Subgrade-filled material properties of fully weathered gravelly sandstone for railway passenger dedicated line

Fully weathered gravelly sandstone was taken as subgrade-filled material for railway passenger dedicated line, the mineral constituents of the material was analyzed by using X-diffraction, the expansion coefficient and cation exchange ratio were tested, the grain size distributions under loop compacting and field compacting were contrasted, disintegration cyclic tests under wetting and drying cycle were studied, and coarse granule compression test and relaxation behavior in site were analyzed. Analysis result indicates that the material does not contain hydrophilic mineral composition, its free-swelling index is 23.6%, its cation exchange rate is 70.7 mmol·kg^-1, its disintegration rate is 0.81%, its fine particle content is 13.5% under dynamical force, its detection indexes are stable after rain, its secondary consolidation coefficient is 5.8×10^-4 under load. The experimental data show that the material has good water suitability, dynamical stability and low compressibility, and is a kind of better subgrade-filled material for railway passenger dedicated line.