CN216898575U - Charging means of tunnel all ring edge eye presplitting blasting - Google Patents

Abstract

The utility model belongs to the field of blasting, and particularly discloses a charging device for roadway periphery hole presplitting blasting. The presplitting blasting method adopting the spaced loading of the confined water and the air column is provided based on the confined water blasting effect principle, and has positive significance for ensuring the realization of peripheral eye smooth blasting, improving the forming effect of hard rock roadways, controlling the loading cost and ensuring the safe production.

Description

A charging device for pre-split blasting around the roadway

technical field

The utility model belongs to the field of blasting, in particular to a blasting method for underground rock tunnels, tunnels and the like in coal mines.

Background technique

At present, the drilling and blasting method is still the main method for excavation of underground rock roadways in coal mines, which has the advantages of strong adaptability, high reliability and controllable cost. The drilling and blasting method of blasting holes is mainly divided into cutting holes, auxiliary holes and peripheral holes. The peripheral holes are arranged around the excavation section, and the bottoms of the holes are all on the same plane. The blastholes are mainly used to control the excavation profile and roadway section. forming. The surrounding holes of rock roadway excavation generally adopt the straight-hole bottom charging structure. In soft rock roadways, technologies such as directional slit pre-split blasting can be used to realize smooth blasting of roadway and control roadway formation. The structure of the charge can make the explosive energy propagate in the direction of pre-splitting, and reduce the impact pressure of the explosion on the surrounding rock. , the blasting vibration effect is more severe, causing serious damage to the surrounding rock.

Utility model content

The purpose of this utility model is to provide a charging device for pre-split blasting around the tunnel, which is based on the blasting principle of confined water and adopts a pre-split blasting method in which the confined water and the air column are spaced to charge. It is of positive significance to blast, improve the forming effect of hard rock roadway, control the cost of charge, and ensure safe production.

The technical scheme of the utility model is a charging device for pre-split blasting around a roadway, which is characterized in that the charging device is a seismic isolation and energy gathering pipe, and the middle of the seismic isolation and energy gathering pipe is recessed inward to form an energy gathering groove, The upper end of the seismic isolation and energy gathering tube is provided with a top cover plate, and the lower end is provided with a bottom cover plate. The space between the explosive pack and the air column is designed in the seismic isolation and energy gathering tube. There is a sawdust spacer bag between the columns; when the actual downhole blasting is performed, the seismic isolation and energy accumulating pipe needs to be assembled.

Further, the separation distance between the two explosive packs is not greater than the detonation distance of the explosive in the blasthole.

Further, the direction of the energy collecting groove of the seismic isolation energy collecting pipe is consistent with the direction of the roadway section outline.

Further, during the assembly of the seismic isolation energy-gathering tube, an additional layer of hole wall protection shell is covered on the side near the roadway wall to further protect the stability of the surrounding rock of the roadway wall.

The utility model has the following beneficial effects

1. The directional energy-gathering tube structure provided by the utility model realizes directional energy-gathering blasting through directional slit pre-splitting, and ensures that the explosive energy is concentrated on the fracture surface for roadway contour forming.

2. The peripheral eye of the utility model adopts the energy-gathering tube to charge the medicine, and the energy-gathering groove is in the same direction as the roadway section outline. Through directional pre-splitting, blasting isolation and shock absorption can be achieved, the damage degree of surrounding rock can be reduced, and the stability of the roadway can be improved.

3. The utility model adopts the air column interval charging method. Under certain rock and explosive conditions, the uniformity of the blast load distribution along the blast hole can be increased, the energy can be released evenly along the bore hole in the heading direction, and the smooth blasting effect can reach the best. .

4. Confined water promotes blasting kerf pre-splitting effect

On the basis of directional and concentrated release of energy along the profile of the roadway section and uniform release along the length of the tunnel face, a specially made pressurized water medium is arranged around the explosive. It can promote the further expansion of the explosive products along the blasting cracks. Under the certain premise of the surrounding eye charge spacing and charge, the roadway forming effect can be improved and the disturbance effect of blasting on the surrounding rock can be controlled.

