Protective layer blasting energy-gathering buffer device

Abstract

The utility model relates to the technical field of blasting, in particular to a protective layer blasting energy-gathering buffering device which comprises an upper energy-gathering reflecting cushion layer, a lower buffering cushion layer, a middle-layer hourglass-shaped tube and a hollow steel ball, the upper energy-gathering reflecting cushion layer comprises an upper-layer cylindrical tube and a plurality of protruding structures, and the lower buffering cushion layer is arranged on the upper-layer cylindrical tube. The lower buffering cushion layer comprises a cavity thin-shell closed structure bobbin, and the top end and the bottom end of the middle-layer hourglass-shaped bobbin are fixedly connected with the bottom end of the upper-layer cylindrical bobbin and the top end of the cavity thin-shell closed structure bobbin respectively. A hollow steel ball is clamped in the middle of the inner wall of the middle-layer hourglass-shaped tube, an inner cavity of the upper-layer cylindrical tube is filled with explosives, and the explosives make compaction contact with the multiple protruding structures; the utility model provides the energy-gathered buffer device which can reduce the rock damage of the foundation slab, enhance the blasting energy and reduce the undercut of the slab at the same time.

Description

Technical Field

[0001] This utility model relates to the field of blasting technology, and in particular to a protective layer blasting energy-concentrating buffer device. Background Technology

[0002] Nuclear power plant engineering typically employs blasting excavation. The nuclear island demands extremely high standards for the bearing stratum and its integrity, making ensuring the quality of the foundation a persistent challenge in blasting projects. To prevent the formation of numerous joints and fissures on the bedrock surface after blasting, ensuring good rock mass integrity and that the bearing stratum meets design requirements, a protective layer blasting method is commonly used. This involves leaving a 20cm thick flexible cushion layer at the bottom of the borehole to minimize damage to the foundation slab from blasting energy. While simple to implement, this method has significant drawbacks and limitations. For example, after drilling, water and debris easily accumulate at the bottom of the borehole, preventing the filling material from settling properly. Furthermore, the amount and size of the filling material vary, making it difficult to place the flexible cushion layer in its intended position. This significantly weakens the effectiveness of the flexible cushion layer, failing to achieve the expected blasting protection effect, and resulting in substantial damage to the rock strata.

[0003] While existing blasting techniques take into account the installation of protective layers, the protective effect of flexible cushion layers is unsatisfactory due to various factors, and the bedrock surface cannot form a complete excavation face. Furthermore, nuclear power plants typically have large plant areas with numerous and closely spaced civil engineering structures. The main structure places high demands on the crack prevention, sealing, and concrete strength and rigidity of the concrete structure. To protect surrounding structures from structural damage caused by blast shock waves, current deep blasting methods generally employ small-diameter boreholes and small explosive charges. This results in a limited range of shock wave penetration into the rock mass and its reach around cracks, leading to low utilization of explosive energy. Consequently, significant under-excavation occurs after blasting, requiring subsequent secondary treatment with hydraulic breakers and manual labor, resulting in low construction efficiency. Utility Model Content

[0004] The purpose of this invention is to provide a protective layer blasting energy-concentrating buffer device to solve the technical problems existing in the background art.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] A protective layer blasting shaped charge buffer device includes: an upper shaped charge reflector layer, a lower buffer layer, a middle hourglass-shaped tube, and a hollow steel ball. The upper shaped charge reflector layer includes an upper cylindrical tube and several protruding structures, which are evenly distributed on the inner wall of the upper cylindrical tube. The lower buffer layer includes a hollow thin-shell closed structure tube. The top and bottom ends of the middle hourglass-shaped tube are respectively fixedly connected to the bottom end of the upper cylindrical tube and the top end of the hollow thin-shell closed structure tube. A hollow steel ball is clamped in the middle of the inner wall of the middle hourglass-shaped tube. The inner cavity of the upper cylindrical tube is filled with explosives, which are in close contact with the several protruding structures. The upper shaped charge reflector layer, the middle hourglass-shaped tube, and the lower buffer layer are all filled into blast holes opened in the rock of the foundation pit, and the bottom end of the lower buffer layer is in contact with the bedrock surface at the bottom of the blast hole.

[0007] Furthermore, the protruding structure is a shell structure with a hollow interior and a closed outer wall, and the number of the protruding structures does not exceed eight.

[0008] Furthermore, the protruding structure is a protrusion formed by the inner wall of the upper cylindrical tube, and the number of the protruding structures does not exceed eight.

[0009] Furthermore, the explosive is an explosive roll, the length of the upper cylindrical tube is not less than the length of a single explosive roll and not less than the length from the bottom of the single explosive roll to the borehole opening, and the diameter of the upper cylindrical tube is greater than the diameter of the explosive roll and less than the diameter of the borehole.

[0010] Furthermore, the length of the hollow thin-shell closed structure tube is 20cm when the borehole depth is no more than 3m.

[0011] Furthermore, the upper cylindrical tube, the middle hourglass-shaped tube, the hollow thin-shell closed structure tube, and the protruding structure are all made of plastic and have a thickness greater than 1 mm.

