%0 Journal article
%A Sweidan, A. H.
%A Niggemann, K.
%A Heider, Y.
%A Ziegler, M.
%A Markert, B.
%T Experimental study and numerical modeling of the thermo-hydro-mechanical processes in soil freezing with different frost penetration directions
%R 10.1007/s11440-021-01191-z
%J Acta Geotechnica
%V 17
%N 1

%I Springer Berlin Heidelberg
%X This research work presents an experimental and numerical study of the coupled thermo-hydro-mechanical (THM) processes that occur during soil freezing. With focusing on the artificial ground freezing (AGF) technology, a new testing device is built, which considers a variety of AGF-related boundary conditions and different freezing directions. In the conducted experiments, a distinction is made between two thermal states: (1) The thermal transient state, which is associated with ice penetration, small deformations, and insignificant water suction. (2) The thermal (quasi-) steady state, which has a much longer duration and is associated with significant ice lens formation due to water suction. In the numerical modeling, a special focus is laid on the processes that occur during the thermal transient state. Besides, a demonstration of the micro-cryo-suction mechanism and its realization in the continuum model through a phenomenological retention-curve-like formulation is presented. This allows modeling the ice lens formation and the stiffness degradation observed in the experiments. Assuming a fully saturated soil as a biphasic porous material, a phase-change THM approach is applied in the numerical modeling. The governing equations are based on the continuum mechanical theory of porous media (TPM) extended by the phase-field modeling (PFM) approach. The model proceeds from a small-strain assumption, whereas the pore fluid can be found in liquid water or solid ice state with a unified kinematics treatment of both states. Comparisons with the experimental data demonstrate the ability and usefulness of the considered model in describing the freezing of saturated soils.
%U http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11163
%~  FID GEO-LEO e-docs