AMD蚀化砂岩细观力学效应

Mesoscopic mechanical effect on sandstone corroded by acid mine drainage

通过pH值为1.25,3.38的AMD溶液蚀化下砂岩细观结构及力学试验,分析砂岩细观结构及力学性质变化规律;运用分形理论描述砂岩细观结构分布特征,得到AMD蚀化下砂岩表面SEM图像的分形维数(D);基于砂岩弹性模量的变化,引入AMD蚀化下砂岩化学损伤变量(w),建立w与D之间的关系。结果表明:AMD蚀化下砂岩细观结构分布具有分形特征,w与D存在较好的线性关系。pH=1.25时,w=0.78D-1.62;pH=3.38时,w=0.97D-2.04,相关系数均在0.98以上。研究结果从细观层次揭示了AMD蚀化砂岩力学效应。

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.