Abstract: To study the effects of the initial dry density and the initial water content on the strength and stiffness of the frozen soil during freezing. Under the condition of 10 ℃, the frozen soil samples with different initial dry densities and initial water contents were tested for the acoustic wave, and the changes of P-wave velocity during freezing were observed. The test results show that the freezing process of the clayey silt can be divided into three stages, namely, the slow rising stage, the fast-climbing stage and the stable stage. The acoustic test data show that the freezing can significantly improve the P-wave velocity of samples. With the increase of the initial water content, the peak wave velocity of frozen soil increases gradually, and the rising speed of wave velocity accelerates gradually during freezing. The initial dry density has a significant influence on the change of the wave velocity of the frozen soil. The higher the initial dry density, the higher the density of the sample is; the larger the peak wave velocity during freezing, but the rising speed of the wave velocity is almost the same.

Key words: Frozen Soils, Acoustic Waves, Mechanical Properties