CN113107490A - Roof cutting and pressure relief method for high-ground-stress hard roof of coal mine - Google Patents
Roof cutting and pressure relief method for high-ground-stress hard roof of coal mine Download PDFInfo
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- CN113107490A CN113107490A CN202110456551.9A CN202110456551A CN113107490A CN 113107490 A CN113107490 A CN 113107490A CN 202110456551 A CN202110456551 A CN 202110456551A CN 113107490 A CN113107490 A CN 113107490A
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- roof
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D3/00—Particular applications of blasting techniques
- F42D3/04—Particular applications of blasting techniques for rock blasting
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Abstract
The invention discloses a roof cutting and pressure relief method for a high-ground-stress hard roof of a coal mine, which comprises the following steps of: s1: determining the width of the small coal pillar according to the thickness of the coal on the working face; s2: selecting a blast hole; respectively arranging a row of blast holes on the gob-side roadway at certain intervals, wherein the distance between the positions of the blast holes and the coal pillar sides is not more than 500 mm; and the blast holes of the primary blasting are on the same straight line; s3: filling explosives into the blast hole; s4: and detonating the explosive to form a fracture surface, breaking the rock stratum at the fracture surface, and sliding the rock stratum to the goaf to realize the pressure relief of the top-cut part. The invention adopts the scheme design of taking 'advanced pre-splitting joint-cutting and roof reinforcing support' as the main body, and cuts off the connection between the side roof of the goaf and the roof above the roadway through the advanced pre-splitting joint-cutting, thereby weakening the disturbance action of the roof collapse dynamic pressure on the roadway, being beneficial to the disturbance action of the roof of the goaf on the roadway and simultaneously being beneficial to the roof of the goaf to collapse along the joint-cutting to form a roadway side.
Description
Technical Field
The invention relates to the field of coal mining, in particular to a method for roof cutting and pressure relief of a high-ground-stress hard roof of a coal mine.
Background
With the increase of coal mining depth in China, the ground stress borne by the coal face is gradually increased, and the stoping roadway is difficult to maintain. Particularly, under the condition of a high ground stress hard roof, after the coal seam is mined, the coal seam roof is greatly and integrally sunk, the coal side is seriously stripped or extruded, a roadway is seriously deformed, the bottom heave amount is large, and even a part of mines have rock burst accidents. In order to solve the problem of rock stratum control under the condition of high ground stress, a blasting roof cutting pressure relief technology is provided, roof cutting measures are adopted under the condition of a hard thick roof rock stratum, the caving property of a roof is improved, and the load transfer proportion from overlying rock of a stope face to an adjacent face is reduced. The mining load added value is reduced, so that the purpose of reducing deformation and damage of a mining roadway is achieved, and the complete equipment for roof cutting and pressure relief of the high-ground-stress hard roof of the coal mine and the using method are formed.
The scheme design taking 'advanced pre-splitting joint-cutting and roof reinforcing support' as the main body is adopted, and the connection between the goaf side roof and the roof above the roadway is cut off through the advanced pre-splitting joint-cutting, so that the disturbance effect of roof collapse dynamic pressure on the roadway is weakened, the disturbance effect of the goaf roof on the roadway is facilitated, and the goaf roof is facilitated to collapse along the joint-cutting to form a roadway side.
Disclosure of Invention
The invention aims to provide a roof cutting and pressure relief method for a high-ground-stress hard roof of a coal mine, which is beneficial to the roof of a goaf to collapse along a cutting seam to form a roadway side.
In order to achieve the purpose, the invention provides the following technical scheme:
a roof cutting and pressure relief method for a high-ground-stress hard roof of a coal mine comprises the following steps:
s1: determining the width of the small coal pillar according to the thickness of the coal on the working face;
s2: selecting a blast hole; respectively arranging a row of blast holes on the gob-side roadway at certain intervals, wherein the distance between the positions of the blast holes and the coal pillar sides is not more than 500 mm; and the blast holes of the primary blasting are on the same straight line;
s3: filling explosives into the blast hole;
s4: and detonating the explosive to form a fracture surface, breaking the rock stratum at the fracture surface, and sliding the rock stratum to the goaf to realize the pressure relief of the top-cut part.
Further, the method for determining the width of the small coal pillar in step S1 includes:
a＝x0-b-c；
wherein a is the width of the small coal pillar;
x0is the stress reduction zone width; x is the number of0(1.2-1.3) M; m is the thickness of the coal bed;
b is the width of the gob-side entry;
and c is the length of the anchor rod.
When the calculated small coal pillar width value a is less than 3m, taking a to be 3 m; and when the calculated small coal pillar width value a is larger than 8m, taking a to be 6 m.
