Laboratory investigation on the mode-I fracture toughness and its correlation with strength characteristic of sandstone under the different chemical corrosion-rock interaction
Abstract：The long-term immersion is adopted to explore the damage deterioration mechanism and mechanical prosperities of the sandstones under different chemical solutions. The variation regularities in the physical and mechanical prosperities were analyzed by using the sandstone sampled from the hydrofluctation belt of a typical bank slope in the Shanxi Tong chuan reservoir region as the objects of study. Experimental results show that the physical and mechanical prosperities of sandstone specimens have a significant degree of degradation under hydrochemical erosion, however, a difference exists in the deterioration degree of its physical and mechanical prosperities under different chemical solutions, i.e., acid solutions may aggravate the deterioration of chemical damage in sandstone, neutral and alkaline chemical solutions have a certain influence on its damage deterioration. At the early stage of the experiment, its damage deterioration is relatively small in strong alkaline solution. However, the deterioration of chemical damage in sandstones are increasing with the chemical corrosion time, that is, the deterioration degree in acid solution is the greatest followed by that in neutral and alkaline chemical solutions, and in the alkaline chemical solutions is relatively small. The fracture toughness KIC, compression strength and tensile strength of sandstone specimens have a significant damage deteriorating trend after chemical corrosion; however, there is a difference in the degree of damage deterioration in mechanical prosperities; that is, the damage deterioration of its fracture toughness KIC is the greatest, followed by that of tensile strength; that of compression strength is the smallest. There are obvious consistency among fracture toughness KIC, compression strength and tensile strength of sandstone specimens, those are obvious linear relationship. The crack propagation radius r can be used to indicate the degree of damage deterioration in mechanical prosperities under different chemical solutions.
2017, Vol. 38 
