Method to predict outburst hazard of development drifts

FIELD: mining.

SUBSTANCE: method consists in detection of mining operations performance depth from surface, section of a mine by coal, pressure of gas in an untouched bed massif, coefficient of weighted average coal strength in a bed, coal adhesion, stress in a coal massif along a face line and area of coal massif unloading in front of the face. The specified data is substituted into a mathematical formula, with the help of which prediction of outburst hazard of a development drift R is made. If R>0, the bed is related to outburst hazardous, and if R<0 - to safe regarding coal and gas outbursts.

EFFECT: possibility to apply the method both when tunnelling and at the design stage due to use of technical characteristics of mines carried out under similar conditions or being at the stage of design solutions.

1 dwg

 

The invention relates to the mining industry and can be used to predict the outburst zones when driving or design development workings.

There is a method of prognosis outburst areas, including the drilling of a borehole parallel to the longitudinal axis of the generation, measurement pointervalue the initial velocity of the gas and exit of the drilling rubble, the definition of the indicator of the outburst and the separation layer on outburst-hazardous and non-hazardous areas (Puzyrev V., N. Vershinin, Khashin NR. and Packagin VA Method of forecasting the outburst layers and monitor the effectiveness of preventive measures in small diameter wells. Proceedings Of VostNII. 20. Kemerovo, 1973, s-174).

The disadvantage of this method is the lack of evaluation of the outburst of the reservoir in disturbed areas, when the output of the rubble does not correspond to the stress distribution ahead of a moving face. Furthermore, the method allows to determine the position of outburst areas only a short distance from the chest of the face (up to 5 m).

As the prototype accepted method of determining outburst zones when conducting preparatory development, including the drilling of a borehole parallel to the longitudinal axis of the workings at a depth of 15-30 m, determination of hardness of coal, 5-10 see its value calculated active power, causes the matter of the release, and passive forces that prevent the release, and the index of the outburst is determined by the well-known formula

Rin=Fa-Fp,

where Fa- active power, causing the release;

Fp- passive forces, preventing the release.

When Rin>0 the area belongs to the outburst, and when Rin<a 0 - to neveraskopen (USSR author's certificate No. 979644, CL E21F 5/00, declared 17.12.1975, the authors Vghginen, Beglarian, Wearage, Welbalance, Dry and Bscreen, published in 1982, B. No. 45)Preimushestva known method is that it leads to reduction in the use of protivovirusnyh activities in the preparatory workings. The disadvantage of this method is the inability to use his design of mine workings, when there will be no holes and no data on production parameters, the coefficients of the fortress of coal, the voltage on the data line of the face, etc.

The technical result of the use of the invention is the possibility of its application as the excavation and at the design stage due to the use of the technical characteristics of the mine workings, passable in similar conditions or under design decisions.

The method of prediction of the outburst mines, including the determination of the depth of mining RA is from the surface, section mining for coal, active and hindering forces acting on the coal in the bottom space can move him in the face and forecast of the outburst on the difference between these forces.

The difference is that further define the gas pressure in the intact rock mass layer, the coefficient of the weighted average of the fortress of coal seam grip coal, the voltage in the array coal slaughtering and coal unloading area of the array in front of the face, and forecast vibrocompaction carry out mathematical formula

where S is the cross-section generation, m2;

f - weighted average of the hardness of the coal;

Pois the gas pressure in the intact rock mass, determined directly by the formula

Po=0,092×(H-45), MPa;

H - depth of mining from the surface, m;

- the voltage on the data line of the face, directly measured or

determined by the formula

K - coefficient of coupling of coal, directly measured or determined by the formula

X - discharge zone the preparatory development of m is determined by the formula

where α is a rheological parameter defined by the formula

, /h;

lW- width of the Executive body, m;

V is the average speed of advance of slaughter, m/day.

When R>0, the layer is referred to outburst, and when R<0 for non-hazardous to sudden outbursts of coal and gas.

The proposed method for prediction of the outburst can be used for passable roadways, when parameters generation and coal characteristics of the array are used directly by measurement, or for projected openings, when the parameters and specifications are accepted on the basis of design decisions or by analogy with other ongoing workings.

