SU1004641A1 - Method of forming cut-off slit - Google Patents

Description

(54) METHOD OF EDUCATION OF THE CUT TO

one

The invention relates to the field of underground mining of powerful ore deposits in conditions of high mining pressure.

There is a known method for developing powerful ore deposits, which includes preparation, the formation of cutting gaps and the extraction of ore by bricks, and temporary support pillars are left to ensure the stability of the sides of the gaps.

The disadvantage of this method is the increased laboriousness of the work due to the need for temporary support pillars in the cutting gaps.

The closest technical solution to the present invention is a method for developing ores, including the formation of a cutting gap by drilling and blasting wells, followed by releasing the ore and maintaining the walls of the gap in a steady state, and to increase the stability of the cutting slats steak with a rigid foamy material.

The disadvantage of this method is the additional labor and material costs associated with filling the gaps with foam material, and the inability to ensure the stability of the sides of the cutting gap in a changing stress-strain state of the rocks.

The purpose of the invention is to increase the stability of the cutting gaps and without work in conditions of high stress-strain state of the rocks.

The goal is achieved by the fact that according to the method including drilling and

, Q blasting wells, the release of ore and the maintenance of the walls of the gap in a steady state, the sides of the cutting gap in height are formed in a parabola, the top of which is located at the base of the block.

FIG. 1 shows a longitudinal cut15; in fig. 2 - the same cross section.

In order to implement the proposed method, the ore body 1 is preliminarily cut at the entire height of the floor by a cutting slit 2, the edges of the edges of which are performed along the line of parabola 3, and the slit is directed along the stretch of the ore body 1. The cutting slit is performed by the usual drilling and blasting method.

The collapse of block 4 is carried out simultaneously on the cutting slot and clamping medium 5 by explosive charges of explosives in downward 6 and upward 7 wells.

Under the influence of the cleaning pit, the original stress field changes. The absolute value of the stresses in the zone of influence of the refining work can reach values commensurate with the ultimate strength of rocks and ores. In this connection, conditions may be created for the formation of rock pressure in a dynamic form. Therefore, the sides of the gap give the most stable form. Thus, the formation of the sides of the cutting gap along parabolas provides the most stable state of the gap in conditions of high stress-strain state of rocks. In this case, the opening of the parabolic branches (gap width) is taken depending on the magnitude of the stresses.

For example, at voltages of 500 kgf / cm, the width of the gap should be 5 m, and at voltages of more than 800 kgf / cm, u m.

The use of the invention makes it possible to increase the efficiency of developing powerful mineral deposits while ensuring the safety of mining operations under conditions of high mining pressure.

Claims (1)

Invention Formula The method of formation of the cutting gap, including drilling and blasting wells, the release of ore and maintaining the walls of the gap in a steady state, characterized in that, in order to increase the stability of the cutting gap and work safety in conditions of high stress-strain rock formation the slots in height are formed in a parabola, the top of which is located at the base of the block.