Effect of frost heave on a silt column filled with rubber-asphalt-fiber

Frost damage to railway subgrade restricts the normal operation of railways and roadways in seasonally frozen areas. This paper proposes using stress release holes as a measure to alleviate frost heave force. Using a prediction model based on heat conduction and the seepage of unsaturated soil, a one-dimensional freezing experiment is conducted to calculate the frost heave of a soil column. Results suggest that stress release holes filled with mixed-materials can effectively alleviate frost heave and reduce vertical frost heave deformation from 36.8% to 65.3%. It is recommended that stress release holes be filled with a low stiffness, non-shrinking, cylindrical mixed-material which improves their waterproofing and strength enhancement. Furthermore, the burial depth of the stress release hole filling be kept above the height of supplementary water level, and that the filling's elastic modulus hold a value of 1/4 to 1/2 that of the surrounding soil. •A new mixed-material compound of rubber, asphalt, and fiber is applied as the filling to the Stress Release Holes (SRHs) to decrease frost heaves of silt soils in seasonal frost areas.•The effect of the mixed-material in relieving the frost heave is obviously afffected by the mass ratio of fillings, and becomes more significant with increases to the mass fraction of skeleton material.•The reasonable parameters of mixed-materials to relieve frost heave are proposed, and proves that the burial depth and elastic modulus of mixed-materials has a remarkable influence on frost heave alleviation of silt soil.