CONSTRUCTON OF THE MINES AND THE UNDERGROUND STRUCTURES
Mine and underground construction
The production of shallow emplacement play a special role in the life of cities. They may provide the movement of people from one point to another city in a short time; building for the installation of networks of municipal services or for example to move the water diversion tunnels of hydroelectric power plants.
Since these development play an important role in the life of the city and the people living in it. The life of the city continued need to build literate generation. The risk of accidents (falls or collapses) in the workings of the place to be, and often happens through the fault of hardware. Fixation workings - one of the main production processes in the construction, any underground facilities.
Design and construction technology of mounting openings must meet the following criteria:
The whole complex underground structure should being built in uniform design and technological solutions are mutually linked together.
Since a large number of ways to the construction of tunnels meant by a labor-intensive as the development of soil and its structure are separate parts rather than the entire cross section of the tunnel. I drew his attention to the construction of tunnels using advanced fiber-concrete lining.
Fastening generation using fiber-reinforced concrete have a number of advantages, namely:
The aim is to study the parameters of advanced fiber-reinforced concrete lining with, having regard to the workings of shallow emplacement (tunnels).
The main objectives of the study:
Object of research: anticipatory Fiber-reinforced lining used in shallow workings laying.
Subject of research: ACL parameters and composition of fiber-reinforced concrete used in it.
Idea: the use of fiber-reinforced concrete in the advanced concrete lining in the construction of shallow workings inception.
Scientific novelty: identification and dependency strength characteristics of fiber-reinforced concrete used in the ACL, for laying the shallow workings.
The practical significance: work involves contributions to a foundation and advanced calculation methods and its lining with the use of fiber-reinforced concrete structure with the geological features of shallow workings inception.
I drew his attention to the construction of tunnels using advanced fiber-concrete lining.
To avoid confusion between the terms sprayed mortar
and shotcrete
, we prefer to use the term shotcrete
for each spray a mixture of cement and an inert filler.
Shotcrete &ndas one way device concrete structures. Along with the traditional methods of placing concrete, shotcrete also has special requirements for the quality of the mixture during the concreting.
Fiber-reinforced - one of the varieties of cement concrete, which contains fiber or fiberglass as a reinforcing material.
After the sinking of excavation in the natural rock massif gradually transforms from an elastic state to state buckling and further in an unstable state. Installing temporary support during penetration should ensure the sustainability of the array. This lining can act as a rigid support for the surrounding array, or as a supple design, allowing deformation in conjunction with an array.
Supple lining design allows maximum use of its own bearing capacity of the rock mass. This fixture development should be carried out as quickly as possible after the development of the breed, in order to effectively use the natural resistance of the rock to its transition into an unstable state. This is achieved by creating a compliant set consisting of a thin shell fiber-reinforced densely deposited on rock and reinforced (if necessary) mesh or arches.
Erected thus temporary support interacting with the breed and tightly pressed against her around the perimeter of the development, artificially lengthens preserve the stability of rocks as long as there is no built permanent lining. The cross section of the tunnel is released, which makes it possible to widely use high-mining mechanisms and the permanent lining can be built at a considerable distance from the bottom and from the whole section using mechanized formwork and concreting machines.
In this method, during the sinking to systematically conduct test measurements of rock pressure, stress and strain on the lining and lining of the array. This allows the measurement results to increase or decrease the thickness of the layer [2].
Figure 1 – Longitudinal section constructed tunnel
Consider also any fiber used better. The primary reinforcing fibers are made of polypropylene and steel fibers.
Fiber made from synthetic fibers - the cheapest and most chemically stable. However, polypropylene and glass still do not have sufficient resistance and quickly applied to improve the characteristics of concrete in initial curing period.
In contrast, the metal fiber improves the mechanical characteristics of concrete after a set them strength. However, the steel fibers have a high consumption per cubic meter of concrete, because of what is necessary to look for more affordable ways of reinforcing concrete[4].
In my opinion, the best-reinforced concrete used for the construction of advanced fiber-reinforced concrete lining in a shallow workings laying - a basalt fiber.
This fiber is a basalt fiber segments of a certain size, the introduction of which considerably increases the tensile strength of concrete, having a number of advantages compared with the synthetic fibers and steel fibers considered earlier.
Figure 2 – Basalt fiber
We note a number of advantages over other basalt fiber:
An analysis of the literature to determine the purpose and objectives of the master's work.
In the master's work will be carried out laboratory tests and production schedules developed construction workings way ALC using fiber-reinforced concrete, taking into account the geological features of shallow workings inception.
In writing this essay master's work is not yet complete. Final completion: January 2016. Full text and materials on the topic can be obtained from the author or his manager after that date.