# Evaluation of the Strength Characteristics of Sility-Clayey Soils during Freezing-Thawing Cycles  
[PERSON]  
1 Department of Civil Engineering, L.N. Gumilyov Eurasian National University,  
Nur-Sultan 010008, Kazakhstan; [EMAIL_ADDRESS] (A.Z.); [EMAIL_ADDRESS] (A.S)  
[PERSON]  
2 Department of Construction Operations, Industrial University of Tyumen, 62500 Tyumen, Russia; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Civil Engineering, L.N. Gumilyov Eurasian National University,  
Nur-Sultan 010008, Kazakhstan; [EMAIL_ADDRESS] (A.Z.); [EMAIL_ADDRESS] (A.S)  
[PERSON]  
5 Department of Construction Operations, Industrial University of Tyumen, 62500 Tyumen, Russia; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Civil Engineering, L.N. Gumilyov Eurasian National University,  
Nur-Sultan 010008, Kazakhstan; [EMAIL_ADDRESS] (A.Z.); [EMAIL_ADDRESS] (A.S)  
[PERSON]  
6 Department of Architecture and Design, S.Seifullin Kazakh Agro Technical University,  
Nur-Sultan 010011, Kazakhstan; tumor230@mail.  
A significant part of the conducted experiment deals with road construction in areas with seasonally frozen soils, as well as problems associated with freezing-thawing of the roadway and its subgrade, such as settlement, frost heaving, and slope sliding ([PERSON] et al., 2009; [PERSON] et al., 2016; [PERSON] et al., 2016)[14; 15; 16].  
Destructuring settlement and heave settlement during the exploitation of buildings and structures are not taken into account in most construction design standards, although they are indirectly related to the strength characteristics of the soil. According to [17], the vertical deformation of foundations on a natural base is determined as the sum of four components Equation (A1) (Appendix A): calculated settlement, elastic settlement, destructuring settlement, and heave settlement.  
Destructuring settlement \(S_{destr}\) and heave settlement \(S_{heave}\) are not taken into account by domestic standards [18] and are indirectly related to the strength characteristics of soil. The change to these characteristics caused by freezing-thawing is studied in this paper.  
Many geotechnical scientists have paid great attention to studying the changes caused by freezing in the cohesion and the angle of internal friction of the soil as these are the main strength characteristics. It is generally accepted that with an increase in the number of freezing-thawing cycles, cohesion decreases, but the stabilized value of cohesion after several freezing-thawing cycles remains controversial [19; 20; 21; 22; 23; 24]. However, some results show that cohesion increases or defies the obvious law when exposed to freezing-thawing [25]. Studies of changes in the angle of internal friction of soil are rather contradictory: according to some studies [1; 21; 22; 25], the angle of internal friction increases; according to other studies [19], it decreases or remains constant [24; 26; 27]. Some studies note the inconsistent nature of the change in the angle of internal friction during freezing-thawing [20; 23; 28]. One way or another, the obtained scientific results are difficult to apply in engineering practice unambiguously. In 2018, [PERSON] et al. were the first to propose a mathematical equation using correction factors for calculating the shear strength of soil during freezing-thawing, which had never been considered before [21]. However, the dependence is only for clays with a moisture content of 18.5%.  
The purpose of this research is to analyze and to study the mathematical dependence of changes in the strength characteristics of clayey soils with different void ratios and initial moisture content due to freezing-thawing cycles.