Micro-constructive Damage Model of Dry-Wet Cyclic Red Clay Based on Weibull Distribution

Abstract

Abstract To address the strength damage of red clay under dry-wet cycles, systematic conventional triaxial tests under specific circumferential pressure and scanning electron microscope observation were carried out to describe the damage evolution of soil units under load conditions of dry-wet cycle red clay microunits based on the Weibull distribution. Damage variable expressions obeying the Weibull distribution were established and the micro-parameter pore area ratio and the macro-parameter dry-wet cycle number were introduced. The cross-scale characterization of macroscopic and microscopic parameters was realized by combining the damage mechanics equation of red clay under loading. The microscopic damage intrinsic model of red clay considering the number of dry-wet cycles was constructed. The model was verified to be reasonable and effective based on triaxial tests, in which the calculation errors of the secant modulus damage threshold, probability density function shape parameter, and dry-wet cycle red clay damage stress were within 10 %, 5 %, and 5 %, respectively.