SU877002A1 - Method of driving mine workings - Google Patents

Description

one ;

The invention relates to mining, in particular, to the technology of burgh explosive blasting of rocks, and can be used in the excavation of mine workings.

There is a known method of rock blasting, in which an advance compensatory well in a cut-hole is drilled in an array in which the explosive charge is placed to a depth equal to the length of the drill holes and the camouflage blasting ahead of it is performed charges and small hole breaking of the rock mass in the mine working circuit C.

The disadvantage of the method lies in the laboriousness of the work on the design of the vault, which is fraught with the danger of collapse.

There is also known a method of excavating mines in which drifts are conducted from a blasting roof. For demolitions, predominantly powerful jackhammers are used to avoid the inevitable disruption of the rock strata during blasting operations, which would further complicate the formation of a vault. The grooves are very high.

the roof, at the very top of which a short crossbar is placed, and extending wider below than required in the calculation. Such drifts can last for years without repair 2.

The disadvantages of this method are the dangers and difficulties in the design of a set of jackhammers 10.

The purpose of the invention is to ensure the safety of work and reduce the complexity of the design of the code of production.

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The goal is achieved in that the advance well is drilled in the center at a height determined from the expression

. (-. D

) c-bg-t,

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L.J - the height of the equipment being divorced in the development;

D - the gap between the equipment and the wall;

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b is the width of the equipment located in the excavation;

ot arctg. TO;

K - the fortress of the rock according to Proto 30 b.

and each slit in the shell is oriented at an angle of / 2k of the vertical along the preliminarily curved collapse planes. ,

FIG. 1 shows the production section with parameters; in Fig.2, the cross-section of generation along the well; in fig. 3 is a diagram of the explosive charge with a shell with gaps.

The shell can be made of various materials (concrete, metals, plastics). The longitudinal slots should be 1-15 mm wide. The shell can also be made by applying a layer with a thickness of at least 2-5 mm (preferably 5-20 mm) of a hardening material, such as fast-hardening concrete or plastic, on the walls of the well. The shell is filled with explosives and blasting, as a result of which cracks are formed that are directed at an angle / 1k of the vertical axis of the excavation, i.e. a pre-formed arch is formed which has a triangle shape with an apex angle. Next, small-bore breaking of the rock mass in the contour of generation is carried out, for example, with a leading compensation well in the pit. As the excavation progresses, the rock between the two created cracks falls out and forms a vault, which can cost many years.

Production is characterized by the following parameters:

Ц- height of the equipment, placed in the mine; , 2 - 0.7 m - the gap between the equipment and the wall of the excavation;

b is the width of the equipment placed in the excavation, for example a vehicle

(conveyor, electric locomotive); and - width of development; HQ is the well setting; - the angle between the sides of the arch H - the height of the arch; C - board generation; .li.- projected (by known methods) height; development; h - the height of generation above the equipment

The method is carried out as follows.

Bouris leading well 1 in the center of generation at the height H determined from the expression a. jol

H 2

e -S4.) (U -T-) ct

For weak rocks, ut, j7t fp (where f is the angle of internal friction 38-42), and for fastening rocks

4 arctg K, where K - fortress of rocks by Protod Konov.

The calculated parameters give the optimal shape of the output section while maintaining its operational dimensions and the minimum area in comparison with all other sections that have the same shape.

In this well, a shell 2 is formed with longitudinal slots oriented along the planes of the future walls of the roof 3 (Fig. 1 and 3) at an angle to the base of the excavation. The shell can be made of steel: plastic or plastic pipes with a thickness of 3-20 mm. Along the pipe in the given planes, slits 4 are made with a width of 1-1.5 mm. The shell 2 can also be made by applying a layer with a thickness of at least 2-5 mm (preferably 520 mm) of hardening material. .. for example, high-speed concrete

0 or plastics on the walls of the well.

Shell 2 is filled with explosive 5 and undermined. Thanks to slits 4, a highly concentrated blow to

5 the wall of the well 1, which is opposite to the slit 4, which cuts the cracks b. The subsequent movement of the walls of the shell 2 and the well 1, which are under high pressure, leads to

0 further growth of nicked cracks oriented along the formation planes of the roof of the mine.

Then, small-bore breaking of the rock mass in the extraction circuit is carried out, for example, with a leading compensation well in the pit. As the excavation progresses, the rock between the two cracks created falls out and forms an arch.

The proposed method will make it possible to significantly improve the safety of grading and safety in the mine. .

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Claims (2)

1. USSR author's certificate for application No. 2675525, class E 21 C 37/00, 1978. 2.Prodod konov M.M. Rock pressure and miner mount. M., GNTIGI, 1933, p. 175 (prototype).