Resonant Column Apparatus Tests on Intact and Jointed Rock Specimens with Numerical Modelling Validation

Abstract

The determination of rock mass dynamic parameters including the influence of joints/discontinuities on wave propagation is of interest for solving problems in geophysics, rock protective engineering, rock dynamics and earthquake engineering. This topic is covered in this paper by means of laboratory tests on intact and jointed rock specimens performed with the resonant column apparatus (RCA). Attention is dedicated to the determination, with this equipment, generally used for testing soils, of the shear modulus at small strain and the damping ratio of intact and jointed rock specimens. A correction procedure based on the RCA tests performed on aluminium specimens is described. The results of the tests performed are analysed in detail. Three-dimensional distinct element method modelling is used to evaluate the applicability of the RCA and the correctness of the laboratory tests performed. A comparison with the results obtained using the scattering matrix method is also presented.