A mechanistic theory of ice lens formation in fine-grained soils

TLDR

Unsteady heat flow causes temperature‑dependent variations in the segregation‑freezing temperature and frozen‑fringe permeability, producing rhythmic ice banding, and the authors present a model that predicts the overall permeability without detailed fringe‑scale measurements. The study shows that freezing soils are characterized by a segregation‑freezing temperature and an overall frozen‑fringe permeability that remain constant across tests and are independent of the cold‑side step temperature.

Abstract

This study reveals that a freezing soil can be characterized by two parameters, the segregation-freezing temperature T s and the overall permeability of the frozen fringe [Formula: see text]. During unsteady heat flow, the variation of these parameters with temperature produces rhythmic ice banding in fine-grained soils. At the onset of steady-state conditions, freezing tests conducted at a fixed warm end temperature showed that T s was independent of the cold side step temperature. In addition, a model is presented that indicates how the overall permeability of the frozen fringe can be calculated without detailed measurements at the scale of the frozen fringe. It is also constant in the tests reported here.