Efficient low-vibration strip mine deep hole step blasting method and pre-splitting hole charging structure

Abstract

The invention discloses an efficient low-vibration strip mine deep hole step blasting method and a pre-splitting hole charging structure. The method comprises the following steps that A, main blasting holes which are located in the front row and arranged in a staggered mode and presplitting holes located in the rear row are drilled; b, after the main blasting hole and the presplitting hole are drilled, explosive filling operation is conducted, explosive filling is continuous, filling is continuous and compact, and after explosive filling is completed, the explosive filling condition and the filling condition are checked through a measuring rope; c, safety disposal; and D, blasting operation is carried out, a signal is sent out before blasting, and blasting is started after personnel in the dangerous area are removed to a safe place. The method has the advantages that by optimizing blasting parameters (such as aperture and spacing) and adopting a brand-new pre-split hole charging structure, slope quality can be improved from the source, follow-up repair investment is reduced, indirect loss caused by safety accidents is avoided, core requirements of enterprise cost management and control are met, technical reference is provided for industry operation cost reduction, and the method is worthy of popularization and application. The method is an important path for promoting economic and efficient operation of mines.

Description

Technical Field

[0001] This invention relates to a blasting technology for open-pit mines, specifically a high-efficiency, low-vibration deep-hole bench blasting method for open-pit mines and a pre-splitting hole charging structure. Background Technology

[0002] With the rapid development of my country's economy, the demand for mineral resources such as limestone is increasing, and mining activities are becoming more frequent. However, in the slope treatment stage of open-pit mining, the traditional backhoe loader method often suffers from problems such as lack of compliance, high costs, and prominent safety hazards, posing multiple threats to the legal operation of mines, cost control, and the safety of personnel and equipment. Existing slope treatment methods can no longer meet the needs of enterprises for efficient and safe operation. They not only fail to comply with national safety regulations, but also increase long-term repair costs due to uneven slopes (failing to meet the ±150mm standard) and poor stability. Furthermore, there is a risk of landslides and collapses, which not only directly threaten the lives of on-site workers but may also limit the expansion of mining operations, shorten the mine's service life, and restrict the implementation of the enterprise's long-term mining plans. Taking our company as an example: the use of conventional backhoe loader methods has resulted in frequent slope repair needs for 2-3 consecutive years, with slope repair costs exceeding 100 million yuan in 2024 alone. The costs can amount to tens of thousands of yuan, directly increasing the company's operational burden. In addition, slope instability can also induce landslides and collapses, causing damage to mining equipment and interrupting production processes, resulting in unpredictable indirect costs. At the same time, the operation of loader trucks can easily generate additional dust emissions, which is inconsistent with the company's environmental protection requirements for promoting green mine construction (dust emission concentration <20 mg / m³, 100% greenable area). The dual demands of safe production and green operation place urgent demands on the upgrading of open-pit mine technology. Therefore, how to solve a series of pain points of traditional methods while ensuring mineral supply capacity has become a key issue that the company urgently needs to overcome.

[0003] According to the "GB16423-2020 Safety Regulations for Metal and Non-metal Mines," controlled blasting technology must be used in key areas such as the final slope near the mining area. This involves precisely controlling the blasting process to achieve slope smoothing, protect the rock mass structure, and ultimately form a naturally stable slope. Traditional backhoe blasting methods completely fail to meet this stringent requirement, leading to long-term policy compliance risks for enterprises. Failure to rectify this in a timely manner could hinder normal production and operation. Furthermore, controlled blasting technology has extremely high requirements for parameter matching and detonation accuracy, and existing technological reserves are insufficient to meet the implementation needs, resulting in a gap with the industry's standardized development direction. Developing pre-splitting blasting technology adapted to the actual conditions of mining areas can effectively solve the compliance problem. This aligns with national safety policies and regulations for production and mining, and also responds to the industry's technological upgrading requirements, making it an inevitable choice for enterprises to avoid policy risks and achieve legal operation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a highly efficient and low-vibration deep-hole bench blasting method and pre-splitting hole charging structure for open-pit mines that can significantly improve slope stability, eliminate safety hazards, reduce slope repair work and reduce environmental interference.

