PSI - Issue 72

G. Gusev et al. / Procedia Structural Integrity 72 (2025) 458–463

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are located, affect safety and cause the development of defects in structures. The influence of seasonal changes in the resonant properties of surface soils on seismic safety of structures is reflected, for example, in the works by Kolesnikov et al. (2021). Most building structures in permafrost-affected environments are built on pile foundations, which are also affected by seasonal freezing-thawing soils as shown in Guan et al. (2022). The piles are buried in the frozen soil and are in essence stand-off piles. The performance characteristics of piles in frozen soils can be found in the works by Chen et al. (2012), Xiao et al. (2018), Yang et al. (2023). The study of performance characteristics of boring piles is shown in the article by Aksenov (2014). The modulus of elasticity of permafrost soils has values comparable to the modulus of elasticity of rock foundations. It is this fact that allows designing and building various structures without much concern about the values of non-uniform vertical displacements in the base of the structures. However, in the process of thawing, the characteristics of such a base change significantly, as shown in the works by Mohammadi Z., Hayley J. (2025). Thawing rates of permafrost soils are quite high, which is reflected in the works by Errington R. et al. (2024) and works by Li X. (2023). All this requires the development of approaches to prevent the development of catastrophic phenomena in building structures that stand on such foundations. The study is devoted to the analysis of values and gradient of vertical displacements of a group of construction structures that were built on permafrost soils in the Arctic zone of the Russian Federation. Due to the decrease of permafrost soil horizon by 3-5 meters over the last decades and the development of cryolithozone thawing processes, many building structures receive additional displacements in their foundations. These displacements are not designed, and they cause defects in bearing structures. One of the options for predicting and controlling the processes of development of non-design settlements of building structures is the organization of vertical displacement monitoring systems. This paper shows the magnitudes and gradients of settlement of a group of structures located on a thawing base. The data on the cryolithozone horizon lowering are taken from geotechnical surveys in the territory of Yakutsk in the Russian Federation. The possible values of additional settlements have been analyzed. This is necessary in order to evaluate the possibility of applying the hydroleveling methods for controlling the elevation of buildings in the future. The application of hydraulic leveling systems for building structures in various conditions of non-design effects is shown in the articles by Tsvetkov R.V. et al. (2021). Also, in these works are shown the errors of the method of hydraulic leveling and its capabilities for controlling the vertical displacement of building structures.

Nomenclature T temperature E

ground elasticity modulus

2. Problem statement On the example of a group of model buildings typical for the Arctic conditions in Yakutsk, in the numerical finite element formulation, the study of the influence of changes in the properties of the soil base on their stress-strain state is carried out. It is assumed that initially the buildings are built on frozen soils, the properties of which are defined and specified in the model. Conditionally, we will assume that in the zone of pile foundations resting on permafrost soils the soil properties change in the process of their thawing. Reference dependences of elastic modulus on temperature are given in Figure 1 by Tsytovich, N. A. (1975).