[en] A coupled T-H-M analysis was carried out for KENTEX, which is a facility for validating the coupled T-H-M behavior in the engineered barrier system of the Korean reference HLW disposal system. The changes of temperature, water saturation, and stress were estimated based on the coupled THM analysis, and the influence of the types of mechanical constitutive material laws was investigated by using elastic model, porous elastic model, and porous elastic Drucker-Prager model. The analysis was done using ABAQUS, which is a commercial finite element code for general purposes. From the analysis, in the steady state, the temperature was maintained at 90 .deg. C at the interface between the heater and the bentonite and at about 70 .deg. C the interface between the bentonite and the confining cylinder. The variation of the water saturation with time in bentonite was almost same independent of the material laws used in the coupled T-H-M processes. It was found that the buffer saturation near the heater was higher than that from the coupled HM calculation mainly because of the thermal flux, which seemed to speed up the saturation. By comparing the stress change in HM calculation using porous elasetic and porous-elasetic Drucker-Prager model, it was possible to conclude that the influence of saturation on the stress change is higher than the influence of temperature. It is, therefore, recommended to use a material law, which can model the elasto-plastic behavior of buffer, since the coupled THM processes in buffer is affected by the variation of void ratio, thermal expansion, as well as swelling pressure