A Superposition Based Diffraction Technique to Study Site Effects in Earthquake Engineering

Figure 5

Partition of the domain to compute the free-field. Regions of existence of different rays are identified. corresponds to the zone illuminated by the main incident front; is the region of existence of reflection over the horizontal free surface; and and correspond to the reflections over the inclined surfaces. Since multiple rays may exist over a given region the total number of rays is described by a number enclosed by circles (bottom part of the figure).