Holography—A New Tool for Soil Dynamics

Abstract

Holographic interferometry was used to find dynamic displacement of the surface of a sand half-space model excited by a harmonically vibrating circular footing. The screening effectiveness of wave barriers composed of rows of vertical cylindrical holes was studied using this technique. The general results indicate that: (1) holographic interferometry is a powerful tool for measurement of static as well as dynamic displacement of the surface of sand half-space model; and (2) stroboscopic double exposure, holographic interferometry can be used to get “stopped motion” records of traveling waves. Specific results for barriers indicate that the scaled hole diameter (diameter/wave-length of Rayleigh wave) should be at least 1/6, the net scaled spacing [(c-c spacing - diameter)/wavelength] should be less than 1/4, and the solid-filled hole barriers behave fundamentally differently than fluid-filled or void holes.