Cracking blasting method for controlling blasting vibration of large stone in strip mine

Abstract

The invention discloses a cracking blasting method for controlling blasting vibration of a large stone in a strip mine, which belongs to the technical field of blasting engineering and comprises the following steps: S1, determining a drilling position and depth between a main blasting area and a protection target according to geological conditions and blasting design requirements, and drilling based on the determined drilling position and depth; s2, coupling charge is carried out in each hole, and the charge structure is a single-hole single-sound explosion network; s3, the charging structure in each hole is sequentially detonated in a delayed mode, a rock fracturing belt with cracks distributed in a dendritic mode is formed, blasting vibration is attenuated after being reflected and refracted in the cracks of the rock fracturing belt and is difficult to spread to a protection target, and the purpose of protecting the protection target is achieved; according to the method, the blasting vibration isolation belt is arranged between the main blasting area and the protection target, a rock cracking belt is formed through drilling blasting, blasting vibration is effectively attenuated, the blasting effect is not affected, and the influence of blasting vibration on the protection target can be effectively controlled.

Description

Technical Field

[0001] The invention belongs to the technical field of blasting engineering, and in particular relates to a cracking blasting method for controlling blasting vibration of large stone blocks in an open-pit mine. Background Art

[0002] In large-scale rock blasting and excavation projects such as open-pit mines, the strong ground vibration caused by blasting vibration will not only disturb nearby residents, but also may cause cracks in the walls of surrounding buildings and loosen the foundations, posing a serious threat to the stability of infrastructure. At the same time, excessive vibration may also cause slope rock instability, leading to geological disasters such as landslides and collapses, seriously affecting the safe production and ecological environment of the mining area. Therefore, how to effectively control the vibration of large-scale rock blasting in open-pit mines is particularly important.

[0003] At present, the main methods for controlling blasting vibration include blasting design optimization, charge structure improvement, and vibration propagation path control. However, the existing methods have the following problems: 1. In terms of blasting design optimization, by reducing the amount of single-stage explosives and adopting segmented charging or hole-by-hole detonation technology, although this technology can disperse the energy release, it will sacrifice some blasting effects; 2. Improvement of charge structure: uncoupled charge technology and low detonation velocity explosives can prolong the energy release time, but increase the construction complexity and cost; 3. In terms of vibration propagation path control, shock-absorbing trenches are excavated and pre-splitting blasting is used. However, due to geological conditions, shock-absorbing trenches can only be excavated on the soil layer, and the excavation depth is limited and the width is large, which poses a risk of falling. Although pre-splitting blasting has a better effect, it is costly, complex in construction, and highly dependent on geological conditions, and the effect is unstable in complex strata.

[0004] In view of this, a cracking blasting method for controlling blasting vibration of large stone in open-pit mines is designed to solve the above problems. Summary of the invention

[0005] To solve the problems raised in the above background technology, the present invention provides a cracking blasting method for controlling blasting vibration of large-scale stone in open-pit mines, which has the characteristics of simple construction, low cost, strong adaptability and significant vibration reduction effect, and is suitable for blasting projects under various geological conditions.

[0006] To achieve the above object, the present invention provides the following technical solution: a cracking blasting method for controlling blasting vibration of large-scale stone in an open-pit mine, comprising the following steps: S1: According to geological conditions and blasting design requirements, determine the drilling location and depth between the main blasting area and the protection target, and drill based on the determined drilling location and depth; S2: Coupled charge in each hole, the charge structure is a single-hole single-shot detonation network; S3: The explosive structure in each hole is detonated in sequence with a delay, forming a rock crack zone with tree-like cracks. The blasting vibration is reflected and refracted in the cracks of the rock crack zone and then attenuated, making it difficult to propagate to the protected target, thereby achieving the purpose of protecting the protected target.

[0007] Furthermore, in step S1, the principle for determining the drilling positions is: every five holes are encrypted once, that is, the hole spacings of the first four holes in every five holes are the same, and the hole spacings of the fourth hole and the fifth hole are encrypted.

[0008] Furthermore, in step S1, the principle of increasing the hole spacing between the fourth hole and the fifth hole is as follows: the hole spacing between the fourth hole and the fifth hole is 75% of the hole spacing between the first four holes.

[0009] Furthermore, in step S1, the hole spacing between the first four holes drilled is preferably 1.8 m, and the hole spacing between the fourth hole and the fifth hole is preferably 1.35 m.

[0010] Furthermore, in step S1, the diameter of the drilled hole is preferably 90 mm, and the depth of the hole is preferably 5-35 m.

