Shakedown Behavior of Yellow River Alluvial Silt Stabilized with Lignin–Lime Combined Additive

Abstract

The utilization of Yellow River alluvial silt as the main filler for railway embankments can lead to a series of embankment problems. Therefore, the silt must be improved before it can be used. In this paper, a series of cyclic triaxial tests were performed to find an optimum percentage of composition of lignin–lime combined additive. According to the shakedown concept, permanent deformation of silt samples stabilized by different proportions of additives was classified and evaluated. The recommended proportions from unconfined compressive strength tests were verified, and the optimal proportion of additive was obtained. In addition, under different confining pressures and relative compactions, shakedown behavior of stabilized silt samples with optimal additive proportion was investigated. The experimental results revealed that the plastic shakedown limit and plastic creep limit of silt samples with 6% lignin and 3% lime were 4 and 8 times those of untreated silt samples, respectively. With the increase of confining pressure and relative compaction, the permanent deformation of the stabilized silt was reduced, and its shakedown limits were enhanced.