Long Wavelength Propagation of Elastic Waves Across Frictional and Filled Rock Joints with Different Orientations: Experimental Results

A study on long wavelength propagation of shear and compression waves across jointed rocks is important as this condition exists in field. Wave propagation velocities and damping of waves across a jointed rock mass depend on many factors and orientation of rock joints is one of them. The experimental study on influence of joint orientation during wave propagation is carried out using resonant column apparatus. The jointed Plaster of Paris samples with and without infill material have been used to simulate the jointed rock mass with different orientations. The experiments and analyses are centered on propagation of shear and compression waves in jointed rocks with different orientations. Wave velocities and wave attenuations across frictional and filled rock joints are obtained for different strain levels and confining pressures. The results show that propagation of shear waves is dependent on joint orientation. Shear waves are attenuated more than compression waves and confining pressure decreases this influence of joint orientation. Results show that filled joints can damp the waves more easily than frictional joints. The joints oriented perpendicular to direction of wave propagation are more effective in damping compared to joints oriented parallel to the direction of wave propagation.