The proposed method for prediction of the outburst illustrated by the scheme of the mechanism of unleashing a sudden outburst of coal and gas in the preparatory development, shown in the drawing. The diagram shows the situation at the time of extraction of coal Zachodni L and shows the state of the array coal zone I-III at the time of occurrence of the outburst of the situation. When the magnitude of zagadki L is such that the resultant of the forces of gas pressure in some close to the newly formed face parallel to the crack will be more limiting to the resultant force of the resistance of the coal separation, untied outburst. As will be rejected more remote from the original position of the layers occurs rapidly is a kind of transfer of separated pieces of coal from the zone of high pressure gas into the low-pressure zone due to which there is an effect of the gas crushing coal. Thus, ahead of preparatory development held for outburst layer, formed three zones (I-III)that are different from each other according to the state of the coal of the array. Closest to the slaughter zone I consists of a compressed moving rocks intensively destroyed the coal mass, having a low filtration properties. The next zone II is characterized by the fact that it forces the rock pressure formed a dense network oriented parallel to the bottom of the crack, which accumulates a significant amount of under pressure free gas. The third zone III is the transition from the elastic state of the array to the plastic-elastic. Significant factors contributing to the preparation of coal array to implement energy of free gas, such as a change along the strike of the seam strength properties of the coal massif (f, R0,, K, X, and others) towards their reduction and technical parameters of conducting production (cross-section generation for coal's value Zachodni average daily rate of podvigina slaughter v, width of the Executive body of the lWand others). The proposed method allows not only to determine the specific conditions of the possibility of outburst sieve the Nations, but also to identify the most significant factors and to determine the impact on them to prevent the outbreak of sudden outbursts of coal and gas.

Forecast of the outburst carry out mathematical formula

where S is the cross section of the driven working, affects the extent of the region of reduced stress, m2;

f - weighted average of the hardness of coal is determined by well-known methods;

Pois the gas pressure in the intact rock mass directly measured or determined by the formula

Po=0,092×(H-45), MPa;

H - depth of mining from the surface;

- the voltage on the bottom line, measured or determined by the formula

K - coefficient of coupling of coal, measured or determined by the formula

;

X - discharge zone preparatory development, determined by the formula

α - rheological parameter defined by the formula

, 1/h;

lW- width of the Executive body, m;

ν is the average velocity prodigene slaughter, m/day.

On the basis of the performed measurements and calculations according to the formulas obtained the following source data: S=14 m2; f=0,3; Po=3,45 MPa; N=420 m; =0,13 MPa; K=2,2; X=26,79 m; α=3,88 1/h; lW=0.3 m; ν=4 m/day. Substituting these values into the formula to determine the value of R=1,29. Since R is a positive value, then the result of the forecast of the outburst is that this preparatory development refers to prone to sudden outbursts of coal and gas.

A significant advantage of the proposed method for the prediction of the outburst mines is its high efficiency and the possibility of using directly measured when driving this generation or in similar conditions and design parameters, making prediction of the outburst at the stage of penetration, and at the design stage of production.

The method of prediction of the outburst mines, including the determination of the depth of mining operations from the surface, cross-section mining for coal, active and hindering forces acting on the coal in the bottom space can move him in the face and forecast of the outburst on the difference of these forces, characterized in that it further determine the gas pressure in the intact rock mass of coal seam grip coal, the voltage of coal slaughtering and the discharge zone of the coal face in front of the face, and the forecast of the outburst carry out mathematical formula where S is the cross-section generation, m2; ƒ - weighted average of the hardness of the coal; P0is the gas pressure in the intact rock mass directly measured or determined by the formula R0=0,092(H-45), MPa; H - depth of mining from the surface, m;- the voltage on the data line of the face, directly measured or determined by the formula, MPa; K - coefficient of coupling of coal, directly measured or determined by the formula, MPa; X - discharge zone preparatory development, determined by the formula
α - rheological parameter defined by the formula, 1/h; lW- width of the Executive body, m; ν is the average velocity podvigina slaughter, m/day; R>0, the layer is referred to outburst, and when R<0 is not dangerous to sudden outbursts of coal and gas.



 

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