The article is devoted to the study of the physical and mechanical characteristics of alluvial sandy soils in the process of strengthening, in order to improve the efficiency of development of floodplain-alluvial territories for construction after the completion of the alluvial process. The studies were conducted in the territory of the Khabarovsk region, where the thickness of the alluvial layers was 2.5–5.5 meters. The study made it possible to substantiate the optimal timing for the start of construction on alluvial territories and to develop a method for assessing the mechanical properties of the soil, increasing the reliability of construction solutions.

Keywords: alluvial soil, stage of diagenesis, alluvial map, penetrometer, granulometric composition, pit, sounding borehole, conditional dynamic resistance of soil

The article discusses the use of liquid chlorides of natural genesis to combat winter slipperiness. The aggressive effect of liquid chlorides on snow removal equipment, road structural elements and the environment as a whole is also studied. Methods for assessing the effect of liquid chlorides on metal and cement concrete are developed. The article presents conclusions and recommendations on the use of liquid natural chlorides to combat winter slipperiness on roads.

Keywords: liquid chloride, formation water, brine, corrosion rate, cement concrete pavement, winter slipperiness

The article examines the application of the method of mathematical planning of an optimal experiment in determining the strength characteristics of reinforced soils. For the analysis, a multicomponent soil system was studied, consisting of unsalted and saline soils reinforced with bitumen with cement additives and surfactants. During the planning of the experiment, factors affecting the strength characteristics and their levels, as well as the intervals of variation of factors, were determined. As a result of solving the problem, mathematical models of adhesion and angle of internal friction of reinforced soils were obtained. Based on the obtained regression equations, the main conclusions were drawn.

Keywords: stabilized soils, complex soil strengthening, experiment planning, complete factor experiment, mathematical model, regression equation

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