Further, the length of the side anchor rod is 2.5 m.
Further, in step S3, the explosive hole loading is as follows:
Q＝k×H×q；
wherein Q is the single-hole loading quantity, and the unit is g/hole;
h is the drilling depth;
k is the charge factor, wherein K is 2/3;
q is the single-hole charge density in g/(m.hole).
Further, in step S3, the explosive hole is charged in the following manner:
(1) the charging section is divided into an upper part, a middle part and a lower part, and charging is respectively carried out on the three parts.
(2) The lower part is positioned at the bottom of the explosive charging section, and the number of the explosive sticks is 17 percent of the total number.
(3) The middle part is positioned in the middle of the medicine charging section, and the number of the medicine rolls is 33 percent of the total number.
(4) The upper part is positioned at the top of the explosive charging section, and the number of the explosive sticks is equal to the total number of the explosive sticks, the number of the explosive sticks at the lower part, and the number of the explosive sticks at the middle part.
(5) Length L of hole sealing segmentSealing device＝H-LClothes (CN)。
Furthermore, the hole sealing section is divided into two parts, namely a blister section and a stemming section; wherein the length of the blister mud is 1m, and the rest is stemming.
Furthermore, the detonation mode of the explosive is that a coal mine allowable electric detonator is adopted for detonation, the electric detonator charges positively, 2 power generation detonators are arranged on each part of the upper part and the middle part of the explosive charging section, 1 power generation detonator is arranged on the lower part, and 5 power generation detonators are arranged in each blasting hole; the electric detonators are arranged in the blast holes in parallel, and the blast holes are arranged in series.
Compared with the prior art, the invention has the beneficial effects that:
the invention adopts the scheme design of taking 'advanced pre-splitting joint-cutting and roof reinforcing support' as the main body, and cuts off the connection between the side roof of the goaf and the roof above the roadway through the advanced pre-splitting joint-cutting, thereby weakening the disturbance action of the roof collapse dynamic pressure on the roadway, being beneficial to the disturbance action of the roof of the goaf on the roadway and simultaneously being beneficial to the roof of the goaf to collapse along the joint-cutting to form a roadway side.
Description of the drawings:
in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram of a method for designing small coal pillars of a mining roadway according to the invention;
FIG. 2 is a schematic view of the charging and hole sealing structure of the present invention.
The specific implementation mode is as follows:
the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to figures 1-2 of the drawings,
a roof cutting and pressure relief method for a high-ground-stress hard roof of a coal mine comprises the following steps:
s1: determining the width of the small coal pillar according to the thickness of the coal on the working face;
s2: selecting a blast hole; respectively arranging a row of blast holes on the gob-side roadway at certain intervals, wherein the distance between the positions of the blast holes and the coal pillar sides is not more than 500 mm; and the blast holes of the primary blasting are on the same straight line;
s3: filling explosives into the blast hole;
s4: and detonating the explosive to form a fracture surface, breaking the rock stratum at the fracture surface, and sliding the rock stratum to the goaf to realize the pressure relief of the top-cut part.
In this embodiment, the method for determining the width of the small coal pillar in step S1 includes:
a＝x0-b-c；
wherein a is the width of the small coal pillar; the unit is meter;
x0is the stress reduction zone width; x is the number of0(1.2-1.3) M; m is the thickness of the coal bed; the thickness of the coal bed is measured in meters;
b is the width of the gob-side entry; the unit is meter;
and c is the length of the anchor rod.
When the calculated small coal pillar width value a is less than 3m, taking a to be 3 m; and when the calculated small coal pillar width value a is larger than 8m, taking a to be 6 m.
In this embodiment, the length of the upper anchor rod is 2.5 m.
In this embodiment, in step S3, the explosive loading of the blast hole is:
Q＝k×H×q；
wherein Q is the single-hole loading quantity, and the unit is g/hole;
h is the drilling depth; the unit is meter, and H is 23.7 m;
k is the charge factor, wherein K is 2/3;
q is the single hole charge density in g/(m · hole), where Q is 300g/(m · hole).
The main factor influencing the stability of the gob-side entry driving roadway is the distribution rule of lateral supporting pressure, the top plate residual boundary above the roadway in the gob is an important influence factor influencing the lateral supporting pressure distribution, and the top plate residual boundary above the roadway in the gob is mainly positioned in a basic top above a coal seam. Therefore, the advance presplitting kerf height H0 of the roof cutting pressure relief gob-side entry driving roof is determined to be the basic roof boundary of the roof of the coal seam.
