Water-sand-bag interval charge smooth blasting structure and blasting method

Abstract

This invention provides a water-sandbag spaced-charge smooth blasting structure and method, specifically relating to the field of controlled blasting technology. The water-sandbag spaced-charge smooth blasting structure is installed within a peripheral hole, comprising several explosive rolls and water-sandbags spaced apart. A detonator and detonating cord are placed at the bottom of the peripheral hole. One end of the detonating cord is connected to the detonator, and the other end extends outward from the hole opening. All explosive rolls are in contact with the detonating cord. The blast hole positions of the peripheral hole are sealed with stemming material. During blasting, the detonator and detonating cord are buried at the bottom of the hole, and explosive rolls are sequentially inserted into the peripheral hole in the following order: first explosive rolls, then water-sandbags, then more explosive rolls… until the required number of explosive rolls is reached. The detonating cord is then pulled out of the peripheral hole, and the blast hole positions are sealed with stemming material. The smooth blasting method provided by this invention allows for a more pronounced crack propagation effect and a smoother, more even surface during smooth blasting.

Description

Technical Field

[0001] This invention patent relates to the field of controlled blasting technology, specifically to a smooth blasting structure and blasting method using water-sandbags with spaced explosive charges. Background Technology

[0002] During blasting, the surrounding rock will be damaged to varying degrees, affecting the stability and integrity of the surrounding structures. Smooth blasting construction technology causes less disturbance and damage to the surrounding rock, resulting in fewer cracks and thus maintaining the stability and integrity of the surrounding rock, enhancing its own load-bearing capacity, and reducing the amount of support work. Furthermore, smooth blasting allows cracks to grow and penetrate better, resulting in a smoother and more even surface, which better utilizes the self-supporting capacity of the surrounding rock, preventing damage to the surrounding rock and reducing adverse effects such as rockfall and collapse.

[0003] The paper "Construction Technology of Water Bag Interval Loading for Peripheral Eyeholes in Smooth Blasting of Tunnels" published in the third issue of the journal "Western Exploration Engineering" in 2022 discloses a method using... The standard explosive cartridges are loaded with explosives, and water bags are used to separate the cartridges. The detonation connection between the cartridges is made by detonating cord. This improves the blasting gas gap-forming effect while buffering and reducing the damage to the blast hole.

[0004] However, the key to smooth blasting lies in the charge structure of the perimeter holes. The traditional water-bag intermittent charge smooth blasting method uses the high-temperature vaporization of water in the water bag to buffer the explosive effect on the rock wall, which can avoid the energy of the explosive being concentrated at the explosive position. However, it is not conducive to the formation of a smooth contour surface, and the growth and penetration of cracks are generally not effective, and it cannot fully utilize the self-supporting capacity of the surrounding rock. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology and address the problems of water-bag interval-charge smooth blasting methods which are unfavorable for forming a smooth profile surface and have limited crack growth and penetration effects, thus failing to fully utilize the self-supporting capacity of the surrounding rock, this invention provides a water-sandbag interval-charge smooth blasting structure and blasting method. The specific technical solution is as follows:

[0006] A smooth-surface blasting structure with water-sandbag intermittent loading is installed in a peripheral hole, comprising a plurality of explosive rolls and water-sandbags arranged at intervals. A detonator and a detonating cord are installed at the bottom of the peripheral hole. One end of the detonating cord is connected to the detonator, and the other end extends outward from the hole opening. All explosive rolls are in contact with the detonating cord. The blast hole positions of the peripheral hole are blocked by blasting mud.

[0007] Preferably, the explosive roll is a standard explosive roll with a diameter of 32mm, a length of 200mm, and a weight of 200g.

[0008] Preferably, the water-sandbag comprises an outer packaging bag, fine sand, and water.

[0009] Preferably, the water and fine sand in the sandbag are mixed at a mass ratio of 7:3.

[0010] Preferably, the particle size of the fine sand is in the range of 0.25 mm to 0.35 mm.

[0011] More preferably, the length of the water sandbag is 15-35cm and the diameter is 25-35mm.

[0012] A blasting method employing the above-mentioned water-sandbag interval-loaded smooth blasting structure specifically includes the following steps:

[0013] S1. First, select the charge concentration in the smooth blasting parameter table according to the type and properties of the surrounding rock, and determine the number and size of explosive rolls and sandbags according to the length of the peripheral holes;

[0014] S2. Based on the results obtained in step S1, make water sandbags and explosive rolls of the corresponding sizes; explosive rolls that are insufficient in quantity are obtained by cutting standard explosive rolls to the required size.

[0015] S3. Insert the detonator and detonating cord into the bottom of the hole, and place the explosive rolls and sandbags in the order of first explosive rolls and then sandbags, and arrange them in an intermittent manner, until the number of explosive rolls reaches the blasting requirements obtained in step S1; at the same time, pull the detonating cord out to the outside of the opening of the surrounding holes, and finally use stemming clay to block the blasting hole positions of the surrounding holes.

