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

Figure 2

Elementary wedge forming the basis of the SBD approach. The incident ray corresponds to a plane front impinging against an infinite wedge. As the incident front is reflected by the free surface zones illuminated by the incident and reflected rays develop. However, ahead of the illuminated free surface, the absence of incident and reflected rays forms a shadow zone. The boundary resulting in between the illuminated and shadow zone corresponds to a region of discontinuity of the incoming field; however continuity is restored by a cylindrical diffracted wave that penetrates into the shadow zone and generated by the point singularity.