METHOD FOR DYNAMIC RESPONSE OF SUBGRADE SUBJECTED TO HIGH-SPPED MOVING LOAD

This paper presents the experimental validation of a numerical model for the dynamic response of subgrade subjected to high-speed moving loads. The numerical model is of three-dimensional (3D) and created in the platform of ABAQUS, adopting consistent viscous-spring artificial boundaries (VSAB). It fully accounts for the dynamic interaction between the track and soil. By the introduction of viscous-spring boundary elements the computation efficiency can be improved without losing any precision.The track geometry is assumed to be invariant in the longitudinal direction and the track irregularity is considered. The model is validated through several comprehensive experiments that have been performed in the Qin-Shen passenger line. Herein, this paper analyzes the wave propagation behaviors in subgrade structure induced by the high-speed train, including the dynamic stress and the deformation of the subgrade under different speeds and wheel loads, the stress variation along the horizontal and vertical directions, and the stress attenuation with depth. The adoption of this 3D artificial boundary increases computation efficiency. The proposed model is expected to contribute to the study on the dynamic stress of non-ballast track.