Chemo-mechanical modeling of artificially and naturally bonded soils

TL;DR

This paper develops a chemo-mechanical model for bonded soils that captures the effects of cementation and dissolution, validated against experimental data on carbonate and microbial cemented materials.

Contribution

It introduces a multi-scale constitutive model specifically for reactive-bonded soils, linking microscopic bond evolution to macroscopic behavior, which is a novel approach.

Findings

Model accurately reproduces experimental chemo-mechanical behavior.

Applicable to both artificially and naturally cemented soils.

Enhances understanding of bond dynamics in geomechanical processes.

Abstract

Chemo-mechanical effects are known to be significant in a number of applications in modern geomechanics, ranging from slope stability assessment to soil improvement and CO2 sequestration. This work focuses on coupled chemo-mechanical modeling of bonded geomaterials undergoing either mechanical strengthening, due to increased cementation, or weakening, due to cement dissolution. A constitutive model is developed that accounts for the multi-scale nature of the chemo-mechanical problem, introducing some cross-scale functions establishing a relationship between the evolution of microscopic variables and the macroscopic material behavior, realistically following the evolution of the reactive surface area, cross-sectional area and the number of bonds along with dissolution/deposition. The model presented here builds up on a previously introduced framework. However, at variance with existing works, it is specialized on materials with only reactive bonds, such as carbonate cemented sandstone or microbially cemented silica sand. Model validation is provided upon reproducing different types of chemo-mechanical experimental datasets, on different naturally and artificially cemented materials, to establish the reliability of the proposed framework.