A 1 2-SPACE RESPONSE TO A FINITE SURFACE GROOVE SOURCE OF AN IMPULSIVE SHEAR DISTURBANCE/

The response of an ideal elastic half-space to an impulsive shear load is obtained by a computational method based on the theory of characte ristics. The impulsive load is distributed unevenly but tangentially o ver the entire boundary of a semicircular infinite canyon embedded in the surface of the half-space. For this configuration, a wave characte ristics formulation is presented where its differential equations are extended to accommodate strong discontinuities that occur in the mater ial motion of the half-space. A step-by-step numerical integration of these extended differential equations is then carried out in a two-dim ensional curvilinear wavegrid formed by the bicharacteristic curves of the wave characteristics formulation. The resultant transient deforma tion of the half-space is shown by plots which give the time history b ehavior of the dependent variables at a specific spatial location. In these plots, the various wave fronts traversing the half-space explici tly reveal themselves.