CN105627849A - A rapid blasting demolition method for closed walls in underground coal mines - Google Patents

Abstract

The invention discloses a fast blasting demolition method for an underground coal mine fire dam, and relates to the technical field of underground coal mine fire dam demolition. The method is used for solving the problems that in the prior art, the demolition cost of the underground coal mine fire dam is high, efficiency is low, and safety is not high. The method comprises the steps that the fire dam to be demolished is subjected to blast hole cutting, and the angle of a blast hole ranges from 45 degrees to 60 degrees; water is injected into the blast hole; a pressure trigger device is fixed in the blast hole, and an explosive is placed in the pressure trigger device; a guard railing is arranged on the blasting face of the fire dam to be demolished according to the blasting safety distance; and the explosive in the pressure trigger device is detonated outside the blasting safety distance, and blasting demolition is achieved.

Description

A rapid blasting demolition method for closed walls in underground coal mines

technical field

The invention relates to the technical field of dismantling an underground coal mine airtight wall, and more particularly relates to a rapid blasting demolition method for an underground coal mine airtight wall.

Background technique

my country is a country with a large coal output, and 64% of the mines in the central and western regions are high-gas mines. With the continuous development of coal mining technology, mine thermodynamic disasters occur very frequently. To avoid casualties and equipment and property losses, it is urgent to take effective measures to seal the working face and coal seam. However, when the disaster is effectively controlled, the airtightness needs to be removed first.

At present, the demolition methods of mine closed walls mainly include manual demolition method, static silent blasting and expansion demolition method, but the manual demolition method takes a long time to remove, has low efficiency and high labor intensity; although the operation of static silent blasting and expansion demolition method is relatively safe, but The removal efficiency is low, the removal time is long, and the cost is high. The surrounding environment of the mine airtight wall is complicated, the project period is tight, the mining pressure is high, the environment is complex and changeable, the roof and floor of the airtight section and the surrounding rocks of the roadways on both sides are easily broken, etc. Therefore, the existing demolition technology cannot meet the needs of efficient mine airtight wall demolition .

To sum up, in the prior art, there are problems of high cost, low efficiency, and low safety for dismantling the closed wall of the coal mine.

Contents of the invention

The embodiment of the present invention provides a rapid blasting demolition method for an underground coal mine airtight wall, which is used to solve the problems of high cost, low efficiency, and low safety in the prior art.

An embodiment of the present invention provides a rapid blasting demolition method for a closed wall in a coal mine, including:

Carry out blast hole cutting on the airtight wall to be demolished, and the blast hole angle is between 45° and 60°;

Inject water into the blast hole;

fixing a pressure triggering device in the blast hole, and explosives are placed in the pressure triggering device;

According to the blasting safety distance, set up a protective fence on the blasting surface of the airtight wall to be demolished;

Outside the blasting safety distance, the explosive in the pressure trigger device is detonated to realize blasting demolition.

The depth of the blast hole is determined by the following formula:

$\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>$

Among them, l is the depth of the blasting hole, α is the angle of the blasting hole; H is the height of the closed wall to be demolished; h ₁ is the overdrilling at the bottom.

The blasting safety distance is the blasting flying stone distance with high underground water pressure, which is determined by the following formula:

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; g</span>}}}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\frac{{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; g</span>}}$

Among them, S is the blasting safety distance, V ₁ is the speed of flying rocks; h is the drop of flying fragments; g is the acceleration of gravity.

The speed of the flying stone is determined by the following formula:

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; \&lsqb;</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;\&rho;R</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; \&rsqb;</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}$

Among them, K ₁ and K ₂ are the energy utilization coefficients of the first and second underwater shock waves respectively, and K ₁ =0.31, K ₂ =0.17; μ is the explosion work, and μ=4×10 ⁵ ; Wall density; R is the distance from the explosion source center to the closed wall to be demolished; δ1 is the equivalent wall thickness _of the closed wall to be demolished.

In the embodiment of the present invention, water is injected directly into the blasting hole with an inclination, which is simple to operate, cost-saving, and high in efficiency; a protective fence is set on the blasting surface of the closed wall to be demolished to ensure the safety of personnel and equipment during the demolition process of the closed wall, reducing the Construction difficulty.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the embodiments and accompanying drawings. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Fig. 1 is a schematic flow chart of a rapid blasting demolition method for a closed wall in a coal mine provided by an embodiment of the present invention;

Fig. 2 is a layout diagram of blast holes provided by the embodiment of the present invention;

Fig. 3 is a schematic diagram of a pressure trigger device provided by an embodiment of the present invention.

Explanation of reference signs:

1-shock wave tube, 2-medicine chamber, 3-detonation mechanism, 4-detonation pull rope.

detailed description

An embodiment of the present invention provides a rapid blasting demolition method for an airtight wall in a coal mine, comprising: cutting a blast hole in the airtight wall to be demolished, the angle of the blast hole is between 45° and 60°; injecting water into the blast hole; The pressure triggering device is fixed in the blasting hole, and explosives are placed in the pressure triggering device; according to the blasting safety distance, a protective fence is set on the blasting surface of the closed wall to be demolished; outside the blasting safety distance, the pressure triggering device is detonated. Trigger the explosive in the device to realize blasting demolition.

