Numerical simulation of freezing pipe deformation during artificial ground freezing

Abstract

The present work is devoted to study of integrity of steel freezing pipes during artificial freezing of a rock mass and subsequent it thawing on the basis of a numerical simulation. To estimate pressure acting on the pipe by a surrounding soil, a thermo-hydro-mechanical model is used. The constitutive relations of the model are derived within the framework of the linear theory of thermo-poroelasticity under the assumptions that the rock mass is layered linear isotropic porous media that undergoes small deformation. The developed model allows one to take into account strain induced by frost heave and soil thawing. Strength analysis of the pipe is performed according to technical standard on the basis of the linear theory of elasticity. Several critical situations for pipe integrity such as nonhomogeneous distribution of the external pressure along the pipe wall and corrosion of the pipe wall is considered.