ESTIMATING JOINT ROUGHNESS COEFFICIENTS

Eight parameters that have used used to characterize numerically the roughness of surfaces have been measured on the ten profiles presented by Barton and Choubey [1] as typifying different joint roughness coefficients. Values of two of these parameters, Z2 and SF, respectively, the root mean square and the mean square of the first derivative of the profile, are strongly correlated with values of the joint roughness coefficient. The equations JRC=32.2 + 32.47 log Z2JRC=37.28 + 16.58 log SF avoid the subjectivity of estimates of JRC by comparison with typical profiles. They will be useful checks on values of JRC estimated from profiles of rough surfaces. © 1979.