It is assumed that a conceptual disposal repository for nuclear waste is located in a saturated jointed rock mass with certain water head

and a supporting system composed of rock bolts and shotcrete is installed after excavation of the drift. The construction of drift and a coupled thermo-hydro-mechanical(T-H-M) operation process of 50 years are simulated numerically by using UDEC code. The changes of stresses

displacements

plastic zones

temperatures

water flow in the rock mass of near field are analysed for cases with and without supporting; and the loading states of bolts and shotcrete are investigated under the conditions of coupling with different fields (temperature

water and stress). The results show: not only the rock bolts and shotcrete have the routine support function

but also are able to block free seepage of groundwater from the drift surface

so making plastic zone decrease

fracture pressure and temperature rise; compared with the case of action only by single stress field

the stability of surrounding rock mass is reduced

and the loading state of supporting structure is degenerated in the case of thermo-hydro-mechanical coupling.