Introduction

In recent years, most major cities around the world have seen increased interest in the widespread use of underground space.

It is caused by increased urbanization, the rapid development of land transport, a shortage of urban territory and a number of other reasons. Intensive development of underground spaces in cities is an indispensable condition for the development of modern urban planning, which predetermines the possibility of effective use of urban territory, improving the state of the external environment, preserving the architectural and spatial integrity of historically established areas of the city, as well as solving a complex of many other, including socio-economic problems .

The degree of use of underground space, equipment and technology of work depend on the size of the city, the nature and content of historical and future development, the concentration of the daytime population in various parts of the city, the estimated number of cars, natural-climatic, engineering-geological and other conditions.

Principles of using urban underground space: Russian and foreign experience

The development of underground space is most relevant in the central, densely built and most visited areas of the city. Public centers of the city include: the central zone of the city, main highways, large public transport hubs. These zones are places of concentration of the “daytime” population, services for which should be as close as possible to their locations. In the central zone of the city, the presence of a valuable historical and architectural heritage, the integrity of urban planning ensembles of the past does not allow the development of administrative, business, cultural, entertainment and trade functions to a sufficient extent, as well as the expansion of the street network and landscaping areas of open spaces. Therefore, the central part of the city is the place of the most intensive use of underground space to accommodate these objects. Bringing trade and catering enterprises, entertainment and public utility facilities closer to areas of population concentration increases their attendance, increases their purchasing power and profitability of operation.

Such enterprises are located:

• - under central streets (in Kyiv, Belgrade, Tokyo)
• - under squares and intersections of central streets (in Vienna, Bellaria, Babenbergeni Schottentor, in Munich, in Moscow)
• - in the system of public shopping centers (in Stockholm, Philadelphia, Montreal)

In the capital of the Celestial Empire, Beijing, by 2020 the Chinese are planning to build an underground city. The area of ​​the developed territory will be about 90 million m2. It is planned to create several financial districts in the city, which will house banks and other economic structures, as well as transport interchanges and large shopping centers. According to the architects, it is planned to commission up to 10 million m2 annually.

In world practice, the list of underground and semi-underground structures is very extensive and includes theater, concert and exhibition halls (the Laterna Magica theater and the Alhambra hall in Prague, the conservatory and the Center for Arts and Crafts in Paris, the Museum of Modern Art in New York), trading floors of department stores and markets (Galeries Lafayette in Paris, Bull Ring in Birmingham), shopping and pedestrian malls and passage streets (Helsinki, Vienna, Osaka), railway stations (Warsaw, Brussels, Copenhagen, Naples, Sydney, Montreal ), bus stations (Chicago, New York, Los Angeles) and air terminals (in Paris, Rome, Brussels, Washington), subways operating in more than 150 cities around the world.

Now the longest underground transport network in the world is the London Underground. Today, the underground has 275 stations, the length of the tracks is 408 kilometers, and the passenger flow of the London Underground is 3 million people. By 2020, the total length of the Beijing metro lines in the capital, according to the plans of Chinese metro builders, will be 561 km; there will be 19 metro lines in the city.

In connection with the widespread use of underground space in large cities for transport purposes, many designers think about the feasibility of constructing entire underground multi-purpose complexes, which could accommodate not only transport structures, but also all the premises for serving passengers along their route.

In recent years, transport facilities are increasingly being developed in conjunction with service and trade institutions. Examples include a bus station in Finland in conjunction with a shopping center, a bus station in Holland included in a shopping center, a bus station in Hamburg combined with a shopping center, public transport centers in Tokyo, Munich and other cities.

In many US cities, a number of large shopping centers have been created, providing the utmost concentration of services. Such shopping centers usually include food and department stores, cafes, restaurants and other public facilities, including concert halls, artificial ice skating rinks and swimming pools. For example, the La Rochelle shopping center with an area of ​​44 hectares houses a railway and bus station, a garage for 5 thousand cars, a theater, a multi-purpose hall, and a hotel. the area of ​​retail premises is 72 thousand m2.

For transport services in new public centers, as a rule, several underground levels are created, used for the movement of underground rail transport, pedestrian crossings, underground parking lots and garages. Typically, the lowest underground level contains a subway station and underground sections of city underground roads; above there are underground tunnels for vehicles and underground structures for pedestrians.

For new public centers in Paris, Montreal, Helsinki, Los Angeles, London and other cities, underground sections of highways are being designed, often crossing the entire city in several tiers.

Several years ago, construction of a community center in Paris was completed.

The new center includes public, administrative and residential buildings. It completely separates the paths of pedestrians and vehicles. The building complex has a multi-tiered composition with four to five underground floors. All types of urban transport in the new public center are concentrated in the underground space.

The main transit highway Paris-Normandy passes within the public underground, along it there will be main bus routes and an express metro line connecting the new center with the old central areas of the city.

On the lower (fourth from the surface) underground level there is an express metro line with a station located near the main public buildings of the complex. The next (third from the surface) underground level is reserved for the movement of long-distance vehicles. Even higher are local bus lines with a bus station. The uppermost underground level is occupied by building entrances connected to peripheral one-way roads with interchanges at three points.

In Finland, a project is underway to plan and build a new 3-level community center in Helsinki. It is designed on the shores of Teele Bay on an area bordered by the railway station and the parliament building. To completely separate the movement of pedestrians and vehicles, underground interchanges are provided at intersection points on all highways. The underground space will house parking lots and garages for the area, and passages connected to underground parking lots, retail and service establishments will be built.

To serve the population of Montreal, as well as nearby cities and suburbs, a large complex of retail, public and transport facilities is being created in the downtown area. The new public transport center of the city is being built on the site of old buildings.

The complex includes three large department stores, 4 hotels, 8 cinemas, 5 high-rise administrative buildings, 30 restaurants, 20 large specialty stores and indoor markets, underground multi-level parking lots for 9 thousand cars. The usable area of ​​shops, restaurants, cinemas, bookstores and pedestrian galleries located in the center will exceed 1 million square meters. feet (90 thousand m2).

The city's main transport arteries pass through the new center: three underground metro lines, underground highways and two railway lines (National and Pacific). An underground expressway would connect the downtown area with the Trans-Canada Highway. It should be adjacent to pedestrian and shopping crossings with a length of 6.4 km, connected to underground parking lots, metro stations, service entrances for trucks and two central railway stations.

In Moscow, on the site of the Rossiya Hotel, a multifunctional complex will be built with hotels, a cinema and concert hall, a hall for chamber music, and retail and catering establishments.

It is planned to make maximum use of the underground space - parking lots for more than a thousand spaces will be equipped. In the underground part of the complex, the appearance of Moscow streets will be recreated; a system of underground passages will connect Red Square and the Manezhny complex on Okhotny Ryad.

In world practice, the construction of underground parking lots and garages is developing at a rapid pace. The advantages of underground garages and parking lots are obvious. Underground structures provide significant savings on territory (or practically do not require it at all, with the exception of an exit device), since they can be placed under existing parks, squares, squares, buildings, etc. In addition, territories can be used for underground (semi-underground) garages that could not be used for other purposes (ravines, areas with a large slope, various types of excavations, small quarries, etc.)

Functionally, underground garages contribute to the separation of transport and pedestrian traffic and the general unloading of ground space. For example, several such projects are being implemented in Moscow. In the underground space under Tverskaya Zastava Square, a transport interchange with a multifunctional complex with a total area of ​​107,387.5 square meters is being built. m., including a multi-tier underground garage - parking for 731 cars, with a total area of ​​27,715 sq. m. A three-level parking lot for 1000 cars will be built under Pushkinskaya Square. Additionally, there will be souvenir shops, cafes and a small exhibition hall.