[0011] Furthermore, in step S2, the charge structure of the coupled charge in each hole includes a blocking material, explosives and detonators arranged in the hole from top to bottom, the blocking material and the explosives are coupled to the hole, and the leg line of the detonator passes through the explosives and the blocking material and extends to above the hole.

[0012] Furthermore, in step S2, the height of the blocking material is preferably ≥4 m.

[0013] Furthermore, the specific steps of step S3 include: When detonating the charge structure in the first hole, since it has only one open surface, energy is released evenly to the surroundings along the central axis of the charge column, causing tree-like cracks to form in the rock. When the charge structure in the secondary hole is detonated with a delayed detonation, under the influence of the tree-like cracks that have already formed in the rock, energy is inclined in the direction of the first explosion, causing tree-like cracks to form in the rock along the direction of the holes. By analogy, after detonating the charge structures in all the holes, a rock crack zone is formed. When the blasting vibration propagates to the rock crack zone, it will be reflected and refracted along the cracks. Since the cracks in the rock crack zone are distributed in a tree-like manner, the blasting vibration is difficult to propagate to the protected target after multiple attenuations, thereby achieving the purpose of protecting the protected target.

[0014] Furthermore, in step S3, the delay time is preferably 500 ms.

[0015] Furthermore, in step S3, the width of the rock crack zone is preferably >50 cm.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention sets a blasting vibration isolation zone between the main blasting area and the protected target, and uses drilling blasting to form a rock crack zone, which effectively attenuates the blasting vibration, does not affect the blasting effect, and can effectively control the impact of the blasting vibration on the protected target.

[0017] 2. The holes of the blasting vibration isolation belt of the present invention do not require high precision and do not need to be in a straight line, so the construction difficulty is low.

[0018] 3. The present invention can realize blasting to form rock crack zones by using common emulsion explosives, effectively attenuating blasting vibrations, without the need for detonating cords, and at a low cost.

[0019] 4. The present invention is applicable only when the geological conditions are capable of forming a hole, has low requirements on the geological conditions, and is applicable to blasting projects under various geological conditions.

[0020] 5. The rock crack zone formed by the present invention is wide, the cracks are distributed in a dendrite-like manner, and the vibration reduction effect is better than that of pre-splitting blasting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the drilling position of the present invention; Figure 2 This is a schematic diagram of the charge structure of the present invention; Figure 3 It is a schematic diagram of the crack zone structure of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention provides the following technical solution: a cracking blasting method for controlling blasting vibration of large-scale stone in an open-pit mine, comprising the following steps: S1: According to geological conditions and blasting design requirements, determine the drilling location and depth between the main blasting area and the protection target, and drill based on the determined drilling location and depth; The drilling position and depth can be changed according to the geological conditions and blasting design requirements, so that it can be applied to blasting projects under various geological conditions; The change in the location and depth of the drill hole was a design change based on the experience of experienced blasting personnel; S2: Coupled charge in each hole, the charge structure is a single-hole single-shot detonation network; Coupled charging means that the diameter of the explosive is equal to the diameter of the hole, and there is no gap between the explosive and the hole wall. The energy generated by the explosion of the explosive can directly act on the hole wall. This charging method has high energy transfer efficiency. The single-shot detonation network means that only one charge structure is detonated at a time, which can accurately control the detonation time and energy release of a single charge structure, and achieve fine control of the detonation effect; The purpose of setting up a single-shot detonation network is to sequentially detonate the charge structures in holes at different locations, so that the rock will gradually produce dendritic cracks according to the designed sequence. S3: The explosive structure in each hole is detonated in sequence with a delay, forming a rock crack zone with tree-like cracks. The blasting vibration is reflected and refracted in the cracks of the rock crack zone and then attenuated, making it difficult to propagate to the protected target, thereby achieving the purpose of protecting the protected target.

[0024] Specifically, in step S1, the principle for determining the drilling positions is: every five holes are encrypted once, that is, the hole spacings of the first four holes in every five holes are the same, and the hole spacings of the fourth hole and the fifth hole are encrypted.

[0025] Specifically, in step S1, the principle of increasing the hole spacing between the fourth hole and the fifth hole is as follows: the hole spacing between the fourth hole and the fifth hole is 75% of the hole spacing between the first four holes.

[0026] Specifically, in step S1, the hole spacing between the first four holes drilled is preferably 1.8 m, and the hole spacing between the fourth hole and the fifth hole is preferably 1.35 m.

[0027] Specifically, in step S1, the diameter of the drilled hole is preferably 90 mm, and the depth of the hole is preferably 5-35 m.

[0028] Specifically, in step S2, the charge structure of the coupled charge in each hole includes a blocking material, explosives and detonators arranged in the hole from top to bottom, the blocking material and the explosives are coupled to the hole, and the leg line of the detonator passes through the explosives and the blocking material and extends to above the hole.

