RU2478789C1 - Precast support of vertical shaft - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: precast support of a vertical shaft comprises an upper layer of shotcreting, middle and inner layers of precast and cast-in-situ reinforced concrete. The middle layer is erected from blocks with protrusions of reinforcement along all end and inner surfaces with eyes from reinforcement steel at upper and lower ends. Blocks represent a composite structure, comprising a latticed frame made in the form of reinforced concrete beams and a composition filling the cells from tailings of ore dressing activated in a disintegrator, of the first and second phase of treatment and granules of foamed polystyrene.

EFFECT: reduced labour intensiveness of operations performed in a downhole, higher speed of construction, reduced probability for distribution of underground waters from separate water-bearing horizons crossed by a shaft in the entire thickness of underlying rocks, reduced metal intensity.

2 dwg

Description

The invention relates to the mining industry, in particular to the structures of the lining of vertical shafts, and can be used in the shafts of coal mines and mines under construction in difficult geological conditions.

Known designs of multilayer reinforced concrete supports [1, 2], including bearing and pliable layers. The closest in technical essence is the support of the shaft shaft [3], which includes a bearing compensation shell with vertical stiffeners separated by stiffeners and an outer shell. To increase the reliability of operation, the lining is equipped with a filler of vertical channels from ductile foam material. Part of the stiffeners is made of metal elements fixed in the supporting and outer shells, and metal sheets, channel blocks or I-sections can be used as metal elements, and anchor rods can be used for pinching and fixing in the rock mass. The support of this design has several advantages.

1. The possibility of use in difficult mining and geological and mining conditions.

2. High bearing capacity.

3. The presence of a compensating shell, providing flexibility of the lining.

4. The ability to provide thermal insulation when driving trunks in frozen rocks.

5. The solidity of the inner layer of the lining structure allows you to make it smooth, which reduces the cost of ventilation during operation of the trunk.

However, the existing solution has several disadvantages.

1. The high complexity of the construction of the lining.

2. The low penetration rate during sequential operations and the decrease in the safety of tunnel workers, the high cost of the necessary equipment, the clutter of the cross section of the shaft and shaft surface when conducting work in a parallel circuit, as proposed in [4].

3. The presence on the external contour of the lining of vertical channels filled with foam material, leads to the penetration of groundwater into previously not flooded layers. This can lead to erosion of individual sections of rocks containing soluble particles, the formation of voids, the growth of uneven loads on the lining, and ultimately to its destruction.

4. The presence of metal stiffeners in the lining increases the metal consumption and reduces durability, since under the influence of aggressive mine water the metal actively corrodes.

5. The need for temporary support.

6. The presence of compensatory voids that do not resist deformable rocks will lead to large voltage drops in the rocks and the development of local plastic deformations in them. As a result, the entire load will be perceived only by stiffeners.

7. The bulk of the support erection operations is carried out in cramped conditions of the bottom of the trunk, which reduces the quality of work and adversely affects the speed of its implementation.

The aim of the invention is the creation of a reinforced concrete prefabricated monolithic support structure suitable for use in difficult mining and geological and mining conditions and allowing to reduce the complexity of the work performed in the face, to increase the construction rate, to reduce the likelihood of groundwater spreading from individual aquifers crossed by the trunk throughout the thickness underlying rocks, reduce metal consumption, exclude the use of temporary support, optimize the nature of the adjacent rock mass as well as individual support elements.

To achieve this goal, it is proposed the construction of a three-layer reinforced concrete precast-monolithic lining, including an outer layer of sprayed concrete (see figure 1, position 2), applied to the rock walls of the barrel (see figure 1, position 1), the middle layer of blocks with monolithic joints (see figure 1, position 3) and the inner layer of monolithic reinforced concrete (see figure 1, position 4).

The block is a reinforced concrete structure with releases of reinforcement on all end and inner surfaces (see figure 2, item 8). In the upper and lower ends, at the manufacturing stage, eyelets made of reinforcing steel are installed (see figure 2, item 7), designed to suspend the blocks to the previously installed lining ring. The installation of the reinforcing mesh (see figure 2, item 9) for the construction of the inner reinforced concrete shell is made on the shaft surface, and the block is lowered into the barrel in a form that is completely ready for installation. The body of the block consists of two main elements: a lattice frame (see figure 2, position 5), made in the form of reinforced concrete beams, and filling the cells of the composition (see figure 2, position 6). The specified composition is a mixture of ore dressing tailings activated in the disintegrator, the first and second processing stages, exhibiting enhanced rheological properties, and expanded polystyrene granules. With a slow increase in loads, in a state that has reached design strength, this material is deformed without breaking continuity [5, 6]. Thanks to this selection of components, an environment with increased "distributed" porosity is created, which, combined with the ability to actively deform under load without damage, gives the structure as a whole section flexibility. It also allows you to unload adjacent rocks during the operation of the lining, while maintaining the volumetric stress state of the fixed massif.

