Rockfall motion characteristics on natural slopes of eastern Australia

Deeply weathered tertiary basalt rocks occur along many major highways and rural roads of New South Wales (Australia) and the nature of the associated rockfall hazard is poorly characterized. In order to quantify the restitution coefficient in this specific geological situation, real scale rock fall tests were performed on a natural slope derived from basalt rock. The slope, with an average inclination of around 22 degrees, was covered by scattered rock and vegetal debris of variable size. During the tests, the motions of 21 blocks were recorded to estimate the pre- and post-impact velocities with the objective to quantify the normal and tangential restitution coefficients k(n) and k(t). This paper presents the preliminary results of these series of tests. They include the restitution coefficients determined for 10 blocks and a study of rotational and translational energy for 4 blocks.