[0016] The beneficial effects of this invention are:

[0017] Compared with existing technologies, the smooth blasting method using water-sandbag interval loading provided by this invention exhibits a relatively uniform weight distribution and stability of the water and fine sand mixed in the water-sandbag during peripheral hole detonation. On the one hand, the water-sandbag can evenly distribute the explosive charge, reduce the peak value of the initial blast pulse pressure, and store some energy in the intervals, extending the overall borehole action time and improving energy utilization and blasting effect. On the other hand, the water in the water-sandbag vaporizes and expands, wedging into the blast-induced fracture. Simultaneously, the fine sand particles in the water-sandbag rapidly invade the blast-induced fracture. Under high temperature and pressure, the fine sand particles exert a strong scouring effect on the medium on both sides of the fracture while invading the fracture, forming a significant cutting effect. This is beneficial for the growth and penetration of the fracture, and also plays a positive role in forming a smooth and flat contour surface. Attached Figure Description

[0018] The accompanying drawings constituting this application are provided to further understand this application and do not constitute an undue limitation of this application.

[0019] Figure 1This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a diagram of the smooth blasting arrangement in Embodiment 1 of the present invention;

[0021] Figure 3 This is a diagram of the smooth blasting arrangement in Embodiment 2 of the present invention;

[0022] In the diagram, 1-peripheral hole; 2-explosive roll; 3-water sandbag; 4-detonator; 5-blasting mud; 6-detonating cord. Detailed Implementation

[0023] The specific implementation of the water-sandbag interval-filled smooth blasting structure and blasting method provided by the present invention will be further described in conjunction with the accompanying drawings and embodiments.

[0024] A water-sandbag-filled, smooth-surfaced blasting structure is installed in a peripheral hole 1, comprising several explosive rolls 2 and water-sandbags 3 spaced apart. A detonator 4 and a detonating cord 6 are installed at the bottom of the peripheral hole 1. One end of the detonating cord 6 is connected to the detonator 4, and the other end extends outward from the opening of the peripheral hole 1. Preferably, the detonation connection between the explosive rolls 2 can be achieved by using the same detonator and detonating cord, or by using a separate detonator for each explosive roll 2, depending on the project procurement conditions. The blast hole positions of the peripheral hole 1 are blocked by blasting mud 5.

[0025] Preferably, the explosive roll 2 is a standard explosive roll with a diameter of 32mm, a length of 200mm, and a weight of 200g. The amount of explosive roll 2 that is insufficient for a full roll can be obtained by cutting the standard explosive roll.

[0026] Preferably, the water-sandbag 3 includes an outer packaging bag, fine sand, and water; wherein the water and fine sand inside the water-sandbag are mixed in a mass ratio of 7:3; the length of the water-sandbag is 15-35cm and the diameter is 25mm-35mm; the particle size of the fine sand is best selected when it is 0.25mm-0.35mm.

[0027] During demolition, the structure shall be arranged according to the following steps:

[0028] S1. First, select the charge concentration in Table 1 of smooth blasting parameters according to the type and properties of the surrounding rock, and determine the number and size of explosive rolls 2 and sandbags 3 according to the length of the peripheral holes 1.

[0029] S2. Based on the results obtained in step S1, make explosive rolls 2 and water sandbags 3 of the corresponding sizes; if the explosive roll 2 is insufficient for the full roll of explosives, simply cut the standard explosive roll to the required size.

[0030] S3. Insert the detonator 4 and detonating cord 6 into the bottom of the hole, and place them in the following order from the inside out: first explosive roll 2, then water sandbag 3, then explosive roll 2 again... in an intermittent manner, until the number of explosive rolls 2 reaches the blasting requirement obtained in step S1; at the same time, lead the other end of the detonating cord 6 out to the outside of the hole opening of the peripheral hole 1, and finally use the stemming clay 5 to block the blasting hole position of the peripheral hole 1 to complete the blasting arrangement.

[0031] The quantity and size of the explosive rolls 2 and the water sandbags 3 are determined based on parameters such as the depth of the boreholes 1, the properties and types of the surrounding rock, and the smooth blasting parameters in Table 1 below.

[0032]

[0033] Table 1. Smooth Blasting Parameters

[0034] Example 1:

[0035] Taking a blast hole 1 with a depth of 2m and surrounding rock of hard rock as an example, according to the smooth blasting parameter table 1, the charge concentration is selected as 0.16kg / m. The total charge for a single blast hole is calculated to be 0.32kg, which means a total of 1.6 standard explosive cartridges with a length of 200mm are required. These are divided into two explosive cartridges 2, each of which consists of 0.8 standard explosive cartridges with a length of 200mm. Four sandbags 3, each 27cm long, are needed for spacing.

