Frost-induced deformations and stresses in pipelines

Forst-induced soil-pipeline interaction is modelled using a time-dependent thermo-mechanical process. A simplified one-dimensional frost heave model is used to evaluate frost heave, and a beam on elastic foundation finite element is used to model the buried pipeline. The time-dependent creep displacements of frozen soil are determined based on the elastic theory for the multi-layer half space. The frost-related soil stiffness is obtained using an average elastic modulus and treating the freezing soil as a multi-layer half space. The contact pressure exerted on the pipeline by frost heave and by creep effects in the frozen soil is represented by a simple distributed load. A computer program based on the time-dependent finite element method is developed which can be used to calculate frost-induced stresses and deformations of the pipe. A numerical example is presented which demonstrates reasonable agreement between the results from the proposed analysis and available experimental data.