21 February 2025
Snow and cold affect roads in cold climates
Researchers at Luleå University of Technology have investigated how snow cover and road culverts influence frost heave in roads during the winter. The results could contribute to better road maintenance and more sustainable road construction in cold climates.
How does the thermal impact of culverts and accumulated roadside snow influence the thermal regime of roads during a prolonged winter? Researchers at Luleå University of Technology have investigated this through field measurements in northern Sweden. The study demonstrates that both snow cover thickness and the presence of road culverts significantly influence the depth of ground freezing beneath the road.
“We have studied how snow and culverts affect the temperature distribution in the road structure during winter. Our results show that snow acts as an insulating layer and has a clear significant effect on frost heave, says Zahra Motamedi,” a geotechnical researcher at Luleå University of Technology.
Snow as an insulating factor
One of the key findings of the study is that snow accumulating in ditches insulates the ground and affects how deeply it freezes. TThe researchers observed that once the snow depth in the ditch reaches 65 cm, it effectively prevents the ground beneath from freezing completely
“As snow starts to accumulate in the ditch, it provides some insulation, but once it reaches a certain thickness, it fully prevents the ground from freezing. This is an important factor to consider when planning roads and maintenance in cold climates,” says Zahra Motamedi.
Culverts accelerate freezing
The study also shows that road culverts can accelerate the freezing process in roads. Because cold air flows through the culvert, the surrounding soil cools down more quickly, leading to deeper frost penetration depth.
– We observed that the ground near road culverts freezes faster than the rest of the road. However, when the culvert is covered by snow, this effect decreases, and frost depth increases more slowly, says Karina Tommik.
This could impact road durability, as uneven frost front progression leads to uneven frost heave, which can damage the road structure. Better understanding these processes allows for road designs that minimize damage risk and reduce costly maintenance in cold climate regions.
Contact
Zahra Motamedi
- Doktorand
- 0920-491322
- zahra.motamedi@ltu.se
- Zahra Motamedi
Karina Tommik
- Doctoral student
- 0920-493996
- karina.tommik@associated.ltu.se
- Karina Tommik
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