrease underground water inflow of North tunnel– NIAYESH tunneling project. World Tunneling. Congress (WTC2012), Bangkok, Thailand
[2] Bowers, K.H., (1997). An Appraisal of the New Austrian Tunneling Method in Soil and Weak Rock. Ph.D. Thesis, University of Leeds, 240 pp.
[3] Geisler, H., Wagner, H., Zieger, O., Mertz, W., & Swoboda, G., (1985). Theoretical aspects of the three dimensional analysis of finally lined intersections. Proceedings of 5th International Conference on Numerical Methods in Geomechanics, Nagoya, 1175–1183.
[4] Ghorbani, M., & Sharifzadeh, M., (2012). Geotechnical, structural and geodetic measurements for conventional tunneling hazards in urban areas – The case of Niayesh road tunnel project. Tunneling and Underground Space Technology 31, 1–8.
[5] Hoek, E., (2001). Big tunnel in bad rock. J. Geotech. Geoenviron. Eng. 127 (9), 726–740.
[6] Jethwa, J.L., (2001). National Tunneling Policy. In: National Workshop on Application of Rock Engineering in Nation’s Development. IIT Roorkie: Ind Inst Tech, 63–81.
[7] Mair, R.J., (1998). Geotechnical Aspects of Design Criteria for Bored Tunneling in Soft Ground. World Tunnel Congress 98 on Tunnels and Metropolises. Balkema, Sao Paulo, Brazil. 183–199.
[8] Romero, V., (2002). NATM in soft-ground: a contradiction of terms? Views on NATM and its application to soft-ground tunneling dispelling some misconceptions about this sometimes controversial. World Tunneling, 15, 338-344.
[9] Sozio, L.E., (1998). General Report: Urban Constraints on Underground Works. World Tunnel Congress 98 on Tunnels and Metropolises. Balkema, Sao Paulo, Brazil, 879–897.
[10] Szechy, K., (1967). The Art of Tunnelling. Akademiai Kiado, Budapest, pp. 891.
[11]. Yu, C.W., & Chern, J.C., (2007). Expert system for D&B tunnel construction. In: Underground Space 4th Dimension of Metropolises, London, England.