The desire to create an integral system of underground structures serving the central zone of the city deserves attention.

In many of the world's largest cities, during the reconstruction and construction of public centers, the main pedestrian movement is designed under the streets and squares at a depth of 3.5 m. along underground pedestrian streets-transitions with underground distribution halls that have light-green wells (for illuminating underground premises). At the same level with these pedestrian underground communications, underground shopping, cultural, entertainment, sports facilities, cafes and restaurants are being built with entrances oriented directly to the pedestrian underground level. The length of underground pedestrian communications is measured in hundreds and thousands of meters.

The current level of development of underground construction in megacities makes it possible to solve most problems regarding the cost-effective and environmentally safe placement of socially significant objects in a comprehensive and efficient manner. The annual rate of construction of underground facilities in the total volume of construction is in a fairly large range: from 5-8% in cities that are just developing this area of ​​​​economic activity (for example, in Moscow), to 25-30% in the largest metropolitan areas with extensive experience in this area (for example, in Paris, Tokyo, London).

Domestic and foreign practice of using underground space indicates the great importance of underground construction in cities. The scale and types of urban facilities located underground should be determined by social, economic and urban planning considerations, based on the need to create the best conditions for serving the population, as well as ensuring the most rational use of urban areas, increasing the efficiency of capital investments in urban planning.

The purposeful use of underground space in cities has a long history. Under the ground, the ancestors located defensive and religious structures, galleries of secret passages, storage facilities and housing. Construction began to be especially active below the surface of the earth with the development of engineering support systems. It is difficult to list what is hidden there in the modern city. However, all underground structures can be combined into five groups.

Networks and utility equipment urban development belongs to the first group. Plumbing systems are the most common. These include infrastructure for cold and hot water supply, as well as water disposal: domestic, storm and industrial sewerage.

Not only network pipelines, but also equipment are placed within urban areas. Very often it is installed in underground structures. Inspection rooms, pumping and transfer stations, boiler rooms, boiler rooms and heating points are buried underground.

Steam and gas pipeline systems are laid underground, equipped with special equipment, which is often hidden underground. If necessary, build tanks for water, other liquids and compressed gases.

In the engineering sector of cities, a special place is occupied by power supply and electronic communication systems. Typically, electricity and weak current potential are transmitted through metal or fiber optic cables. Together with the equipment of transformer, relay telephone and relay stations, they are also buried in the ground.

As a result of technical progress, engineering systems are updated and further developed. Today it is difficult to predict what new equipment will present to the cities of the 21st century. For example, local systems for pneumatic transport of solid waste already exist. They currently operate within a neighborhood or residential group, moving waste to storage, sorting and packaging stations. Perhaps in the future waste will be transported through such systems to waste treatment plants.

Industrial, technical, household and warehouse facilities are often located underground. There are entire underground factories of defense significance. Separate workshops and laboratories are buried, which need to be protected from dust and noise. Or vice versa, to prevent environmental contamination from industrial sources (for example, radiation).

Rice. 14 Underground shopping and pedestrian streets:

a – longitudinal section of a building in Northbrook (USA), b – the same, in Edinburgh (England).

In order to save urban areas, consumer service enterprises such as laundries and dry cleaners are being created underground. Warehouses are also located there. Vegetable storage facilities, refrigerators, fuel and lubricant warehouses, water and gas storage facilities are widespread in cities.

Cultural and entertainment institutions, trade and public catering are the most attractive to the population. The underground space is convenient enough to accommodate institutions of this group. In occasional service premises, the absence of daylight is acceptable, since people are not expected to be in them permanently. But when choosing a design solution, as a rule, they consider an alternative: to build underground or on the surface.

The construction of underground structures involves serious investments that significantly exceed capital investments in above-ground facilities. However, inflating the cost of underground construction can be economically justified, and above all, in densely built-up areas of the city center where land is very expensive. In addition, the ground requires less energy to heat spaces during the colder months, which can lead to lower operating costs.

Entire pedestrian and shopping streets of considerable length are being built underground. As a rule, galleries are located on several levels.
In Fig. 14a shows a cross-section of such a structure. Here, citizens move along rented retail premises in straight paths from one level to another. To reach the galleries of another level, there are stairs and ramps, but there are also wall-mounted decorative elevators.

The esplanades are illuminated artificially. However, the core, whose height reaches two tiers, also receives natural light. This made it possible to use natural green spaces in the interior.

A cross-section of another linear structure built under an open market is shown in Fig. 14.6. It interestingly combines old buildings with new volumes. Escalators are used instead of ramps and elevators. Although the surface has skylights, it is successfully used as a market area. The commissioning of a shopping and pedestrian mall increased the attractiveness of ground-based stores and shopping pavilions.

Rice. 15 Compact underground center in Minneapolis (USA), section through the central part.

Rice. 16. Underground shopping and recreational complex on Manezhnaya Square in Moscow (a team of authors led by architect.
MM. Posokhin):

a – section; b – plan; 1 – entrance from the metro station lobby, 2 – the same, from the surface of the square.

In the practice of urban planning, the construction of compact malls takes place. A section of one of them is shown in Fig. 15. The structure represents a three-level system, two of which are working levels, and the lower one is used as a warehouse. It is equipped with ramps for cargo transport with goods.

Rice. 17. Underground transport highway in the existing development:

a – laid under buildings, b – the same, under the walking esplanade; 1 – steel pipes with a monolithic reinforced concrete core laid by the punching method; 2 – vertical structures made using the “wall in soil” method; 3 – dimensions of existing foundations; 4 – anchor fastenings with pile bushes; 5 – retaining layer of the embankment, 6 – drainage layer; 7 – collector for communications; 8 – additionally buried foundations.

The rectangular central courtyard, somewhat elongated between two rows of shops, has one peculiarity. Its lightweight steel roof is raised above the roof of these stores, allowing the spaces to be illuminated with natural light through skylights.

Rice. 18. Project for the reconstruction of Tverskaya Street in Moscow. Fragment of the section using underground space for the roadway and for parking (Workshop No. 2 of Mosproekt-2).

Many very diverse structures of the road transport group are removed underground, pursuing two goals. Firstly, to reduce the harmful effects of noise on the urban environment, and secondly, to achieve savings in areas occupied by transport communications.

Traffic at street intersections and stretches between intersections is organized by building overpasses and tunnels. Let's consider methods for constructing underground structures. On stages, passages are laid underground in certain cases. For example, when a highway is straightened in a densely built-up area or a new highway is cut through the development. In Fig. 17a shows one of the options for constructing a tunnel in the protected zone of the historical and architectural environment of the city.

It has a dual function. On the one hand, within its boundaries there is a diversified traffic flow, which is carried out along two parallel streets, shown as a dotted line below on the plan. On the other hand, the tunnel is a two-level intersection with a city street perpendicular to it.

An interesting interpretation of the “wall in soil” method is interesting here. The side walls of the tunnel could not be completed by traditionally installing equipment on top, so they were erected by horizontal tunneling, pumping the solution using a water-air method. The adit coverings were made by pressing steel pipes and then installing a reinforced concrete core in them.

Another example, illustrated in Fig. 17, b, is simpler, since it was carried out on a route free of buildings. Through traffic was transferred underground, which made it possible to build a walking esplanade in place of the roadway of the river embankment, while simultaneously reducing the impact of traffic noise on the adjacent buildings.

Rice. 19 Underground garages

a – pitched-screw type; b – the same, rotary with an elevator cabin rotating around a vertical axis; c – with a monorail conveyor lift, 1 – lift machine room; 2 – lift cabin; 3 – installed vehicle, 4 – conveyor monorail; 5 – a platform for cars moving on a monorail.

