Proportional stress and strain paths in barodesy

Abstract

Asymptotic behaviour of soil deserves particular attention: If soil is deformed with a proportional strain path, the resulting stress path approaches asymptotically a proportional stress path. In this arcticle, we review existing experimental evidence on this phenomenon and discuss it in the frame of barodesy. Here, the presented relation is a modification of a barodetic expression and includes Jáky's relation, inhibits tensile stress and is able to predict asymptotic stress ratios based on experimental findings. The proposed relation is compared with experimental data as well as with the so-called stress-dilatancy relations and other constitutive relations proposed so far.

An improved version of barodesy for clay

“…Results are presented in Appendix 1. A detailed explanation and further results are given by Medicus et al [21].…”

“…R 0 and T 0 are the normalized tensors of proportional stress paths R and actual stress, respectively. R is a tensorial argument 5 of normalized stretching D 0 and is chosen according to Medicus et al [21]:…”

“…In a, certain stress paths, simulated with barodesy for clay [20], approach proportional stress paths in the tensile region. In b, all stress paths, simulated with the improved version of barodesy for clay according to (1)- (10), stay in the compression regime 6 A detailed description of the R-function according to (3)- (5) is given in Medicus et al [21]. 7 E.g., for u c ¼ 22:6 (London clay), tensile stresses occur for w _ e \ À 128:3 and w _ e [ 138:9 , cf.…”

“…Experiments by Bergholz [1] of saturated reconstituted clay show that, also for highly overconsolidated clay, the stress ratio q/p (in triaxial compression) does not exceed three (i.e., the stress paths stay in the compression regime). The R-function according to Medicus et al [21] explicitly prohibits tensile stresses and is chosen as one of the equations for the improved version of barodesy for clay. However, an article [21] reviews existing experimental evidence on stress-dilatancy relations and discusses it in the framework of barodesy, but does not provide a constitutive model.…”

“…The R-function according to Medicus et al [21] explicitly prohibits tensile stresses and is chosen as one of the equations for the improved version of barodesy for clay. However, an article [21] reviews existing experimental evidence on stress-dilatancy relations and discusses it in the framework of barodesy, but does not provide a constitutive model. The main differences of barodesy for clay [20] and the version presented here are shown in this article.…”