Evaluation of joint roughness and dilatancy of schistosity joints

Since natural discontinuities show a roughness nature influencing their shear behaviour, sheer strength have been investigated by several authors (Barton, 1973; Swan & Swonqi, 1985; Ferrero & Giani, 1990; Cravero et Al., 1995; Scavia & Re, 1998). The sheer behaviour of rock discontinuities is influenced by both scale effects due to the discontinuity dimensions and by the precision of the asperity measurements. This work has been aimed to analyse rock joint behaviour by in situ survey on rock discontinuity up to 15 m(2) and by laboratory survey on discontinuities of different dimensions. Analytical model have been set up for the shear strength prevision and calibrated by the comparison with the direct test results.