One of the most serious transport problems in Russian cities is the problem of storing individual vehicles. In past times, it was not given due attention. Urban planners assumed that the country's engineering industry could not meet the demand for cars.

Rice. 20. Semi-underground parking garages:

a – inscribed in a hill; b – in the courtyard, combined with an underground passage for loading goods into stores (entry into the underground space from the ends);
c – in the “well” courtyard, covered at the floor level of the second floor and using the dimensions of the building; d – the same, but under part of the yard, 1 – air exhaust from the garage, 2 – gas-tight ceiling; 3 – surface of the cut hill; 4 – travel to shops; 5 – ramp (arrows indicate entrances to the garage).

The projects of new urban formations included solutions with a minimum number of parking lots by international standards. During the reconstruction of old built-up areas, they were practically not provided for due to the lack of free space within the blocks. As a result, the streets, alleys and courtyards of large cities were filled with settling cars.

Within old buildings, the described phenomenon can be mitigated by constructing underground parking lots. Temporary parking lots must be built simultaneously with administrative buildings and shopping and recreational complexes. Sometimes combined with retail buildings, placed in specially designated tiers of shopping and pedestrian streets. One such solution is shown in Fig. 18. The fragment shows how the parking areas in the lower tiers of the underground structure under Tverskaya Street in Moscow were designed.

Multi-storey parking lots are being built within the courtyard space of the blocks (Fig. 19). As a rule, they should be compact and not occupy large areas. Therefore, ramp entrances to tiers of multi-person parking lots, such as those shown in Fig. 19, d, rarely done. More often, ramps are replaced with elevators (Fig. 19, b and c).

Multi-storey multi-person parking lots are complex engineering structures, the construction of which can take years. In the conditions of functioning residential buildings, such construction is not always feasible, therefore, all over the world, when reconstructing residential areas, they resort to the solutions shown in Fig. 20. In one case, the terrain is used (scheme a and c), in another - they are combined with entrances to the warehouse areas of stores (scheme b), in the third - short ramps are arranged (scheme d).

Partial placement of a parking lot within the dimensions of a building is rational if it is built according to two- and three-bay schemes, but with internal supports in the form of columns. Adapting the basements of houses with internal walls is irrational, since it requires large expenses for punching and strengthening openings or replacing walls with pillars.

The problem of creating and using underground space in the largest, largest and largest cities is becoming increasingly relevant due to the shortage of free territories and the accelerated development of mass and individual transport. Its solution is relevant in the densely built-up central part, as well as in individual public transport complexes of mass attendance.

The use of underground space not only facilitates transfer conditions, but also makes it possible to completely or partially relieve the central areas from transport structures and devices (garages and parking lots, service stations and gas stations, bus stations), traffic flows transiting in relation to the center, and highway routes and stations. rail transport (metropolitan).

Underground space can be “natural”, located below the surface of the earth, or “artificial”, formed by large-area floors

It is advisable to use it for transport, auxiliary and technical structures, premises and devices, the operation of which is not associated with a long stay of visitors and personnel. These include book depositories, automatic telephone exchanges, refrigerators, pawn shops, vegetable stores, and warehouses.

Public buildings with short-term stays for visitors include cinemas, shops, reception centers of consumer service institutions, libraries, archives, and museums. In a number of cases, transport structures and hubs in the centers of large cities operate in close connection with cultural and public service institutions. So-called public transport centers are emerging.

The principles of vertical zoning of underground space in the city can be formulated as follows:

· the levels closest to the ground level up to -4 m are reserved for pedestrians, continuous passenger transport, moving sidewalks, parking lots, local utility distribution networks;

· levels at levels from -4 to -15 (-20) m are intended for subway routes or other rail transport and shallow vehicle tunnels, for multi-level underground garages, warehouses, reservoirs and main collectors;

· levels at levels from -15 to -40 m are reserved for tracks
deep rail transport, including urban railway diameters.

In the foreign practice of building a business center outside the historical core of the city, the experience of French urban planners is interesting. The new largest administrative, business and public center in the area of ​​Place de la Défense (in Paris) is located on the continuation of the main city thoroughfare, outside the historical city center.

During its design, much attention was paid to the organization of pedestrian and transport routes. Thus, the entire ensemble of new buildings has a multi-tiered composition and rises on a giant platform-podium, raised above the ground by 15-33 m, with a length of up to 1 km. This makes good use of the terrain. In this way, up to 4-5 floors of underground and semi-underground levels were created.

The main level of pedestrian traffic is a wide esplanade raised above the ground and located at the top of the platform, along the perimeter of which - mainly underground and in several tiers - there is transport. In the fourth underground level, express and local metro lines are laid, united by a station. The third is reserved for high-speed transit traffic in the Paris-Normandy direction. In the second, long-distance and local bus routes are laid out and an underground bus station is built. The first is designated for access to buildings and exits to peripheral one-way roads with developed junctions and interchanges. The railway line runs at approximately the same level. the Paris-Versailles road, which encircles the city from the north and west.

The project to renovate the center of Paris is based on something else. It was proposed to build a large underground complex of structures under the Tuileries Garden and the Louvre courtyard; This solution makes it possible to almost completely free the Tuileries area and st. Rivoli, the embankment of the Seine River from the Louvre to the Place de la Concorde, as well as to build underground parking garages of large capacity.. The complex of underground structures includes garages, parking lots, underground public buildings (theaters, cinemas, a hummock: a club, self-service eateries, a restaurant, shopping galleries/auxiliary and exhibition spaces of the museum). The construction of underground expressways helps to relieve the surface of the earth from transport.

The Philadelphia reconstruction project involves construction in the central areas of this large industrial, commercial, financial and cultural center of the United States while preserving, as far as possible, the historical appearance of the city. The most interesting is the reconstruction of its oldest part. One of the first multi-level public transport complexes in the world is being created here, in which, according to the project, enterprises and institutions of citywide importance will be concentrated, visited not only by city residents, but also by visitors. Therefore, a community center must be served by several types of surface and underground transport.

The main feature of the plan is the maximum separation of traffic and pedestrian routes. Transport traffic is organized on several levels with extensive use of underground space. In the lower, second underground level, there are subway lines and a shallow high-speed railway (25 stations). The upper one is reserved for pedestrians. It has pedestrian crossings and lighted squares-courtyards buried below ground level with entrances to shops, restaurants, bars and other commercial enterprises. This technique provides natural lighting to all service institutions located below ground level and the underground passages themselves, facilitating orientation conditions. At the ground level there is a tier of the main retail premises, as well as the so-called “freight” station. Even higher, above the pedestrian and shopping tier at the level of the second above-ground floor, a passenger bus station is designed. Garages, technical and auxiliary premises were built at the top. All pedestrian levels are connected by escalators and mechanical lifts. Passenger car entrances are designed along the entire perimeter of the center, at the level of city streets. The project included 9 large parking lots.

The main ones are located near the ring road, the highway serving the center. Entrances and exits are provided by short special tunnels, as well as systems of distribution streets and local traffic passages.

An interesting project is the reconstruction of the central mouth of the largest city in California - Los Angeles. The new compact multi-level center should be served by several modes of transport. The entire movement is organized on four levels. In the lower underground there is a line of a shallow underground highway. Two express metro stations are planned in the area. In the upper, underground section there are pedestrian crossings connected to the underground lobbies of both stations. It is planned to build an underground transport tunnel with a length of about 500 m along the streets. A three-story garage has been built under Pershing Square. The main feature of the reconstruction plan is the creation of pedestrian inter-block boulevards at two levels - streets and overpass boulevards raised to a height of 5 m above the ground, which have a great length, up to 7 km, and pass not only along the main streets, but also inside the blocks, providing convenient and quick access to shops, restaurants, the central bus station, public and other buildings. All levels of pedestrian traffic are connected by stairs, ramps, and escalators, exclusively by which passengers are lifted.