The support of the proposed design is constructed as follows. After blasting and loading the rock to the required depth, the first layer of lining made of spray concrete is applied to the rock walls of the barrel. Further, the lining blocks are lowered into the bottom of the trunk and proceed to their installation with the help of a loading machine or a special manipulator. The block is suspended to the upper ring through the eyes 7 (see figure 2) made of reinforcing steel. After suspending all the blocks in the ring, pneumatic jacks are installed at their ends, the mounted ring is bursting into the barrel walls, individual blocks are wedged, reinforcement outlets between the blocks are welded or bonded and reinforcing cages are designed for the installation of an internal monolithic reinforced concrete lining. Then the jacks are removed. If the ring of blocks is the last in the entry, then from below it is sprinkled with rock. Next, the formwork is lowered and sprinkled with rock. After installing, leveling and wedging the formwork, the concrete mixture is laid, first of all, supplying the solution for the blocks and between them. After the concrete has set the required minimum strength, the rock continues to be loaded.

The support of this design has the following advantages.

1. Less laborious, easy installation.

2. Installation works can be carried out both in parallel and in parallel-panel, combined or serial technologies.

3. For the construction of the lining does not require installation of additional equipment in the trunk, which reduces construction costs, frees up the cross section of the trunk, reduces the number of winches located on the surface, etc.

4. The localization of compliance zones in individual cells does not lead to the formation of continuous drainage channels in the body of the lining and minimizes the risk of groundwater penetrating into the underlying horizons.

5. The location of all metal elements in concrete minimizes the risk of corrosion and destruction.

6. There is no need to use temporary support.

7. The cells in the outer layer of the lining are filled with material capable of decreasing in volume with increasing resistance. Thus, it is possible to ensure the operation of the lining in a given compliance mode with increasing resistance.

8. The lining comes into operation immediately after its construction.

9. The construction of complex multilayer structures in cramped conditions of the trunk, with a significant influx of water, leads to a decrease in their quality. And the manufacture of a cellular structure in the factory and the bonding of the reinforcing cage on the surface can guarantee to give the lining the required properties for a given quality.

The proposed design can be used both for fastening the entire trunk, and for its individual sections crossing the layers of weak unstable rocks.

Literature

1. Patent No. 2060394 C1 RF, E21D 5/04, "A method for attaching a mine shaft with monolithic reinforced concrete and sliding formwork for its implementation."

2. Patent No. 3332967 A1 DE, E21D 5/04, "Schachtausbau mit dreiachsig ge-druckten Stahlbeton-Tragringen".

3. Copyright certificate No. 1747704A1 SU, E21D 5/04, “Support shaft shaft”.

4. Patent No. 2060394 C1 RF, E21D 5/04, “A method for attaching a mine shaft with monolithic reinforced concrete and sliding formwork for its implementation”.

5. Stradanchenko S. G. Report on research on the topic: “Reducing the risk and mitigating the effects of technological disasters by creating environmentally friendly technologies for the development of industrial deposits with the extraction of useful components from them by mechanochemical activation” (intermediate, stage No. 2). The name of the stage: “Justification of the technologies for the elimination of technogenic deposits” / SC No. 14.740.11.0427, State Registration No. 01201065283 / С.Г. Stradanchenko, V.I. Golik, S.A. Maslennikov et al. 2011 - 92 p.

6. Stradanchenko S.G. Report on research on the topic: "Reducing the risk and mitigating the effects of technological disasters by creating environmentally friendly technologies for the development of industrial deposits with the extraction of useful components from them by mechanochemical activation" (intermediate, stage No. 3). The name of the stage: “Justification of technologies for the elimination of technogenic deposits (stage 2)” / GK No. 14.740.11.0427, state registration number 01201065283 / S.G. Stradanchenko, V.I. Golik, S.A. Maslennikov et al. 2011 - 101 p.

Claims (1)

Precast and monolithic support of a vertical trunk, consisting of an outer layer of spray concrete, middle and inner layers of precast and monolithic reinforced concrete, characterized in that the middle layer is erected from blocks with reinforcement outlets along all end and inner surfaces, with reinforcement steel eyes on the upper and lower ends, as well as the fact that the blocks are a composite structure, including a lattice frame made in the form of reinforced concrete beams, and filling the cell composition of the tailings of ore dressing, The first and second stages of processing and granules of expanded polystyrene are disintegrated.

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