[0012] Furthermore, the hollow thin-shell closed structure tube is hollow inside.

[0013] Furthermore, the interior of the hollow thin-shell closed structure tube is filled with low wave impedance particulate material.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] During blasting, the explosives fill the gaps between the protruding structures on the inner wall of the upper cylindrical tube, forming energy-concentrating grooves that can reflect the high-speed, energy-concentrating jet laterally around the borehole. The hollow steel spheres, acting as high-impedance pads, ensure that when the blast shock wave undergoes its first reflection at the interface of the spherical pads, a large number of shock waves are directed upwards, reducing damage to the bottom rock. When the shock wave transmitted through the interface undergoes its second reflection in the lower part of the sphere, the reflected shock wave is directed upwards, achieving double reflection. The shock wave transmitted to the lower buffer layer is absorbed and dissipated due to the different wavebands transmitted by the low-impedance particles or air. At the same time, the change in curvature of the middle funnel-shaped tube during blasting allows the shock wave to converge in the horizontal direction, generating a high-speed jet in the horizontal direction. This jet splits the rock fissures in the horizontal direction, reducing under-excavation of the bedrock surface while ensuring its flatness. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a top view of the present invention;

[0018] Figure 3 This is a structural diagram of the inner concave end face of the upper cylindrical tube in this utility model;

[0019] Figure 4 This is a schematic diagram of the transmission and reflection principle of the explosive shock wave of this utility model.

[0020] The labels in the attached diagram are as follows: 1-Upper cylindrical tube, 2-Middle hourglass-shaped tube, 3-Hollow steel ball, 4-Cavity thin-shell closed structure tube, 5-Protruding structure, 6-Explosive. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] See Figures 1-4As shown, a protective layer blasting shaped charge buffer device includes: an upper shaped charge reflector layer, a lower buffer layer, a middle hourglass-shaped tube 2, and a hollow steel ball 3. The upper shaped charge reflector layer includes: an upper cylindrical tube 1 and protruding structures 5, with several protruding structures 5 evenly distributed on the inner wall of the upper cylindrical tube 1. The lower buffer layer includes: a hollow thin-shell closed structure tube 4. The top and bottom ends of the middle hourglass-shaped tube 2 are respectively fixedly connected to the bottom end of the upper cylindrical tube 1 and the top end of the hollow thin-shell closed structure tube 4. A hollow steel ball 3 is clamped in the middle of the inner wall of the middle hourglass-shaped tube 2, serving as a high wave impedance pad. When the explosive shock wave is reflected at the interface of the spherical pad, it can cause a large number of shock waves to be directed upwards, reducing damage to the bottom rock. At the same time, the middle funnel-shaped tube 2 can concentrate the blasting shock wave in the horizontal direction, reducing the under-excavation of the bedrock surface while ensuring the flatness of the bedrock surface. The inner cavity of the upper cylindrical tube 1 is filled with explosive 6. The explosive 6 is in close contact with several protruding structures 5 to form an energy-concentrating groove, which can reflect the energy-concentrating high-speed jet to the periphery of the blast hole. The upper energy-concentrating reflective pad, the middle hourglass-shaped tube 2 and the lower buffer pad are all filled into the blast holes opened on the foundation pit rock, and the bottom end of the lower buffer pad is in contact with the bedrock surface at the bottom of the blast hole.

[0023] In this embodiment, the protrusion structure 5 is a shell structure with a hollow interior and a closed outer wall, or a protrusion formed by the concavity of the inner wall of the upper cylindrical tube 1. The shape of the protrusion structure 5 is not limited and can be a sharp triangle or an arc-shaped protrusion. The number of protrusion structures 5 does not exceed eight.

[0024] In this embodiment, the explosive 6 is an explosive roll. The length of the upper cylindrical tube 1 is not less than the length of a single explosive roll and not less than the length from the bottom of the single explosive roll to the borehole opening. The diameter of the upper cylindrical tube 1 is greater than the diameter of the explosive roll and less than the diameter of the borehole to ensure the blasting quality.

[0025] In this embodiment, the length of the hollow thin-shell closed structure tube 4 should be consistent with the depth of the allowable over-excavation range of the foundation pit. It should be selected according to the depth of the blast hole. When the depth of the blast hole is no more than 3m, the length should be 20cm. When the depth of the blast hole is greater than 3m, the length should be appropriately increased.

[0026] In this embodiment, the upper cylindrical tube 1, the middle hourglass-shaped tube 2, the hollow thin-shell closed structure tube 4, and the protruding structure 5 are all made of plastic and have a thickness greater than 1 mm.

[0027] In this embodiment, the interior of the hollow thin-shell closed structure tube 4 may be left unfilled to form an air buffer pad, or it may be filled with low wave impedance particulate material, such as artificial sand, to enhance the energy dissipation and buffering effect and form an energy dissipation and buffering flexible pad.

