Mesoscopic mechanical effect on sandstone corroded by acid mine drainage

Through meso-tests and mechanical tests of sandstone corroded by AMD solution with pH values of 1.25 and 3.38,the change rules of meso-structure and mechanics characteristic of sandstone were analyzed.Fractal theory was applied to describe the distribution of the meso-structure and fractal dimensions(D) of SEM image of sandstone by AMD were obtained.A chemical damage variable(w) was introduced based on the variety of elastic modulus,and the relationship between w and D was established.The results show that it has fractal characteristics,there is linear correlation between w and D,while pH value of AMD solution is 1.25,w=0.78D-1.62,while pH value is 3.38,w=0.97D-2.04.The linear coefficient between w and D is higher than 0.98.The mechanical effect of sandstone by AMD is revealed on meso-level.