ABSTRACT
The results of the field studies in Chapter 2 and the discussion of impact mechanics in Chapter 4 illustrate how rock fall behavior can be defined by values for the normal and tangential coefficients of restitution (eN and eT) that are applicable to the particular site conditions. The coefficients of restitution quantify velocity changes during impact and help in understanding how conditions at the impact points influence rock fall behavior. Figure 5.1 shows three impacts and two trajectories and clearly illustrates the reduced velocity and height of the second trajectory due to the loss of energy at the first impact, that is, eN < 1. Figure 5.1 shows the typical behavior of a rubber ball; rock falls will always have lower trajectories than these because of the relatively low eN of rock.