[0005] To solve the above-mentioned technical problems, the present invention provides a high-efficiency, low-vibration deep-hole bench blasting method for open-pit mines, comprising the following steps:

[0006] A. Drill main blasting holes in the front row and pre-splitting holes in the rear row, arranged in an alternating pattern. The main blasting holes have a drilling angle of 50-80°, a diameter of 115-152 mm, a hole depth of L = 10-17 m, a hole spacing of a = 4-6 m, a row spacing of b = 3-4 m, and a total number of 15-25 holes. The pre-splitting holes have a drilling angle of 50-80°, a hole depth of L = 15-19 m, and a pre-splitting spacing of 1-1.6 m.

[0007] B. After drilling the main blasting hole and pre-splitting hole, carry out the explosive loading operation. After loading, the explosive consumption per unit of the main blasting hole is q = 0.42~0.46 kg / m. 3 The blasting filling length L1 is 3-4.5m, and the charge amount per hole Q is 110-120kg; the linear charge density of the pre-splitting hole is 0.65-1kg / m, the pre-splitting filling length L2 is 1.5-2.5m, the charging is continuous and the filling is continuous and compact. After the filling is completed, the charging and filling conditions are checked with a measuring rope.

[0008] C. Safety procedures: Before the blasting operation begins, a warning line is set up at the boundary of the danger zone to make the blasting operation area relatively closed. Before detonation, the blasting materials, detonating power supply and instruments used are inspected. Only after the warning line is completed and safety is confirmed can the main line be connected to the detonator and wait for the detonation command.

[0009] D. Before blasting, a signal is given. Blasting begins after personnel in the danger zone have been evacuated to a safe location. During blasting, the detonation direction is controlled. After detonation, the power supply is cut off in time, and the main line is separated from the detonator.

[0010] Furthermore, in step C, 30 minutes before detonation, all passages leading into the blasting hazard zone must be guarded by designated personnel.

[0011] Furthermore, 15 minutes after the detonation is completed, the blast zone is entered to check for any misfires. Once safety is confirmed or misfires are dealt with and safety is confirmed, the alert is lifted.

[0012] Furthermore, in step B, during the loading and packing of explosives, personnel unrelated to the blasting operation are prohibited from entering the site.

[0013] Furthermore, in step B, before loading the explosive charge, the detonator and the initiating charge are first loaded into the borehole.

[0014] Furthermore, in step B, if the main blast hole is a water hole, the end of the delivery hose is lowered to the bottom of the main blast hole, and the delivery hose is slowly raised according to the loading speed.

[0015] Furthermore, in step B, 10 minutes after the mixed emulsion explosive is loaded, it can be filled only after passing the inspection, and the length of the filling section is measured to see if it meets the blasting design requirements.

[0016] Furthermore, in step B, when the mixed emulsion explosive is loaded to the last borehole, the remaining explosive in the hose is loaded into the borehole, and after loading is completed, the remaining explosive in the hose is cleaned out.

[0017] Furthermore, if any blockage is found in the hole, it should be dealt with promptly; when filling water holes, the filling speed should be slowed down to allow water to drain out of the hole and avoid the formation of suspended material.

[0018] A pre-splitting hole charging structure for the above-mentioned high-efficiency, low-vibration open-pit deep-hole bench blasting method includes a support sleeve installed at the center of the pre-splitting hole and explosives strung on a detonating cord. The explosives strung on the detonating cord extend from the top opening of the support sleeve to the bottom of the support sleeve. The top opening of the support sleeve is also filled with filler material. The detonating cord is connected to an electronic detonator located outside the pre-splitting hole.

[0019] The advantages of this invention are:

[0020] (1) By optimizing blasting parameters (such as hole diameter, spacing, etc.) and adopting a brand-new pre-splitting hole charging structure, the quality of the slope can be improved from the source, reducing subsequent repair investment and avoiding indirect losses caused by safety accidents. This not only meets the core needs of enterprise cost control, but also provides technical reference for the industry to reduce operating costs. It is an important path to promote the efficient operation of the mining economy.

