## 3 Subdivision of the City Territory into Conditionally Homogeneous Geological Zones
Analysis of the scatter plots in Figures 3-6 made it possible to divide soil layers into geological elements, i.e., on taxonomic units of mapping, as well as to assess the behavior of soils on the site under the impact of structures on the geological environment. Based on the assessment of the built-up area of the city, in which six main engineering-geological elements (EGE) were identified and the analysis of the physical and mechanical properties of soils was performed, it can be noted that the created program \"Geoinformation database\" also allows the built-up area to be divided into conditionally homogeneous zones by type of base (Table 2). EGE-1 includes technogenic deposits (\(t_{IV}\)) represented by the topsoil (EGE-1a) and backfill (EGE-1b) layers throughout the construction site. The topsoil mainly consists of sandy clay loam and sandy loam, construction and household waste, which cannot serve as a reliable foundation soil for construction.The thickness varies from 0.2 to 2.0 m. The density of the topsoil and backfill layers fluctuates within 1.87 g/cm\({}^{3}\). Figure 6: Deformation modulus E scatter plot for alluvial and eluvial clay deposits. EGE-2 is represented by alluvial mid-Quaternary modern deposits \(a(Q_{II-IV})\) with a thickness of 0.9 to 10.0 m, consisting of sandy clay loam (EGE-2a) with interlayering loamy sands and sandy loam soils (EGE-2b), clays (EGE-2c) and silty soils (EGE-2d). Over their entire thickness, they have lenses and inter layers of sands of various sizes up to 1-3 cm, sometimes up to 10 cm. EGE-2 is located directly under the EGE-1 and is a part of the stratum of weak water-saturated soils spread over the territory of Nur-Sultan in a medium plastic, highly plastic, and liquid state and can be considered as a highly compressible base. EGE-3 is located at the depth of 2, 5-8, and 0 m and consists of sands of various sizes (EGE-3a), gravelly sands (EGE-3b) and gravel soils (EGE-3c), belonging to alluvial medium-Quaternary sand and gravel formations \(a(Q_{II-IV})\). The thickness of sands of various sizes varies from 0.4 to 6.3 m, gravelly sands from 0.5 to 6.5 m, gravel soils from 1.0 to 9.2 m. According to the field description, all sand and gravel soils are similar in color, some presence of clayey lenses and differ only in the amount of the determining fraction. All these deposits have a horizontal stratification. EGE-4 eluvial formations of the weathering crust \(e(C_{1})\) are presented in the form of sandy clay loams and located beneath the sand and gravel alluvial formations at a depth of 6.0-10.0 m. They are mainly presented in the form of gray, greenish-gray and yellowish-gray and loans, ferruginous, manganese, with the inclusion of coarse material up to 25%, and in some intervals up to 40%. EGE-5 includes gravelly, gruss and rubble soils of eluvial formations of the weathering crust \(e(C_{1})\). EGE-5 is widespread on the site and have been found at a depth of 7.0 to 23.0 m. The thickness of rubble-gravel soils varies from 1.7 to 9.0 m. According to the particle size analysis, grit-crushed gruss and rubble soils are characterized by the content of the defining fraction (particles larger than 2.0 mm) from 81.3% to 98.5% with an average value of 92.3%. The density of the soil is 2.14 g/cm\({}^{3}\). EGE-6 is consists of sedimentary rocks of the Lower Carboniferous (\(C_{1}\)) that are represented mainly by sandstones, which are inter bedded with siltstones and mudstones of the same age throughout their entire thickness. They occur at depths from 11.6 to 26.2 m, the thickness of which varies from 3.8 to 23.0 m. Sandstones and siltstones are gray, dark gray and greenish gray, fractured, along the fractures ferruginous and manganese, weathered. In accordance with the above sequence of constructing a map of the first group, using the \"Geographic Information Database\" program, engineering-geological sections were built, which made it possible to assess the conditions of soil occurrence.