A powerful and extensive system of underground pedestrian and transport communications is an integral part of the reconstruction of the center of Montreal (Canada), which provides for the construction in the central area of ​​the city of a large complex of shopping, public and service institutions for the population of Montreal itself, as well as small towns and settlements gravitating towards it; The new center is being created on the site of the old building. On its territory there are department stores, hotels, cinemas, administrative buildings, restaurants, and multi-tiered underground garages. The city's main transport routes, three metro lines, underground sections of expressways and two railway communications pass through it. This creates a good connection between the public and shopping center and all areas of the city and suburbs.

All buildings have several underground levels. The upper one is a system of entrances to the metro, stations and pedestrian crossings, directly connected to all buildings, parking lots and garages. In the passages of downtown Montreal you can find numerous retail establishments, the front of which stretches for many kilometers. Thus, a new type of underground shopping center developed in length is created. To illuminate passages, cafes and shops located below ground level, illuminated landscaped courtyards and squares with swimming pools and fountains are designed. The pedestrian levels are connected by escalators and elevators. All buildings in the future will have a common multi-level podium with an underground lower part. The largest structure will have twelve underground tiers.

A different approach was used in the reconstruction of the old center of Helsinki. It is based on the relationship of new engineering and transport structures with existing and planned buildings and the urban landscape. The new public center will be connected to the northern and southern parts of the city by a powerful eight-lane highway, which will pass near the railway and partly above it. In addition, it is planned to reconstruct the main existing highway, the capacity of which will be increased, and the construction of traffic interchanges at different levels with underground tunnels. The construction of a multi-tiered structure is planned under the triangular square. The underground levels will house parking lots and garages, tunnel passages associated with retail and service establishments. For organizations of continuous traffic movement, all highways at intersections have interchanges with curves of large radii.

The other part of the center includes administrative and business buildings. Under them there is an underground three-tiered area, partially open. There are highways at the top and parking lots below. A complex system of tunnels, bridges and entrance ramps connects all underground levels with the surface. A central bus station has been designed on a separate site (below the level of local city streets). The underground space is effectively used in the project of the business center on Vokzalnaya Square. Seven-story office buildings enclose a spacious parking lot on all sides, raised to the height of the second floor. The system of retail premises on the ground floor and basement is connected by passages connecting the center with the station and public transport stops.

In Moscow, one of the first urban planning complexes using underground space was the ensemble of buildings and structures on Kalinin Avenue. The structures and premises located on the southern side of the avenue occupy two floors, on which all warehouse, utility and engineering services are concentrated, united by a common transport tunnel 900 m long, 9 m wide. Variations in relief are successfully adapted for entrances and exits. In addition to the service tunnel with unloading areas and two-story warehouse, technical and utility rooms, the first underground level contains the banquet hall of the Arbat restaurant, showrooms of the House of Clothes, and a large beer hall. A three-tier underground parking garage is planned under the pedestrian zone on the southern side of the avenue.

The complex of underground passages of the shopping center was built in the crowded central part of Yerevan, at the intersection of three busy transport arteries and the ring boulevard. This decision arose in connection with the need to ensure safe traffic. A single urbanized underground space has been created with the placement of trade, public catering, cultural and consumer services.

Lecture No. 1. State and prospects for the development of underground space.

Underground construction has a history almost as long as the history of mankind. Primitive people used natural caves as homes. Later, in the Bronze Age, workings appeared for the extraction of ores, precious metals and stones. The ancient civilizations of Egypt and Hindustan left behind impressive monuments of underground architecture - temples, underground labyrinths of the tombs of the pharaohs. In the city of Petra (Jordan), religious buildings and dwellings carved into red sandstone are still preserved. In the Roman Empire, underground construction reached a high level. To this day, several road and hydraulic tunnels operate in Europe, built by the hands of slaves according to the designs of Roman engineers. The drainage tunnel near Lake Fucino (Italy) has a length of 5.6 km and a cross-section of 1.8´3 m.

Tunneling in rocks was carried out as follows. A strong fire was lit in the face of the tunnel, then cold water was poured over the hot chest of the face. Due to strong thermal stresses, the rocks cracked to a shallow depth and could be disassembled with hand tools.

Underground construction continued to develop in the Middle Ages. The systems of defensive structures of fortresses and castles certainly contained underground passages. During the assault on Kazan, Ivan the Terrible’s troops used a mine charge planted in a tunnel that was passed under the city wall. Medieval mine workings, such as the Wieliczka Salt Mines in Poland, surprise modern engineers with their stability, which is due to the skill and “feeling for stone” of their builders. Medieval water supply and sewerage systems function to this day in many cities in Europe and Asia. The underground caves of the Kiev Pechersk Lavra indicate that the medieval church considered the underground space quite suitable for the life of monks, and not just the abode of “evil spirits.”

The era of the industrial revolution provided new opportunities for underground construction - powerful explosives, mechanical methods of drilling, loading, and transporting rocks. At the same time, the need for various types of underground structures has increased. Since the mid-19th century, construction of railway tunnels has been underway: the Mont Cenis tunnel, 12,850 m long, between France and Italy, was built in 1875–71, Saint Gotthard, 14,984 m long, in 1872–82. and Simgayun with a length of 19,780 m - in 1898–1906. between Italy and Switzerland. In Russia, the first railway tunnel, 1280 m long, was built in 1868; The Suram tunnel, 3998 m long, built in 1886–90, remained the longest tunnel in the USSR before the construction of the Baikal-Amur Mainline.

Underground mining of coal and ores has become widespread. Even a number of underground tunnels were built - channels for passing ships through watershed areas, including the Rhone tunnel on the Marseille-Rhone waterway (France) 7118 m long with a cross-sectional size of 24.5 x 17.1 m.

Since the beginning of the 20th century, the role of underground construction in urbanism has increased. Almost simultaneously, urban underground transport arteries - the metro - were being built in a number of European capitals and the largest cities in America. With the development of military aviation before the Second World War, European cities began building bomb shelters, and underground military factories were built in Germany.

Currently, at the turn of the 20th and 21st centuries, underground and buried structures have become a full-fledged element of urban development and are present in many technological complexes.

Underground structures play an important role in environmental protection, helping to preserve the surface of the earth. The advantages of underground premises include protection from atmospheric influences, the ability to maintain the desired temperature regime at low energy costs. An underground room reduces or eliminates the connection between the objects located in it and the environment, so it is advisable to locate harmful and dangerous industries there.

The volume of underground construction (excluding workings of the mining industry) in a number of developed capitalist countries has been characterized over the past decades by the following figures, million m3:

Considering the small population of Sweden, it should be recognized as the country with the most intensive underground construction: over the decade (1970–80) 4.5 m 3 of underground space was built there per inhabitant. The total volume of underground construction in Sweden is distributed approximately as follows: power plants - 50%, transport (tunnels, garages) - 5%, communications - 5%, oil storage facilities - 40%.

The section “Underground structures” of the course “Foundations, foundations and underground structures” is new for students of the specialty “Industrial and civil engineering”. In contrast to the courses “Underground structures” taught in mining and hydraulic engineering universities, in this course the greatest attention is paid to shallow underground structures, which are elements of industrial complexes or urban urban planning.

Lecture No. 2-3. Classification and designs of underground structures.

