Modeling the temperature-dependent response of saturated cohesive soils in a generalized bounding surface framework
Date
2018
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
Understanding the effects of temperature on the hydro-mechanical behavior of cohesive soils has gained signicance over the last two decades. This is due to new applications where such soils are subjected to non-isothermal conditions, including
energy geo-structures, thermo-active waste disposal and geothermal systems, to name a few. The solution to such problems requires at least the solution for displacement, pore fluid pressure and temperature, thus classifying the problem as a thermo-hydromechanical
one. ☐ The present research extended the Generalized Bounding Surface Model (GBSM) for saturated cohesive soils to non-isothermal conditions. In its most general form, the GBSM is a fully three-dimensional, temperature and time-dependent model that
accounts for both inherent and stress induced anisotropy. The present formulation employs a novel approach involving coupling terms in the scalar loading index. Thus, unlike all previous formulations for thermo-hydro-mechanical analyses, the outer (bounding)
surface in stress invariants space is not a function of temperature. Instead, the thermal eects enter the formulation through thermoplastic strain components. In addition to the mechanical parameters associated with the generalized GBSM, six parameters
have been added to account for the non-isothermal elastic and plastic response in their most general form. The quantities describing the initial material state and the parameters entering the extended GBSM formulation are identied. A procedure for their determination is next suggested, and the results of select parametric analyses are presented. Finally, the predictive capabilities of the extended GBSM are assessed by comparing model simulations to experimental results. ☐ Development of the aforementioned constitutive model for thermo-hydromechanical problems requires an understanding of the macroscopically observed behavior of cohesive soils (e.g., reversible and irreversible volumetric strains, compressibility in the elastic and elastoplastic ranges, and the eect of temperature cycles on the response of cohesive soils) when subjected to thermal loading. Therefore, fundamental studies related to temperature eects on interparticle forces and the knowledge of material behavior as a function of temperature were also reviewed and summarized so as to more realistically simulate the non-isothermal response of cohesive soils.