Why should there be a slit between the rails

One is thermal expansion and contraction, which is a property of any physics.

The second is that there are gaps for easy installation, and you can think of how to move and install the rails if there is no gap between them.

Third, downstairs, do you understand you, I will build the railway, when the track is installed, there is no large gap, the gap is controlled at 5mm, plus or minus 1mm, most of the gap you see is caused by thermal expansion and contraction, and some of it should be caused by the subsidence of the roadbed, don't understand, don't talk nonsense! Mistaken children.

In order to prevent thermal expansion and contraction.

Easy to install is not established. The slits between the rails are quite large, and if not to prevent thermal expansion and contraction, they should be close together.

The reality is that in the summer they are next to each other, and in the winter the gap is relatively larger.

Thermal expansion and cold contraction.

In the summer heat, the rails expand slightly, and if there are no cracks, the expansion will cause the rails to twist and deform.

It is easy to cause train accidents.

The heat rises and shrinks, and in summer it is the temperature of the high rail that will expand and lengthen, and if there is no gap, it will bend up.

The thin slit in the rails expands when heated. If the rails are tightly connected when laid, this bulges out.

The heat rises and shrinks, and it will be deformed if there is no seam.

Halo: .: Is the landlord okay to do? Leaving the rails is a buffer!

According to the thermal expansion and contraction of the substance.

the nature of the rails.

Leave a little gap in the joints to ensure that in the process of seasonal changes or frictional heating, although the temperature changes, there are gaps between the rails, so they can withstand this change and will not cause damage.

Due to the characteristics of thermal expansion and cold contraction of the rails, a certain gap must be maintained when the rails are connected (to prevent the rails from being pushed and deformed due to thermal expansion and elongation when the temperature rises), and then the iron rails are connected with fishtail sheets and screws. In this way, the rails will not be squeezed and deformed by thermal expansion. Prevent traffic accidents and reduce the harm to humans.

Now there are also seamless rails. Seamless rail is not thousands of kilometers without gaps, but the 25-meter-long rail is welded together into hundreds of meters or even thousands of meters long, and then paved on the roadbed, there is still a gap of 11 mm between a section and a section of seamless rail, now the Shanghai-Nanjing line is 303 kilometers long ultra-long seamless rail, seamless rail to solve the hot expansion and cold shrinkage is not enough to rely on a small number of gaps, now there are two ways to solve the thermal expansion and cold contraction, one is that the long rail section itself bears all the temperature stress, that is, the long rail is locked on the sleeper, This method is suitable for areas where the temperature does not vary much throughout the year, such as in southern China. In some areas with large temperature differences, another method should be adopted, that is, the long rail section itself does not bear the temperature stress, and the method of automatic stress release or regular stress release is used to make the long rail section not shrink freely with the temperature rise and fall, and the best temperature is also selected to lay when laying, so that the expansion and contraction value of the rail is in the minimum range, so that no matter whether the temperature rises or falls, the expansion and contraction of the rail is always controlled in the minimum range.

The first point is the technological improvement of high-speed rail tracks. In fact, although the track of the high-speed rail looks seamless, there are still gaps, but the welding process has been improved. When the rails are transported, they are relatively long, hundreds of meters long, and then welded.

Before laying, the temperature will be taken into account, through professional instruments, a large amount of data will be tested, and then after a certain calculation, the local extreme temperature will be calculated and then the rail will be properly stretched, so as to reduce the impact of air temperature. Therefore, whether it is in the extremely cold northern region or in the extremely hot southern region, it can make the high-speed rail operate normally. The second point is to fix the rail with fasteners.

The traditional steel rails are fixed together by piling up stones with sleepers and rails, while the high-speed rail is poured concrete, and specially made fasteners are used, using strong force to firmly buckle the rails, and ballastless tracks are used.

Any substance willThermal expansion and cold contractionThe same goes for rails, if there are no gaps between them, once the rails are thermally expanded, the rails will be squeezed out of shape. The gaps between the rails are used to solve this problem. The thermal expansion of the rails fills the voids.

However, the latest technology can be used in other ways to overcome the thermal expansion and contraction effect of ear potatoes and make them seamless. Now there are manyHigh-speed railSeamless rail technology is used, and they weld the gap between the original rails, so that there is no longer a gap between the rails and the rails, so that the train runs smoothly and greatly reduces the noise between the wheels and the rails.

However, I have learned in the physics knowledge of middle school that there should be a little gap between the rails and the rails, because if you don't keep it, in the summer, the temperature will rise, and the thermal expansion and cold contraction will make the rails and rails squeeze and deform each other, causing damage to the road and endangering driving safety.

1.The junction of two adjacent rails is concave at one end and convex at the other end. When connected, the concave and convex ends are embedded in each other.

The concave end also plays the role of fixing the convex end, so that the concave end and the convex end can only have longitudinal displacement, but not transverse displacement. The connection between two adjacent rails is free of a complete horizontal gap, and the train passes through the junction continuously and smoothly without additional noise and resistance, and the effect is equivalent to that of a seamless connection.

2.The difference between the maximum and minimum temperature limits does not exceed 100 degrees Celsius in a year.

The length of a single track can be more than 250 meters, and the whole line can be seamlessly connected.

3.The use of this mosaic rail connection device can also be used to seamlessly transform the existing rails, which is convenient to operate and inexpensive. Take the existing railroad track as an example, which is 25 meters long.

