Why are there no sleepers on the high-speed rail?

Conventional railways are based on pebbles, and then sleepers or concrete sleepers are laid, and finally rails are laid, but this line is not suitable for high-speed trains. The development history of high-speed railway proves that if the conventional track system is used in its foundation engineering, it will cause serious ballast pulverization, frequent line maintenance and relatively poor safety, comfort and economy. Ballastless track overcomes the above shortcomings and is the development direction of high-speed railway engineering technology. The traditional railway track usually consists of two parallel rails fixed on sleepers, and the bottom is ballast paved with small gravel. Ballast and sleeper can increase the stress surface, disperse the train pressure, help the rail bear the load, and prevent the rail from falling into the soil due to excessive pressure. In addition, ballast (small gravel) has several functions: noise reduction, heat absorption, shock absorption and water permeability increase. This is a ballasted track. Traditional ballasted track has the characteristics of simple laying and low comprehensive cost, but it is easy to deform, frequent maintenance and high maintenance cost. Meanwhile, the speed of the train is limited.

Sleepers of ballastless track are poured with concrete, and the subgrade does not need gravel. Rails and sleepers are laid directly on the concrete pavement. Ballastless track is an advanced track technology in the world today, which can reduce maintenance, prevent dust and beautify the environment, and the train speed can reach more than 200 kilometers per hour.