SEISMIC VELOCITIES OF UNSATURATED SOILS

摘要

The speed of seismic wave propagation in a medium can be related to the properties of the medium. Common seismic waves used are body waves (compression and shear waves) and surface wave (Rayleigh wave). Recently there has been an increased use of seismic waves in the laboratory for measuring small-strain elastic properties of soil, notably shear modulus. This paper investigates the effect of degree of saturation on the compression and shear wave velocities of unsaturated soils. Relationship between seismic wave velocities and soil parameters are also presented. Ultrasonic test for velocity measurement has been used in the laboratory for three types of compacted soil samples made from mixtures of kaolin and sand with different degrees of saturation. It was found from the experiments that the P-wave velocity depends more on the water content but the S-wave velocity depends more on the soil structure.