“…Indeed, attempting to solve numerically the boundary value problems for unsaturated soils using BEM leads one to search for the associated fundamental solutions.The comprehensive state-of-the-art review by Gatmiri and Kamalian [4], Gatmiri and Nguyen [5], Gatmiri and Jabbari [6, 7], Seyrafian et al [8] provides clearly presented information on the fundamental solution applied to the soil and the porous media. For unsaturated soils, Gatmiri and Jabbari [6,7,9,10] have derived the first fundamental solutions for the nonlinear governing differential equations for static and quasi-static poroelastic media for both two and three dimensional problems. The corresponding thermo-poro-mechanic fundamental solutions for static and quasi-static problems are, respectively, derived by Jabbari and Gatmiri (for both two and threedimensional problems) [11] and Gatmiri et al (for two-dimensional problems) [12].According to the authors' knowledge, the three-dimensional fundamental solutions of the governing partial differential equations for unsaturated porous media by considering the thermohydro-mechanical behaviour have not been developed so far, hence the development of a BEM model for unsaturated phenomena is not yet possible.In this paper first, the set of fully coupled governing differential equations of thermo-hydromechanical behaviour of unsaturated porous media subjected to quasi-static loadings is presented based on the suction-based mathematical model presented by Gatmiri [13] and Gatmiri et al [14].…”