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| THE EFFECT OF PRINCIPAL STRESS RATIO ON CREEP BEHAVIOUR OF OVER-CONSOLIDATED CLAY UNDER PLANE STRAIN CONDITIONS |
| LI Guowei1，2，HUANG Kai1，3，RUAN Yusheng1，3，LI Xiang1，3，YIN Jianhua4 |
(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering，Hohai University，Nanjing，Jiangsu 210098，China；2. Highway and Railway Research Institute，Hohai University，Nanjing，Jiangsu 210098，China；
3. Geotechnical Research Institute，Hohai University，Nanjing，Jiangsu 210098，China；4. Department of Civil and Structure Engineering，The Hong Kong Polytechnic University，Hong Kong，China) |
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Abstract The effect of principal stress ratio on creep behaviour of over-consolidated soil was studied through tests on undisturbed soft clay samples under plane strain conditions. The over-consolidation shear stress ratio (OCRq)，defined with the generalized shear stress，was found to be a function of the principal stress ratio and the pre-consolidation pressure. OCRq can provide a better and more direct description of the creep behaviour of over-consolidated soft clay under plane strain conditions compared with the over-consolidation spherical stress ratio(OCRp). There is a one-to-one relationship between the creep coefficient and the OCRq：as the OCRq increases，the corresponding creep coefficient decreases. For the same OCRq，over-consolidated soils with smaller principal stress ratios will have larger creep coefficients. For different principal stress ratios，the over-consolidated soft clays will have smaller generalized shear stress than normally consolidated ones. Under certain conditions，the generalized shear stress increases with decreasing principal stress ratio and the corresponding over-consolidated soil will have greater long-term creep deformation.
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2015, Vol. 34 
