Shear Waves in Plane Infinite Structures

A numerical procedure is developed for the dynamic analysis of plane, linearly elastic systems consisting of an irregular zone joined to semi-infinite layered zones. All exciting forces are assumed to be harmonic and perpendicular to the plane of the structure. This implies that only shear waves (SH-waves) are generated and that no displacements occur in the plane of the structure. The method employs a finite element analysis of the irregular zone of the structure. The effect of the semi-infinite layered zones is accounted for by boundary conditions developed from a new discrete theory for standing and propagating Love waves in layered systems. The method is used to evaluate the screening effect of a trench and the accuracy of a currently used method to predict the motion of a foundation subject to ground induced vibrations.