Stima della conducibilità idraulica in ammassi rocciosi.

ABSTRACT This paper presents some experimental results from estimates of hydraulic conductivity in rock formations using empirical and semi empirical methods in the literature. Given that direct measurement of hydraulic conductivity in frac- tured rock formations is impossible at the surface and complicated and costly at depth, the study of some rock masses in Valtellina has provided us with the opportunity to apply empirical methods in investigating the hydraulic conductivity of rock fonnations. The study has show that the simplest empirical methods for calculating permeability which estimate permeability exclusively on the basis of depth, cannot be considered satisfactory in that they do not account for eventuallateral variations in permeability asso- ciated with changes in the geomechanical or fracture characteris- tics of the rock formation. The Interlayer Model provided permeability estimates in the case in question relatively close to the results of direct field meas- urements. The error was reduced by inserting into the equation a factor accounting for variation of spacing with depth.