Permeability of xanthan gum-improved silty soil and its prediction model.

Using traditional materials to improve the permeability of silty soils can cause irreversible damage to the environment. Therefore, it is necessary to develop environmentally friendly biopolymers, such as xanthan gum (XG), to replace traditional materials to improve resistance to water erosion by reducing the permeability coefficient. In this study, a series of permeability tests and scanning electron microscope (SEM) tests were conducted on xanthan gum-improved silty soil (XGS). The variations in the permeability coefficient of XG-improved silty soil and the effects of initial dry density, XG-soil ratio, and curing age on the permeability were investigated. Test results show that the permeability coefficient of XGS decreased with the increase of initial dry density, XG-soil ratio, and curing age. With increasing the initial dry density, soil particles compressed against each other, decreasing the actual water flow crossing area, which leads to a decrease in the permeability coefficient. With the increase of the XG-soil ratio, the fill-blocking effect of xanthan gum with hydrogel connections becomes more and more obvious, which leads to a reduction in the permeability coefficient. Xanthan gum hydration takes time, and a lot of crystals are produced in XGS as the curing age increases; these crystals fill larger pores, resulting in the permeability coefficient decrease. At last, a model was developed to predict the permeability coefficient of XG-improved silty soil by using the initial dry density, XG-soil ratio, and curing age. The model can be used to rapidly predict the permeability coefficient of the improved silty soil under different conditions. This research can provide a scientific basis for the safe and scientific application of xanthan gum in seepage damage control and prevention projects. [ABSTRACT FROM AUTHOR]