Abstract: Using SYC-2 type supersonic wave test instrument and 20 kHz energy transducer, the authors are able to measure the longitudinal wave velocity of frozen silty clay under different temperature and moisture conditions. Experiment results show that the velocity increases as frozen temperature decreasing in general when moisture is kept constant. The velocitytemperature curve has two turning points, which appear at -7℃ and 20℃ , respectively. The former indicates the velocity increasing and the latter is the indication of a faster velocity increasing. Fixing the frozen temperature, the velocity and strength of the frozen clay show a decreasing trend as moisture increasing. 20% moisture is the velocity changing turning point. When the moisture content is larger than 24% , the wave velocity increases gently.

Key words: frozen temperature, moisture content, frozen silty clay, longitudinal wave velocity