The crushed stone laid under the railway track is called ballast, which is used for railway subgrade bed. Its main function is shock absorption and drainage. At the same time, the weight of the train and track is dispersed on the subgrade, which can reduce the vibration and noise caused by the train. Why should the railway track be paved with gravel? The use of ballast can make it easy to drain water and adjust the track position, reduce the vibration and noise caused by the train passing, and increase the comfort of passengers.
At the same time, the crushed stone can disperse the vibration and high heat generated by the train, keep the gauge of the steel rail unchanged, prevent derailment accidents, and the gap between the stones can quickly drain the rainwater.
The ballast has strong water permeability, which can prevent weeds from growing on the railway track. There are sleepers with equal distance on the ballast, which can also inhibit the growth of plants. （TieGuiWeiShenMeYaoPuSuiDan）