Deformation and Fabric in Compacted Clay Soils

TL;DR

This paper investigates the microstructural changes in kaolin clay related to deformation and moisture content using neutron scattering, revealing a simple relationship between strain and fabric tensors that can inform future anisotropic models.

Contribution

It introduces a neutron scattering technique to directly characterize microstructure and fabric in clay, establishing a link between deformation and fabric orientation.

Findings

Identifies a simple relationship between deviatoric strain and fabric tensors.

Provides a physical basis for anisotropic constitutive modeling.

Demonstrates the impact of moisture content on microstructure.

Abstract

Hydro-mechanical anisotropy of clay soils in response to deformation or deposition history is related to the micromechanics of plate-like clay particles and their orientations. In this letter, we examine the relationship between microstructure, deformation and moisture content in kaolin clay using a technique based on neutron scattering. This technique allows for the direct characterisation of the microstructure within representative samples using traditional measures such as the orientation density function and soil fabric tensor. From this information, evidence for a simple relationship between components of the deviatoric strain tensor and the deviatoric fabric tensor emerged. This relationship provides a physical basis for future anisotropic constitutive models based on the micromechanics of these materials.