In regions with high snowfall such as Norway, Quebec Province of Canada, Siberia of Russia, and Hokkaido of Japan, the single snowfall in some places can reach 80 cm. Ordinary brick and wood warehouses are difficult to bear this weight. Even thick concrete warehouses often suffer from roof cracking and wall tilting problems. But does a steel structure warehouse really can't withstand it and will collapse under heavy snow? Is that really the case?
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The "inherent advantage" of steel structure warehouses in resisting snowfall
1. Light in weight but high in strength:
The overall weight of a steel structure warehouse is only 1/3 of that of a concrete warehouse of the same area. Although it is light, the tensile strength of steel is more than 10 times that of concrete. When snow falls on the roof, the steel structure will distribute the force evenly, dispersing the load and reducing the risk of collapse.
2. Good toughness, resistant to impact:
The elasticity of steel is particularly excellent, like a rubber band. When the instantaneous impact force of falling snow occurs, it can be resolved through slight deformation, while concrete will crack upon impact, reducing the durability of the entire building.
Six Key Details for Building Steel Structure Warehouses in Snowy Areas
1. Calculate the snow load
This is the foundation of all designs. Find professional engineers and calculate the total load of "snow accumulation + ice accumulation + instantaneous wind force" based on the local maximum snowfall over the past 50 years. For example, 1 square meter of loose snow weighs approximately 150 kg, and if it becomes icy, it can reach 300 kg. Adding the impact force of the wind, the total load could reach 400 kg per square meter. The engineers will use this data to determine the type of steel beams and columns. For areas with heavy loads, they will use Q355B high-strength steel instead of the ordinary Q235 steel.
2. Roof Design
If the roof design is good, the snow can slide off by itself without the need for manual removal:
Firstly, the roof slope should be at least 30°, preferably 35° - 45°. This way, the snow can slide off quickly after the snowfall. If the slope is lower than 25°, the snow is likely to accumulate and over time will become too heavy.
Secondly, the roof material should primarily use color steel plates + 100mm thick polyurethane insulation foam. The surface of the color steel plates is smooth, making it less likely for the snow to stick. The insulation foam not only keeps the roof warm but also enhances the overall integrity of the roof. Additionally, anti-slip strips should be added to the roof (one every 2m), to prevent the snow from sliding off and injuring people or equipment on the ground.
Lastly, the roof should not have any depressions or protrusions. For example, pipe interfaces and ventilation openings should be level with the roof. Otherwise, if the snow accumulates in large amounts, the local pressure will be too high and easily damage the roof.
3. Snow removal system
Just relying on the slope is not enough; active snow removal equipment is also needed:
Snow melting cables: Lay heating cables beneath the roof. When powered on in winter, they can melt the accumulated snow. This is suitable for countries like Norway and Sweden where there is abundant electricity. The advantage is that no manual labor is required, but the disadvantage is high power consumption;
Roof snow melting pipes: Lay high-temperature-resistant pipes on the roof. In winter, supply hot water or steam through these pipes to melt the snow, and then let it flow away through the drainage outlets. This is suitable for regions like Canada and Russia that have centralized heating;
Mechanical snow removal channels: Reserve a 1.5-meter-wide channel on both sides of the warehouse. In winter, use an aerial work vehicle equipped with a snow removal shovel to remove snow manually. This is suitable for small and medium-sized enterprises with limited budgets;
Openable skylights: Install an openable skylight every 10 meters on the roof. When there is a lot of snow, open it. Utilize gravity to let the snow slide down. The cost is low, but it requires manual operation.
4. Node Reinforcement
The thickness of the steel plates at the connections between the roof of the steel structure warehouse and the steel beams, between the steel beams and the columns, and between the columns and the foundation should be 5mm thicker than that of the main structure. At each connection point, at least 4 high-strength bolts of grade 8.8 or above should be installed, with double nuts for locking, to prevent the bolts from loosening due to snow vibration. During welding, full welding should be carried out, and only half of the weld should not be welded. The weld height should reach 70% of the steel thickness. After welding, ultrasonic testing should be conducted to ensure there are no pores or slag inclusions.
5. Foundation Treatment
In areas with heavy snowfall, the ground will freeze in winter. If the foundation expands due to freezing, it can cause the warehouse to tilt. To prevent this, the foundation needs to be dug deep enough, with the foundation depth exceeding the thickness of the local permafrost layer. Additionally, steel reinforced concrete piles are driven into the foundation, and the top of the piles is made into a reinforced concrete platform. The steel columns are fixed on the platform. In this way, even if the permafrost layer deforms, it will not affect the main body of the warehouse. At the same time, the ground of the warehouse should be higher than the outdoor ground by more than 30 cm to prevent water from accumulating and freezing after the snow melts from flowing back.
6. Daily Maintenance
During winter, regular inspections are necessary:
1. Every week, check the snow accumulation on the roof. If there is a local accumulation of more than 30cm, remove the snow immediately.
2. Check if the bolts are loose, especially at the roof connections. If they are loose, tighten them immediately.
3. Check if there are any cracks in the welds. Use a telescope to observe after snowfall. If there are cracks, repair them promptly.
4. Clean the drainage outlets to prevent them from getting clogged after the snow melts, which could cause water accumulation on the roof and freezing.
Summary: Building a steel structure warehouse in a snowy area poses no problem at all!
By following these 6 construction details, the steel structure warehouse will be an invincible entity in snowy regions. It is lighter than concrete warehouses, more sturdy than brick and wood ones, has lower maintenance costs, and there is no need to worry about it being damaged by heavy snow.
