Thermal stabilization of the base from thawed permafrost viscoelastic soils

Under the influence of climatic conditions, highly compressible thawed soil layers appear in the foundation of a construction object. Therefore, the study of the deformed state of such a foundation is relevant, since the creep properties of thawed soil can lead to additional foundation settlements. To prevent the process of soil creep, thermal stabilization of the foundation is considered. The object of research is heaving freezing dispersed soils. The work aims to analyze the nature of freezing of the soil base when using thermal stabilization systems and to study soil deformations under gradual loading of foundations. Presents studies of the freezing soil massif, its temperature regime and settlement of pile foundations during thermal stabilization of the soil base. Method. Based on the results of experimental, the dependences of soil deformation in the process of ice-soil mass formation are established. An increase in the bearing capacity of the pile during soil freezing from 225 kN to 540 kN was revealed, as well as a gradual decrease in the intensity of the increase in foundation precipitation with its stabilization at around 33 mm. Results. Based on the results of field observations and numerical modeling of the soil temperature regime, the nature of soil base freezing was revealed in the form of the formation of individual ice-soil massifs with the presence of thawed soil between them in the first and second years of thermal stabilization and the gradual freezing of thawed zones until the formation of a solid frozen massif. According to the results of the experiment, in the initial period of construction, the foundation settlement of up to 5 mm in the first winter period was caused by frost heaving. With further loading of the base and a decrease in temperature due to thermal stabilizers, the foundation settlement increased to 32 mm according to a linear law. The formation of a solid frozen massif under the entire structure occurred at the end of the third winter period of thermal stabilization.