Research on Confining Pressure Effect on Mesoscopic Damage of Rock Salt Based on CT Scanning
The Rock salt is the optimal surrounding rock of underground energy storage, so its damage is directly related to the impermeability and stability of the storage. In this study, CT scanning technique was used to analyze the microscopic damage characteristics of rock salt, which damaged under the three-dimensional stress state. The distribution and evolution characteristics of porosity, crack area, crack volume and crack quantity of damaged rock salt under different confining pressures were obtained. The results revealed the confining pressure effect of the mesoscopic damage of rock salt. With the increase of confining pressure, the quantity and size of cracks in rock salt gradually decreased. The confining pressure of 10 MPa is the turning point where the porosity decreased from fast to slow and the failure characteristics of rock salt changed from the apparent shear failure surface to the surface micro cracks.
KeywordsRock salt CT scanning Microscopic damage Confining pressure effect
The authors are grateful for the financial support from the National Natural Science Foundation of China (Grant No. 51374148, No. 51641405), Sichuan Youth Science and Technology Fund (Grant No. 2017JQ0003). The authors wish to offer their gratitude and regards to the colleagues who contributed to this work.
- 4.Hou, Z., Wu, W.: Improvement of design of storage cavity in rock salt by using the Hou/Lux constitutive model with consideration of creep rupture criterion and damage. Chin. J. Geotech. Eng. 25, 105–108 (2003)Google Scholar
- 5.Liu, J.F., Xu, J., Yang, C.H., Hou, Z.M.: Mechanical characteristics of tensile failure of salt rock. Chin. J. Geotech. Eng. 33, 580–586 (2011)Google Scholar
- 6.Liu, J.F., Xu, J., Pei, J.L., Zhang, R.: Research on unloading modulus for salt rock damage testing. J. Sichuan Univ. (Eng. Sci. Ed.) 43, 57–62 (2011)Google Scholar
- 7.Chen, J.W., Yang, C.H., Gao, X.P., Li, X.H., Jiang, D.Y.: Study on the coupled damage of temperature and mechanics for salt rock. Chin. J. Rock Mech. Eng. 24, 1986–1991 (2005)Google Scholar
- 8.Ge, X.R., Ren, J.X., Pu, Y.B., Ma, W., Zhu, Y.L.: Primary study of CT real - time testing of fatigue meso-damage propagation law of rock. Chin. J. Geotechn. Eng. 23, 191–195 (2001)Google Scholar
- 9.Zhou, H.W., He, J.M., Wu, Z.D.: Permeability and meso-structure characteristics of bedded salt rock. Chin. J. Rock Mech. Eng. 28, 2068–2073 (2009)Google Scholar
- 10.Liu, Z.H., Xu, S.G., Hu, Y.Q., Feng, Z.C., Liang, W.G., Zhao, Y.S.: Experimental study of corrosion of glauberite salt rock. Chin. J. Rock Mech. Eng. 29, 3616–3621 (2010)Google Scholar
- 11.Liu, Y.D., Yuan, F.L., Dong, J.H.: CT analysis of meso-structure changes in rock salt with Brine corrosion. Adv. Mater. Res. 960–961, 82–86 (2014)Google Scholar
- 17.Chen, J., Liu, J.X., Jiang, Y.D., Fan, J.Y., Ren, S.: An experimental study of strain and damage recovery of salt rock under confining pressures. Rock Soil Mech. 37, 105–112 (2016)Google Scholar
- 18.The Professional Standards Compilation Group of People’s Republic of China. GB/T 50 266-2013 Standard for Tests Method of Engineering Rock Massas. China Planning Press, Beijing (2013)Google Scholar