On the basis of the existing work and Mohr-Coulomb yield criterion
an elasto-plastic analysis solution for circular underground cavern is established considering the combined thermo-hydro-mechanical action. Under the conditions of single stress field
thermo-mechanical field
hydro-mechanical field and thermo-hydro-mechanical field and changing strength parmeters of a medium
the distribution and change of stresses and plastic zones in the surrounding rock mass are computed and compared respectively. The results show that the temperature field makes the radius of plastic zone some decrease
but the action of temperature is not obvious on the whole; compared with the action of the single stress field
the pore water pressure makes the plastic zones
radial stresses and tangential stresses increase greatly.