Abstract: Through a lot of tests under triaxial stress, rock salt dissolving characteristics have been studied. The results show that the influence of triaxial stress on rock salt dissolving velocity can not be ignored; the relationships between macro dissolving velocity (can be equal to dissolved mass in tests) and confining pressure, plastic volumetric strain and dissolving time, can be used to quantitatively describe the variation of rock salt dissolving velocity under the effect of triaxial stress according to the test data; the numerical expressions between macro dissolving velocity and confining pressure, plastic volumetric strain and dissolving time, are obtained; at the same dissolving time and plastic volumetric strain condition, under the different confining pressures, the obvious difference between the shape of rock salt sample before and after dissolved exists; dissolved mass with stress effect changes greatly, and with increased confining pressure, dissolved mass with stress effect on the variation for the shape decreases; the obtained mechanism of rock salt dissolving characteristics under triaxial stress is that the direct relationship between rock salt dissolving velocity under triaxial stress and development of surface cracks under different confining pressures is obtained. The achieved results can provide a foundation for the further analyses of coupled stress-dissolving mechanism of rock salt.

Key words: rock salt, dissolving characteristics, triaxial stress, plastic volumetric strain, confining pressure, crack