Formulation of a three‐dimensional rate‐dependent constitutive model for chalk and porous rocks |
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| Authors: | R J Hickman M S Gutierrez |
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| Institution: | 1. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061‐0105, U.S.A.Geomechanics Department, Sandia National Laboratories, Albuquerque, NM 87123, U.S.A.;2. Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061‐0105, U.S.A. |
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| Abstract: | Rate‐dependent behaviour of chalk and other porous rocks has undergone widespread study in geomechanics due to its implications on the performance of engineering structures. We present a rate‐dependent constitutive model for chalk and other porous rocks with several new features. The model formulation is based on a viscoplastic rate‐lines approach in which the axial strain rate depends on the proximity of the stress point to an elliptical reference surface. A non‐associated viscoplastic potential surface and an axial scaling algorithm are used to determine the viscoplastic strain components. The model predicts that axial yields stress varies as a power function of applied axial strain rate, as shown by published laboratory data. Comparisons with published experimental data indicate that the model is capable of reproducing observed rate‐dependent behaviour of chalk under a variety of loading conditions. Copyright © 2006 John Wiley & Sons, Ltd. |
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| Keywords: | chalk porous rock cap plasticity creep |
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