In recent years, construction has increased at previously uninhabited high altitudes with the development of winter tourism and population growth. Therefore, it is necessary to examine the soil behaviour at low temperatures and high altitudes. This study investigated the physical properties and mechanical behaviours of soil samples collected from four mountainous regions, including settlement areas. In addition, new frost- heaving pressure and strength prediction charts have been developed. Based on sieve analysis, the soil samples from the Ka & ccedil;kar, Paland & ouml;ken, Erciyes, and Ilgaz Mountain areas were classified as silty gravel or sand. With increasing elevation, the percentage of coarse particles in soil samples increased, whereas the proportion of fine particles decreased. A new device was developed to investigate the mechanical behaviour of soil samples at low temperatures (0 degrees C and below). The highest frost strength (7274.5 kPa) and heaving pressure (43.97 kPa) were measured in soils with high fine-grain content. A statistical evaluation of the test results was performed, and it was determined that the most influential variables for estimating frost heaving and strength were the fine-grain ratio, soil temperature, and water content. ANN analyses were performed using these variables, and ternary strength and frost-heaving pressure estimation diagrams were developed.

Differential frost heaving can damage buried pipelines, with catastrophic outcomes. It is necessary to consider the interactions between the pipeline and soil as well as the stress characteristics of frost heaving. In this study, a mechanical behavior model of buried pipe suffering from frost-heaving force based on the Winkler elastic foundation beam theory is proposed. The concept of a frost heaving spring is proposed to replace the foundation spring of Winkler's theory. The frost heaving spring is a pre-compression spring that is dependent on the relationship between the frost-heaving force and frost heaving amount, the frost heaving state is similar to precompressed spring resilience. Since the pipeline is continuous, soil in the non-frost-heaving area is squeezed by the pipeline and generates a corresponding elastic response. Modeling mechanical behavior of buried pipe suffering from frost-heaving force based on a linear frost heaving spring assumption provided analytical solutions under two conditions. Results show that the modeled pipeline deformation and stress values conformed well to measured data of Huang Long and Caen test. The proposed model is mathematically simple and easy to apply to studies of mechanical behavior of buried pipe suffering from frost-heaving force.

The stabilization and application of expansive geomaterials are critical in geotechnical engineering. These naturally expansive materials exhibit complex hydro-chemo-mechanical properties because they undergo volumetric changes in response to variations in moisture content and/or temperature. The characteristic shrink-swell behavior of these materials makes their use problematic and plays a substantial role in influencing the stability of geo-infrastructure applications. However, there is a lack of comprehensive knowledge of the mechanisms and factors impacting their behavior to ensure mechanical integrity in natural and built infrastructure and geo-engineering projects. This work provides a comprehensive review of the intrinsic and extrinsic factors contributing to the shrink-swell behavior and expansion mechanisms of frost-heaving and natural-expansive geomaterials, such as expansive clays and sulfate minerals. We reviewed and synthesized peer-reviewed published works in various databases and academic repositories in the last 100 years. The influence of shrink-swell behavior of these geomaterials and the critical role they play in engineering infrastructure were highlighted, explicitly focusing on their involvement in geotechnical-related hazards, such as the freeze-thaw cycle, and the damage and sulfate-attack of geo-infrastructure. We analyzed the interactions between clay minerals, especially how bentonite enhances grout stability and acts as a buffer material in high-level nuclear waste repositories. The findings indicate that water interaction with geomaterials and concrete can cause about a 10% volume expansion when frozen. Also, the exposure of fractured rocks to low (0 degrees C) temperatures can greatly change rock deformation and strength. Finally, gypsum interacting with water can theoretically increase in volume by 62% to form ice crystals. This forward-leading review presents the advantages, disadvantages, and unresolved issues of expansive natural geotechnical materials that improve the resiliency and sustainability of geological infrastructure.