Railway bridge: general characteristics and varieties

After the appearance of the railway transport, it became necessary to stretch the way through the rivers. Since that time, bridges designed for this type of transport have been massively built all over the world. They are often erected also in the creation of transport interchanges in places of intersection with highways. представляет собой сложное инженерное сооружение, позволяющее поездам преодолевать любые препятствия (например, овраги, ущелья, каналы, проливы и даже объекты городской инфраструктуры). The modern railway bridge is a complex engineering structure that allows trains to overcome any obstacles (for example, gullies, canyons, canals, straits and even urban infrastructure).

The beginning of construction in Russia

In 1773 Ivan Kulibin created a project of a bridge with latticed trusses, and a quarter of a century later proposed the use of metal structures for the construction of such facilities. Later, after the advent of rail transport, these ideas played a very important role in the development of domestic bridge construction. необходимо предъявлять повышенные требования, применяя более прочные материалы. Even then, engineers were aware of the fact that such an object as the railway bridge, it is necessary to make higher demands, using more durable materials. Moreover, it was very important to ensure the protection of rolling stock from derailment.

In the late nineteenth century, the construction of bridges began to use metal, concrete and reinforced concrete structures, while their supports were built of stone. The shape and design of such structures in the future repeatedly changed in connection with the development of technology and the emergence of new design solutions.

Types of railway bridges

Currently, railway bridges are classified according to several basic 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 - extra-curricular.

Depending on the number of paths, single-track, double-track and multi-track bridges are allocated. According to the method of perceiving the load, the supports are arched, beams hanging, frame, screw and combined types. Depending on the material used in the construction (the most common variant of classification), it is customary to allocate metal, reinforced concrete, stone, wooden and combined bridges.

It should be noted that when building all types, as a rule, combinations of various materials are used. считается одним из самых практичных вариантов среди такого рода объектов. The railway and automobile bridge is considered one of the most practical options among such objects. Its feature is that it allows you to skip both road transport and trains.

Wooden bridges

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

Stone bridges

Most of the existing stone bridges were built in the nineteenth century. Their main advantage is durability and durability. Moreover, they are not sensitive to impact loads and increase the mass of trains. из камня представляет собой очень трудоёмкий процесс. Nevertheless, the construction of railway bridges from stone is a very time-consuming process. They can be built only with short spans and on strong ground. If there is good protection from moisture and proper care, they can stand for several hundred years.

Metal bridges

This species is the most common in the world. представляет собой сооружение, в котором из металла выполнены только пролёты. Such a railway bridge is a structure in which only spans are made of metal. They are usually made of carbon steel or alloy grades. They are installed on concrete, stone or reinforced concrete supports. The main advantage of this type is the possibility of mechanization of assembly and industrial production of structural elements. In addition, the spans can be installed in a hanging way or delivered on water. The only drawback of such a structure is the susceptibility of the structure to the action of corrosion.

Reinforced bridges

или другое препятствие представляет собой сооружение, в котором пролёты перекрываются железобетонными конструкциями. The reinforced concrete railway bridge across the river or other obstacle is a structure in which the spans overlap with reinforced concrete structures. Their length, as a rule, is in the range from 6 to 16 meters. In this case, in the spans, ribbed structures or with a box section are usually used. The supports are constructed of concrete or reinforced concrete.

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

The Finnish bridge

через Неву является одной из ярчайших достопримечательностей Санкт-Петербурга. The Finnish 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 among 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 adjoin each other. The total length is 538.2 meters.

является разводным. The Finnish railway bridge is a drawbridge. It was built between 1910 and 1913. Its construction consists of four metal arched structures with a divergent part in the center. The bridge is considered a strategic object, so the movement of pedestrians on it is prohibited. The project was created by such famous engineers as G. Krivoshein, N. Belolyubsky and I. Aleksandrov. It should be noted that the structure plays an important role in the Russian economy, since with its appearance the railway communication of our country with all the Scandinavian states has significantly increased.