Every 10 if you transfer an interface, you only need to transform 1 and the other 9 interfaces can be directly welded. The cost of renovation per kilometer is estimated to be about 40,000 yuan. And as long as the scheduling is reasonable, it will not have much impact on the normal operation of the train, and the economic benefits.

The social benefits are huge.

Because in this way, the smooth operation of the train or high-speed rail can be ensured, so that the impact of thermal expansion and cold contraction can be avoided, and the density of the Yuansunyan connection of the rail can be guaranteed.

Because these gaps can better dissipate heat and better convey noise, there will be gaps in the gaps, which can ensure the normal operation of the rails.

This is because the rails will not be broken after the external temperature expands and contracts, so the rails must leave gaps.

This is to better ensure the safety of the rails. Rails are affected by thermal expansion and contraction.

The reason why there are gaps between the rails is because the metal increases in volume when heated. Although the coefficient of expansion of the metal is small, if the rails are several kilometers or even longer, the total amount of extension will be very large. If there are no gaps, the rails will be bent and deformed, and there will be safety hazards or even impossible driving during the train.

Not only railroad tracks, bridges, roads and other buildings also leave gaps, all to prevent them from elongation and deformation to prevent breakage, which can better facilitate the operation of the train, railway tracks, referred to as rails, rails, tracks, etc., are used on the railway, and cooperate with the switcher, so that the train can walk without turning. The track is usually composed of two parallel rails, the rails are fixed on the sleeper, and the ballast is under the sleeper; Rails made of steel can bear more weight than other materials. Sleepers, also known as sleepers, or sleepers, are used to distribute the weight of the rails separately, and to keep the rails fixed and maintain the gauge of the rails.

Generally speaking, the bottom of the track is made of gravel-paved ballast, also known as ballast, gravel or track bed, which provides elasticity and drainage functions for the track. Rails can also be laid on concrete pedestals (as is common on bridges) or even embedded in concrete. Railway tracks must be maintained frequently to maintain good working order.

In the second half of the 16th century, mines and quarries in England and Germany were paved with rails made of wood. Cars traveling on rails are propelled by human or animal power. 1767, British.

There should be a gap at the junction of the train tracks, which is reserved for thermal expansion and contraction, so as to prevent the deformation of the rails after thermal expansion when the weather is too hot, resulting in train accidents.

The gap left at the junction of the train track is based on the change of weather and season, and the track will rise and shrink at different temperatures, so the gap will be left according to the scientific method during construction.

Thermal expansion and cold contraction

If it is too hot, the gap will be reconnected, if it is cold, there will be a certain gap but it does not affect, if it is completely connected, it will not be separated in hot days and winters, and the whole track area will resonate when the train is running, and it is also convenient to replace when the track is damaged, because it is enough to take out the damaged part.

This is because the rails expand and contract, i.e. they become longer in the summer when the temperature is high, and shorter in the winter when the temperature is low. In 1825, the first railroad rails laid in Britain were welded one after the other. As a result, on a hot summer day, it becomes crooked, and even arches upwards; On a cold winter day, the rails froze and cracked into several sections.

So, then the rails on the railroad were made into sections. However, the current high-speed railway adopts a new type of ballastless track, adopts the most advanced seamless welding technology, and alleviates the impact of thermal expansion and contraction on the rail through new technology, so the high-speed train ride is both stable and does not have the sound of Yedakada.

It is mainly to consider the hot expansion and cold contraction. Now the material has been improved, and the Peng expansion coefficient is smaller, so almost all the rails are welded together without leaving a telescopic opening, which can greatly reduce the noise.

When we ride the train, we often hear intermittent rattling sounds, and the gaps between the rails are the main reason for this sound. This void is designed for the rail to expand and elongate when heated.

Ordinary rails should have expansion joints, thermal expansion and cold contraction.

Prevents thermal expansion and contraction, resulting in internal cracking.

Prevent the harm caused by thermal expansion and contraction.

Facilitates cornering and prevents instability or breakage.

Reserve room for cold contraction and heat expansion.

The principle of heat and cold contraction of the original Nirvana.

Railway tracks, referred to as rails, rails, tracks, etc., are used on railways and cooperate with switches to allow trains to travel without turning.

When the temperature of the rail rises greatly, there will be a certain expansion, leaving some gaps to prevent the rail expansion from squeezing and deforming each other and causing accidents; The general law of thermal expansion of objects: generally objects expand when the temperature increases, and shrink when the temperature decreases, under the same conditions, the gas expands most obviously, the liquid is second, and the solid expands the least.

If there is a gap between the rails, the reason is that the rails will deform when the temperature is too high or the pressure is too high, and if there are gaps, the rails will not be squeezed and loosened due to the expansion of body fluids.

Railway tracks, referred to as rails, rails, tracks, etc., are mainly used on railways and work with switches to allow trains to travel without steering.

A railway track usually consists of two parallel rails, which are fixed to the sleeper and ballast under the sleeper. It is fastened by rail braces, fasteners, rail compressors, plywoods, elastic bars, railway studs and other railway accessories.

Railway rails are made of steel and can bear a greater weight than other materials. Sleepers, also known as sleepers, gray sleepers, or sleepers, are used to distribute the weight of the rail and the pressure on the rail separately, and to maintain a fixed gauge to maintain the gauge of the rail. The original wooden sleeper was changed to a concrete sleeper.