Study on the stabilization mechanism of aeolian sandy soil formation by adding a natural soft rock

Abstract

Abstract The study of the distribution of cementitious materials in soil aggregates is important for understanding the formation of aggregates in soil due to the addition of soft rock rich in clay. Soft rock and sand in the ratios of 1:1(C1), 1:2(C2), 1:5(C3), and 1:0(CK) were collected in a test field, and the wet sieve method was used to separate large water-stable soil aggregates. The microstructures of the aggregates and the amounts of iron–aluminum compounds and clay minerals were measured. The result shows that the addition of soft rock improves the ability to create effective soil formations in sand. The order of the amounts of >0.5 mm sized water-stable aggregates based on the different treatments is C1 > C3 > C2 > CK. In the later stages of improvement, iron–aluminum oxides, clay minerals, and calcareous cements in modified soil were important for the formation of water-stable aggregates. The enhancing effect of minerals gradually increases, among which amorphous alumina and complexed iron oxide promote the formation of large water-stable aggregates in improved sandy soil. It is concluded that the engineering technique of compounding soft rock and sand is a new technology that can promote sand-forming soil and permanently change the properties of aeolian sand soil.