Experimental Research on Physical and Mechanical Properties of High-Speed Railway Subgrade Filler

Abstract

In order to reveal the mechanical properties of the subgrade fillers, they are studied by screening test of coarse-grained soils, compaction test and large-scale triaxial test in the track-subgrade model in high-speed rail laboratory of Central South University. The experimental results show that the coarse particle content for filler of the bottom layer is larger than that of the underlying embankment. The optimum water content of the filler of the bottom layer is less than that of the underlying embankment, while the maximum of dry density is similar, All samples have shown strain hardening characteristic, the higher the confining pressure is, the more obvious the strain hardening characteristic is. the volumetric strain of samples changes from shear contraction to shear dilation with the increment of axial strain. The cohesion and internal friction angle for filler of the bottom layer is greater than that of the underlying embankment. The tangent modulus for filler of the bottom layer is larger than that of the underlying embankment, and with the confining pressure increases, the difference also increases.