Stability of a circular tunnel in presence of pseudostatic seismic body forces

Sahoo, Jagdish Prasad and Kumar, Jyant (2014) Stability of a circular tunnel in presence of pseudostatic seismic body forces. In: TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY, 42 . pp. 264-276.

PDF Tunn_Under_Space_Tech_Vol.42_264-276.pdf - Published Version Restricted to Registered users only Download (5MB) | Request a copy

Abstract

The stability of a long circular tunnel in a cohesive frictional soil medium has been determined in the presence of horizontal pseudo-static seismic body forces. The tunnel is supported by means of lining and anchorage system which is assumed to exert uniform internal compressive normal pressure on its periphery. The upper bound finite element limit analysis has been performed to compute the magnitude of the internal compressive pressure required to support the tunnel. The results have been presented in terms of normalized compressive normal stress, defined in terms of sigma(i)/c; where sigma(i) is the magnitude of the compressive normal pressure on the periphery of the tunnel and c refers to soil cohesion. The variation of sigma(i)/c with horizontal earthquake acceleration coefficient (alpha(h)) has been established for different combinations of H/D, gamma D/c and phi where (i) H and D refers to tunnel cover and diameter, respectively, and (ii) gamma and phi correspond to unit weight and internal friction angle of soil mass, respectively. Nodal velocity patterns have also been plotted for assessing the zones of significant plastic deformation. The analysis clearly reveals that an increase in the magnitude of the earthquake acceleration leads to a significant increment in the magnitude of internal compressive pressure. (C) 2014 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copyright for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Keywords:	Earthquakes; Finite elements; Limit analysis; Soils; Stability; Tunnels
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	17 Jul 2014 05:57
Last Modified:	17 Jul 2014 05:57
URI:	http://eprints.iisc.ac.in/id/eprint/49451

Actions (login required)

View Item