Abstract
Southern Ontario is known for very high horizontal in-situ stresses and time dependent behavior of shale formations, which has resulted in continued rock deformation and distress in final linings in several previous projects in the region, sometimes years after installation. Billy Bishop Toronto City Airport Pedestrian Tunnel is a passenger access tunnel under the Western Channel of Lake Ontario. This paper discusses a series of numerical approaches used for predicting time dependent deformations, both during, as well as after the completion of the tunnel, to determine the optimal timing of the placement of the final lining, such that the remaining time-dependent movements can be sufficiently accommodated within the structural capacity of the tunnel lining. The paper also discusses the design process using a series of numerical analysis and construction sequencing considerations pertaining to the long-term time dependent deformation of the shaley rock formation, the instrumentation and monitoring program, and a comparison of the predicted against the actual movements during construction. Results from a custom-made FLAC sub-routine are provided in addition to the details of the numerical analysis - both the problems that were identified during the analyses as well as their solutions - throughout the discussion.
Similar content being viewed by others
References
Hawlader, B. C, Lee, Y. N., and Lo, K. Y. (2003). “Three-dimensional stress effects on time-dependent swelling behavior of shaly rock.” Canadian Geotechnical Journal, Vol. 40, pp. 501–511, DOI: 10.1139/t03-006.
Hawlader, B. C., Lo, K. Y., and Moore, I. D. (2005). “Analysis of tunnels in shaly rock considering three-dimensional stress effects on swelling.” Canadian Geotechnical Journal, Vol. 42, pp. 1–12, DOI: 10.1139/t04-083.
Lo, K. Y. and Micic, S. (2010). Evaluation of swelling properties of shales for the design of underground structures, ITA-AITES 2010 World Tunnel Congress, Vancouver, B.C. Canada.
Lo, K. Y. and Yuen, C. M. K. (1981). “Design of tunnel lining in rock for long term time effects.” Canadian Geotechnical Journal, Vol. 18, pp. 24–39, DOI: 10.1139/t81-004.
Lo, K. Y., Wai, R. S. C., Palmer, J. H. L., and Quigley, R. M. (1978). “Time-dependent deformation of shaley rocks in Southern Ontario.” Canadian Geotechnical Journal, Vol. 15, pp. 537–547, DOI: 10.1139/t78-057.
Exp Services Inc. (2012). Billy Bishop Toronto City Airport Pedestrian Tunnel, Toronto Supplementary Geotechnical Investigation Report, Interim Report Prepared for Arup, Project Number: ADM 00010154-A0, PART 1 Field and Laboratory Works–Factual Results and Discussion.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lee, S.S. Numerical model for shaley rock masses displaying long-term time dependent deformation (TDD) behavior and its application to a pedestrian tunnel constructed under Lake Ontario. KSCE J Civ Eng 21, 2919–2931 (2017). https://doi.org/10.1007/s12205-017-1359-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12205-017-1359-2