[0021] (2) By designing a pre-splitting hole charging structure with a support sleeve, the stability of the charging is ensured. At the same time, by adapting to different pre-splitting blasting parameters, the slope stability can be significantly improved (target half hole ratio ≥60%, slope gradient ±1°), safety hazards can be eliminated, and the amount of slope repair work can be reduced to reduce environmental interference, providing technical support for the mine to achieve integrated operation of "safety-environmental protection-efficiency". Attached Figure Description

[0022] Figure 1 This is a plan view of the main borehole and pre-splitting borehole arrangement in this invention;

[0023] Figure 2 This is a schematic cross-sectional view of the pre-cracked hole in this invention;

[0024] Figure 3 This is a schematic diagram of the present invention and the pre-splitting hole charging structure. Detailed Implementation

[0025] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the efficient, low-vibration deep-hole bench blasting method for open-pit mines and the pre-splitting hole charging structure of the present invention. Example 1:

[0026] As shown in the figure, the efficient and low-vibration deep-hole bench blasting method for open-pit mines of the present invention includes the following steps:

[0027] A. Drill the main blast holes in the front row and the pre-splitting holes in the rear row, arranged in an alternating pattern. The drilling angle of the main blast holes is 50-80° (preferably 65°), and the diameter of the main blast holes is 115-152 mm, preferably... 115 mm, the depth of the main blast hole is L = 10-17m (preferred). 16 ~ 17 The main blasting hole spacing a = 4-6m (preferably m). 5 The spacing between the main blast holes is b = 3-4m (preferably m). 3.5 The number of main blasting holes is 15-25 (preferably 18); the drilling angle of the pre-splitting holes is 50-80° (preferably 65°), and the hole depth of the pre-splitting holes is L = 15-19m (preferably). 17 The preferred pre-crack spacing is 1–1.6 m. 1.2 m);

[0028] B. After drilling the main blast hole and pre-splitting hole, proceed with the charging operation. Before charging the main blast hole, first insert the detonator and detonator into the main blast hole, then perform on-site mixing and charging of the explosives. The explosive consumption per main blast hole is q = 0.42~0.46 kg / m. 3 The blasting and filling length L1 is 3–4.5 m, and the charge per hole Q is 110–120 kg. Pre-splitting holes are charged using a method where emulsion-based small charges are bundled onto the detonating cord. The linear charge density in the pre-splitting holes is 0.65–1 kg / m (preferred). 0.65 kg / m), pre-splitting filling L2 = 1.5~2.5m (preferred) 2 m), the charging and packing are continuous and compact. After the charging is completed, the charging and packing are checked with a measuring rope. Some emulsified small charges are used to be loaded into the main blasting holes with water at the bottom. During the charging and packing process, personnel unrelated to the blasting operation are prohibited from entering the site.

[0029] C. Safety procedures: Before the blasting operation begins, a designated person must be in charge of directing the operation. First, set up warning posts and signs at the boundary of the danger zone to make the blasting operation area relatively closed and prevent unauthorized personnel from entering. 30 minutes before detonation, all passages leading into the blasting danger zone must be guarded by designated personnel. At the same time, the blasting materials, detonating power supply and instruments used must be inspected. Only after the warning is completed and safety is confirmed can the main line be connected to the detonator and wait for the detonation command.

[0030] D. Before blasting, a signal is given. Blasting begins after personnel in the danger zone have been evacuated to a safe location. During blasting, the detonation direction is controlled. After detonation, the power supply is cut off in time, and the main line is separated from the detonator. After detonation, the pre-splitting hole explodes, followed by the main blasting hole to complete the blasting operation.

[0031] E. Fifteen minutes after detonation, enter the blast zone to check for misfires. Once safety is confirmed or misfires are dealt with, the warning is lifted.

[0032] Furthermore, in step B, the charge of the front row of blasting holes is adjusted appropriately according to the conditions of the free face. If the minimum resistance line of the front row of main blasting holes is too small, the charge amount should be controlled to prevent flyrock and forward rushing caused by the small resistance line.

[0033] Furthermore, in step B, if the main borehole is a water borehole, the end of the delivery hose is lowered to the bottom of the main borehole, and the delivery hose is slowly raised according to the loading speed.

[0034] When filling the holes, the mixed emulsion explosives should be loaded for 10 minutes after completion and inspected before filling can begin. The length of the filling section should be measured to ensure it meets the blasting design requirements. When loading the mixed emulsion explosives to the last main borehole, the remaining explosives in the hose should be loaded into the borehole. After loading, the remaining explosives in the hose should be cleaned out. If any packing material is found stuck in the hole, it should be dealt with promptly. When filling water holes, the filling speed should be slowed down to allow water to drain out of the hole and avoid suspended material.

