The subway tunnel. Metropolitan of Moscow

The classical underground tunnel in Moscow was built without the existing plan and without planning the further development of roads. This led to some chaos in the creation of the transport system, which has been observed to this day. Currently, they are guided by unified rules, according to the document SNiP 32-02-2003.

How was the underground transportation system created?

The first subway tunnel was decided to start building in 1931. Projects were created on the basis of geological data. Materials for building at that time were selected reinforced concrete floors, which have been preserved since that time.

The subway tunnel was dug during the year, about 2 million cubic meters were shipped to create long-term mines. About 88 thousand tons of metal was spent on laying ways and strengthening vaults. The first buildings contained wooden structures and were equipped with massive insulating materials.

The subway tunnel was a costly project, it took more than 800 million rubles. The reinforced concrete vaults were later replaced by butovoe masonry, but at that time the first version of the building was more actively used. The inclined vaults were strengthened with cast-iron tubings, roofing material, glassine, glued with bitumen were chosen from waterproofing materials.

Such structures require careful and constant maintenance, which is no less expensive after the facility is put into operation. Metropolitan Moscow wears over the years and requires a reconstruction, comparable in cost with the arrangement of the new tunnel. Therefore, new projects already contain recovery options in a few dozen years and provide for the modernization of buildings.

Materials for the Early Subway

The construction of tunnels was carried out with reinforced concrete ceilings, on which were applied the outer layers of gravel, the layer of earth. The vaulted floors provided high strength and reliability of structures. On open sections of the metro, the tracks were made with flat ceilings. Due to the lack of load, the land routes were carried out in a rectangular manner.

Tunnel construction continues all the time. Moscow is expanding, and the requirements for passenger transportation are also increasing. Materials of the early construction no longer withstand the current speeds and intensity of the movement of the cars. But the circular shape of the tunnels still survives to this day. This design is easier and more reliable can be isolated from the water that flows over the heads of citizens during a trip to the metro.

Metropolitan of Moscow has several levels of laying underground. This is necessary to avoid overlapping lines. The design itself includes a direct landing zone for passengers and track tunnels. All branches are connected by transitions, which facilitates the movement over long distances along a complex route.

Subway Device

Underground transitions of metro stations have arched vaults similar to tunnels. In places where platforms for landing and disembarking passengers were equipped, supporting columns were installed. Here, too, the upper part was performed in an arc-shaped fashion.

The platforms were tried to be located between the ways to facilitate the landing and disembarkation of passengers. But some stations still have side platforms, such as the station "Comintern". Under the platform itself, office space is often located, less often they are carried to the area of the funnels, where there is a deep level of laying ways.

Subway tunnels end in dead-end branches, where the convoys are turned to move in the opposite direction. In the same place there are spare settling tanks for storage of faulty cars. On some routes dead ends are mounted in the middle of the train. Such turnover routes are available at the station "Komsomolskaya", it is located in the center of the city. This measure was required to ensure more intensive train traffic.

Features

Underground metro is laid not at several levels, which helps to organize an efficient routing system. The stations are within walking distance of each other. The depth of the deposit varies within the following limits:

• Deep tunnels - the size is counted up to the platform level from the street surface and ranges from 16 to 35 meters.
• Surface tunnels are laid to a depth of 7 to 9 meters.
• Tunnels of medium depth are located at a level between 9 and 16 meters.

The length of the stations is fixed, designed for 8 wagons. A width varies from 10 to 21 meters and depends on the depth of the tunneling. Each room is equipped with emergency lighting in case of emergency. The norm of lighting at stations is organized according to the standard specifying the requirement of 100 lux.

The distance between the stations varies from 500 to 1400 meters. Tunnels with lifts, called escalators, are inclined at an angle of 30 degrees to the horizon. Heating tunnels by air is carried out from the distances to stations, so the possibility of cooling the paths is excluded.

Decoration of premises

Some stations are attributed to the architectural heritage. Each of them has its own unique image. For finishing previously used materials such as granite and marble. Patterns filled the surfaces of columns, walls, arches. Lighting was carried out by massive lighting devices.

Railway tunnels have a track similar to the metro. If desired, an ordinary car can safely follow the underground branches. New metro routes often intersect with already existing railway tracks, which simplifies the modernization of the subway and the opening of new branches.

Tunnel lighting is carried out around the clock. To avoid accidents in the subway, signaling traffic lights with a red and green signal are installed. Prohibiting light engineer can not overcome. An automatic locking system is provided, when the brakes are switched on independently when the special lever is grabbed by the car.

Automation

The transport tunnel is a complex structure, equipped with dispatching systems, protective mechanisms, control devices. At the edge of the tunnel, there are feeding lines with a high DC voltage of 825 volts. The required value is produced by special substations located deep underground.

The leading car is equipped with 4 engines of 150 kW. The brakes of each car work on pneumatics with an electric drive. Automation system ensures normal movement of trains with a repetition interval of 1.75 minutes. The speed of each train is estimated at an average speed of 40 km per hour. The maximum possible for each car is 75 km per hour. Modern trains can follow much faster, but this requires the laying of new track lines.

Variants of modernization of ways

To prolong the operational capabilities of tunnels, constant supervision and interior finishing are required. This is done by accredited organizations that have vast experience in carrying out this kind of work. To do this, strengthening the vaults and supporting parts of the tunnels.

Increase the waterproofness of the foundation and finishing materials. Retraction of accumulated moisture in the common drains. Changes in the characteristics of the adjacent soil. Replacement of worn out parts of reinforced concrete. For this purpose, the injection of solutions into the cavities formed, the newest waterproofing materials, and also the moisture resistant coatings are used.

Condition monitoring

To prevent accidents, the monitoring commission is constantly working, able to identify in time the voids in the arches, cracks in the bearing parts of the walls and the foundation. Recent developments in instrumentation help to identify the smallest initial processes in concrete, metal parts.

For arches of tunnels it is important to stop the removal of soil covering the outer walls of the fortifications. To eliminate the negative effect, the injection method is widely used. A dense liquid composition is introduced into the formed space, which changes the properties of the soil. At the same time, internal surfaces are treated with moisture-retaining substances.