Variation of permeability of natural filled jointed rock under repeated loading and unloading conditions

Abstract

To enrich understanding of how fluid flows through the natural filled jointed rock, the permeability experiments of the natural filled jointed dacite rock under repeated loading and unloading conditions are carried out. Experimental results show that the response of permeability of filled jointed dacite rock to confining pressure under repeated loading and unloading conditions is considered as porous media. Permeability and gas pressure are positively correlated under repeated loading and unloading conditions. Relationship between permeability and gas pressure shows that the higher confining pressure, the smaller permeability increasing rate. The calculated equivalent crack apertures are very small at the order of magnitude about 10⁻⁸ m. The power law is found to well describe the relationship between equivalent crack aperture and effective stress of natural filled jointed dacite rock. With the parameters determined based on experiment results, an empirical expression is proposed.

Keywords:

• Filled jointed rock
• loading-unloading cycles
• permeability
• equivalent crack aperture
• effective stress

Disclosure statement

No potential conflict of interest was reported by the authors.

The work presented in this paper is supported by the National Key R&D Program of China (No. 2017YFC1501100), the Natural Science Foundation of China (Grant Nos. 51939004, 11772116, 11572110), the Qing Lan Project, China Huaneng Group Science and Technology Project HNKJ18-H24, the Fundamental Research Funds for the Central Universities (Grant No. 2019B73514) and Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant No. SJKY19_0452)