Fig. 1 is a schematic flow chart of a rapid blasting demolition method for a closed wall in a coal mine provided by an embodiment of the present invention; it includes the following steps:

Step S101, performing blasting cutting on the airtight wall to be demolished, and the blasting angle is between 45° and 60°;

The blast hole depth is determined by the following formula:

$\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>$

Among them, l is the depth of the blasting hole, α is the angle of the blasting hole; H is the height of the closed wall to be demolished; h ₁ is the overdrilling at the bottom.

The row spacing of the blast holes is shown in Figure 2;

As shown in Figure 2, for the blast holes on the airtight wall to be demolished, two rows of blast holes are cut in the vertical middle of the wall, and one row of blast holes is cut in the horizontal middle of the wall.

Step S102, injecting water into the blast hole.

Step S103, fixing a pressure trigger device in the blast hole, and explosives are placed in the pressure trigger device;

Preferably, as shown in Figure 3, the pressure trigger device includes a shock wave tube 1, a drug chamber 2, a detonation mechanism 3 and a detonation pull cord 4; the pressure trigger device is fixed in the blast hole of the closed wall to be demolished, One end of the shock wave tube 1 extends into the blast hole, a drug chamber 1 is arranged in the shock wave tube 1, and the other end of the shock wave tube 1 is connected to the detonating mechanism 3, and the detonating mechanism 3 is connected to the detonating mechanism 3. Drawstring 4 connection.

Step S104, according to the blasting safety distance, set up a protective fence on the blasting surface of the airtight wall to be demolished;

The blasting safety distance is the blasting flying stone distance with high underground water pressure, which is determined by the following formula:

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; g</span>}}}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\frac{{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; g</span>}}$

Among them, S is the blasting safety distance, V ₁ is the speed of flying rocks; h is the drop of flying fragments; g is the acceleration of gravity.

The speed of the flying stone is determined by the following formula:

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; \&lsqb;</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;\&rho;R</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; \&rsqb;</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}$

Among them, K ₁ and K ₂ are the energy utilization coefficients of the first and second underwater shock waves respectively, and K ₁ =0.31, K ₂ =0.17; μ is the explosion work, and μ=4×10 ⁵ ; Wall density; R is the distance from the explosion source center to the closed wall to be demolished; δ1 is the equivalent wall thickness _of the closed wall to be demolished.

Step S105, detonating the explosive in the pressure trigger device outside the blasting safety distance to realize blasting demolition;

It should be noted that, outside the blasting safety distance, the detonating pull rope 4 on the pressure triggering device is pulled to detonate the explosives in the pressure triggering device, and a large pressure wave is generated after the shock wave tube 1 is hit, and the pressure wave breaks the liquid storage device , and spread through the water in the blast hole in the form of static water pressure, so that the water-propagating shock wave is used to break the closed wall to be demolished.

In the embodiment of the present invention, water is injected directly into the blast hole with an inclination, which is simple to operate, cost-saving, and high in efficiency; a protective fence is set on the blast-facing surface of the closed wall to be demolished to ensure the safety of personnel and equipment during the demolition process of the closed wall, reducing the Construction difficulty.

While preferred embodiments of the invention have been described, additional changes and modifications to these embodiments can be made by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (4)

1. A quick blasting demolition method for an airtight wall in a coal mine, characterized in that it comprises: Carry out blast hole cutting on the airtight wall to be demolished, and the blast hole angle is between 45° and 60°; Inject water into the blast hole; fixing a pressure triggering device in the blast hole, and explosives are placed in the pressure triggering device; According to the blasting safety distance, set up a protective fence on the blasting surface of the airtight wall to be demolished; Outside the blasting safety distance, the explosive in the pressure trigger device is detonated to realize blasting demolition. 2. method as claimed in claim 1, is characterized in that, the depth of described blast hole is determined by following formula: $\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; \&Greater\; Equal;</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>$ Among them, l is the depth of the blasting hole, α is the angle of the blasting hole; H is the height of the closed wall to be demolished; h ₁ is the overdrilling at the bottom. 3. the method for claim 1 is characterized in that, described blasting safe distance is the large blasting flying stone distance of downhole water pressure, is determined by following formula: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\sqrt{\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; g</span>}}}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; g</span>}}$ Among them, S is the blasting safety distance, V ₁ is the speed of flying rocks; h is the drop of flying fragments; g is the acceleration of gravity. 4. method as claimed in claim 3 is characterized in that, described flying stone velocity is determined by following formula: ${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; \&lsqb;</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; \&pi;\&rho;R</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; \&rsqb;</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}$ Among them, K ₁ and K ₂ are the energy utilization coefficients of the first and second underwater shock waves respectively, and K ₁ =0.31, K ₂ =0.17; μ is the explosion work, and μ=4×10 ⁵ ; Wall density; R is the distance from the explosion source center to the closed wall to be demolished; δ1 is the equivalent wall thickness _of the closed wall to be demolished.