The pre-splitting kerf drilling parameters are determined by combining surrounding rock conditions of a working face, and the basic roof above a roadway and the basic roof above a coal pillar can be completely cut off through pre-splitting blasting, so that the peak value of lateral supporting pressure is reduced and transferred to a deep part, and meanwhile, the range of a stress reduction area is enlarged, and the arrangement of gob-side entry driving is facilitated.
In order to form through cracks in the connecting line direction between blast holes, cracking conditions must be met, and when the cracks cannot be stopped before the through cracks are formed, redundant cracks must not be generated, so that the purpose of blasting joint cutting can be achieved.
In this embodiment, in step S3, the explosive charging mode of the blast hole is as follows:
(1) the charging section is divided into an upper part, a middle part and a lower part, and charging is respectively carried out on the three parts.
(2) The lower part is positioned at the bottom of the charge section, and the number of the cartridges is 17 percent (rounded down) of the total number.
(3) The middle part is positioned in the middle of the medicine charging section, and the number of the medicine rolls is 33 percent (rounded up) of the total number.
(4) The upper part is positioned at the top of the explosive charging section (namely the bottom of the explosive hole), and the number of the explosive sticks is equal to the total number of the explosive sticks, the number of the explosive sticks at the lower part, and the number of the explosive sticks at the middle part.
(5) Length L of hole sealing segmentSealing device＝H-LClothes (CN)。
The damage range of the small-diameter blast hole on surrounding rocks is small, and the shape of a pre-splitting surface is easy to control; pre-splitting blasting adopts a small-diameter cartridge spaced loading structure, so that radial and longitudinal air gaps are formed between the wall of a blasting hole and the cartridges; the explosive explosion uses air as a medium to transfer pressure, the density of the air medium is much lower than that of a rock medium, the acoustic impedance is reduced, the crushing effect of shock waves on the rock near the wall of the hole is greatly weakened, and the purpose of preventing surrounding rocks from being excessively crushed is achieved; because the compression wave is propagated into the rock body in a cylindrical shape, uniform stress can be generated in a plane formed by the axes of two adjacent blast holes, thereby creating conditions for obtaining a regular fracture surface.
In the embodiment, the hole sealing section is divided into two parts, namely a blister section and a stemming section; wherein the length of the blister mud is 1m, and the rest is stemming.
In the embodiment, the detonation mode of the explosive is that a coal mine allowable electric detonator is adopted for detonation, the electric detonator charges positively, 2 power generation detonators are arranged on each part of the upper part and the middle part of the explosive charging section, 1 power generation detonator is arranged on the lower part, and 5 power generation detonators are arranged in each blasting hole; the electric detonators are arranged in the blast holes in parallel, and the blast holes are arranged in series.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (7)
1. A roof cutting and pressure relief method for a high-ground-stress hard roof of a coal mine is characterized by comprising the following steps of: the method comprises the following steps:
s1: determining the width of the small coal pillar according to the thickness of the coal on the working face;
s2: selecting a blast hole; respectively arranging a row of blast holes on the gob-side roadway at certain intervals, wherein the distance between the positions of the blast holes and the coal pillar sides is not more than 500 mm; and the blast holes of the primary blasting are on the same straight line;
s3: filling explosives into the blast hole;
s4: and detonating the explosive to form a fracture surface, breaking the rock stratum at the fracture surface, and sliding the rock stratum to the goaf to realize the pressure relief of the top-cut part.
2. The method for roof cutting and pressure relief of the high-ground-stress hard roof of the coal mine according to claim 1, wherein: the method for determining the width of the small coal pillar in the step S1 comprises the following steps:
a＝x0-b-c；
wherein a is the width of the small coal pillar; x is the number of0Is the stress reduction zone width; x is the number of0(1.2-1.3) M; m is the thickness of the coal bed; b is the width of the gob-side entry; c is the length of the anchor rod;
when the calculated small coal pillar width value a is less than 3m, taking a to be 3 m; and when the calculated small coal pillar width value a is larger than 8m, taking a to be 6 m.
3. The method for roof cutting and pressure relief of the high-ground-stress hard roof of the coal mine according to claim 2, wherein: the length of the side anchor rod is 2.5 m.
4. The method for roof cutting and pressure relief of the high-ground-stress hard roof of the coal mine according to claim 1, wherein: in step S3, the explosive loading of the blast hole is:
Q＝k×H×q；
wherein Q is the single-hole loading quantity, and the unit is g/hole; h is the drilling depth; k is the charge factor, wherein K is 2/3; q is the single-hole charge density in g/(m.hole).
