Experimental study on resistance of EICP and lignin joint-modified silt slope to rain erosion

By setting up six groups of specimens and using the rainfall test, the resistance of modified silt slopes to rain erosion was analyzed through the changes in the surface erosion condition of specimens with respect to the amount of erosion, surface strength and calcium carbonate content. The results show that after spraying the enzyme induced carbonate precipitation (EICP) solution on the surface for EICP and lignin joint-modified samples, the surface integrity is better, the strength and calcium carbonate content are higher, the quality loss is smaller, and the resistance to rain erosion is improved obviously. As results, the erosion amount of the slope soil is reduced by 75.0% on average compared with other specimens, the surface strength is increased by 33.8% on average, and the calcium carbonate content is increased by 235.2% on average. The slope surface sprayed with EICP solution can form a hard shell layer that effectively avoids the erosion of the slope surface, while lignin can provide nucleation sites for the calcium carbonate. Therefore, the distribution of scattered calcium carbonate attaches to lignin, so that the addition of lignin improves the calcium carbonate content and the surface strength also increases with the increase of calcium carbonate content.