Railway bridge: general characteristics and varieties

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

After the advent of rail transport, it became necessary to stretch the path through the river. Starting from that time, bridges designed for this type of transport began to be massively built all over the world. They are also often erected when creating transport interchanges at intersections with highways. A modern railway bridge is a complex engineering structure that allows trains to overcome any obstacles (for example, ravines, gorges, canals, straits, and even urban infrastructure).

Begin construction in Russia

In 1773, Ivan Kulibin created a project for a bridge with lattice trusses, and a quarter of a century later, he first suggested using metal structures in the construction of such objects. Later, after the advent of railway transport, these ideas played a very important role in the development of domestic bridge building. Even then, engineers were aware of the fact that such an object as a railway bridge must be subjected to increasedrequirements, using more durable materials. Moreover, it was very important to ensure the protection of rolling stock from derailment.

At the end of the nineteenth century, metal, concrete and reinforced concrete structures began to be used in the construction of bridges, while their supports were built of stone. The shape and design of such structures changed several times in the future due to the development of technology and the emergence of new design solutions.

Types of railway bridges

At present, railway bridges are classified according to several main characteristics. If the length is less than 25 meters, then they are considered small, from 25 to 100 meters - medium, from 100 to 500 meters - large, more than 500 meters - out of class.

Depending on the number of tracks, single-track, double-track and multi-track bridges are distinguished. According to the way the load is perceived by the supports, there are arched, beam hanging, frame, screw and combined types. Depending on the material used in the construction (the most common classification option), it is customary to distinguish metal, reinforced concrete, stone, wooden and combined bridges.

It should be noted that in the construction of all types, as a rule, combinations of various materials are used. The railway-road bridge is considered one of the most practical options among such facilities. Its peculiarity lies in the fact that it allows the passage of both road transport and trains.

Wooden bridges

This variety was especially popular in the history of bridge building at the initial stage. This is due to the cheapness, simplicity and speed of construction. However, over time it became clear that the wooden railway bridge is a fire hazard. Do not forget also about its fragility and difficult care. In this regard, with the development of building technologies, such structures were gradually replaced by their stone, metal and reinforced concrete "brothers". Nowadays, the construction of this type is almost not practiced.

Stone bridges

Most of the existing stone bridges were built in the nineteenth century. Their main advantage is durability and strength. Moreover, they are insensitive to shock loads and increased mass of trains. However, the construction of railway bridges from stone is a very laborious process. They can only be erected with short spans and on solid ground. With good moisture protection and proper care, they can stand for several hundred years.

Metal bridges

This variety is the most widespread in the world. Such a railway bridge is a structure in which only spans are made of metal. They are usually made from carbon steels or alloys. They are installed on concrete, stone or reinforced concrete supports. The main advantage of this type is the possibility of assembly mechanization andindustrial production of structural elements. In addition, spans can be installed on a hinged way or delivered by water. The only drawback of such a structure is the susceptibility of the structure to corrosion.

Reinforced concrete bridges

Reinforced concrete railway bridge across a river or other obstacle is a structure in which spans are covered with reinforced concrete structures. Their length, as a rule, is in the range from 6 to 16 meters. At the same time, ribbed structures or with a box section are usually used in the spans. Supports are built of concrete or reinforced concrete.

A significant advantage of this variety is considered to be a long service life, as well as relatively low maintenance costs. As for the shortcomings, here it is necessary to note only the likelihood of chips and cracks due to the large mass.

Finland Bridge

Finland railway bridge across the Neva is one of the brightest sights of St. Petersburg. It is one of the most important objects of the country's transport infrastructure and is one of the best in the world. The origin of the name is due to the fact that the railways of Russia and Finland are connected through it. In fact, the structure is two separate bridges that are adjacent to each other. The total length is 538.2 meters.

Finland railway bridge isadjustable. It was built between 1910 and 1913. Its design consists of four metal arched structures with an adjustable part in the center. The bridge is considered a strategic object, so the movement of pedestrians on it is prohibited. Such well-known engineers as G. Krivoshein, N. Belolyubsky and I. Alexandrov worked on the creation of the project. It should be noted that the structure plays an important role in the Russian economy, because with its appearance, the railway communication of our country with all the Scandinavian states has significantly increased.