5. The method for roof cutting and pressure relief of the high-ground-stress hard roof of the coal mine according to claim 1, wherein: in the step S3, the explosive charging mode of the blast hole is as follows:
(1) the charging section is divided into an upper part, a middle part and a lower part, and charging is respectively carried out on the three parts;
(2) the lower part is positioned at the bottom of the explosive charging section, and the number of the explosive cartridges is 17 percent of the total number;
(3) the middle part is positioned in the middle of the explosive charging section, and the number of the explosive cartridges is 33 percent of the total number;
(4) the upper part is positioned at the top of the explosive charging section, and the number of the explosive sticks is equal to the total number of the explosive sticks, the number of the explosive sticks at the lower part, and the number of the explosive sticks at the middle part;
(5) length L of hole sealing segmentSealing device＝H-LClothes (CN)。
6. The method for roof cutting and pressure relief of the high-ground-stress hard roof of the coal mine according to claim 5, wherein: the hole sealing section is divided into two parts, namely a blister section and a stemming section; wherein the length of the blister mud is 1m, and the rest is stemming.
7. The method for roof cutting and pressure relief of the high-ground-stress hard roof of the coal mine according to claim 1, wherein: the explosive is detonated by adopting an electric detonator allowed to be used in a coal mine, the electric detonator charges in a positive direction, 2 power generation detonators are arranged on each part of the upper part and the middle part of the explosive charging section, 1 power generation detonators are arranged on the lower part of the explosive charging section, and 5 power generation detonators are arranged in each blasting hole; the electric detonators are arranged in the blast holes in parallel, and the blast holes are arranged in series.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110456551.9A CN113107490A (en) | 2021-04-27 | 2021-04-27 | Roof cutting and pressure relief method for high-ground-stress hard roof of coal mine |
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| CN202110456551.9A CN113107490A (en) | 2021-04-27 | 2021-04-27 | Roof cutting and pressure relief method for high-ground-stress hard roof of coal mine |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113356863A (en) * | 2021-07-26 | 2021-09-07 | 中国矿业大学 | High-low combined presplitting blasting method for hard top plate of coal face in subareas |
| CN113417638A (en) * | 2021-07-21 | 2021-09-21 | 中国矿业大学 | Advanced roof cutting pressure relief and surrounding rock control method for hard roof of gob-side roadway |
| CN113914861A (en) * | 2021-12-15 | 2022-01-11 | 中国矿业大学(北京) | Non-pillar self-entry balanced mining method and equipment |
| CN115143851A (en) * | 2022-07-19 | 2022-10-04 | 北京科技大学 | Deep high-stress rock roadway periphery fine control blasting method based on ground stress induction effect |
| WO2023201906A1 (en) * | 2022-04-22 | 2023-10-26 | 山东科技大学 | Releasing-cracking-supporting cooperative burst prevention method based on coal body pressure relief and roof pre-cracking |
| US11834949B2 (en) | 2022-04-22 | 2023-12-05 | Shandong University Of Science And Technology | Collaborative erosion-control method of releasing-splitting-supporting based on coal mass pressure relief and roof pre-splitting |
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2021
- 2021-04-27 CN CN202110456551.9A patent/CN113107490A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113417638A (en) * | 2021-07-21 | 2021-09-21 | 中国矿业大学 | Advanced roof cutting pressure relief and surrounding rock control method for hard roof of gob-side roadway |
| CN113417638B (en) * | 2021-07-21 | 2022-05-06 | 中国矿业大学 | Advanced roof cutting pressure relief and surrounding rock control method for hard roof of gob-side roadway |
| CN113356863A (en) * | 2021-07-26 | 2021-09-07 | 中国矿业大学 | High-low combined presplitting blasting method for hard top plate of coal face in subareas |
| CN113914861A (en) * | 2021-12-15 | 2022-01-11 | 中国矿业大学(北京) | Non-pillar self-entry balanced mining method and equipment |
| WO2023201906A1 (en) * | 2022-04-22 | 2023-10-26 | 山东科技大学 | Releasing-cracking-supporting cooperative burst prevention method based on coal body pressure relief and roof pre-cracking |
| US11834949B2 (en) | 2022-04-22 | 2023-12-05 | Shandong University Of Science And Technology | Collaborative erosion-control method of releasing-splitting-supporting based on coal mass pressure relief and roof pre-splitting |
| CN115143851A (en) * | 2022-07-19 | 2022-10-04 | 北京科技大学 | Deep high-stress rock roadway periphery fine control blasting method based on ground stress induction effect |
| CN115143851B (en) * | 2022-07-19 | 2023-09-05 | 北京科技大学 | Deep high-stress rock roadway periphery fine control blasting method based on ground stress induction effect |
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