ABSTRACT
Deeply weathered tertiary basalt rocks predominate along the major highways and rural roads along the Great Dividing Range of New SouthWales (Australia). In spite of the main importance for safety for road and highways in such environments, the nature of the associated rockfall hazard in these environments is poorly characterized. In particular, no quantitative values of restitution coefficients are available. The restitution coefficients are a necessary input in most numerical rockfall codes to estimate the energy acquired by a block during its travel. Typical values of restitution coefficients for different natures of impacted surface are available in the literature (Piteau and Clayton, 1976; Pfeiffer and Bowen, 1989,Azzoni and de Freitas, 1995). However, these data are somehow incomplete since other factors such as block shape, mass and velocity – to name a few – tend to affect the values of the restitution coefficients as discussed by Giani (1992) and Labiouse and Heidenreich (2009). Due to inherent technical difficulties, only a limited number of real scale tests are available in the literature, among which are Azzoni and de Freitas (1995), Giani et al. (2004). Many studies on restitution coefficients are conducted in laboratory (Chau et al., 2002, Labiouse and Heidenreich, 2009) or after a natural rock fall event (Paronuzzi, 2009). This paper presents some preliminary results of real scale rock fall tests performed in the upper Hunter Valley of New South Wales, Australia, in order to quantitatively study the rock fall motion. The restitution coefficients and the energy of the blocks have been evaluated. The results highlight the influence of rotational energy and impacting angle on the normal restitution coefficient.
