RU2314490C1 - Cover of blasting sites by wornout automobile tires - Google Patents

Abstract

FIELD: mining industry, in particular, mining of hard rocks in hindered conditions, when it is necessary to prevent the spread of the blasted rock mass-at re-activation of temporarily inactive edges of deep pits, blastings near the complexes of cyclic-line production, applicable in highway engineering at separation of the edges of deep rock recesses and other similar operations.

SUBSTANCE: the cover of blasting sites by wornout automobile tires is accomplished in the form of a single-layer mat composed of interconnected wornout automobile tires of various dimensions with placement of tires of smaller dimensions in the gaps between the tires of larger dimensions. The mat is fastened on the surface of the bench with the aid of ropes or chains for the anchors installed in not deep boreholes beyond the boundaries of the blasted block. The tires are interconnected with the aid of clamps of a metal strip, and provided with coupling piece, and replaceable nets of chains or grips of bars with windows of various dimensions freely hanging on the clamps are placed inside the tires.

EFFECT: enhanced reliability and service life of the cover from automobile tires due to the use of their elasticity and control of the dimensions of scattered pieces.

3 dwg

Description

The invention relates to the field of mining, in particular to the development of strong rocks in cramped conditions, when it is necessary to reduce the spread of blasted rock mass: when mothballed temporarily idle sides of deep pits, explosions near cyclic-flow technology complexes, and can be used in road construction when posting the sides of deep rocky excavations and other similar works.

Shelters of blast sites are widespread to reduce the expansion of pieces of rock during explosive crushing of various structures installed above a horizontal blasting surface, arched, panel, as well as filling the blasted surface with soil, automobile tires in bulk in several layers [1]. Their main disadvantages are the small protected area in mobile structures and the one-time use in bulk.

The closest to the essence of the problem being solved is the shelter of the places of explosion from car tires, made in the form of a single-layer mat composed of interconnected car tires of different sizes so that the smaller tires fit into the gaps between the large tires. The mat is fixed on the surface of the ledge using ropes or chains for anchors installed in shallow wells outside the blasting unit. This design allows you to cover surfaces of various sizes, not only from above, but also on the escarpment of the ledge, from where there is a significant dispersion of pieces of rock [2].

The disadvantage of this design is the low reliability and short service life of the connecting elements in the form of cables or chains due to the high dynamic load during the development of the explosion. At the same time, the elastic properties of the tires themselves are not used much.

The technical problem to which the invention is directed is to increase the reliability and service life of the shelter from car tires by using their elasticity and regulating the size of flying pieces.

The task is achieved in that in the shelter of the places of the explosion with worn-out automobile tires made in the form of a single-layer mat of worn automobile tires of various sizes interconnected with the placement of smaller tires in the gaps between the large-sized tires fixed to the surface of the ledge using ropes or chains for anchors installed in shallow wells outside the blasting block, according to the invention, the tires are interconnected using clamps from a metal strip fixed to diametrically opposite parts of the tires and equipped with connecting elements, and inside the tires there are interchangeable nets of chains or lattices of rods with different window sizes, hanging freely on the clamps.

The shelter of the places of explosion from automobile tires is shown in Fig. 1 (side view of the shelter), Fig. 2 (view along arrow A in Fig. 1) and Fig. 3 (section B-B in Fig. 2).

On the sole of the ledge 1, a single-layer mat 2 is assembled from separate worn automobile tires 3, the size of which is selected according to the diameter based on the height of the ledge so that the bend of the mat along the upper and lower edges of the ledge passes through the joints of the individual tires. The tire size range of heavy dump trucks, for example, BelAZ type is quite wide: from 1.6 m for BelAZ-540 to 3.1 m for BelAZ-7519 [2]. To connect the tires in a single-layer mat 2, they are diametrically opposed to them, clamps 4 made of strip metal, equipped with connecting elements 5, for example, hooks and earrings, are criss-cross. The connection of worn tires 3 by elements 5 through clamps 4 allows the use of elastic deformation of tires 3 and their friction against the surface of the rock mass when they are loaded at the time of the explosion. To reduce the size of a piece of rock that can be thrown out through the inner hole of tire 3, reaching 0.6 m for BelAZ-540 tires and 1.3 m for BelAZ-7519 tires, grilles or nets of chains 6 are installed inside the tires. They are fixed to the clamps 4 using flexible connections 7 made, for example, of chains with significant weakness, allowing the lattice or chain mesh 6 to move in height, which will increase their damping ability and resistance to dynamic effects. The size of the lattice windows is determined by the necessary degree of protection of the protected object according to the size of the pieces of rock mass, since the range of the pieces depends on their size. Then, into the gaps between the large tires, insert the smaller tires 8 with the same elements 4 and 5 as the large tires. At the same time, in places where the mat is bent, small tires are inserted in half on the edge of the ledge so that they can bend around the ledge along the edge. For example, tires 3 can be used from BelAZ-7519 with a diameter of 3.1 m, and small size 8 from BelAZ-540 with a diameter of 1.6 m. A single-layer mat 2 is collected either immediately over the entire width of the covered volume or in separate strips of the length of the slope and the surface of the ledge, and then connect several strips after being placed on the covered volume in a single shelter, using auxiliary mechanisms, for example automobile towers.

