Seismic stability of a long unsupported circular tunnel

Sahoo, Jagdish Prasad and Kumar, Jyant (2012) Seismic stability of a long unsupported circular tunnel. In: COMPUTERS AND GEOTECHNICS, 44 . pp. 109-115.

PDF comp_geot_44_109_2012.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

The stability of a long unsupported circular tunnel (opening) in a cohesive frictional soil has been assessed with the inclusion of pseudo-static horizontal earthquake body forces. The analysis has been performed under plane strain conditions by using upper bound finite element limit analysis in combination with a linear optimization procedure. The results have been presented in the form of a non-dimensional stability number (gamma H-max/c); where H = tunnel cover, c refers to soil cohesion and gamma(max) is the maximum unit weight of soil mass which the tunnel can support without collapse. The results have been obtained for various values of H/D (D = diameter of the tunnel), internal friction angle (phi) of soil, and the horizontal earthquake acceleration coefficient (alpha(h)). The computations reveal that the values of the stability numbers (i) decrease quite significantly with an increase in alpha(h), and (ii) become continuously higher for greater values of H/D and phi. As expected, the failure zones around the periphery of the tunnel becomes always asymmetrical with an inclusion of horizontal seismic body forces. (c) 2012 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	COMPUTERS AND GEOTECHNICS
Publisher:	ELSEVIER SCI LTD
Additional Information:	Copyright for this article belongs to Elsevier Science
Keywords:	Earthquakes; Finite elements; Limit analysis; Optimization; Stability; Tunnel
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	29 Jan 2013 12:29
Last Modified:	29 Jan 2013 12:29
URI:	http://eprints.iisc.ac.in/id/eprint/45297

Actions (login required)

View Item