Experimental and numerical investigations on a solar energy-based active heating method for achieving frost-resistant embankments

The primary objective of this study is to address the embankment frost heave issues in cold regions with an active heating method. The applicability of various heat sources was compared with the heating demands of embankments, and the results demonstrated that the seasonally frozen areas of China are rich in solar energy resources. A specialized device for heating embankments, comprising a solar collector section and an embankment heater section, was developed. The device integrates energy conversion, storage, and transfer with no moving parts and can therefore be used for self-driven operations on an “isolated island”. Performance tests showed that the maximum heating temperature exceeds 60 °C with an average range of 20–40 °C, which increases with solar radiation. The effective heat utilization rate of the soil is approximately 26%. A predictive model that considers latitude and the daily ordinal number was proposed for heating temperature. The long-term heating performance of the embankment was numerically simulated. The results revealed that the heating mode in all seasons is capable to overcome the limitations of existing insulation measures and effectively enhance the potential of frost-resistant embankments in winter.