[0036] After the explosive roll 2 and the water sandbag 3 are prepared, first put the detonator 4 and the detonating cord 6 into the bottom of the hole, then put in the first explosive roll 2, then put in the water sandbag 3, and then put in the second explosive roll 2. Each explosive roll 2 is in contact with the detonating cord 6. Finally, lead the detonating cord 6 out to the outside of the hole 1 of the surrounding hole, and at the same time, use the drilling mud 5 to plug the hole. The plugging length of the drilling mud 5 is 0.6m.

[0037] Example 2:

[0038] Taking a 3m deep borehole 1 with hard rock as an example, according to Table 1 of smooth blasting parameters, a charge concentration of 0.22kg / m is selected. The calculated charge for a single borehole is 0.66kg, requiring 3.3 standard explosive cartridges of 200mm length. These are divided into three explosive cartridges 2, each consisting of 1.1 standard explosive cartridges of 200mm length. Three sandbags 3, 19cm long, are needed for spacing.

[0039] After the explosive roll 2 and the water sandbag 3 are prepared, first place the detonator 4 and the detonating cord 6 at the bottom of the hole, then put in the first explosive roll 2, then put in the water sandbag 3, then put in the second explosive roll 2, then put in the water sandbag 3, then put in the third explosive roll 2, and each explosive roll 2 is in contact with the detonating cord 6; finally, lead the detonating cord 6 out to the outside of the hole 1 of the surrounding hole, and at the same time, plug the hole with the drilling mud 5, where the plugging length of the drilling mud 5 is 1.2m.

[0040] Comparing the effects of smooth blasting using water-bag intervals and water-sandbag intervals under the same conditions, compared with the smooth blasting method using water-bag intervals, the blasting method provided by this invention, when detonating in the peripheral hole 1, exhibits a relatively uniform weight distribution and stability of the water and fine sand mixed in the water-sandbag 3. On the one hand, the water-sandbag 3 can evenly distribute the explosive roll 2, reduce the peak value of the initial blasting pulse pressure, and store some energy in the intervals, extending the entire borehole's action time, thereby improving energy utilization and blasting effect. On the other hand, the water in the water-sandbag 3 vaporizes and expands, wedging into the blast-induced fracture. Simultaneously, the fine sand particles in the water-sandbag 3 rapidly invade the blast-induced fracture. Under high temperature and pressure, the fine sand particles, while invading the fracture, exert a strong scouring effect on the medium on both sides of the fracture, forming a significant cutting effect. This is beneficial for the growth and penetration of the fracture, and also has a positive effect on forming a smooth and flat contour surface.

[0041] In this invention, terms such as "upper," "lower," "bottom," and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are merely used to facilitate the description of the structural relationships of the various components or elements of this invention and do not specifically refer to any particular component or element in this invention, nor should they be construed as limiting the invention. Terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of the above terms in this invention based on the specific circumstances, and they should not be construed as limiting the invention.

[0042] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A smooth-surface blasting structure with water-sandbags spaced and loaded with explosives, disposed within peripheral holes, characterized in that, It includes several explosive cartridges and sandbags spaced apart. A detonator and a detonating cord are installed at the bottom of the peripheral holes. One end of the detonating cord is connected to the detonator, and the other end is led out to the outside of the hole along the peripheral holes. All explosive cartridges are in contact with the detonating cord. The blast hole positions of the peripheral holes are blocked by blasting mud. The water-sandbag includes an outer packaging bag and fine sand and water filled inside the outer packaging bag; the water and fine sand inside the water-sandbag are mixed at a mass ratio of 7:

3.

2. The water-sandbag intermittently loaded smooth blasting structure according to claim 1, characterized in that, The explosive cartridges used are standard cartridges with a diameter of 32mm, a length of 200mm, and a weight of 200g.

3. The water-sandbag intermittently loaded smooth blasting structure according to claim 1, characterized in that, The particle size range of the fine sand is 0.25mm to 0.35mm.

4. The water-sandbag intermittently loaded smooth blasting structure according to claim 1, characterized in that, The water-filled sandbags are 15-35cm long and 25-35mm in diameter.

5. A blasting method for a smooth-surface blasting structure with water-sandbag intermittent loading as described in any one of claims 1 to 4, characterized in that, Specifically, the following steps are included: S1. First, select the charge concentration in the smooth blasting parameter table according to the type and properties of the surrounding rock, and determine the number and size of explosive rolls and sandbags according to the length of the peripheral holes; S2. Based on the data obtained in step S1, make water sandbags and explosive rolls of the corresponding size; explosive rolls that are insufficient in quantity are obtained by cutting standard explosive rolls to the required size. S3. Insert the detonator and detonating cord into the bottom of the hole, and place the explosive rolls and sandbags in the order of first explosive rolls and then sandbags, and arrange them in an intermittent manner, until the number of explosive rolls reaches the blasting requirements obtained in step S1; at the same time, pull the detonating cord out to the outside of the opening of the surrounding holes, and finally use stemming clay to block the blasting hole positions of the surrounding holes.

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