Classification.

Underground structures are distinguished according to their purpose: for public utility purposes (basements of buildings, underground garages, underground store warehouses, underground refrigerators, food storage facilities, underground cinemas, etc.);

– industrial and technological structures (tanks of water treatment and sewerage facilities, buried parts of crushing and screening shops of processing plants, metallurgical plants, underground nuclear boiler houses, etc.);

– civil defense and defense structures (shelters of various classes, command posts, mines for storing and launching ballistic missiles, etc.); transport and pedestrian tunnels (mountain road and railway tunnels for overcoming high passes, underwater tunnels under rivers and sea straits, metro tunnels, city road and railway tunnels, pedestrian underground passages);

– tunnels of city utility networks (sewage, collector tunnels for laying power, telephone cables, water supply, etc.);

– hydraulic underground structures (pressure tunnels, chambers of turbine rooms of hydroelectric power plants, underground pools of pumped storage power plants);

– workings for mining (for coal mining – mines, ore – mines);

– storage facilities for petroleum products and gases, toxic and radioactive waste.

Underground structures can be located: in combination with above-ground buildings; in combination with underground engineering and transport structures: in specially constructed excavations under streets, squares, public gardens; in special workings outside the city: in exhausted mine workings.

Based on their depth, underground structures are divided into buried, shallow, and deep. There is no layer of soil above the buried structures; they are covered on top with artificial structural materials or generally represent the underground part of the building.

Above underground structures of shallow depth there is a layer of soil up to 10 m. The weight of objects located on the surface contributes to the soil pressure on the lining of underground structures of shallow depth.

Underground structures of greater depth are classified as deep. The pressure on the lining of these structures no longer depends on the situation on the surface, but is determined only by the properties of the surrounding rocks and the depth of their foundation.

The following methods are distinguished for the construction of shallow and buried underground structures (Fig. 2.1):

Pit. This method is used in the construction of buried structures of shallow depth. A pit is opened in the ground, at the bottom of which, as on the surface, a structure is erected. After construction is completed, the pit is filled with soil.

Dwelling well. In this way, buried structures are built. In this case, the side enclosing walls of the structure are erected on the surface. The soil from the middle part is removed layer by layer, and the walls of the structure are lowered into the ground.

"Wall in the ground" This method is also used to construct buried structures. A narrow trench is cut from the surface along the contour of the structure to the depth of the structure. To ensure the stability of the walls, the trench is filled with clay mortar. The trench is dug out in parts and filled with concrete. The excavation is carried out already under the protection of the erected walls of the structure.

“Mountain (closed) construction method. The construction of tunnels and other deep structures is carried out using underground methods and includes (Fig. 2.2.): separation of rock from the massif (breaking, cutting); loading it onto vehicles; transportation; installation of temporary support to ensure safe work in the face; construction of a permanent lining that ensures the stability and watertightness of the mine.

Tunneling methods are divided into mountain and panel tunneling. In mining methods, all operations (mining, loading, transport, construction of temporary support and permanent lining) are divided and performed in a cyclic mode using various means of mechanization. In shield mining methods, rock cutting, loading and erection of permanent lining are performed by mechanisms combined in one unit - the tunneling shield; the role of temporary support is performed by a special moving element - the shield itself. Shallow tunnels can also be built using the pit method.

Buried residential buildings

For many hundreds of thousands of years, primitive man used natural or specially open caves as dwellings, and always turned to the earth to shelter from unfavorable climatic conditions. Only the historically short era of accessible and cheap fuel made it possible to build thin-walled houses rising above the earth's surface and supply these energy-inefficient houses with heat. Now that fossil fuels are dwindling, it's time to rethink construction.

In the USA, Canada, and a number of other countries, the construction of buried houses with earthen thermal insulation is beginning to develop. In the late 1970s, about 5% of new single-family homes in the United States were built in-depth; There is a tendency for this value to increase, especially in areas with severe winters. The advantages of buried dwellings, like other underground structures, include reduced energy costs for heating in winter and cooling in summer, reduced costs for external repairs, better sound insulation, and resistance to storms. The design of in-ground dwellings involves many different methods of energy conservation, for example, passive use of solar energy, heat recovery from ventilation emissions and sewage, etc. There is no doubt that the ambitious housing renewal program in rural areas of the USSR represents exceptional opportunities for the development of this type of housing construction.

The main types of buried dwellings in conditions of flat falling relief are shown in Fig. 1.21. An atrium-type house (Fig. 1.21, a) is located completely below ground level, has a courtyard, and is most protected from the winds. Its disadvantage is the lack of views of the area from the windows facing the courtyard. Typically, atrium layouts are used in warm climates. In flat areas with a harsh climate, semi-buried houses are most often built (Fig. 1.21, b). The “falling terrain” of a hilly area is most favorable for the construction of recessed houses (Fig. 1.21, c and d). In such conditions, it is possible to build one- and two-story houses; At the same time, the main disadvantage of recessed dwellings in flat areas is absent: limited views of the area, which is a rather significant aesthetic and psychological factor.

Proper orientation of a building relative to the sun and wind can provide significant additional energy savings. The energy of solar radiation can be used to generate heat in active and passive forms. Most active solar energy systems have flat plate collectors installed directly on or adjacent to the building. So the systems do not impose strict requirements on the orientation of the building. Heating a room by the sun through windows is called passive use of solar energy; The greatest effect is achieved when the windows are oriented to the south. In the northern hemisphere, the greatest heat loss in winter is associated with winds from the northern directions, so the orientation of window and door openings of a recessed dwelling to the south also provides the best protection from the wind.

Geomechanical processes.

The construction of mine workings and underground structures causes a disruption of the initial stress-strain state of rock masses. The resulting mechanical deformation processes lead to the formation of a new equilibrium stress-strain state of rock masses in the vicinity of the workings. We will conditionally call the new field of stresses and deformations complete, meaning that it was formed as a result of superimposing on the initial field an additional field of stresses and deformations formed during the construction of the excavation.

Knowledge of the basic patterns of rock mass deformation allows us to predict the possible implementation of mechanical processes. The complexity of this task is determined primarily by a large number of influencing factors. In the general case, a rock mass is a discrete, inhomogeneous, anisotropic medium, the mechanical processes of deformation in which are nonlinear in time. In addition to geological factors, the engineering and technical conditions of construction and, in particular, the shape and size of excavations, their orientation in the massif, the method of excavation and maintenance, fastening technology, etc., have a great influence.

It is obvious that with simultaneous consideration of all these factors, an analytical description of the laws governing the formation of a stress-strain state is practically impossible. At the same time, many years of experience and knowledge accumulated in rock mechanics show that with any combination of influencing factors, one or two main ones can always be identified, which are of decisive importance for the nature of the implementation of mechanical processes. So, for example, when constructing a tunnel in rocks, the most important of all factors will be the fracturing of the rocks. It is this that determines in this case the implementation of mechanical processes in the form of local fallouts or continuous arch formation. As another example, we can cite the case when the determining factors are the shape and size of the excavation. Thus, in the roof of a rectangular mine working with a width much greater than its height, tensile stresses that are dangerous for its operation arise. The number of similar examples could be continued.

All of the above makes it possible to determine a methodological approach to the study of the basic laws of the process of formation of the stress-strain state of the rock mass around mine workings.

First, it is proposed to consider the simplest problem, take its solution as the basic one, and then, in comparison with this solution, study the influence of various natural (natural) and artificial (technological) factors on the stress-strain state of the rock mass.

