Thermo-Hydro-Mechanical Coupling Model for Layered Saturated Clays Considering Thermal Contraction under Impeded Boundary

This paper proposes a constitutive relationship to describe the thermal contraction behavior of saturated normally-consolidated clays. With this constitutive relationship, a thermo-hydro-mechanical (THM) coupling model considering the thermal contraction is established for the layered saturated clays subjected to a ramp thermo-mechanical load, and the corresponding semi-analytical solution is derived under an impeded boundary by using Laplace transform method. The correctness and suitability of the proposed model is then validated by comparing with the existing models. Based on this theoretical model, the parametric analyses shows that the soil close to the bottom exhibits expansive deformation in the early stage of consolidation, and the expansive deformation gradually shifts to settlement with time. As the thermal load and/or heating rate increase, the expansion zone in the soil is extended in space, and the expansive deformation becomes pronounced. The permeability of boundaries has a significant impact on the evolution of EPWP and settlement during the thermal consolidation. The outcomes will provide a more general theoretical model for the THM coupling problems in thermal-related geotechnical engineering and a more comprehensive understanding on the THM coupling characteristics of saturated clays.