Clayey soils used as engineered barriers in environmental infrastructures are often subjected to coupled thermal (T), mechanical (M), and chemical (C) loadings, which can induce complex consolidation behaviour and influence long-term barrier performance. In this study, the deformation and transport responses of clayey soils under thermo–mechanical–chemical (TMC) coupling are investigated using a previously benchmarked one-dimensional coupled numerical model. Soil settlement behaviour and clay liner performance are analysed under single (T, M, and C), dual (TM, MC, and TC), and triple (TMC) loading conditions. The results reveal distinct deformation characteristics: an initial compression followed by rebound behaviour under chemical loading and an initial expansion followed by contraction under thermal loading. Under combined TMC loading, the settlement process follows a three-stage pattern: initial expansion offset, rapid consolidation, and late-stage rebound. Notably, the interaction among loadings leads to non-additive deformation, highlighting strong mutual inhibition effects. The indicative clay liner thickness varies significantly among different loading scenarios. The thermal loading has the greatest impact on liner thickness, followed by chemical and mechanical loading. These findings offer valuable theoretical insights into soil deformation under multiphysical couplings and provide a scientific basis for optimising barrier design and assessing long-term performance of engineering barriers in contaminated or thermally active environments.
Han et al. (Mon,) studied this question.