Coupled chemical stress processes in rock fracturing

Abstract

This paper reports some typical results of our study on the coupled chemical stress processes in rock micro‐ and macrofracturing. New devices were first developed. The chemical solutions tested include Na₂SO₄, CaCl₂, NaCl, NaHCO₃ and HCl. The stress paths including uniaxial compression, triaxial compression and creep load, coupled with chemical solutions, were investigated. The results were compared with distilled water and natural water. The new features, including evolution feature of porosity of rock samples under uniaxial or triaxial compression with chemical solution, uniaxial and triaxial compressive strengths, Young’s modulus of granite, sandstone and limestone affected by chemical solutions with and without porous pressure, effect of chemical solutions on creep behaviours of sandstone, and effect of chemical solutions on fracturing schemes, cracking propagation features of sandstone and granite, have been found. Based on the tested results mentioned above, a new numerical method is developed to simulate the fracturing process affected by coupled stress chemical solutions. The results are verified with tests.

Keywords:

• Coupling chemical stress process
• New test devices
• Uniaxial and triaxial compression test
• Creep test
• Numerical simulation
• Rock

The financial supports from the National Nature Science Foundation of China under grant nos. 10872209 and 50920105908 and China National Basic Research Program under grant no. 2010Cb732006 are gratefully acknowledged.