Shear banding in unsaturated geomaterials through a strong nonlocal hydromechanical model

Abstract

We present a strong nonlocal hydromechanical model formulated based on state-based peridynamics for simulating strain localisation in unsaturated geomaterials. The governing equations are integro-differential equations in which length scales are assumed for both the skeleton deformation and pore fluid flow. Recently proposed hydromechanical correspondence principle is adopted to implement the classical local constitutive model for the solid skeleton, and the generalised Darcy’s law for unsaturated water flow into the nonlocal hydromechanical model. Numerical simulations of shear bands in unsaturated geomaterials were conducted to investigate the effect of the hydromechanical length scale and the mechanical loading rate on the formation of shear bands. The numerical results have shown that both the deformation and pore water pressure are concentrated in the shear bands with a finite thickness. The numerical results have demonstrated that both the hydromechanical length scale and the mechanical loading rate affect the formation of shear bands in unsaturated geomaterials and the peak value of the load capacity of unsaturated geomaterials.

Keywords:

• Shear banding
• unsaturated geomaterials
• strong nonlocal
• hydromechanical model
• coupled

Acknowledgement

The authors are grateful to the two anonymous reviewers for their constructive reviews of this article.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The research was supported by the US National Science Foundation under Contract numbers CMMI - 1659932 and 1944009.