The technology of construction of underground stations
Construction of underground metro stations is one of the technically challenging and labour-intensive industries of modern construction with relatively high material and financial costs.
The volume and scope of work at the station is determined by the type and number of facilities included in the station complex. These facilities are designed for boarding, disembarking and transfer of passengers (station tunnels and distribution facilities, escalator tunnels with suspended cameras engine room, underground and surface halls, connective and transitional passages), the organization of movement of trains (traction-secondary substation, circulating devices and stubs) and for compliance with appropriate sanitary-hygienic conditions (ventilation shafts, tunnels, chambers and kiosks, toilets and drainage pumping chambers).
In addition to constructing tunnels and chambers for different purposes, at stations is a large amount of construction, installation and finishing works. These include the construction of the in-tunnel structures (passenger platforms, trackside devices, catwalks, stairs, office space, cable channels, foundations under escalators, etc.), installation of waterproof umbrellas and architectural design of passenger buildings, installation of escalators equipment, traction-secondary substation, ventilation and drainage installations,sanitary units, lighting.
Thus, the construction of underground metro stations involves a complex system of interrelated production processes, which resulted in creating a complex of facilities necessary for normal operation of the station.
The peculiarity of the organization of work is that certain types of work and production processes in different parts of the station complex should be technologically linked with each other. While some of them need to combine in time, while others run in a strict sequence.
The subway lines are deep underground stations constructed by the closed method (without opening the earth’s surface), and shallow – an open way (generally in open pits, followed by backfilling of the construction). Obviously, these methods require various techniques of production of works, the sequence of their execution, the technology and necessary equipment. However, the advanced experience of construction and modern level of technical equipment industry allow us to identify General principles, which in any case should be the basis for the decision of a question on the organization of works on construction of the station.
First of all, note that the methods of production of works, their sequence and order of construction of underground stations generally accept in direct dependence not only on the engineering-geological conditions, structural type of station, but also on the materials of the structures, the sizes of these elements, their mutual arrangement in the structure and nature of relationships between them. Organization of works on construction of the station must conform to modern scientific and technical progress of construction and include:
the construction of the station complex or individual structures on-line method, which provide the rhythm, uniformity and continuity of the technological process;
the possibility of increasing the scope of work to reduce construction time;
the high technical level of construction with the least labour intensity;
industrial methods work through the use of complex mechanization and automation of primary and secondary processes;
high quality work with the least labor, material and financial costs;
full safety all types of construction.
The procedure and methods of work are prescribed so that they are eliminated or reduced to the minimum precipitation and the shifting of the earth near the station under construction, not have a negative impact on the environment, architectural and historical monuments and did not violate the prevailing conditions of city life. Towards the realization of the above principles will look at specific examples from practice of domestic metro construction.