Estimating Subgrade Reaction Modulus for Transversely Isotropic Rock Medium
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 136, Issue 8
Abstract
Most of the rock medium possesses intrinsic grain orientation or preferred bedding and joint directions, thus requiring the use of at least transverse isotropy to describe its elastic behavior. This paper presents a series of charts, based on extensive finite element parametric studies along with nonlinear regression analysis of FE simulation results, for estimating the subgrade reaction modulus (or initial tangent to the curve) using five elastic constants of a transversely isotropic rock mass. The proper characterization of subgrade reaction modulus is critical for accurate prediction of the elastic lateral deflection of a rock socketed drilled shaft under the applied lateral loads. The sensitivity of the response of a laterally loaded drilled shaft to the degree of anisotropy and orientation of the plane of anisotropy (bedding plane direction of the rock medium) was demonstrated in this paper for an actual lateral load testing case in Ohio. It is highly recommended to use five elastic constants to estimate subgrade reaction modulus of rock medium exhibiting high degree of cross anisotropy.
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Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 136 • Issue 8 • August 2010
Pages: 1077 - 1085
Copyright
© 2010 ASCE.
History
Received: Dec 27, 2008
Accepted: Oct 16, 2009
Published online: Oct 22, 2009
Published in print: Aug 2010
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