Stability of a long unsupported circular tunnel in soils with seismic forces

Chakraborty, Debarghya and Kumar, Jyant (2013) Stability of a long unsupported circular tunnel in soils with seismic forces. In: Natural Hazards, 68 (2). pp. 419-431.

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Abstract

By using the lower-bound finite element limit analysis, the stability of a long unsupported circular tunnel has been examined with an inclusion of seismic body forces. The numerical results have been presented in terms of a non-dimensional stability number (gamma H/c) which is plotted as a function of horizontal seismic earth pressure coefficient (k (h)) for different combinations of H/D and I center dot; where (1) H is the depth of the crest of the tunnel from ground surface, (2) D is the diameter of the tunnel, (3) k (h) is the earthquake acceleration coefficient and (4) gamma, c and I center dot define unit weight, cohesion and internal friction angle of soil mass, respectively. The stability numbers have been found to decrease continuously with an increase in k (h). With an inclusion of k (h), the plastic zone around the periphery of the tunnel becomes asymmetric. As compared to the results reported in the literature, the present analysis provides a little lower estimate of the stability numbers. The numerical results obtained would be useful for examining the stability of unsupported tunnel under seismic forces.

Item Type:	Journal Article
Publication:	Natural Hazards
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Keywords:	Earthquakes; Failure; Limit Analysis; Soils; Stability; Tunnels
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	25 Sep 2013 10:12
Last Modified:	25 Sep 2013 10:12
URI:	http://eprints.iisc.ac.in/id/eprint/47427

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