[0029] Specifically, in step S2, the height of the blocking material is preferably ≥4 m.

[0030] Specifically, the specific steps of step S3 include: When detonating the charge structure in the first hole, since it has only one open surface, energy is released evenly to the surroundings along the central axis of the charge column, causing tree-like cracks to form in the rock. When the charge structure in the secondary hole is detonated with a delayed detonation, under the influence of the tree-like cracks that have already formed in the rock, energy is inclined in the direction of the first explosion, causing tree-like cracks to form in the rock along the direction of the holes. By analogy, after detonating the charge structures in all the holes, a rock crack zone is formed. When the blasting vibration propagates to the rock crack zone, it will be reflected and refracted along the cracks. Since the cracks in the rock crack zone are distributed in a tree-like manner, the blasting vibration is difficult to propagate to the protected target after multiple attenuations, thereby achieving the purpose of protecting the protected target.

[0031] Specifically, in step S3, the delay time is preferably 500 ms.

[0032] Specifically, in step S3, the width of the rock fracture zone is preferably >50 cm.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cracking blasting method for controlling blasting vibration of large rock in open-pit mines, characterized in that: The following steps are involved: S1: According to geological conditions and blasting design requirements, determine the drilling location and depth between the main blasting area and the protection target, and drill based on the determined drilling location and depth; S2: Coupled charge in each hole, the charge structure is a single-hole single-shot detonation network; S3: The explosive structure in each hole is detonated in sequence with a delayed delay, forming a rock crack zone with tree-like cracks. The blasting vibration is reflected and refracted in the cracks of the rock crack zone and then attenuated, making it difficult to propagate to the protected target, thereby achieving the purpose of protecting the protected target.

2. The cracking blasting method for controlling blasting vibration of large-scale rock in an open-pit mine according to claim 1 is characterized by: In step S1, the principle for determining the drilling positions is: every five holes are encrypted once, that is, the hole spacings of the first four holes in every five holes are the same, and the hole spacings of the fourth hole and the fifth hole are encrypted.

3. The cracking blasting method for controlling blasting vibration of large-scale rock in an open-pit mine according to claim 2 is characterized by: In step S1, the principle of increasing the hole spacing between the fourth hole and the fifth hole is as follows: the hole spacing between the fourth hole and the fifth hole is 75% of the hole spacing between the first four holes.

4. A cracking blasting method for controlling blasting vibration of large rock in an open-pit mine according to claim 3, characterized in that: In the step S1, the hole spacing between the first four holes drilled is preferably 1.8 m, and the hole spacing between the fourth hole and the fifth hole is preferably 1.35 m.

5. The cracking blasting method for controlling blasting vibration of large-scale rock in an open-pit mine according to claim 4 is characterized by: In the step S1, the diameter of the drilled hole is preferably 90 mm, and the depth of the drilled hole is preferably 5-35 m.

6. The cracking blasting method for controlling blasting vibration of large rock in open-pit mines according to claim 5 is characterized by: In step S2, the charge structure of the coupled charge in each hole includes a plugging material, explosives and detonators arranged in the hole from top to bottom, the plugging material and the explosives are coupled to the hole, and the leg line of the detonator passes through the explosives and the plugging material and extends to above the hole.

7. A cracking blasting method for controlling blasting vibration of large rock in an open-pit mine according to claim 6, characterized in that: In the step S2, the height of the blocking material is preferably ≥4 m.

8. The cracking blasting method for controlling blasting vibration of large rock in open-pit mines according to claim 7 is characterized by: The specific steps of step S3 include: When detonating the charge structure in the first hole, since it has only one open surface, energy is released evenly to the surroundings along the central axis of the charge column, causing tree-like cracks to form in the rock. When the charge structure in the secondary hole is detonated with a delayed detonation, under the influence of the tree-like cracks that have already formed in the rock, energy is inclined in the direction of the first explosion, causing tree-like cracks to form in the rock along the direction of the holes. By analogy, after detonating the charge structures in all the holes, a rock crack zone is formed. When the blasting vibration propagates to the rock crack zone, it will be reflected and refracted along the cracks. Since the cracks in the rock crack zone are distributed in a tree-like manner, the blasting vibration is difficult to propagate to the protected target after multiple attenuations, thereby achieving the purpose of protecting the protected target.

9. A cracking blasting method for controlling blasting vibration of large rock in an open-pit mine according to claim 8, characterized in that: In step S3, the delay time is preferably 500 ms.

10. A cracking blasting method for controlling blasting vibration of large rock in an open-pit mine according to claim 9, characterized in that: In step S3, the width of the rock crack zone is preferably >50 cm.

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