Experimental and numerical study of heating embankment utilizing solar energy in seasonally frozen regions

Frost heave has a significant influence on the stability of embankment in seasonally frozen regions, where the active heating embankment has become a new method for preventing and controlling frost heave. In this study, a field experiment was conducted based on a solar circulating heating embankment system (SCHES), and the heat collection performance of the SCHES and the heating effect of the soil were analyzed. Additionally, the numerical simulation of the coupled moisture-heat of the embankment under heating conditions was performed, and the heating effects of different buried forms and buried depths of the heat accumulation pipe (HAP) were discussed. The experimental results showed that the SCHES can provide a heating temperature of up to 70 degrees C and a mean heating flux of 87 W m(-2) during the cold season. The heating action of the SCHES makes the temperature of the surrounding soil of HAP above 0 degrees C in cold season, which significantly reduces the freezing depth. The numerical results also show that the maximum freezing depth of the embankment can be reduced by 70%, the volumetric ice content can be reduced by more than 60%, and the heating embankment can reduce the frost heave deformation by more than 60% compared with the normal embankment. The buried form of the HAP is recommended to be the horizontal insertion on both sides and the horizontal insertion on sunny sides. The optimal buried depth is between 0.5 m similar to 1.0 m when the HAP burial form is the horizontal insertion on both sides. As a preliminary study, the concept of the active heating embankment utilizing solar energy can provide a reference for the prevention and control of frost heave in seasonally frozen regions.

Automated summary

In this study, a field experiment was conducted to analyze the heat collection performance of a solar circulating heating embankment system (SCHES) and the heating effect on the soil. Numerical simulations were also performed to discuss the effects of different buried forms and depths of the heat accumulation pipe (HAP) on the heating embankment. The results showed that the SCHES can provide a heating temperature of up to 70 degrees C, significantly reduce freezing depth, and decrease frost heave deformation compared to a normal embankment. The concept of an active heating embankment utilizing solar energy can be a reference for preventing and controlling frost heave in seasonally frozen regions.