Stability charts for unsupported circular tunnels in cohesive soils

Shiau, Jim and Lamb, Brian and Sams, Mathew and Lobwein, Jay (2017) Stability charts for unsupported circular tunnels in cohesive soils. International Journal of GEOMATE, 13 (39). pp. 95-102. ISSN 2186-2982

Abstract

This paper investigates the stability of a plane strain circular tunnel in cohesive soils. A strength
reduction technique and the finite difference program FLAC, are used to determine the factor of safety for
unsupported circular tunnels. Results from the finite difference approach are presented alongside rigorous upper and lower bound limits computed using Optum G2. A thorough comparison between these two methods
finds very good agreement. As the model is shown to be accurate, design charts are presented for a wide range
of practical scenarios using dimensionless ratios. The potential usefulness of this approach is demonstrated
using a number of examples. This is considered a simpler way of analysing the stability of an unsupported
tunnel that may be as practical as similar methods used in slope stability analysis, such as the commonly used
Taylor’s design charts.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying
Date Deposited: 18 Jan 2018 03:07
Last Modified: 18 Jan 2018 03:07
Uncontrolled Keywords: circular tunnel, stability, factor of safety, undrained clay, FLAC, Optum G2, strength reduction method, design chart
Fields of Research : 09 Engineering > 0905 Civil Engineering > 090501 Civil Geotechnical Engineering
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Identification Number or DOI: doi:10.21660/2017.39.47674
URI: http://eprints.usq.edu.au/id/eprint/33233

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