Seasonal freezing of highway sub soils and systematic maintenance by de-icing chemicals steadily affect their thermal regime and moisture distribution. As the result, it leads to significant change of sub soils from the designed engineering characteristics including their bearing capacity. In order to better understand the process and to evaluate the correlation between temperature field and frost heave, and also to simultaneously supply with de-icing chemicals, the modified laboratory method was developed in this research. The current test method is upgraded by increasing height of soil samples up to 1 meter. More soil columns being able to be tested simultaneously in the modified test, proposed in this study, allows better control of each stage of testing. The modified freezing regime in this new test method is closer to the scenario in cold regions in terms of temperature. The obtained results of this research are going to be presented for the first time in scientific literature.

The maturity method is deservedly considered one of the reliable indirect methods for determining the strength at the early stages of concrete curing. The main parameter in the calculation is the internal temperature of concrete that accumulates during the chemical reaction of concrete curing, while external factors such as ambient temperature and relative humidity are fallaciously omitted. In this work, the complex maturity method was developed based on ASTM C1074, accounting for the influence of ambient temperature and relative humidity and coefficients indicating their influence weight. The laboratory testing to measure the concrete strength by compression method and non-destructive sclerometer method were performed on concrete samples according to ASTM C109, GOST 22690, and GOST 10180. According to the calibration dependence of the existing and proposed methods results in comparison with the strength of cubic samples, the highest coefficient of determination R² = 0.976 was revealed for the complex method of maturity, which indicates its reliability in contrast with sclerometer and traditional maturity methods. The determination of complex maturity allows for an evaluation of the current state of concrete strength, but also reduces the waiting time for concrete curing and increases the economic effect during construction.

Development of a geotechnical database for the young capital of Kazakhstan, Nur-Sultan city, became a paramount concern of both the scientific community and industry. The creation of the Kazakhstan model of the geotechnical database was based on a fixed dataset which included a city map with determined X, Y, and H coordinates and the user generated data obtained from the materials of engineering and geological surveys from more than 2000 boreholes. Based on the assessment of the built-up area of the city, six main engineering-geological elements (EGE) were identified. The territory of the city was regrouped into eight zones instead of the previous six based on the geological origin and stratigraphy interposition of the EGE. Engineering properties of the soils were considered for physical and mechanical characteristics, where the plasticity limits demonstrated an accurate correlation to the elasticity modulus E and distribution boundaries between the alluvial and eluvial types of the soil on the graph. So, the increased liquid and plastic limits are replicated by higher values of elasticity modulus E, and hence better strength characteristics of a particular soil layer and vice versa, while the moisture content and soil density did not show any obvious pattern and requires additional verification on the construction site. Finally, a geotechnical map was built for the driven piles and the optimal variations in the pile length for each zone were determined.

In this paper, joint precast piles with a cross-section of 400 × 400 mm and a pin-joined connection were considered, and their interaction with the soil of Western Kazakhstan has been analyzed. The following methods were used: assessment of the bearing capacity using the static compression load test (SCLT by ASTM) method, interpretation of the field test data, and the dynamic loading test (DLT) method for driving precast concrete joint piles, including Pile Driving Analyzer (PDA by ASTM) and Control and Provisioning of Wireless Access Points (CAPWAP) methods. According to the results, the composite piles tested by the PDA (by ASTM) method differ by 15 percent compared to the static load method, while the difference between the dynamic DLT (by ASTM) method and the static load (by ASTM) method was only 7 percent. So, according to the results, the alternative dynamic method DLT (by ASTM) is very effective and more accurate compared to other existing methods.

Destructuring settlements due to frost heave during the structures’ exploitation are often not taken into account at the designing stage, although they are indirectly related to the bearing capacity of the soils. The objective of this research was analyzing the effect of the number of freezing-thawing cycles on the strength characteristics of soils. A paired experiment with various initial parameters (void ratio, initial moisture content, and the number of freezing-thawing cycles) was carried out. According to the experimental results, the cohesion largely depends on the above parameters which might lead to its decrease by up to three times. The angle of internal friction demonstrated an indefinite behavior during the freeze-thaw cycles, which is confirmed by a literature review. Freezing–thawing cycles significantly decrease the soil bearing capacity: up to 44% after 10 freezing-thawing cycles for soil with $e=0.55$ and $w=16.5\%$. However, in the case of $e=0.75$ and $w=22.6\%,$ it increased by 33%. A program based on the least-squares method was used to calculate the approximation coefficients of the dependence describing the changes in strength characteristics from the abovementioned parameters. Changes in strength characteristics must be taken into account when designing structures, as they can lead to additional settlement or even subsidence of the foundations.