[0035] Example 2:

[0036] The pre-splitting hole charging structure of this embodiment for the above-mentioned high-efficiency, low-vibration open-pit deep-hole bench blasting method consists of a support sleeve 2 placed at the center of the pre-splitting hole, with explosives 4 connected in series on a detonating cord 3. The explosives connected in series on the detonating cord 3 extend from the top opening of the support sleeve to the bottom of the support sleeve. The top opening of the support sleeve 2 is also filled with filler material 5. The detonating cord 3 is connected to an electronic detonator 6 located outside the pre-splitting hole. The effectiveness is verified below with reference to a specific application example:

[0037] The blasting area was located at the eastern part of the 15-meter level of a certain mining area.

[0038] This blasting was a deep-hole blasting operation in rock, using digital electronic detonators for initiation with delay times of 0ms, 100ms, 17ms, 25ms, and 42ms. Key parameters included: a 65-degree drilling angle for the main blast holes and a borehole diameter of 115mm; 65-degree drilling angles for the pre-splitting holes; and on-site loading of nitrous oxide (NH3) fuel oil (NO3) explosives using a mixed loading vehicle and manual loading of emulsion explosives.

[0039] The main blast hole depth is L = 16–17 m, and the unit consumption is q = 0.42–0.46 kg / m. 3 Hole spacing a = 5m, row spacing b = 3.5m, blasting filling L1 = 3~4.5m, single hole charge Q = 110~120kg, number of holes is 18, and the charge of the main blasting hole is 2122.14kg.

[0040] The pre-splitting hole depth is L = 17m, the linear charge density is 0.65kg / m, the pre-splitting spacing is a(m) = 1.2m, the pre-splitting filling depth is L2 = 2m, the number of pre-splitting blasting holes is 42, and the amount of charge in the pre-splitting holes is 409kg. Some of the emulsion charge is used to load into the main blasting holes where there is water at the bottom.

[0041] The maximum single-explosive charge is 120 kg, the total charge is 2531.14 kg, and the total number of blasting holes is 60.

[0042] The following experiments were conducted to verify this:

[0043] In January 2025, the planning and design of the technical solution will be carried out. Based on experience, a smaller borehole diameter results in better pre-splitting blasting. The design is based on the soil and rock properties, prioritizing a 115mm borehole diameter. For special soil and rock conditions where the PD45 drilling rig cannot drill, a 152mm borehole diameter is designed. The hole depth is calculated based on the bench height and is unrelated to the effect. The pre-splitting spacing corresponds to 1.2m for a 115mm borehole diameter and 1.6m for a 152mm borehole diameter; these are empirical values ​​from previous experiments and will not be tested in this experiment. This experiment mainly studies the influence of the packing length and linear charge density on the pre-splitting blasting effect, where the packing length cannot be less than the minimum resistance line (2m).

[0044] Three experiments were conducted on January 9, 24, and 25, 2025, respectively. The parameters and results are shown in the table below:

[0045]

[0046] Results Analysis: On the 9th and 25th, the same parameters were selected for tests at different locations. On the 24th, different borehole diameters were selected for tests at different locations. All test results met the target values. Conclusions: 1. All indicators met the target values, indicating that the design parameters are not affected by location and are reliable. However, the number of tests was small, and there was some randomness. Further tests will be conducted at different locations. 2. Although all indicators met the target values, there is still room for improvement in flatness. The parameters (filling length and linear charge density) will be fine-tuned and the results will be observed.

[0047] Three experiments were conducted in February 2025 on February 14, 24, and 27, respectively. The parameters and results are shown in the table below:

[0048]

[0049] Results Analysis: On the 14th and 27th, the same parameters were selected for tests at different locations. On the 24th, different borehole diameters were selected for tests at different locations. All test results met the target values. Conclusions: 1. All indicators met the target values, indicating that the design parameters are not affected by location and are reliable. However, the number of tests was small, and there was some randomness. Further tests will be conducted at different locations. 2. Although all indicators met the target values, there is still room for improvement in flatness. The parameters (filling length and linear charge density) will be fine-tuned and the results will be observed.

