SVOBODA, J. and J. SMUTEK. The experimental in-situ study of gas migration in crystalline rock with a focus on the EDZ. Geological Society Special Publication. 2015, 415(415), 95-105. ISSN 0305-8719. DOI 10.1144/SP415.15.
Centre of Experimental Geotechnics (CEG) participated in the FORGE project within WP4, which was focused on disturbed host rock formations. The Czech deep radioactive repository concept envisages crystalline rock as the host rock environment; therefore the CEG concentrated on such formations. Large-scale gas injection tests were carried out in Josef Underground Laboratory as part of the project aiming to study the behaviour of both the excavation damaged/disturbed zone (EDZ) and the undisturbed rock environment. The project schedule involved the performance of a large number of tests at various pressure levels and flow rates and in different parts of the rock mass. The various phenomena were studied employing gas injection test techniques using both single- and double-packer equipment. The tests performed revealed a significant difference in terms of gas permeability between the EDZ and the undisturbed rock mass. An investigation of the influence of the effect of pressure on gas permeability was also performed in order to study the process of the opening and closing of fractures (pathway dilation).
