The article examines the application of properties of polyethyleneimine (PEI) and polyacrylic acid (PAK) polycomplex composition for soil strengthening. During the studies, the ratio of PEI and PAA (by dry weight) was established, at which the reagents most fully enter the complexation reaction. The polycomplex composition of the optimal composition was used to strengthen the soils of some varieties. When studying the properties of hardened soils, dependencies were obtained: the ultimate strength of the hardened soil on the relative humidity and the thickness of the layer of hardened soil on the consumption of complexing reagents. The paper concluded that the use of polycomplexes for soil strengthening is promising.

Keywords: polycomplex composition, soil strengthening, polyethyleneimine, polyacrylic acid, impregnation method, dedusting, optimal humidity

This article presents the results of a study of the process of decompaction of clay soils when they are used in soil structures. To study this issue, the following factors were chosen: the dimensions of the test samples, the amount of load on the samples, swelling when soils are moistened and shrinkage when they are dried, and the loss of strength of the samples during their decompaction was also estimated. All studies with soils were carried out in laboratory conditions. In the course of the research, dependences of relative decompaction on vertical load and changes in shear forces depending on the degree of moisture during decompaction of soils were obtained. The main conclusions of the work are given.

Keywords: clayey soil, decompaction of soils, mineralogical composition, optimal soil moisture content, density of the soil skeleton