Experimental study on the damage evolution and characteristics of the structured red clay in Guilin

Xiang  Huang; Hong-bin  Chen; Xue-Jun  Chen; De-xian  Liang; Han-ying  Bai; Yu  Song

doi:10.6180/jase.202006_23(2).0020

Experimental study on the damage evolution and characteristics of the structured red clay in Guilin

Xiang Huang^1,2, Hong-bin Chen¹, Xue-Jun Chen This email address is being protected from spambots. You need JavaScript enabled to view it.^1,2, De-xian Liang², Han-ying Bai², Yu Song^1,2

¹Guilin University of Technology, Guilin 541004，P.R. China
²Guangxi Key Laboratory of Geotechnical Engineering，Guilin 541004, P.R. China

Received: December 12, 2018
Accepted: February 28, 2020
Publication Date: June 1, 2020

Download Citation: ||https://doi.org/10.6180/jase.202006_23(2).0020

ABSTRACT

To develop a damage index to describe the stress-strain relationship of red clay in Guilin, the undrained triaxial tests of intact red clay under various confining pressures were conducted. Firstly, the initial deformation modulus was analyzed based on the hyperbolic strain-stress relationship and deformation modulus-confining pressure relationship. The change law of secant modulus and strain threshold value were determined based on the relationship between the axial strain and secant modulus. The variable D related with the initial elastic modulus and secant modulus are used as damage index, which increased with the increase of the principal stress difference, showing a linear relationship. The damage index was correlated with the axial strain exponentially, indicating that the damage of red clay was irreversible. The proposed variable D was used in the nonlinear damages mechanics model to compare with experimental data, and the constitutive model based on the damage index D reflected the experiment results and fitted the stress-strain curves of the red clay.

Keywords: red clay; triaxial test; damage index; evolution law of damages

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