Description of drawings

Figure 1 is a schematic diagram of the blasting arrangement of the present invention.

Fig. 2 is a schematic diagram of the structure of the seismic isolation and energy collecting pipe of the present invention.

Figure 3 is a diagram of a peripheral hole drilling arrangement.

Description of reference numerals: Seismic isolation and accumulating tube 1, pressurized water medium 2, air column 3, sawdust spacer pack 4, explosive pack 5, top cover 6, bottom cover 7, energy gathering tank 8, hole wall protection shell 9 .

Detailed ways

The technical content of the present utility model will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 , the peripheral eye of the present utility model adopts a shock-isolating energy-gathering tube 1 for charging, the upper end of the shock-isolating energy-gathering tube 1 is provided with a top cover 6, and the lower end is provided with a bottom cover 7. The air column 3 is designed to be spaced apart, and the spaced distance between the two explosive packs 5 is generally not greater than the detonation distance of the explosive in the blasthole. A circle of pressurized water medium 2 is arranged around the explosive pack 5. After the explosion, the high-pressure water-vapor mixture formed by the mixing of the surrounding pressurized water can promote the further expansion of the explosive product along the blasting crack, and the distance between the surrounding eye charge and the charge can be increased. Under certain premise, it can improve the tunnel forming effect and control the disturbance effect of blasting on surrounding rock.

Between the explosive pack 5 and the air column 3, a sawdust spacer pack 4 is arranged. Due to the low density and high porosity of the sawdust spacer pack, it can play a very good cushioning effect, and at the same time, the material will not react with the explosive to affect the blasting effect. .

As shown in Fig. 2, the center of the isolation energy-concentrating tube 1 is recessed inward to form an energy-concentrating groove 8. The energy-concentrating groove plays the role of orientation, so that after the shock wave of the explosive explosion hits the blast hole wall in a predetermined direction, the shock crack reaches the maximum length, while the generated explosive gas continues to expand the crack, pushing it to continue to expand.

The directional fracture of the rock is realized by the energy-gathering effect of the energy-concentrating device. When charging the peripheral eye, first load the coil into the energy gathering device according to the designed charging structure, and then send the energy gathering device into the blast hole, so that the direction of energy gathering is consistent with the direction of fracture control (as shown in the direction of the groove in Figure 2). ), and plug the blast hole. When the explosive is detonated, the energy-gathering device has an instantaneous inhibition and guiding effect on the pre-detonation products. The detonation products are preferentially released from the energy-gathering holes of the device, and a high-energy flow is formed at each energy-gathering hole, which concentrates on the corresponding blast hole wall, so that the plastic crushing zone and radial initial cracks are preferentially generated in the control direction. The high-temperature, high-pressure, high-speed gas and confined water generated by the detonation still preferentially act on the pore wall corresponding to the direction of energy accumulation after the stress wave, and flow into the radial initial crack, where a "water-gas wedge" effect is generated. When the stress intensity factor at the crack tip exceeds the fracture toughness of the rock, the crack becomes unstable and drives crack propagation. As a result, new free surfaces are continuously provided for subsequent compressive stress waves. The compressive stress wave is transformed into a tensile wave by reflection from the free surface; therefore, a tensile stress concentration is generated in the direction perpendicular to the propagation direction of the crack, which accelerates the propagation of the crack. During the whole blasting process, the above process is carried out continuously until the explosive in the blast hole is exhausted, and the final result is that the rock mass is stretched and cracked along the set direction.

In the non-set direction, due to the certain thickness and strength of the energy-gathering device, it has an instantaneous buffering and inhibiting effect on the detonation products, and the detonation products are preferentially unloaded from the energy-concentrating hole; the stress in the blasting hole drops sharply. At the same time, there is also a small part of the stress wave that transmits through the wall of the device, but it still needs to pass through the annular space between the device and the wall of the blast hole, and then acts on the wall of the hole, which greatly reduces the direct effect and degree of damage of the detonation products on the wall of the hole. The development of cracks is inhibited and the integrity of the surrounding rock is protected. When two or more two-way shaped charge blastholes are detonated at the same time, a superimposed stress field is generated between the blastholes.

