Aperture measurements and flow experiments on a single natural fracture

The aim of the experimental work presented in the paper has been to carry out flow experiments and aperture measurements on the same specimen of a single natural fracture, in order to compare measured flow with predicted flow based on geometrical description of the fracture void space. A technique to measure the aperture was developed utilizing injection of fluorescent epoxy in the fracture specimen. An image analysis system was used to take measurements along sections across the fracture surface. The method was successfully applied to a fracture in granite having a mean aperture of 360 mu m at 0.45 MPa normal stress. The spatial correlation of the aperture was about 1 cm. The predicted and measured flow through the fracture specimen are in good agreement. (C) 1996 Published by Elsevier Science Ltd.