As such a basic problem, we consider the complete stress field in the vicinity of a horizontal extended mine working of circular cross-section, driven at a sufficiently large depth in a continuous homogeneous isotropic rock mass with an equal-component initial stress state q, assuming a linear physical relationship between stresses and deformations, i.e. considering the rock mass as linearly deformable. We will assume that the reactive resistance of the support R evenly distributed along the excavation contour. In this formulation, the boundary conditions have the form

s r = p at r = 1 at rà ¥. (7.1*)

Solving the corresponding problem of the theory of elasticity in the formulation of plane strain at m= 0.5, we obtain in a cylindrical coordinate system (r, q – in the plane of the cross-section of the excavation, z – longitudinal axis of the excavation) the following total stresses:

and dimensionless displacements

(7.2)

Where s q,s r – tangential (circumferential) and radial normal stresses, respectively; s z– normal stress in the direction of the longitudinal axis of the excavation; t r q,t rz,t qz – shear stress; And - dimensionless radial displacements; E – rock deformation modulus; r – dimensionless radial coordinate of the rock mass point under consideration, expressed in units of excavation radius, in the excavation Rb.

The corresponding initial stress field is characterized by the components

and the additional voltage field is the components

For clarity, the distribution of components s q And s r The complete (solid lines), initial (dash-dotted lines) and additional (dashed lines) stress fields are shown in Fig. 7.1.

The rocks surrounding the excavation have limited bearing capacity, that is, the ability to resist increased stress, and can be deformed without destruction within certain limits. Therefore, the consequence of the new stress-strain state formed as a result of workings can be the processes of destruction of rocks, manifested in some rocks in the form of brittle fracture, in others - in the form of plastic flow. As a result, areas of extreme conditions and complete (ruinous) destruction are formed around the excavation, which can cover the entire contour of the excavation or its individual parts. The deformability of destroyed rocks increases, and this in turn causes a significant increase in displacements of the rock contour.

Thus, the formation of partially or completely destroyed rock areas in a rock mass is one of the forms of implementation of mechanical processes of rock deformation or, as they say, one of the forms of manifestation of rock pressure. Partial or complete arch formation, significant displacements of the rock contour, i.e. the main sources of the formation of loads on the structures of underground structures, are a consequence of destruction processes. Therefore, knowledge of the basic patterns of pore destruction around workings is necessary for a qualitative and quantitative assessment of possible manifestations of rock pressure and, consequently, a scientifically based choice of methods and means to combat these manifestations.

As noted earlier, rock destruction occurs in different ways, both in the form of brittle fracture and through plastic deformation. Therefore, various geomechanical models are used for mathematical analysis of mechanical destruction processes.

In brittle-fractured rocks, the formation of a region of limit equilibrium can lead to a violation of the continuity of the massif on the outer boundary of this region, which is expressed mathematically in the form of inequality of tangential normal stresses acting on both sides of the specified boundary; the process of destruction changes the mechanical characteristics of rocks in the region of limit equilibrium and, in In particular, the compressive strength of rocks is reduced to the value of the residual strength. This case corresponds to the model of an ideal-brittle medium, defined by the deformation diagram Oab(Fig. 8.1) by the physical equation (5.69) in the beyond-limit region of deformation.

In plastic rocks, the formation of a region of limiting equilibrium can occur without such noticeable destruction as in brittle rocks, and manifests itself in the form of plastic flow without discontinuities. In this case, in a certain deformation range, no significant change in mechanical characteristics occurs. This allows us to use in this case the ideal model of a plastic medium, shown in Fig. 8.1 as a diagram Oas, and the physical equation (5.67) at the extreme deformation region.

Loads and impacts.

Calculations when designing wells must be made for loads and impacts, which are determined by the conditions of construction and operation of the structure (Fig. 1).

Calculated weight values ​​of walls G 0, kN, bottom G d, kN and thixotropic solution G T, kN are determined by the design dimensions of the elements, taking the weight of reinforced concrete structures in accordance with the requirements of the SNiP chapter on the design of concrete and reinforced concrete structures (II).

The horizontal soil pressure on the well is formed by the following loads:

a) the main soil pressure is determined as the soil pressure at rest according to the formula:

, (1)

Where g – specific gravity of soil, kN/m 3 ;
z – distance from the ground surface to the section under consideration, m;
j – angle of internal friction of the soil.

For wells immersed below the groundwater level, the specific gravity of the soil is taken taking into account the weighing effect of water, i.e.

Where g s – specific gravity of soil particles, kN/m 3 ;
g w – the specific gravity of water is assumed to be 10 kN/m 3 ;
e – soil porosity coefficient.

b) the main pressure of the thixotropic solution during the period of immersion of the well is determined by the formula:

Where g 1– specific gravity of the thixotropic solution, kN/m3 .

c) additional soil pressure caused by the tilting of the layers:

where a is a coefficient depending on the inclination of the layers (accepted according to (2), p. 14).

d) hydrostatic pressure of groundwater, taken into account in all soils except water-resistant ones:

, (5)

Where h b – distance from the ground surface to the groundwater level, m.

e) additional pressure from a continuous vertical load uniformly distributed around the structure q:

, (6)

e) additional pressure from a vertical concentrated load<2 или от нагрузки, равномерно распределенной по прямоугольной площади поверхности. Определяется по рекомендациям работы (2), с. 19-24.

The friction forces of the well knife on the ground are determined by the formula:

, (7)

Where T– coefficient of working conditions. When calculating for ascent T= 0.5, per dive m = 1;

And– outer perimeter of the well knife, m,

h u– knife height, m;

f– soil resistance along the lateral surface of the blade part, kPa. Determined from the table (/2/, p. 17). For approximate calculations, you can take (when immersing the well to a depth of up to 30 m):

– gravelly sands, large and medium-sized 53 – 93

– fine and dusty sands 43-75

– loams and clays, hard and semi-solid 47 – 99

– hard and plastic sandy loams, hard and soft plastic loams and clays 33 – 77

– sandy loam, loam and clay, fluid and fluid-plastic 20 – 40

The friction forces of the well walls in the thixotropic jacket zone are determined by the formula:

, (8)

Where N t–height of the thixotropic jacket, m;
T°– specific friction force of the well walls in the thixotropic jacket zone, assumed to be 1–2 kPa . When calculating for floating (after plugging the crack of the thixotropic jacket with cement-sand mortar) 40 kPa .

The soil resistance forces under the banquet knife are determined by the formula:

Where R – the calculated resistance of the foundation soil is taken in accordance with the recommendations of the work /12/, p. 37 (Table 1-5); F u – area of ​​the knife sole, m2.

Well calculation.

Calculation of well immersion is made from the condition:

, (10)

Where G– weight of the well and additional loads, taking into account the load safety factor g f = 0,9;
g f1– immersion reliability coefficient: g f1 > 1-at the moment the well moves, g f1= 1 – at the moment the well or tier stops at the design level.

Wells immersed below the groundwater level, after installing the bottom, must be designed to float in any soil (except for the case when drainage is carried out under the bottom) for design loads from the condition:

, (11)

where SG is the sum of all constant vertical loads taking into account the additional load with a safety factor for the load g f = 0,9;
F g– bottom area, m2;

h w– distance from the bottom of the bottom to the groundwater level, m;

gfw– safety factor against ascent equal to 1.2.

Calculation examples.

Calculate a well with an internal diameter of 20 m, a depth of 30 m, for loads and impacts arising under construction conditions (Fig. 2 a). The well is immersed in a thixotropic jacket (g 1 = 15.0 kN/m 3) using water reduction. The soils are homogeneous, represented by refractory loam ( g= 16.6 kN/m 3, g s = 26.8 kN/m 3 , e= 0.7, j = 18°, With= 17 kPa).

