Describing Settlement Troughs over Twin Tunnels Using a Superposition Technique
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 133, Issue 4
Abstract
It has been observed in many tunneling projects that surface settlement troughs caused by twin tunnels have a variety of shapes unlike single tunnels, where symmetric surface settlement troughs are usually observed. The surface settlement troughs observed over twin tunnels can be symmetric with respect to the midpoint between the two tunnels or symmetric but shifted toward either side or they can also be asymmetric. Settlement troughs both over single and twin tunnels (when symmetric) can often be described by a Gaussian curve. Most of the cases reported in the literature do consider the effect of ground conditions, tunnel size, and depth on the surface settlement. However, these cases do not consider the effect of construction operation. A study of settlements above tunnels driven with earth pressure balance shields in Bangkok made it possible to include operational parameters such as face pressure, penetration rate, and grouting pressure. This is possible by comparing the effect of twin tunnels which are geometrically and geologically identical but differ in the operational characteristics. These operational differences make it, however, more difficult to describe the resulting settlement troughs over twin tunnels using existing methods. Therefore, this paper introduces a superposition technique to describe surface settlement troughs over twin tunnels. It appears that one can construct settlement curves induced by the first shield and the second shield using the Gaussian function and combine the curves to obtain a total settlement trough as a result of the twin tunnels. Using extensive data from the Bangkok Subway Tunnel project, this approach was found to be suitable both for twin tunnels excavated side-by-side and also for stacked twin tunnels. Right now this superposition technique is basically descriptive. Eventually it will be possible to use this approach to predict settlement troughs over twin tunnels.
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References
Chiorboli, M. A., and Marcheselli, P. P. (1996). “Analysis and control of subsidence due to earth pressure shield tunneling in passante ferroviario of Milano.” Proc., Int. Conf. on North American Tunneling’96. Balkema, Rotterdam, The Netherlands, 97–106.
Cording, E. J., and Hansmire, W. H. (1975). “Displacements around soft ground tunnels.” General Rep. 5th Pan American Conference on Soil Mechanics and Foundation Engineering, Session IV, 571–632.
Finno, R. J., and Clough, G. W. (1985). “Evaluation of soil response to EPB shield tunneling.” J. Geotech. Engrg., 111(2), 155–173.
Leca, E. (1989). “Analysis of NATM and shield tunneling in soft ground.” Ph.D. thesis, Virginia Institute and State Univ., Blacksburg, Va.
Maconochie, D. J., and Suwansawat, S. (1999). “Bangkok MRTA: Chaloem Ratchamongkon line.” Tunnels Tunnel. Int., 31(11), 19–22.
New, B. M., and Bowers, K. H. (1993). “Ground movement model validation at the Heathrow express trial tunnel.” Tunnelling 94, IMM, London, 301–329.
O’Reilly, M. P., and New, B. M. (1982). “Settlement above tunnels in the United Kingdom—Their magnitude and prediction.” Tunneling 82, Institute of Mining and Metallurgy, London, 173–181.
Peck, R. B. (1969). “Deep excavations and tunneling in soft ground.” Proc., 7th Int. Conf. on Soil Mechanics and Foundation Engineering, State of the Art Volume, Mexico City, 225–290.
Shirlaw, J. N., Doran, S., and Bejamin, B. (1988). “A case study of two tunnels driven in the Singapore ‘boulder bed’ and in grout coral sands.” Publication, No. 5, Engineering Geology and Underground Movements, Geological Society Engineering Geology Special 93–103.
Suwansawat, S. (2004). “Shield tunneling database management for ground movement evaluation.” Proc., 30th World Tunnel Congress, Singapore.
Suwansawat, S. (2006). “Superposition technique for mapping surface settlement troughs over twin tunnels.” Proc., Int. Symp. on Underground Excavation and Tunnelling, Bangkok, Thailand.
Suwansawat, S., and Einstein, H. H. (2006). “Artificial neural networks for predicting the maximum surface settlement caused by EPB shield tunneling.” Tunn. Undergr. Space Technol., 21(2), 133–150.
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© 2007 ASCE.
History
Received: Jun 5, 2006
Accepted: Sep 13, 2006
Published online: Apr 1, 2007
Published in print: Apr 2007
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