Mechanism Damage to Mode-I Fractured Sandstone from Chemical Solutions and Its Correlation with Strength Characteristics
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The fracture toughness of rock is very important in rock cutting, blasting, and hydraulic fracturing for tunnel excavation. To evaluate factors that reduce rock fracture toughness, we emulated the environment of joint rock in the hydro-fluctuation belt of a typical bank slope in the Shanxi Tong Chuan reservoir region. We tested long-term immersion of sandstone samples in different chemical solutions to determine the resulting mechanical characteristics and damage degradation. Variations in the physical and mechanical properties of the samples were analyzed under the effects of the chemical solutions. Experimental results show that the sandstone was significantly damaged by the chemical solutions, but its peak strain increased, and different chemical solutions had distinct influences on the degree of mechanical damage. These differences varied with the acid–base properties of the solutions. Also, there were clear consistencies among the solutions in the degree of their damage to mechanical parameters, physical parameters, and ion concentrations. Therefore, we were able to obtain correlations among the physical and mechanical parameters of the sandstone samples, damage variables, and the ion concentrations of calcium and magnesium. The surfaces of the samples were seriously degraded after being subjected to the corrosive effect of various chemicals; for example, there were different amounts of holes and pitting corrosion. The sizes of the holes and the degree of surface pitting gradually increased with an increase in corrosion time.
KeywordsChemical erosion correlation jointed rock mass mechanical characteristics mode-I fracture toughness rock mechanics
The authors gratefully acknowledge the support of the National Natural Science Foundation of China (Nos. 11302167, 11572244, and 51478272), the joint funds of the National Natural Science Foundation and Guangdong Province of China (U1301241), the International Cooperation and Exchange of the National Natural Science Foundation of China (51520105012), and the Collaborative Innovation Research Centre for Environment-Friendly Materials and Structures in Civil Engineering, Southeast University, the Science and Technology Foundation for the Basic Research Plan of Shenzhen City (JCYJ20160422095146121).
- Chen, M., Jin, Y., & Yuan, C. Y. (2001). Study on the experimental for fracture toughness under confining pressure. Mechanics and Engineering, 23(4), 32–35.Google Scholar
- Deng, H. F., Zhu, M., Li, J. L., Wang, Y., Luo, Q., & Yuan, X. F. (2012). Study of mode-I fracture toughness and its correlation with strength parameters of sandstone. Chinese Journal of Rock and Soil Mechanics, 33(12), 3585–3591.Google Scholar
- Han, T. L., Shi, J. P., Chen, Y. S., et al. (2015). Salt solution attack induced mechanical property degradation and quantitative analysis method for evolution of meso-structure damages of mortar. Chinese Journal of Materials Research, 29(12), 921–930.Google Scholar
- The Professional Standard Compilation Group of People’s Republic of China, DL/T5368. (2007). Specifications for rock tests in water conservancy and hydroelectric engineering. Beijing: China water Power Press. (In Chinese).Google Scholar
- Wang, Y. X., Cao, P., Chen, Y., Wan, L. H., Huang, Y. H., Zhao, Y. L., et al. (2011a). Test study on damage and fracture mechanical effects for swelling soft rock during water corrosion. Journal of Central South University (Science and Technology), 42(6), 1685–1691.Google Scholar
- Wu, X. D. (2013). Experimental study on the time-dependent behaviour of Xiangjiaba sandstone. Applied Mechanics and Materials, 256–259, 174–178.Google Scholar
- Zhang, S., & Wang, Q. Z. (2009). Determination of rock fracture toughness by split test using five types of disc specimens. Rock and Soil Mechanics, 30(1), 12–18. (In Chinese).Google Scholar
- Zhang, F. C., Wang, X. C., Lu, J., et al. (1981). Fracture mechanics (pp. 49–56). Beijing: China Architecture and Building Press.Google Scholar
- Zhang, S., Wang, Q. Z., & Xie, H. P. (2008). Size effect of rock dynamic fracture toughness. Explosion and Shock waves., 28(6), 544–551.Google Scholar