Based on the initial data, we determine the weight of the well walls:

G 0= 3.14 × (10.6 2 – 10.0 2) × 30 × 25 = 29108 kN.

The main pressure of the thixotropic solution during the immersion period (3):

– at 0.00 Р r – 0;

– at around 28.00 Р r= 15×28 = 420 kPa.

Additional pressure from continuous vertical load q= 20 kPa (6):

P g= 20× tg 2 (45-18/2) = 10.5 kPa.

Based on the obtained values, we construct a pressure diagram (Fig. 2a). Friction forces of the well knife on the ground (7):

T u=1×2×3.14×10.8×2×77 = 10445 kN.

Friction forces of the well walls in the thixotropic jacket zone (8):

Tm=1×2×3.14×28×2 = 352 kN.

Total friction forces:

T =T u + Tm=10445 + 352 = 10797 kN.

Ground resistance forces under the knife bench (9):

R u= 3.14 × (10.8 2 – 10.6 2) × 200 = 2688 kN.

We will calculate the immersion of the well using formula (10):

The well is immersed.

Basic soil pressure (1):

– at 0.00 Р r,о= 0;

– at around 19.00 (groundwater level):

– at around 30.00:

Hydrostatic groundwater pressure (5):

Additional pressure from continuous vertical load = 20kPa (6):

Based on the obtained values, we construct a pressure diagram (Fig. 2 b).

Friction forces of the well knife on the ground (when calculating for ascent) (7):

Friction forces of the well walls on the ground after filling the gap with cement-sand mortar (when calculating for floating) (8):

We will calculate the well for ascent using formula (11), taking into account the weight of the bottom

G g= 3.14×10.8 2 ×1.8×25 = 16481 kN .

No loading of the well is required.

Drainage and drainage.

The water content of soils during the construction process causes technological difficulties. During the operation of an underground structure, groundwater generates an Archimedean weighing force, which, if there is insufficient load from above, can lead to the floating of the structure. In addition, even with the most reliable types of waterproofing, water penetrates into the underground structure. Drainage is a system of drains and filters that collect underground water and remove it from a pit or structure, and drainage is a pumping system (pumps, pipelines).

In case of rugged terrain, it is possible to install gravity drainage if there is a sewer collector in the accessible vicinity at a depth greater than the depth of the drainage devices. In all other cases, drainage requires lifting the captured water to the surface using drainage. Since drainage is associated with the consumption of electricity, and in the event of interruptions in its supply, the water content of the massif can quickly change, soil drainage with drainage is usually not provided for the operational period, and the structure is designed to operate under the natural regime of groundwater. During the construction process, on the contrary, as a rule, they strive to completely drain the pit.

Shield method.

To develop soil, tunneling shields are widely used, which are mobile supports that allow the development of soil and the construction of linings under protection. The cross-sectional shapes of the shields are circular, vaulted, rectangular, trapezoidal, elliptical, etc. Based on the loosening method, non-mechanized and mechanized shields are distinguished. In the first case, the soil is developed manually or using hand tools, in the second, all operations are completely mechanized and performed by a special working body. A circular tunneling shield is a steel cylinder consisting of a knife and support rings, as well as a tail shell (see Fig. 1).

The knife ring cuts the soil along the contour of the excavation and serves to protect people working in the face. When driving in soft soils, it has a widened upper part - a foreback, and in weak ones - a safety visor. The support ring together with the knife ring is the main supporting structure of the shield. Along the perimeter of the support ring, panel jacks are evenly spaced to move the unit. The tail shell secures the excavation contour at the site of construction of the next lining ring.

Non-mechanized shields are equipped with horizontal and vertical partitions, retractable platforms, as well as downhole and platform jacks.

Panel penetration work begins with the installation of panels and equipping them with the necessary equipment. Depending on the type of underground structure, its depth and engineering-geological conditions, the panels are assembled in open excavations or pits, lowered entirely through a mine shaft or inside a chamber, or mounted in special underground chambers.

The technology of shield penetration depends mainly on the type of shield, soil properties and type of lining. When excavating with non-mechanized shields, the development, loading and transportation of soil is carried out in the same way as in the mining method of work using standard mining equipment (drill hammers, loaders, trolleys, electric locomotives, etc.). Tunneling shield complexes KT 1-5.6 are successfully used; TSCHB-3, KM-19, KT-5.6B2, which consist of a panel unit and equipment for mining, installation, waterproofing and auxiliary work. The level of mechanization of panel complexes reaches 90...95%, and the speed of tunneling with a diameter of 5...6 m is 300...400 m per month or more.

Mechanization schemes for panel work differ in the methods of excavating the soil, fastening the roof and the face of the face; all other operations for loading and transporting soil, constructing and waterproofing the lining are performed similarly. From the face of the shield, the soil is supplied to the main conveyor-reloader, at the end of which a bunker with two gates is placed, which allows the soil to be unloaded into trolleys. Lower or upper acting pushers are attached to the bridge, with the help of which individual trolleys, trolleys with blocks, pneumatic concrete spreaders, etc. are moved.

As the soil is excavated, the excavation is secured with arch, anchor, shot concrete, and combined temporary contour support (Fig. 2). Arched support is made from rolled metal profiles (I-beams, channels, pipes) curved along the contour of the excavation. Each arch consists of two or four elements connected with bolts. The arches are installed in increments of 0.8...1.5 m, resting on the ground through wooden pads and secured with wooden or metal spacers. The space between the arches is covered with boards, reinforced concrete slabs or corrugated steel sheets. In the vault part, a continuous tightening is arranged, dismantling it before concreting. The support is arranged in the form of anchors located in drilled wells, “suspending” a section of disturbed soil from the undisturbed massif; wedge and expansion metal anchors with a locking device, reinforced concrete (rammed, injection and perforated) anchors fixed throughout the entire depth of the hole, steel-polymer anchors fixed in the holes with epoxy or polyester resins and come into joint work with the surrounding mass after 1...2 hours are used after installation.

In large excavations, prestressed anchors are used, which are embedded in the

Human exploration of underground space began in ancient times. The prototype of underground structures can be considered natural caves and voids in rocks, used by our ancestors. The use of natural underground cavities as dwellings by primitive people is noted already in the period 700,000-800,000 years ago. The earliest underground settlements in anatomically modern people, dating back to 120,000-60,000 BC, were discovered at the mouth of the Klasis River (South Africa) - the oldest in their caves; Katseh in Israel. It is believed that since about 5,000 years ago, natural caves have been used by humans almost everywhere as habitation. Other examples of the use of underground cavities are the Kiik-Koba, Kosh-Koba caves in Crimea, Moustiers in France; The first artificial underground structure was found in Russia near the village of Kustenki. Dozens of similar structures have been found on the East European Plain. In the period 800-1500 years ago, the cave cities of Vardzia (near the city of Borjomi) and the settlement of Derinkuyu (in the lane “dark well”) were already built. In Spain, underground structures exist to this day. In the southern part of Andolusia, more than 8,000 inhabited caves have been recorded at the present time. Currently, the following underground cave cities are: Uplistsikhe - “Fortress of the Lord” (near the city of Gori) and the city of Petra (southern Jordan). There are many known places of traglodyte settlements in France. Most of them were used as shelters near villages and towns. At the beginning of the twentieth century, about 20,000 French citizens still lived in caves. Currently, many caves are equipped with holiday cottages.