[0050] A test was conducted on March 1, 2025. The geological conditions were very poor; the D50 drilling rig could not drill a hole at a depth of 1.6m. Ultimately, the pre-splitting spacing was changed to 2 meters, and the linear charge density was changed to 1.96. The parameters and results are shown in the table below.

[0051]

[0052] Results Analysis: On the 1st, different parameters and locations were selected for the test. The test results were not ideal. The half-pore ratio did not meet the target value, and the sensory effect was poor. The analysis suggests that the pre-splitting spacing and linear charge density were adjusted due to geological reasons, resulting in poor results. This indicates that the original design parameters are more reliable. The pre-splitting spacing and linear charge density should not be increased. It is recommended to reduce the test effect in the future.

[0053] No tests were conducted in April 2025. The specific work involved summarizing the blasting tests conducted from January to March and planning subsequent research and development work. This included: 1. Summarizing the data from seven tests conducted in the first three months and analyzing the data to determine that for a borehole diameter of 115mm, the optimal parameters were a pre-splitting spacing of 1.2, a filling length of 3, and a linear charge density of 0.8; for a borehole diameter of 152mm, the optimal parameters were a pre-splitting spacing of 1.6, a filling length of 3, and a linear charge density of 1.0. 2. Further verification of these parameters will be conducted at different locations. 3. The filling length and linear charge density will be optimized, and the test results will be observed.

[0054] No tests were conducted in May 2025. The specific work involved designing subsequent pre-splitting blasting schemes, including: 1. Changing the filling length from 3m to 2m and observing the pre-splitting blasting effect. A reasonable filling length can ensure that the explosive gas exerts lateral force, forming effective pre-cracks, blocking stress waves, and reducing flyrock, thereby protecting the integrity of the upper rock mass of the bench; 2. Lowering the linear charge density from 0.8 and observing the pre-splitting blasting effect. A smaller linear charge density means a lower explosive charge, effectively reducing production costs.

[0055] Three experiments were conducted in June 2025 on June 3, 10, and 17, respectively. The parameters and results are shown in the table below:

[0056]

[0057] Results Analysis: On the 3rd, 10th, and 17th, tests were conducted at different locations with reduced filling length and linear charge density. All test results met the target values. Conclusions: 1. All indicators met the target values, indicating that the design parameters are not affected by location and are reliable. 2. After reducing the filling length, all indicators not only met the target values ​​but were also better than the previous results, with better flatness and better effect. Furthermore, the integrity of the upper rock mass of the step was better. Since the filling length cannot be less than the minimum resistance line (2m), the smaller the filling length, the better the integrity of the upper rock mass of the step. Therefore, a filling length of 2m is the optimal parameter. 3. After reducing the linear charge density, all indicators not only met the target values ​​but were also better than the previous results, with better flatness and better effect. Moreover, the production cost was lower. Subsequent tests will be conducted at different locations, and the linear charge density will be further reduced to verify the pre-splitting blasting effect.

[0058] Four experiments were conducted in July on July 5th, 11th, 21st, and 28th. The parameters and results are shown in the table below:

[0059]

[0060] Results Analysis: On the 5th, 11th, 21st, and 28th, the linear charge density was lowered, and tests were conducted at different locations. All test results met the target values. Conclusions: 1. All indicators met the target values, indicating that the design parameters are not affected by location and are reliable; 2. After lowering the linear charge density, all indicators not only met the target values ​​but were also better than the previous results, with better flatness, better effect, and lower production cost. Subsequent tests will be conducted at different locations, and the linear charge density will be further lowered to verify the pre-splitting blasting effect.