The structure of the charge determines the energy distribution of the explosive after detonation, and has an important influence on the blasting effect. In the axial direction, the air column spaced charging method is adopted. Under the determined rock strength and charging conditions, the uniformity of the blast load distribution along the blasthole can be increased, and the energy can be released evenly along the borehole in the driving direction, which changes the detonation. The action process of the shock wave on the medium can improve the utilization rate of the explosion energy, control the blasting effect to reduce the unit consumption of the explosive, improve the blasting effect, and achieve the best smooth blasting effect. At the same time, the use of the air column interval charging method has a significant impact on the rock block size, the shape of the blasting pile and the throwing distance of the rock block. The size of the air layer has a significant impact on the blasting effect. With the increase of the air ratio, the rock breaking method When the air ratio is 40%, the rock breaking mechanism is changed from compression shearing to tensile failure, and a better block size gradation is achieved, indicating that there is a reasonable air ratio, which can improve the utilization rate of explosion energy and reduce rock blocks. The long throwing distance can avoid rock damage to drilling machinery and anchor net, save a lot of time for roadway support, and also increase the safety of construction.

As shown in Fig. 2, during the actual downhole blasting, it is necessary to assemble the isolation and energy-concentrating pipe according to the actual situation. In the non-set direction, due to the certain thickness and strength of the energy-gathering device, it has an instantaneous buffering and suppressing effect on the detonation products, but it still damages the hole wall to a certain extent. Therefore, an additional layer of hole wall protection is covered on the side near the roadway wall The shell 9 greatly protects the integrity of the surrounding rock.

After the seismic isolation and concentrating tube is assembled, charge the detonating cord at equal intervals in the energy accumulating device, tie the electric detonator and the detonating cord together and insert it into the energy concentrating tube, with the energy accumulating hole of the electric detonator facing the eye opening. After the seismic isolation and energy collection tube is sent to the bottom of the hole, the hole is sealed and tamped with a cannon stick. Connect the detonating index about 10cm out of the hole to prepare for detonation.

In the prior art, the amount of charge in the surrounding eye is too high, resulting in serious damage to the surrounding eye rock, resulting in over-excavation and uneven formation of the roadway section. As shown in Figure 3, the utility model arranges blastholes in the peripheral holes, and the number of blastholes is greatly reduced compared with the prior art. The reduction in the number of blastholes indicates that the density of blastholes is reduced, which saves explosives.

Claims (4)

1. A charging device for pre-splitting and blasting around an eye of a roadway, characterized in that the charging device is a shock-isolating energy-gathering tube (1), and the middle of the shock-isolating energy-gathering tube (1) is recessed inward to form an energy-gathering groove (1). 8), a top cover plate (6) is provided at the upper end of the shock isolation and energy gathering tube (1), and a bottom cover plate (7) is provided at the lower end, and the space between the explosive pack (5) and the air column (3) in the shock isolation and energy gathering tube is designed , a circle of pressurized water medium (2) is arranged around the explosive pack (5), and a sawdust spacer pack (4) is arranged between the explosive pack (5) and the air column (3). Assemble the vibration isolation tube. 2 . The charging device for pre-splitting blasting around the tunnel as claimed in claim 1 , wherein the distance between the two explosive packs ( 5 ) is not greater than the detonation distance of the explosive in the blasthole. 3 . 3 . The charging device for pre-splitting blasting around a roadway as claimed in claim 1 , wherein the energy collecting groove (8) of the seismic isolation energy collecting pipe is in the same direction as the roadway section outline. 4 . 4. a kind of charging device for pre-splitting blasting around the tunnel as claimed in claim 1, it is characterized in that, when carrying out the assembly of the seismic isolation and energy collecting pipe, one more layer of hole wall protection shell (9) is covered near the tunnel wall side , to further protect the stability of the surrounding rock of the roadway wall.

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