HS-Small Constitutive Model for Innovative Geomaterials: Effectiveness and Limits

Abstract Worldwide, an increasingly huge number of end-of-life tires (ELTs) are disposed of in landfills, illegally dumped, or otherwise unaccounted for, which causes significant environmental and socioeconomic issues. Finding sustainable engineering solutions to recycle and reuse ELTs, which transform them from unwanted waste into useful resources, has become a priority. In geotechnical engineering, researchers have performed laboratory and field tests to determine the mechanical properties of innovative geomaterials that consist of soil–rubber mixtures (SRMs) [i.e., gravel–rubber mixtures (GRMs)] that are obtained using recycled ELT-derived granulated rubber aggregates. Suitable engineering properties and low installation cost encourage the use of GRMs and SRMs in many applications, such as in free-draining energy-adsorption backfill material for retaining walls, underground layers for liquefaction mitigation and geotechnical seismic isolation systems for structures and infrastructures. However, due to the heterogeneity of SRMs, their ultimate adoption as geomaterials must be supported by constitutive relationships that can accurately describe their mechanical behavior under typical field loading conditions. The aim of the paper is to evaluate the effectiveness and limits of the hardening soil model with small strain stiffness (HS-small), which is present in many finite-element (FE) codes, to model the behavior of GRMs in geotechnical engineering applications. An extensive finite-element method simulation of drained triaxial tests was performed.