SU1686183A1 - Method of development and mining of seams with entry pillars recovered - Google Patents

Abstract

The invention relates to the mining industry and m. used in the preparation and development of shock and outburst coal seams. The purpose of the invention is to improve the safety of mining at impact and outburst formations due to instantaneous stress concentrations and the efficiency of cleaning operations during the subsequent mining of pillars by eliminating the gradation of their boundaries. The width (W) of the reference pressure zone is determined, the P pillars are assumed equal to W of the reference pressure zone, and the voltage distribution (H) and the value of the intensity coefficient H for the first extraction column are established. For subsequent excavation pillars, rear pillars устанавлива are set depending on the thickness of the reservoir, the strength of the coal, the angle of incidence of the reservoir, normal H, and the intensity coefficient N. After the extraction block has been completely completed, the security pillars of the stepped shape are smoothed. In this case, the pillars Ш are set equal to the maximum value obtained after estimating the distribution of H in this column when the entire block is removed. w Ё

Description

The invention relates to the mining industry and can be used in the preparation and development of shock hazardous and outburst coal seams.

The purpose of the invention is to increase the safety of mining operations at impact and outburst-hazardous formations due to instantaneous stress concentrations and the efficiency of cleaning works during subsequent mining by eliminating the gradation of their boundaries.

The method is carried out as follows.

The width of the reference pressure zone I is determined. It is assumed that, at the excavation block workings, the protection pillars are equal to the width of zone I. In the process of modeling the excavation pillars, regularities of stress distribution are determined and the average value of their intensity K, for the first extraction column is determined model

oo oo oh

00

with

the lava approach to capital development over a distance equal to the width of the reference pressure zone. For this pillar width, the average value of the intensity factor Ki stresses acting in the first extraction column is determined. After that, for each pillar, the dimensions of the pillars are determined, which must be left at the excavation in the range of the boundary of the excavation column, according to the formula

L-Slf-K

R

m

Oicy6 k un

where m is the seam thickness, m;

Okub - cubic strength of coal, MPa;

k - coefficient taking into account the dip angle of the formation;

un-normal stress, MPa.

Then, the value Ki is substituted into the correlation and the width of the rear sight L is set for the first extraction column. For the subsequent extraction pillars, the approach of the sewage disposal to the capital development for a distance at which the K2 value would correspond to the Ki value obtained in the simulation of the first extraction column is simulated. At the same time, the change in the Ki value is followed when approaching the capital output of the second column. If Ki is changed, then the parameter L is adjusted according to the above dependence. If the method is carried out with the subsequent development of security pillars, to ensure the technological extraction of these pillars by smoothing the boundaries of the pillars stretched along the capital development, the width of these pillars is set to the maximum value obtained after calculating the width of the pillars using the above formula.

Claims (1)

Claims The method of preparing and mining seams without interlacing pillars, including determining the width of the reference pressure zone, the maximum permissible load on the rear sight, the width of the rear sight, cutting the excavation pillars and working them out, leaving the pillars equal to the width equal to the width of the reference pressure zone, distinguishing and the fact that, in order to increase the safety of mining operations at impact and emission hazardous formations, by taking into account instantaneous stress concentrations and the efficiency of cleaning works during the subsequent working out pillars by eliminating aliasing their borders for the first extraction pillar front stope determined the mean intensity ratio stress, and for subsequent excavation pillars, the width of these pillars is calculated by the formula 25 K Ym / Okub k un where m is the seam thickness, m; Okub - cubic strength of coal, MPa; k is a dimensionless coefficient taking into account the dip angle of the formation; un is the stress of an intact mass at a depth, MPa, normal to the bedding; K-average value of the stress intensity factor within the excavation column, MPa, while at mining excavation blocks, the width of the pillars within each excavation column is equal to the maximum of the calculated values for all the excavation columns of the block.