The assembled single-layer mat 2 with the help of a truck crane is placed on the ledge 1 so that it covers all the blast holes 9, leaving on the bottom of the ledge part of the single-layer mat 2 with a size of 1-2 tires. Using ropes or chains 10, the shelter is fixed to the anchors 11.

After placing the shelter on the ledge, all the equipment and workers are removed outside the danger zone and proceed with the installation of the explosive network. To do this, detonating cords or waveguides are removed from the wells through the holes in the tires and an explosive network is mounted on top of the shelter.

In the event of a successive explosion of loosening charges in the wells of step 9, the main share of the explosion energy is spent on crushing the rocks and displacing the gas-permeable single-layer mat 2. Moreover, the part located on the ledge slope begins to shift, since rock swelling begins precisely from the slope. Due to the use of 9 bulging charges in the extreme wells, the first, strongest rock mass strike at the shelter is softened - rock mass swells with movement, but without expansion [3]. This allows a single-layer tire mat to smoothly deform on the ledge slope due to the elasticity of tires 3 and 8 and pulling the tires up from the sole. Together with the expanded rock mass, the shelter creates a buffer layer, damping the explosion of the following rows of wells, similar to blasting in a clamp on an unmade rock mass, and preventing pieces from flying through the gaps in a single-layer mat 2.

The elasticity of the shelter from the tires due to the elasticity of the tires during expansion of the blasted rock does not allow individual pieces to break away from the total mass, the loosened rock mass is tightly wrapped around the mat and kept in a compact state. The part of the single-layer mat 2 located on the slope of the ledge 1, swelling, pulls the lower tires 3 and 8 located on the bottom of the ledge, which will provide the ability to shift the lower part of the shelter to damp the load and at the same time will not allow pieces of rock mass to fly out under cover. At the same time, a load will also arise on the horizontal part of the single-layer mat, but anchors 11 will prevent its displacement through ropes or chains 10. The eyes 12 will prevent the ropes or chains 10 from sliding off the anchors 11, the single-layer mat 2 will begin to slide over the rock mass and, due to friction forces, will provide additional resistance to its movement.

With a sufficiently long length of ropes or chains of 10, they, with a sharp tension, also absorb the jerk for shelter. In addition, each individual tire will deform in different directions under load, while also mitigating the total impact load of the explosion on a single-layer mat. The inertial resistance of the compact mass of the rock, reinforced by the mass of the shelter, balances the force of the explosive shock. The height of the rock toss with shelter depends only on the thickness of the blasting layer and the coefficient of loosening of the rock, since the amount of rock swelling after loosening depends on the latter. Considering that the coefficient of loosening of rocks during blasting in the clamp is 1.05-1.1, and the height of the blown ledges is 10-15 m, the reserve length of the shelter is 1-2 tires (depending on their diameter, it is from 1.6 to 6 m) on the base of the ledge it will be enough so that it does not expand beyond the limits of the rock mass being exploded.

After the explosion, the shelter with the help of ropes removed from the anchors is pulled from the surface of the rock mass with a bulldozer. In case of difficulty, it is disconnected and partially removed from the rock mass. For the next explosion, the same ropes or chains 10 are used.

Thus, the claimed shelter of the places of the explosion with worn-out automobile tires provides rock breaking with minimal dispersion of the rock mass, in addition, the use of the elastic properties of tires to absorb dynamic explosive loads increases the reliability and service life of the shelter, and the possibility of installing grilles inside tires with different window sizes allows you to adjust the range of the possible expansion of pieces of detonated mass, which allows us to solve the problem.

Information sources

1. Instructions for the production of blasting with protective shelters. M .: CPES, 1987 (prototype).

2. Reference. Open cast mining. M.: Mining Bureau, 1994. S. 359-361.

3. G.P. Demidyuk. Application of the energy principle to the calculation of borehole charges in quarries. // Explosive business No. 62/19. M .: Subsoil. 1967. S. 36-51.

Claims (1)

Shelter of the places of explosion with worn-out automobile tires made in the form of a single-layer mat of worn automobile tires of various sizes interconnected with the placement of smaller tires in the gaps between large-sized tires fixed to the surface of the ledge with ropes or chains for anchors installed in shallow wells behind the limits of the blasting unit, characterized in that the tires are interconnected by means of clamps from a metal strip, mounted on diametrically opposite parts of the tires and equipped with connecting elements, and inside the tires they place interchangeable nets of chains or lattices of rods with different window sizes, hanging freely on the clamps.

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