Journal of Cold Regions Engineering

Hydrometeorological conditions of ice field onshore thrusting and its forms were explored in the Szczecin and Vistula lagoons. Five well-documented cases of ice sheet thrusting to more than 100 m inland are presented. Four cases (March 1, 1976; January 14, 1993; January 28, 2003; and February 1, 2004) were observed in the Szczecin Lagoon, one (February 8, 2011) occurring in the Vistula Lagoon. In both areas, the ice field onshore thrusting was driven mainly by strong winds following a cold front in a deep baric low. The longest thrusts, several to 150-m wide, pushed the ice sheet 140 m inland. Near the shore, the sheets were alternated by ice hummocks. The ice sheet base was usually flanked by elongated, low ice piles. The ice sheet tapered inland, its edges rounding off. The thrust ice sheets were finger, tongue, half-ellipse, or semicircle shaped, and they were distinctly rounded in the frontal part.

According to the hydraulic conditions and differences between rivers and long-distance canal systems, a juxtaposition floating ice cover model has been developed to ensure the safety of long-distance canal system operations in winter based on a flow regulation plan for canal systems and predictions of cold waves. The model can describe the ice cover formation process in the pools of each canal and the accompanying hydraulic responses and changes to the gate opening process. The model has been used to simulate the operation processes of the Jingshi canal portion of the middle route of the South-to-North Water Diversion Project in winter. The simulation results show the importance of obtaining accurate data on the ice cover roughness changing process and initial thickness, critical value of the area ice concentration upon formation, and maximization of flow velocity to ensure the juxtaposition of ice cover formation. The model can be used to determine the flow target and predict the gate operations of the canal system when a period of frigid weather is forecast.

With advances in the ability to model complex geothermal conditions, the aspect of soil structure interaction as it relates to long-term changes in the geothermal regime can be considered. Traditional geothermal modeling relied on the so-called $n$-factor approach where the ground surface temperature was represented as the air temperature multiplied by some factor to account for ground surface effects. The application of surface energy balance formulations where the effects of the building including long wave radiation can be incorporated, allows for a more accurate representation of the geothermal regime under the structure. In considering the impact of climate warming on the performance of raised buildings in permafrost terrain, the use of a surface energy balance in the geothermal model is considered to be a more rigorous and technically preferable approach to addressing this problem. This paper addresses the use of a surface energy balance formulation in the geothermal analysis of raised buildings construction in permafrost terrain and its impact on the long-term geothermal regime. Specifically, the impact of building construction on the underlying geothermal regime have direct implication to the ongoing discussion regarding the need for climate change adaptation to address potential foundation capacity degradation in light of climate warming. Both existing field data and geothermal modeling results presented in this paper demonstrate that ground temperatures under a raised building cool over time and become colder than the ground remote from the building. When long-term climate warming is considered, the ground temperatures at depth do warm, but after 20 years of climate warming the ground temperatures under the building are still not warmer than the initial ground temperatures remote from the building.