A Cross-Linked Polymer Soil Stabilizer for Hillslope Conservation on the Loess Plateau

Abstract

The soil of the Loess Plateau is highly susceptible to erosion due to its distinct loess structure with poor water stability and disintegrates easily. Previous research has focused on improving soil strength without considering stability and ecological performance. Comprehensive improvements may be achieved by cross-linked polymers (CLPs), but their effect on loess structure remains unclear. In the present study, we investigate CLPs as a new organic soil stabilizer to improve soil aggregate stability. To determine the effect of CLPs on the stabilization of loess, a series of indoor tests was conducted to assess unconfined compressive strength, water stability, soil-water characteristics, and plant height. The stabilization mechanism was analyzed by comparing the microstructure, mineral composition, and features of functional groups of loess before and after treatment. The results showed that, compared with untreated loess, the unconfined compressive strength and anti-disintegration property of treated loess were significantly increased. The water retention capacity was improved, and the germination rate and growth of plants were promoted. Microscopic analysis showed that the use of CLPs did form new minerals in the loess or change the functional groups, rather, CLPs improved the microstructure, reduced the total volume of pores, and increased the degree of soil compaction. Field tests showed that the erosion of loess hillsides was effectively controlled by CLPs. Under the same erosive conditions, the slope surface treated with CLPs was more intact than the untreated slope surface. Our findings provide new strategies regarding the application of CLPs as soil stabilizers to control loess erosion and promote vegetation restoration.

Splitting tensile strength and microstructure of xanthan gum-treated loess

“…Pu et al 34 showed that polymers could reinforce loess strength. Zhang et al 35 indicated that polymers could improve the anti-disintegration property and water retention capacity of loess. In addition, XG could increase the fatigue life of soil 36 and reduce the rheological properties, permeability, and dispersion of soil 37 – 41 .…”

Effect of the Particle Size Composition and Dry Density on the Water Retention Characteristics of Remolded Loess

“…The soil-water characteristic curve can reflect different soils' water holding and releasing characteristics. It can be used to simulate the unsaturated permeability law [1][2][3][4][5][6][7], the shear strength of soil [8][9][10], the water migration in soil, the influence of water content change in soil on the mechanical properties, and the composition model of soil [11][12][13][14][15][16][17].…”

Mechanical Properties and Microstructure Characteristics of the Loess Modified by the Consolid System

“…In the loess slope treatment with the traditional soil stabilizer, if the rainfall is too concentrated or continuous, the slope surface is easy to be washed away, resulting in a poor slope protection effect, as shown in Figure 1. In addition, for some traditional slope protection materials, the amount added to the slope protection is about 2%-10% [20][21][22], while the Consolid soil stabilizer can achieve the purpose of elimination of loess collapsibility, water erosion prevention, and slope protection when the amount is relatively small, which is beneficial to environmental protection. According to the characteristics of the fragile ecological environment, serious water and soil loss, and prone to geological disasters in this area, it is proposed to apply the Consolid stabilizer to ecological slope protection.…”