[0061] Explosion effect analysis:

[0062] After the blast, there were 4,800 tons of valuable ore. The geological conditions at this location were relatively good, but there were mud layers in some areas. The holes drilled in the small mud layer areas were protected by support casings. The accuracy of the drilling angle was strengthened. Drilling continued with a PD45 drilling rig. Measures such as reducing the spacing of the pre-splitting holes, reducing the density of linear charge, and reducing the filling length of the pre-splitting holes were taken. After the blasted ore was loaded and the slope was combed, the half-hole rate, slope gradient, and slope flatness were measured and continued to improve. The half-hole rate was ≥86%, and the slope gradient was ±0. 95, slope flatness ±128mm, the overall appearance of the slope is very good, which verifies that the filling effect at 2 is very good, and it should continue to be reduced. Only when it is proven that the effect below 2 (1.5) is not as good as 2 can it be proven that 2 is the optimal parameter; the filling length should not be less than the minimum resistance line, which is 2m, so 2 is the optimal parameter. The linear density at 0.65 is very good, and it should continue to be reduced. Only when it is proven that the effect below 0.65 (0.6) is not as good as 0.65 can it be proven that 0.65 is the optimal parameter.

[0063] 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 high-efficiency, low-vibration deep-hole bench blasting method for open-pit mines, comprising the following steps: A. Drill main blasting holes in the front row and pre-splitting holes in the rear row, arranged in an alternating pattern. The main blasting holes have a drilling angle of 50-80°, a diameter of 115-152 mm, a hole depth of L = 10-17 m, a hole spacing of a = 4-6 m, a row spacing of b = 3-4 m, and a total number of 15-25 holes. The pre-splitting holes have a drilling angle of 50-80°, a hole depth of L = 15-19 m, and a pre-splitting spacing of 1-1.6 m. B. After drilling the main blasting hole and pre-splitting hole, carry out the explosive loading operation. After loading, the explosive consumption per unit of the main blasting hole is q = 0.42~0.46 kg / m. 3 The blasting filling length L1 is 3-4.5m, and the charge amount per hole Q is 110-120kg; the linear charge density of the pre-splitting hole is 0.65-1kg / m, the pre-splitting filling length L2 is 1.5-2.5m, the charging is continuous and the filling is continuous and compact. After the filling is completed, the charging and filling conditions are checked with a measuring rope. C. Safety procedures: Before the blasting operation begins, a warning line is set up at the boundary of the danger zone to make the blasting operation area relatively closed. Before detonation, the blasting materials, detonating power supply and instruments used are inspected. Only after the warning line is completed and safety is confirmed can the main line be connected to the detonator and wait for the detonation command. D. Before blasting, a signal is given. Blasting begins after personnel in the danger zone have been evacuated to a safe location. During blasting, the detonation direction is controlled. After detonation, the power supply is cut off in time, and the main line is separated from the detonator.

2. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: In step C, 30 minutes before detonation, all passages leading into the blasting hazard zone must be guarded by designated personnel.

3. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: Fifteen minutes after the detonation is completed, the blast zone is entered to check for any misfires. Once safety is confirmed or a misfire is dealt with and safety is confirmed, the alert is lifted.

4. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: In step B, during the loading and packing of explosives, personnel unrelated to the blasting operation are prohibited from entering the site.

5. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: In step B, before loading the explosive charge, the detonator and the initiating charge are first loaded into the borehole.

6. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: In step B, if the main blast hole is a water hole, the end of the delivery hose is lowered to the bottom of the main blast hole, and the delivery hose is slowly raised according to the loading speed.

7. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: In step B, the mixed emulsion explosives must be loaded for 10 minutes and inspected before filling can begin. The length of the filling section must be measured to ensure it meets the blasting design requirements.

8. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: In step B, when the emulsion explosive is loaded to the last borehole, the remaining explosive in the hose is loaded into the borehole, and the remaining explosive in the hose is cleaned after loading is completed.

9. The efficient, low-vibration deep-hole bench blasting method for open-pit mines according to claim 1, characterized in that: If any obstruction is found in the hole, it should be dealt with promptly. When filling water holes, the filling speed should be slowed down to allow water to drain out of the hole and avoid material suspension.

10. A pre-splitting hole charging structure for the high-efficiency, low-vibration open-pit deep-hole bench blasting method as described in any one of claims 1-9, characterized in that: A support sleeve (2) is placed in the center of the pre-splitting hole and explosives (4) are connected in series on the detonating cord (3). The explosives connected in series on the detonating cord (3) extend from the top opening of the support sleeve to the bottom of the support sleeve. The top opening of the support sleeve (2) is also filled with filling material (5). The detonating cord (3) is connected to an electronic detonator (6) located outside the pre-splitting hole.

Images