Journal of Zhejiang University

Journal of Zhejiang University SCIENCE A 2014 Vol.15 No.4 P.272-281

A modified creep index and its application to viscoplastic modelling of soft clays*

Author(s): Qi-yin Zhu¹,Ze-xiang Wu¹,Yan-ling Li¹,Chang-jie Xu^2,3,Jian-hua Wang¹,Xiao-he Xia¹
Affiliation(s): 1. 1. Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China more
Corresponding email(s): qiyin.zhu@gmail.com
Key Words: Clays, Creep, Consolidation test, Embankment, Finite element method, Viscoplasticity

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Qi-yin Zhu, Ze-xiang Wu, Yan-ling Li, Chang-jie Xu, Jian-hua Wang, Xiao-he Xia. A modified creep index and its application to viscoplastic modelling of soft clays[J]. Journal of Zhejiang University Science A, 2014, 15(4): 272-281.

@article{title="A modified creep index and its application to viscoplastic modelling of soft clays",
author="Qi-yin Zhu, Ze-xiang Wu, Yan-ling Li, Chang-jie Xu, Jian-hua Wang, Xiao-he Xia",
journal="Journal of Zhejiang University Science A",
volume="15",
number="4",
pages="272-281",
year="2014",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.A1300331"
}

%0 Journal Article
%T A modified creep index and its application to viscoplastic modelling of soft clays
%A Qi-yin Zhu
%A Ze-xiang Wu
%A Yan-ling Li
%A Chang-jie Xu
%A Jian-hua Wang
%A Xiao-he Xia
%J Journal of Zhejiang University SCIENCE A
%V 15
%N 4
%P 272-281
%@ 1673-565X
%D 2014
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.A1300331

TY - JOUR
T1 - A modified creep index and its application to viscoplastic modelling of soft clays
A1 - Qi-yin Zhu
A1 - Ze-xiang Wu
A1 - Yan-ling Li
A1 - Chang-jie Xu
A1 - Jian-hua Wang
A1 - Xiao-he Xia
J0 - Journal of Zhejiang University Science A
VL - 15
IS - 4
SP - 272
EP - 281
%@ 1673-565X
Y1 - 2014
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.A1300331

Abstract
Chinese Summary
Academic Network
Reviewer Comment

Abstract: Conventional consolidation tests on reconstituted specimens of numerous natural soft clays show a decreasing of creep index C _αe with increasing soil density. Based on all selected and conducted experimental results, a modified creep index C _αe ^* defined in double logarithmic plane lge-lgt, was plotted for various clays, from which C _αe ^* can be assumed as a constant for different soil densities. Then, the modified creep index was applied to a newly developed elastic viscoplastic model. In this way, the modified creep index C _αe ^* can naturally take into account the nonlinear C _αe revealing the influence of soil density in the soil assemblies without additional parameters. Finally, the enhanced model was incorporated into the finite element code ABAQUS and used to simulate a consolidation test and a test embankment. The improvement of simulations by the modified creep index was highlighted by comparing simulations using the conventional creep index C _αe.

一个修正的蠕变系数及其在软黏土黏塑性模拟中的应用

研究目的：提出一个更优的描述黏土非线性蠕变的方法。
创新要点：1.提出了一个修正的蠕变系数，该系数与土体的密度相关，物理意义明确；2.将修正的蠕变系数嵌入到新开发的一个黏塑性模型中，实现了基于ABAQUS的本构二次开发；3.为工程实例的计算提供更为有效的模型。
研究方法：1.总结广泛的调查土体蠕变试验结果，提出修正的蠕变系数（图3）；2.给出修正的蠕变系数表示方法以及力学特性（图4）；3.将所提系数嵌入到有限元程序中，验证了其准确性（图5）。
重要结论：1.修正的蠕变系数可以很好地描述软黏土蠕变系数随孔隙比变化的规律；2.通过工程案例证实了修正系数的优越性。

关键词：软黏土；蠕变；黏塑性；有限元