Changing the physical and chemical composition of the soil in the area of man-made impact in urban areas

The research analyzes the application of method of horizontal directional drilling (HDD) for the construction of engineering communication for Kyiv's dense urban development. The main advantages of this modern technology of laying pipes of different diameter in complicated hydrogeological conditions are high accuracy and constant control of the trajectory, the possibility of work regardless of the season and work in a confined space without disturbing the surface structures that already exist. The most common depth of HDD in urban areas is about 2–3 m. As a result of intensive anthropogenic and technological impact in urban soils negative processes are developing that impair their strength characteristics. Soil decompression, violations of water-air and thermal balance, chemical and biological contamination lead to the surface deformations in the field of application of horizontal drilling. The negative aspect is that after filling of soil and repair of surface subsidence, these processes do not stop over time and continue to fracture surface. The aim of the research is to establish the causes of the continuation of active deformation processes of soil environment after the construction of engineering communication using the method of horizontal directional drilling. Most of sewage networks are within the impact zone of roads, so the research was conducted for soil near their proximity, samples were taken at various depths to allow man-made human impact on the deformation properties of soil foundations. For the qualitative and quantitative analysis of substances in soils, roentgen spectral analysis was used. It is a non-destructive method for determining element composition. To determine the oil content we used nuclear magnetic resonance spectroscopy.The study was conducted to determine the salt content of soils and their elemental composition depending on the depth and determination of petroleum products, which may reduce the carrying capacity of the soil and affect their deformation.