Comparison of constant dissolution coefficient of gypsum and anhydrite materials in surface flows using the results of laboratory models

Dissolution of soluble minerals in the construction site of dams will lead to the development of cracks and increase the permeability of foundations and abutments, destruction of injection molding and problems in the stability of dams. Increasing the dissolution rate with the development of cracks and fissures leads to increasing the permeability of the foundation and then the currents passing through the joints will not be similar to groundwater flows and the flow behavior will be similar to surface currents. The passage of current through the surface of gypsum and anhydrite-containing materials, the mechanism of behavior of gypsum and anhydrite materials against surface currents have been investigated, and then, using the experiences gained from past research, finally relations to estimate the constant rate of dissolution K It has been extracted in these two materials. the highest correlation with flow and temperature flow is linear and time parameter is exponential. Also, the solubility coefficient of gypsum materials is higher than anhydrite in the presence of surface currents. For a constant temperature, the gypsum K coefficient is about 10,000 times that of anhydrite, and at a constant temperature, K for gypsum is equivalent to 1000 times that of anhydrite. In general, the effect of discharge on the dissolution of gypsum is greater than anhydrite.