Citation

Meng L, Li T. Disaster Adv. 2013; 6(2): 31-38.

Copyright

(Copyright © 2013, Shankar Gargh)

DOI

unavailable

PMID

unavailable

Abstract

Permeability experiments on the deformation and failure processes in phyllites were carried out using a MTS815 Flex Test GT instrument under unloading confining pressure and high-temperature conditions. The permeability of phyllite in deformation and failure processes was analyzed and the relationship between permeability and volume strain was discussed. The effect of temperature on the permeability of phyllite was studied. Results show that the deformation and penetrability of phyllites can be divided into four phases: elastic compression deformation, elastic expansion deformation, expansion damage and after-failure phase. The rock penetrability is small and remains nearly unchanged during the elastic compression deformation phase, but obviously increases during the elastic expansion deformation phase. The rock permeability during the elastic expansion deformation phase is 2.4 times higher than that during the elastic compression deformation phase. The rock permeability during the expansion damage phase is 3.3 times higher than that during the elastic compression deformation phase. The permeability after rock failure is 8.5 times higher than that during the elastic compression deformation phase. Unloading confining pressure causes strong expansion of the rock volume, which leads to higher rock penetrability under unloading than under loading conditions. The test temperature is lower than the phyllite thermal rupture threshold temperature and the phyllite permeability decreases with increased temperature.