Bearing capacity of circular footings over rock mass by using axisymmetric quasi lower bound finite element limit analysis

Chakraborty, Manash and Kumar, Jyant (2015) Bearing capacity of circular footings over rock mass by using axisymmetric quasi lower bound finite element limit analysis. In: COMPUTERS AND GEOTECHNICS, 70 . pp. 138-149.

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Abstract

The ultimate bearing capacity of a circular footing, placed over rock mass, is evaluated by using the lower bound theorem of the limit analysis in conjunction with finite elements and nonlinear optimization. The generalized Hoek-Brown (HB) failure criterion, but by keeping a constant value of the exponent, alpha = 0.5, was used. The failure criterion was smoothened both in the meridian and pi planes. The nonlinear optimization was carried out by employing an interior point method based on the logarithmic barrier function. The results for the obtained bearing capacity were presented in a non-dimensional form for different values of GSI, m(i), sigma(ci)/(gamma b) and q/sigma(ci). Failure patterns were also examined for a few cases. For validating the results, computations were also performed for a strip footing as well. The results obtained from the analysis compare well with the data reported in literature. Since the equilibrium conditions are precisely satisfied only at the centroids of the elements, not everywhere in the domain, the obtained lower bound solution will be approximate not true. (C) 2015 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	COMPUTERS AND GEOTECHNICS
Publisher:	ELSEVIER SCI LTD
Additional Information:	Copy right for this article belongs to the ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
Keywords:	Bearing capacity; Failure; Foundations; Hoek-Brown criterion; Limit analysis; Finite elements
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	05 Nov 2015 06:55
Last Modified:	05 Nov 2015 06:55
URI:	http://eprints.iisc.ac.in/id/eprint/52683

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