Numerical Modeling of Thaw Penetration in Frozen Ground Subject to Low-Intensity Infrared Heating

Abstract

This research investigated the efficacy of low-intensity, radiant, infrared heating for inducing thawing in frozen ground. Specifically, the performance characteristics of a 22 kW infrared tube heater were evaluated. A commercial building site in Park City, Utah, was instrumented with thermocouple piers for field testing over a period of approximately 5 days. The experimental data were used to calibrate a numerical model of the infrared heating process, and several numerical simulations were then performed. The simulations facilitated evaluation of the effects of radiation intensity, air temperature, and ice content on thaw penetration rates achieved using infrared heating. While ice content has a marked influence on thaw penetration rates in all the simulations, the air temperature becomes less important with increasing infrared radiation intensity. The results of the testing also indicate that the tube heater exhibits a steady reduction in emitted radiation between propane tank exchanges and that the heaters should be used in tandem to minimize spatial variations in radiation intensity. Further research is recommended to identify optimal applications of infrared heating in winter construction activities.