68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

EXPERIMENTAL EVALUATION OF CHANGES IN PERMEABILITY OF FROZEN SEDIMENTS AT THAWING

Session: Laboratory Testing in Cold Regions / Essais en laboratoire en ingénierie nordique

Evgeny Chuvilin, Moscow State University (Russia)
Sergey Grebenkin, Moscow State University (Russia)

Testing of water saturated samples of the fine-grained sediments conducted in a special device under a wide range of temperatures (-15 to +30°C) and pressures (up to 100 bar) allowed to evaluate their gas permeability. It has been found that increase in permeability during thawing of frozen samples depends on moisture content (ice content) and it is associated with the change in the structure of the pore space, the possible redistribution of water in the pores and volume changes during phase transitions of ice - water. At the ice saturation below 40% the difference of values of the gas permeability of frozen and thawed samples was less than one order of magnitude. At an ice saturation more 40% the difference in permeability was more than 3 orders of magnitude.