Abstract

Info

Title:: Research on Numerical Simulation About Dynamic Response of Silty Clay Subgrade Under Impact and Grind

Author(s):: SONG Xiu-guang; CHEN Xiao-guang; YU Yi-fan; School of Civil Engineering, Shandong University

Keywords:: foundation engineering; dynamic stress; numerical simulation; subgrade; impact roller compaction; vertical displacement

Abstract:: Relying on the actual project, a subgrade model of silty clay in highway was built by using the numerical calculation software FLAC 3D. Numerical simulation analysis about dynamic response of subgrade model was carried through applying one time dynamic load and different times dynamic load on the top of the subgrade model, and the change laws of dynamic stress and vertical displacement along depth direction and radial direction were researched. The results show that the soil structure is damaged by impact roller impacting subgrade surface, so that the subgrade soil is compacted, impact compaction has obvious reinforcement effect on subgrade. The reinforcement area in soil is like ellipsoid, and its profile is like ellipse. The attenuation velocities of dynamic stress and vertical displacement along radial direction are faster than those along vertical direction, and the radial influence width was greater than the vertical influence depth. When impact roller keeps the normal working speed 12 km·h^-1 and subgrade filling height is 1 m, the time of impact roller compaction should be about 20.