Ultrasonic velocities of the dilatational and shear waves in frozen soils

Abstract

Ultrasonic velocities of the dilatational and shear waves in water‐saturated frozen soils were measured as a function of temperature by both pulse first arrival and critical angle methods. A strong correlation exists between the dilatational wave velocities and the unfrozen water content. The observed hysteresis in the velocities of silt and clay during a freeze‐thaw cycle is considered to be caused by hysteresis in the frozen water content. A general tendency for the shear wave velocity to decrease with ascending temperature exists, but the effect of temperature is not as pronounced as on the dilatational velocity. Calculations based on measured dilatational and shear velocities showed that the Poisson's ratios of sand are almost constant. However, the ratios of silt and clay decrease monotonically with ascending temperature.