Enhanced Cyclic Resistance of Low Plasticity Soil Using Biopolymer

The demand for more eco-friendly and efficient solution for soil stabilisation has become highly imperative in recent years, given the burning issue of climate change and environmental degradation. Although numerous efforts have been carried out to develop new methods adopting naturally occurring materials and processes, there are still very limited their successful applications in practice. Among them, the use of biopolymers has shown great potential. As there is still a significant lack of understanding of how this solution can performance under cyclic loading such as road and railway contexts, this study aims to investigate cyclic behaviour of Xanthan Gum (XG)-treated soil. A low plasticity soil prone to mud pumping was collected from the field and mixed with different XG contents (0.5–2% by mass), followed by a series of cyclic triaxial tests mimicking subgrade work condition. The results show that biopolymer can significantly promote cyclic resistance of soil by substantially reducing the accumulated excess pore pressure and minimising ultimate axial strain (<2.5%). With only 0.5% XG content, the soil can mitigate considerably its localised behaviour induced by heavy cyclic loads, thus alleviating the formation slurry at shallow layers of subgrade foundation.