Experimental Study on Erosion Wear Resistance of Loess Slope Surfaces Solidified by Enzyme-Induced Carbonate Precipitation

To enhance the erosion resistance of loess slopes, urease-induced calcium carbonate precipitation (EICP) technology was introduced to strengthen the loess slope in this study. Through permeability, disintegration, slope model erosion, and microscopic tests, the water stability and erosion resistance of EICP-treated loess under different treatment conditions were systematically studied, and its treatment mechanism was discussed. The results indicate that the permeability and anti-disintegration characteristics of loess can be significantly improved after two rounds of EICP treatment when the soybean urease concentration is 80 g/L, the cementation solution concentration is 1.0 mol/L, and the mixture ratio is 1∶1. Under simulated extreme rainfall conditions, no splash erosion pits or gullies developed on the solidified slope. The runoff rate remained stable, sediment concentration in the runoff was negligible, and the water content of the slope increased significantly less than that of an unsolidified slope. Additionally, the difference in elevation between the two types of slopes after erosion follows the normal distribution approximately. Microscopic analysis shows that the cementation solution concentration dominates the effect of EICP treatment by regulating the size and spatial continuity of calcium carbonate crystals. This technology forms a dense three-dimensional network structure within the loess, which effectively divides the pore structure of soils. Therefore, EICP technology has good engineering application potential in improving the impermeability and erosion resistance of loess slopes.