Abstract:In order to explore the pressure bleeding effect and boundary layer effect of paste filling slurry in the process of pipeline transportation, the side limit compression test and pressure bleeding test were carried out on the paste mixture filled with tailings from a mine. The results show that: The initial void ratio, volume concentration, pressure and pressure acting time of the paste mixture filled with waste rock tailings have a great influence on the pressure bleeding rate. According to the deformation law of e-p curve of filling material, the calculation model of pressure bleeding rate of filling paste slurry is put forward. The material parameter A and stress parameter n that affect the pressure bleeding effect of filling paste mixture are defined. The gradation factor is introduced into the calculation model of pressure bleeding rate, and the evolution rule of stress parameters with stress and initial voidage is analyzed. It is considered that the stress parameter is a polynomial function of compressive stress and initial void fraction. The higher the degree of function, the higher the precision. It is considered that the thickness of the boundary layer is not invariable, and the estimation method of the boundary layer based on the effect of pressure bleeding is established.