Accession Number : AD0286075

Title :   STUDY OF THE PROPAGATION AND DISSIPATION OF 'ELASTIC' WAVE ENERGY IN GRANULAR SOILS

Corporate Author : FLORIDA UNIV GAINESVILLE ENGINEERING AND INDUSTRIAL EXPERIMENT STATION

Personal Author(s) : RICHART,F.E. JR. ; HALL,J.R. JR. ; LYSMER,J.

Report Date : SEP 1962

Pagination or Media Count : 1

Abstract : Laboratory tests were conducted on selected granular materials to determine the velocities of propagation of the shear and compression waves and to evaluate the internal damping. Test variables included the confining pressure, amplitude of vibration, void ratio of the material, saturation, and grain size. Resonant column tests were used for wave velocity evaluation, and the vibration decay method and static torsion tests were used to determine damping. The granular materials used were Ottawa standard sand, two sizes of glass spheres, and a crushed quartz. Confining pressure had the most significant effect on velocities of wave propagation, with velocities increasing about with the 1/4 power of the confining pressure. Damping determined from the decay o steady state vibrations behaved like viscous damping. The values of logarithmic decrement varied from about 0.02 to 0.20 for these materials and test conditions. Higher values of logarithmic decrement were found in the static torsion tests because tresses up to 75 per cent of the failure conditions were used. (Author)

Descriptors :   *PROPAGATION, *SAND, *SOILS, *WAVE PROPAGATION, DAMPING, ELASTIC PROPERTIES, OSCILLATION

Distribution Statement : APPROVED FOR PUBLIC RELEASE