Solution to Permafrost

Around 550km of the railway had to pass through the places with permafrost, which features soft and wet soil in summer and hard and stretching soil in winter. It troubled engineers over the world, but the Chinese successfully figured out ways to solve the problem, and ensure roadbed stability in permafrost regions by gravelling embankments. and vent-pipe roadbed techniques.

 

 Permafrost areas were avoided as possible, by building bridges instead of railroad. Building a bridge over the permafrost, though expensive, has the least impact on the area. The 11.7km Qingshuihe Bridge is the world-longest bridge built on permafrost.

 

The most important solution to permafrost are stone embankments - a layer of loosely piled chunks of granite about the size of baseballs, that allow enough space between the rocks for air to circulate freely.

 

In some places, the engineers buried ventilation pipes in the ground. The pipes simply allow the cold air to circulate underneath the rail-bed. In other spots, though, a pipe called a thermosiphon was sunk 5 meters (15 feet) into the ground and filled at the bottom with ammonia A monitoring system has been established to check the temperature change along the railroad.