Why are there so many stones on the railroad tracks?

If there are no 20 cm thick pebbles under the tracks, the tracks are not stable enough, and the train will move violently when it passes; Trains are heavy, and if they are not paved with stones, the tracks will be concave and the train will not be able to move. If the stones are not paved, when it rains, the drainage function will be blocked, the soil under the rails will be loose, and the rails will fall; In winter, frost columns will be formed under the rails, and the rails will float upwards.

Professionally:

1.The load of the rolling stock is distributed on the subgrade surface through the diffusion effect of the rail, sleeper and through the track bed, which plays the role of protecting the subgrade.

2.It is particularly important to provide resistance to the longitudinal and lateral resistance of the rail row and to maintain the correct geometry of the track, which is especially important for seamless lines.

3.It has good drainage performance, which is very important to reduce the frost damage of the track and improve the bearing capacity of the roadbed.

4.Provides a certain amount of elasticity and damping, and plays the role of cushioning and shock absorption 5It is used to maintain the smoothness and direction of the track.

What about the stones under the railroad tracks? This is because the rails and sleepers have to bear the weight of the train for a long time, and one of the tasks of the broken stone is to act as a buffer to prevent the rails from sinking. In addition, the train passes through the tracks at high speed, which generates noise and high heat, and the other two important jobs of stone crushing are to absorb noise and absorb heat.

If you pay attention, you will find that the stones paved between the railroad tracks are chiseled, and the shape is very irregular, so that the stones are easy to break, so that the high heat generated by the passing of the train can be absorbed because of the fragmentation of the stones; If you pave a round and smooth stone, because it is not easy to break, the effect of heat absorption is not good!

The gap between the pebbles acts as a shock absorber.

The reasons for the gravel laying under the rails are as follows:

1. Disperse the pressure, reduce the seismic force and noise, and a train of hundreds or thousands of tons passes quickly at a speed of more than 100 kilometers, which has caused a huge impact on the wooden box rail.

If there is no ballast, the rails and sleepers are laid directly on the roadbed, which may not be able to bear the weight of the train and will sink downward.

The gaps and textures between the gravel of the ballast play a good role in dispersing the huge pressure generated by the passing train, and evenly distributes the pressure to the foundation. The elasticity of the ballast is used to disperse the vibration force and noise of the train well, making it more comfortable for passengers and protecting the roadbed. The first to pick up the relatives.

2. Easy to drain and protect the roadbed, there is a large gap between the gravel of the ballast, in case of rainy weather, the water can infiltrate down the gap and discharge the roadbed, so as to avoid turning over the slurry and mud, and protect the roadbed well.

The stone laying under the track is mainly used for bridge cleaning, which is to evenly transmit the pressure of the upper part of the sleeper to the roadbed, so that the track is stable and the train will not shake violently when passing by. The stone can fix the position of the sleeper and prevent the track and sleeper from sinking into the ground when the load is loaded, thus playing a cushioning role. When the train is running, it produces violent vibrations, and these small pebbles can absorb some of the vibrations, reducing the noise, so that the train runs more smoothly.

In addition, stones are also good for drainage in rainy days, and by the way, they block the growth of wild grasses.

Most of the traditional rails are rail seam lines, which are also called rail joints of the steel world. At the beginning, the gap of this kind of rail plays the role of thermal expansion and cold contraction, it makes the train pass through the high temperature area in the process of rapid driving without forming the phenomenon of continuous blind cracks, resulting in the serious consequences of deviating from the track, and the safety factor of train driving is improved in the track joint.

But over time, its drawbacks gradually became apparent. First, the train is running on the crack of the track, and the friction between the two will produce a huge noise; Second, the impact between the train track and the rail gap has great damage to the wheels, which directly shortens the use of the tracks.

Later, improvements were made to the rails, and stones were laid under the railroad tracks. The gravel and the track are closely connected, the track and the sleeper are responsible for bearing the weight of the train when passing, and the gravel prevents the track and sleeper from sinking into the ground when the load is loaded, and acts as a cushion and absorbs the noise generated by the train. Hard gravel is most suitable for laying on rails, so hard sandstone is mostly used.

Why are there stones under the tracks?

The reasons for laying stones on the rails are: to protect the roadbed, to remove rainwater from the tracks, to maintain the plane geometry of the track, to cushion and dampen vibrations, to reduce noise and to inhibit plant growth.

1. Protect the roadbed: The stones laid on the track can evenly transmit the pressure from the sleeper to the roadbed, so as to protect the roadbed.

2. Eliminate track rainwater: When it rains, the accumulation of rainwater will cause certain damage to the track, and paving stones can be conducive to the discharge of rainwater, thereby reducing the damage to the track caused by the accumulation of rainwater.

3. Maintain the plane geometry of the line: laying stones on the rails can prevent the sleepers from moving the rails, so that the rails can maintain their original shape.

4. Cushioning and shock absorption: The stones laid on the track make the track elastic enough, which can alleviate the impact on the rail, so as to bring the effect of shock absorption.

5. Noise reduction and inhibition of plant growth: Laying stones on the track can not only reduce the sound generated by the friction between the steel wheel and the rail when the low train passes, but also effectively inhibit the growth of plants on the track.

The stones on the railroad are called "ballast". It can distribute the weight of the train and the track on the roadbed, thereby reducing the vibration and noise caused by the passing train.

When it rains, ballast can quickly infiltrate rainwater into the ground and improve the drainage capacity of the track bed. It also prevents weeds from growing and avoids rail bulges. Ballast can evenly distribute the pressure of the train and the impact force when passing to the roadbed, prevent the uneven force of the roadbed from collapsing, and minimize the noise.

Ballast is also elastic and can absorb a part of the impact force and play the role of fixing the sleeper. The railway is made up of rails and trackbeds, which in turn are made up of sleepers, stones, and other accessories. Ballast is a common track bed structure used as gravel to support track sleepers in the railway transportation system.

The composition of the rails:

The track is composed of a track bed, sleepers, rails, connecting parts, anti-climb equipment and switches. Originally cast rails, the rails were developed into I-shaped rails, and in the 80s of the 20th century, the standard gauge (see Railway Track Geometry) used by most railways in the world was 1435 mm (4 ft 8 in). Those that are narrower are called narrow-gauge railways, and those that are wider are called broad-gauge railways (see Railway Engineering).

The track bed is directly paved on the roadbed surface, and the track bed is made of gravel, pebbles, slag and other materials. Rails, sleepers, and track beds are some materials with different mechanical properties that are combined in different ways.

Generally speaking, the bottom of the track is the track bed, which provides elasticity and drainage functions for the track. Rails can also be laid on concrete pedestals (which is quite common on bridges) or even embedded in concrete.

Sleepers are buried in the track bed and are generally laid laterally and made of wood, reinforced concrete or steel.