## 5 Discussion  
Analysis of a similar interposition of the EGE with a related geological origin made it possible to recreate a 3D model of soils of the foundations of the city of Nur-Sultan. Firstly, it was possible to regroup the territory of the city into eight zones instead of the previous five [23]. Moreover, although the physical-mechanical and engineering-geological properties in the EGE varied within certain limits, this somehow helped to generalize soil stratification and make an overall assessment of the bearing capacity. From the analysis of the scatter plot graphs of physical characteristics, it follows that the scattering ranges, as well as the limiting values of indicators of various soil properties, reflect their dependence not only on the conditions of formation, but also on genetic characteristics. This is most evident when comparing the limiting values of indicators of physical properties and, in particular, such as liquid limit (Figure 3a), the maximum values of which for alluvial deposits almost coincide with the minimum values for eluvial loans and clays. In terms of mechanical properties, such accurate distribution of the data is somewhat confirmed for compressibility values (Figure 6). From the data considered above, the most likely outcome is the probable and significant scattering of soil properties indicators, which leads to the need to take this into account when solving issues related to the assessment of engineering-geological conditions for the construction of various buildings and structures. An objective analysis of these issues can be implemented only if the scattering, with its discernible chaos, will be distributed according to certain regularity. So, the increased liquid and plastic limits replicates to higher values of deformation modulus E, and hence better strength characteristics of a particular soil layer and vice versa. The values of indicators of any soil property in these cases represent a statistical set obtained in the study of a certain number of samples. When considering the indicators of a series of the same type, a statistical population is formed that corresponds to an empirical or experimental distribution, representing the distribution of indicators in certain groups identified during research. Establishing patterns of empirical distribution was necessary to obtain a general assessment of the indicator of the studied soil layer or part of it. Such variation in the tested physical characteristics of alluvial soils like in Figure 3a-d indicates frequent layering of soil varieties both horizontally and in depth. Figure 8: Zoning map for optimization of pile lengths (**a**) and representative borehole profiles (**b**) for each city zone. However, these distributions, in particular those concerning engineering characteristics, often did not obey any obvious pattern and required additional verification on the construction site. Secondly, the main distinguishing feature of this work from the previous studies [10; 11; 24; 25; 29; 31] is the creation of a geotechnical map that was built for the driven piles. According to the geological structure of the foundations, the optimal variations in the pile length for each city zone were determined. As can be seen from Figure 7, the optimal pile length varies from 6 to 8 m in the most stable soils of the city to 12 m near the coast of the Ishim River, in occasionally reaching 16 m of the length necessary to ensure the bearing capacity of the pile-soil system in an area with a large thickness of alluvial soils. In the right coast of the city (upper zone in Figure 7), stronger soils or a shallow location of eluvial soils are noted near the railway line in the area of the old city. The increased depth of piles of 16 m and more in the lower left part of Figure 7 is justified by swampy areas and a high level of groundwater of zone 8 in Figure 6, a high content of subspecies of alluvial soils, which have low rates compared to deeply buried eluvium soils.