Large-scale laboratory tests on artificial ground freezing under seepage-flow conditions

A high seepage-flow velocity represents a potential problem for artificial ground freezing (AGF), as it may hinder the growth of an ice body and the development of a closed ice wall. To avoid such difficulties, careful thermal hydraulic analysis is necessary. This presupposes, of course, that the reliability of the underlying computational models has been verified by means of comparisons with the results of appropriate field tests or physical models. As there are scarcely any results of such tests available in the literature, a new large-scale physical model for AGF under conditions of high seepage-flow velocities has been developed. The present paper documents in detail the experimental set-up, the thermodynamic properties of the soil material, the boundary conditions, and the results of six experiments. These data are valuable as a reliable basis for the evaluation of numerical or analytical prediction models. Additionally, the paper discusses existing closed-form solutions for AGF with and without seepage flow in the light of the experimental results, from the perspective of the refrigeration time and the cooling power required for the merger of a freeze-pipe row.