SU1452995A1 - Method of preparing a level to mining of gently-sloping coal seams - Google Patents

Abstract

The invention relates to the coal industry and improves the safety and efficiency of work in the preparation of the main horizon by reducing the harmful effects on the development of geomechanical and gas-dynamic processes. During the working out of the discharge lava (L) with the preservation after it of the reservoir workings 3 and 4 in the rocks of the soil and the roof of the coal seam, the unloaded zones к ml and norp form. In these zones, after L, field preparatory workings (PT) 1, 2 are conducted, while from reservoir openings 3, 4 there are boreholes in the rocks of the soil (roof) of the reservoir up to the level of the bottom (roof) of the design circuit PV 1 and 2 (in the roof of the reservoir, the well is drilled above the upper contour of the open fracture zone, and in the soil of the reservoir — below the lower contour of the zone of the deflection of the layers of the reservoir soil with a discontinuity of rocks). In these wells, reference points are established and the relative deformations of the rocks are measured, and the distance from the refining line L to the boundary is recorded, where the strain values do not exceed 25-30% of their maximum value. This distance is taken as the value of upholding field MFs 1 and 2 of the main horizon from the OT of the sewage line L. 12 Ido /; g (L cond

Description

 14

The invention relates to coal industry and can be used in the development of thin and medium thickness flat coal seams in very gas-bearing and deep mines.

The aim of the invention is to improve the safety and efficiency of operations in the preparation of the horizon due to the harmful effects on the production and their atmosphere geomechanical processes.

FIG. 1 shows a flow chart for preparing the horizon from

the position of the field workings at the total value of deformations

cutting across the strike in the unloaded part of the soil rock and the zone of complete displacement in the roof of the reservoir; in fig. 2 - the same, along the strike of the reservoir.

The method is carried out as follows.

In preparing the horizon, the main transport strip 1 and the main ventilation drift 2 are conducted in ocher, an-25 zones of abbw and drive (fig. 1), icl and norp (fig. 2), each of which is part of the protection zone .

FIG. 1 and 2 security zones are limited by part of the lines: bg, dH, km5, np - boundaries of open fracture zones; Av, Ez, Il, Op - the boundaries of the protection zone ab, wg and de, zh — boundaries of the complete displacement zone (in the roof) and the unloading zone (in the soil of the formation), respectively; IR, but - the boundaries of the zone of compacted rocks, in which the expansion of the array is 25-30% of the maximum values. The points of intersection of the adjacent boundaries of the indicated zones determine the location of the boundaries of the protection zone.

thirty

40

nor then another reduction of 70-75%. At this moment, the distance from the clearing downhole discharge lava to the border is fixed, where the values of expansion strain are (0.25-0.30) 5d. This distance is taken as the lag of the field horizons of the main horizon from the clearing discharge line of the discharge lava.

When the discharge lava is located below the field workings (Figures 1 and 2), the latter are connected with the formation drifts by inclined crosscuts 5 and 6. The excavation drifts behind them are extinguished in sections. The length of the redeemable part is equal to the distance between the groups of inclined divisional quips. Depending on the degree of versatility of the transport, the required amount of air supply and other conditions, there may be a different number of inclined crosscuts in the group - from 1 to 4. Their number is determined by the project. With modern lengths of lavas, the length of such crosscuts will be small. An unloading lava is developed from the inclined crosscuts, and the quarters are led behind its bottom.

Unloading lava is arranged at the rate of finding the selected one (sanpo-j

ect) of the location of the field current flow traces in the soil and roof of the formation in the protective zones formed during the unloading of the strata of rocks with this unloading lava. The discharge lava is maintained, keeping the location of the field workings, constantly within the protection zone, and field workings are carried out along the planned paths following the discharge lava after the formation of the protection zones has been completed. By this time, the active stage of the process of displacement and deformation of the sequence under the influence of cleaning

The works of discharge lava must be completed.

The practical implementation of the proposed solution is as follows. From the reservoir workings 3 and 4 of the discharge lava, wells of the ground rock (roof) are drilled to the level of the bottom (roof) of the designed production contour. The well is equipped with at least two depth reference points. Frame offsets are measured once every three days as the bottom is removed until the maximum is reached.

five

0

0

five

0

five

nor then another reduction of 70-75%. At this moment, the distance from the clearing downhole discharge lava to the border is fixed, where the values of expansion strain are (0.25-0.30) 5d. This distance is taken as the lag of the field horizons of the main horizon from the clearing discharge line of the discharge lava.

When the discharge lava is located below the field workings (Figures 1 and 2), the latter are connected with the formation drifts by inclined crosscuts 5 and 6. The excavation drifts behind them are extinguished in sections. The length of the redeemable part is equal to the distance between the groups of inclined divisional quips. Depending on the degree of versatility of the transport, the required amount of air supply and other conditions, there may be a different number of inclined crosscuts in the group - from 1 to 4. Their number is determined by the project. An unloading lava is developed from the inclined crosscuts, and the quarters are led behind its bottom.

Claims (1)

When the discharge lava is located above the field workings (Figs. 1 and 2), the latter are connected by field slopes (inclined pitches) 7 and 8 with the reservoir openings of the discharge lava, and unloading lava is removed from the inclined crosscuts, which are also conducted behind the bottom faces of the lavas. The first slanting openings are made from horizontal cross-sections, passed from the near-barrel yards. Invention Formula The method of preparing the horizon for the development of flat coal seams. which includes working off the discharge lava followed by the formation workings, forming an unloading zone in the roof rocks or soil of the reservoir, and carrying out fawn workings in the specified area following the lava, characterized in that, in order to improve the safety and efficiency of the work, the expense of reducing the harmful effects on the workings and their. atmosphere of geomechanical and gasdynamic processes, due to reservoir workings into the contour field workings drilled wells, and in the roof of the reservoir, these wells are drilled above the upper contour of the open fracture zone,  and in the soil of the reservoir, the wells are drilled below the lower contour of the zone of deflection of the layers of the soil of the reservoir with a fracture of the logosity of the rocks, then in the indicated wells , d, the relative deformations of the rocks are measured, and the field workings are carried out before the well, in which the relative deformations do not exceed. 25-30% of their maximum value 15 NIN. 7W / fk Ig) -Shch Thebes.2