The history of engineering development of underground space is much shorter. About 4,000 years ago, a transport tunnel was built under the Euphrates River, which connected the royal palace with the Temple of Jupiter on the other side of the river. The length of the tunnel is 920 meters, height 3.6 meters, width 4.5 meters. The river bed was sectioned by bridges. The tunnel was built using an open method. The tunnel lining was made of stone masonry and bitumen cement. The vault of the structure has an arched shape. The construction of such a tunnel would be an event even today. It should be noted that the next tunnel was built only 4,000 years later in 1842 under the Thames River. Underground structures are repeatedly mentioned by the historian Herodotus. In particular, fragments of the Egyptian pyramids are described. In Armenia approximately 1500 BC. many canals were built. The largest of them was 20 km long. A number of canals built for navigation purposes are still in use. During the same period, in the city of Athens, the Hadriana water pipeline was built for water supply with a total length of tunnel sections of 25 km. These tunnels were built through shafts 10-40 meters deep to supply rock and ventilate the faces. After repairs made 50 years ago, the tunnel is working again. In the Roman Empire, a water supply tunnel 5.5 km long and 2x3 m in size was built on Lake Fucciano. Mayakovsky visited it and wrote about it. It is interesting to note that this tunnel is lined with concrete with a strength of 10 mP on a limestone solution. In 1450, construction began on a tunnel on the road between Nice and Vienna. Soon, unfortunately, work was suspended and resumed only 300 years later.

At the end of the 15th century, several water supply tunnels lined with stone masonry were built on the territory of the Moscow Kremlin. In the 16th century, during the reign of Ivan the Terrible, active underground construction was carried out in Moscow. In 1852, Aznacheev attempted to build an underwater tunnel under the Moscow River. In the 17th century, several underground passages up to 200 meters long with wooden and stone fastenings were soon built in Nizhny Novgorod. In Russia, in Altai, a complex hydraulic power plant was built in 1783-1785. Water passed through different tiers of tunnels. This made it possible to mechanize the entire process of mining and lifting ore from a depth of 150 meters. The father of tunnel construction was M. Brunnel, in 1825 he proposed the shield boring method, with the help of which a 450-meter long tunnel was built in soft rocks under the Thames River. Engineers Traithead and Barrow built a second underwater tunnel under the Thames with a length of 450 meters and a diameter of 2 meters. For its penetration, a circular cross-section shield with lining of cast iron segments was used. This shield is the prototype of modern tunnel-boring shields.

Since the first quarter of the 19th century, intensive construction of tunnels began in many countries (France, England, Switzerland, Italy, Germany, Sweden, USA, Russia). The first railway tunnel was built in 1826-1829 in England on the Manchester-Liverpool line. The second is on the Etienne-Lyon line. In France it was put into operation two months later. The first trans-Alpine railway tunnel, Mont Siny, was built in 1871. The most unique is the 20 km long Symphlon tunnel, built in 1898-1906 under particularly difficult engineering and geological conditions (high rock pressure, inflows of water with a temperature of 55 degrees Celsius). During the construction of these railway tunnels, the following were used for the first time: Brunnel shield (1825), hammer drills (1851), and dynamite.

Since the second half of the 19th century, a number of countries began building subways. An important stage in the development of the era of industrial tunneling is the construction of the London Underground, opened in 1862. The first section was only 3.6 km long, but already in 1863 a parliamentary commission approved the construction of a thirty-kilometer tunnel (underground ring railway). It was put into operation in 1884 and on one of the branches included the Brunnel Tunnel, which turned out to be the oldest section of the London Underground. The New York City subway was completed in 1868. In Chicago - in 1882, in Paris - in 1900, in Berlin - in 1902. The first project of the Moscow metro was developed in 1901, and then improved in 1902. The engineers were P.I. Belinskikh, I.E. Knorov. But the Moscow City Duma rejected this project on September 18, 1902. The main opponents of the construction were: the Moscow Archaeological Society, which united the most prominent historians of Russia, and the Moscow clergy. Only in 1931 was the city bureau of the Metrostroy technical department organized and construction began.

The first railway tunnels in Russia were built in 1859-1862 on the St. Petersburg – Warsaw railway. In 1892, the construction of a four-kilometer tunnel through the Suran Pass was completed in Georgia. Construction was carried out in fractured rocks with high rock pressure using a supported vault method. In this tunnel, for the first time in Russia, a hydraulic machine was used for drilling holes. The calculation of the vault as an elastic arch was carried out at the suggestion of Professor L.F. Nikolaev.

At the end of the First World War in Italy, a railway tunnel with a length of 18,510 meters was built on the Florence-Bologna line. In 1936-1941, the world's first extended underwater tunnel was built under the Simones Strait in Japan. Its length was 6330 meters. In 1939, the world's first underground garage was built in Cardifall, buried 10.6 meters under one of the city squares; it also served as a shelter for the population for a special period. Since 1940, limestone has been actively used in the United States for storing perishable foods. Before the outbreak of World War II, intensive construction of underground factories was carried out in Germany. For this purpose, the following were used: existing mine workings with the expansion of individual sections to the required size, horizontal mine workings inside hills or mountains, underground and semi-underground structures erected in deep pits.

One of the largest factories for the production of V-1 and V-2 rocket launchers at Northouse was located inside a large hill. The plant consisted of two parallel tunnels with a length of 2.3 km, located at a distance of 1.4 km from one another. The tunnels were connected to each other by forty-six transverse workings. The total usable area of ​​the underground space was about 15 hectares. In 1948, several underground storage facilities were built in Anantalya (Finland).

Speaking about the history of underground space, one cannot ignore such an aspect as the construction of underground hydraulic structures, which are characterized by the greatest complexity and labor intensity compared to industrial and civil facilities. The following comparison can be made: the cross-sectional area of ​​chamber workings for turbine rooms, surge tanks and distribution devices of underground hydroelectric power plants often exceeds 1000 m 2 while the distillation cross-sectional area is 20-25 m 2 .

As an example, we will give the project of the underground hall of the Ragun hydroelectric station. It is 320 meters long, 20 meters wide and 64 meters high. It is designed at a depth of 500 meters from the surface of the earth. In Finland, from 1956-1975, 4 underground hydroelectric power stations were built. The largest of them are called “Pirt-tikoski”. Built at a depth of 100 meters above sea level. Water is supplied to the hydraulic turbines through two pressure tunnel conduits, each 60 meters long with a cross-sectional area of ​​130 m2 (considered the second largest in the world). In 1979, a hydraulic tunnel with a length of 120 km (cross-sectional area 15.5 m2) was built in Finland. It is used for Helsinki's water supply. The construction of underwater tunnels is no less difficult. In 1983, a road tunnel with a length of about 1 km was built in St. Petersburg, providing transport links between Kanonersky and Gutunersky islands. The underwater section has a length of 375 meters. Constructed from lowering sections 75 meters long, 13.3 meters wide and 8.05 meters high, made of monolithic reinforced concrete with external metal insulation.

The use of underground space, along with the conservation of land resources, allows us to solve a number of social and economic problems:

1) Placement of gas, vapor and liquid objects Sources of noise and other harmful factors affecting human life and the natural environment; 2) Construction of mechanical engineering facilities with high precision manufacturing of products, as well as automated workshops and complexes of industrial enterprises (including educational and scientific laboratories);

3) Reliable and safe storage of petroleum products, gases, chemicals and medicines, flammable and dangerous substances, archival materials, museum and cultural values;

4) Construction of hospitals, sanatoriums and hospitals, sports facilities in underground structures located in specially selected rocks;

5) Economical placement of processing enterprises in the food, chemical, meat, dairy, wine and other industries, the technology of which is most effective in underground conditions;

6) Organization of movement of people, cars, trains, water, industrial waste.

All this is possible with a good organization of a comprehensive study of the engineering-geological, hydrological and geometric conditions of the construction area.