A simplified numerical method to simulate the thawing of frozen soil

• Published in: Proceedings of the Institution of Civil Engineers - Geotechnical Engineering
• Main Authors: Loli, Marianna, Tsatsis, Angelos, Kourkoulis, Rallis, Anastasopoulos, Ioannis
• Format: Article in Journal/Newspaper
• Language: English
• Published: Thomas Telford Ltd. 2020
• Subjects: permafrost; Alaska; Siberia
• Online Access: http://dx.doi.org/10.1680/jgeen.18.00239; https://www.icevirtuallibrary.com/doi/pdf/10.1680/jgeen.18.00239

Thawing weakens the frozen soil supporting buildings and lifelines from Siberia to Alaska, resulting in settlements up to hundreds of millimetres during a single season. This paper presents a simplified sequentially coupled numerical approach that can be implemented in a general purpose, commercially available finite-element analysis model. It is intended to provide a reasonably accurate computational tool for the analysis of structures on degrading permafrost, allowing modelling of complex three-dimensional geometries and boundary and loading conditions. The method permits simulation of the temperature-dependent thermal and mechanical properties of soils in an approximate manner. It accommodates large-strain consolidation theory, also allowing use of plasticity constitutive relationships. A thorough validation study was carried out involving comparison with monotonic and cyclic thaw consolidation element tests, analytical solutions and a well-documented case study of an unstable roadway embankment. The latter was complemented by an investigation of thaw-settlement remediation solutions using thermosyphons, with emphasis on the three-dimensional response and their transverse spacing.