ABSTRACT
All shear tests were performed with a shear rate of 0.1 mm/min. This shear rate was chosen in order to avoid uncontrolled displacements and failures.
2.2 Joint characteristics
The intact rock consists of grey coarse grained granite with small intrusions of pegmatite. From visual inspection, surface roughness was characterized as rough and undulating, with JRC estimated to be in the range of eight to twelve. However, pull tests gave considerable lower values of the JRC in the range of three to eight. This effect most likely originated from the poor matedness between the upper and lower part of the joint surfaces of the samples as suggested by Zhao (1997a,b). The poor matedness was due to the fact that the joint was slightly weathered. The aperture of the joint in the samples varied between 0-5 mm. In general, the joint was unfilled, but some infilling of weathered materials existed.
