Abstract: The experimental study on the relationship between P-wave velocity and physical parameters of calcareous sand has important theoretical guiding significance and engineering application value for non-destructive testing of calcareous soil foundation and geophysical exploration. By controlling the state of the tested specimens under different conditions, the P-wave velocity was measured to investigate the relationship between the P-wave velocity and physical parameters. Experimental results show that the water content is the main factor that affects the variation of compression wave velocity in a certain density range, and there is a quadratic curve relation between P-wave velocity and water content. Generally, the results of CT scanning show that the larger the particle size, the more abundant inner pores in the particles, which leads to the larger the void ratio and the smaller the P-wave velocity. The P-wave velocity has a negative correlation with particle size and pore ratio. When the density is fixed and uniformity coefficient is different, the compression wave velocity is basically the same in well-graded sand. After compression, a good quadratic relationship is established between P-wave velocity and void ratio under the constant water content. The P-wave velocity is linearly related with soil density. Therefore, the results can be applied to the nondestructive detection of calcareous soil foundation compactness.

Key words: calcareous sand, compression wave velocity, physical and mechanical properties, confined compression