Abstract: Rock salt sample dissolution tests under on the condition of triaxial stress with self-designed triaxial testing machine, rock salt dissolution rate orthogonal experiment under the mutual coupling of concentration, temperature, flow and deviatoric stress under the condition of triaxial stress, are carried out. Various factors influencing rock salt dissolution rate are studied. Any two factors are the binary linear regression, the relative importance ratio according to the standardized regression coefficients for rock salt dissolution rate to build judgment matrix; analytic hierarchy process is used to calculate weights of various factors. The results show that: Rock salt dissolution rate decreased rapidly with the concentration increasing. Dissolution rate increases with the temperature rising. Dissolution rate increases slowly with the flow increasing and did not change significantly. Dissolution rate decreases first and then slowly increases with increasing deviatoric stress. Range analysis and weights calculation show that primary and secondary factors affecting the rock salt dissolution rate are concentration, temperature, flow and the deviatoric stress. The weights of concentration, temperature, flow and the equivalent stress affecting the dissolution rate are 0.570, 0.384, 0.048, 0.005 respectively; the weights of the two factors, concentration and temperature, account for 95%.

Key words: rock salt, dissolution rate, triaxial stress, orthogonal, analytic hierarchy process