[0028] Installation and blasting procedures for the entire device:

[0029] (1) Drilling. Drilling equipment is used to drill blasting holes in the area to be blasted. The hole diameter is generally 89mm. The blasting holes are arranged in rows at equal intervals. The blasting hole angle is generally vertical. In special areas, the blasting holes are arranged according to the calculated inclination angle, with an angle error of ±0.5°.

[0030] (2) Inspect the borehole. After drilling is completed, assign a person to inspect the depth of the borehole and whether there is water or slag at the bottom of the hole. Ensure that the depth of the borehole meets the allowable over-excavation depth of the protective layer. Any water or slag at the bottom of the hole should be cleaned up.

[0031] (3) Place the protective layer blasting energy-concentrating buffer device. Ensure that its bottom fully contacts the bedrock surface at the bottom of the hole.

[0032] (4) Loading explosives. Load explosives according to the amount and length of explosives in the blasting design, so that the gap between the protruding structures 5 on the inner wall of the upper cylindrical tube 6 of the explosives is filled. After loading the explosives, install the detonator or detonating cord.

[0033] (5) Hole plugging and detonation. Plug the blast holes according to the designed plugging length. After plugging, clear out any irrelevant personnel and remove them from the site. Then connect the detonation network and detonate.

[0034] Working principle: During blasting, the explosive 6 fills the gaps between the raised structures 5 on the inner wall of the upper cylindrical tube 1, making the raised structures 5 form energy-concentrating grooves, which can reflect the high-speed energy-concentrating jet to the periphery of the blast hole. The hollow steel ball 3 acts as a high wave impedance pad, which can make a large number of shock waves move upward when the blast shock wave undergoes the first transmission reflection at the interface of the spherical pad, reducing the damage to the bottom rock. When the shock wave transmitted through the interface undergoes the second transmission reflection in the lower part of the sphere, the reflected shock wave moves upward, achieving double reflection. The shock wave transmitted to the lower buffer pad is absorbed and dissipated due to the different wave bands transmitted by the low wave impedance particles or air. At the same time, during blasting, the change in curvature of the middle funnel-shaped tube 2 can make the shock wave converge in the horizontal direction, generating a high-speed jet in the horizontal direction, splitting the rock cracks in the horizontal direction, reducing the under-excavation of the bedrock surface and ensuring the flatness of the bedrock surface.

[0035] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", "top / bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the present utility model's technical solution and based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model's technical solution.

Claims

1. A protective layer blasting shaped charge cushioning device, characterized by, The utility model relates to a kind of explosive reflection cushioning layer, including: upper energy-gathering reflection cushion layer, lower buffer cushion layer, middle layer hourglass cylinder (2) and hollow steel ball (3), the upper energy-gathering reflection cushion layer includes: upper layer cylindrical cylinder (1) and protruding structure (5), the protruding structure (5) is provided with several, several protruding structures (5) are evenly arranged on the inner wall of upper layer cylindrical cylinder (1), the lower buffer cushion layer includes: cavity thin-shell closed structure cylinder (4), the top end and bottom end of the middle layer hourglass cylinder (2) are fixedly connected with the bottom end of upper layer cylindrical cylinder (1) and the top end of cavity thin-shell closed structure cylinder (4) respectively, hollow steel ball (3) is clamped in the inner wall middle portion of the middle layer hourglass cylinder (2), the explosive (6) is filled in the inner chamber of the upper layer cylindrical cylinder (1), and the explosive (6) is extruded contact with several protruding structures (5);The upper energy-gathering reflection cushion layer, middle layer hourglass cylinder (2) and lower buffer cushion layer are filled in blast hole that is opened on foundation pit rock and the bedrock surface contact of lower buffer cushion layer bottom end and blast hole bottom end. The protruding structure (5) is a hollow shell structure with a closed outer wall, and the number of the protruding structure (5) is not more than eight.

2. A protective layer blasting shaped charge cushioning device according to claim 1, characterized in that: The protruding structure (5) is a protrusion formed by concave in the inner wall of the upper layer cylindrical cylinder (1), and the number of the protruding structure is not more than eight.

3. The protective layer blasting shaped charge cushioning device of claim 1, wherein: The explosive (6) is an explosive roll, the length of the upper layer cylindrical cylinder (1) is not less than the length of a single explosive roll and not less than the length from the bottom end of the single explosive roll to the blast hole orifice, and the diameter of the upper layer cylindrical cylinder (1) is greater than the diameter of the explosive roll and less than the diameter of the blast hole.

4. The protective layer blasting shaped charge cushioning device of claim 1, wherein: When the depth of the blast hole is not more than 3 m, the length of the cavity thin-shell closed structure cylinder (4) is 20 cm.

5. The protective layer blasting shaped charge cushioning device of claim 1, wherein: The upper layer cylindrical cylinder (1), the middle layer hourglass cylinder (2), the cavity thin-shell closed structure cylinder (4) and the protruding structure (5) are all made of plastic material with a thickness greater than 1 mm.

6. The protective layer blasting shaped charge cushioning device of claim 1, wherein: The cavity thin-shell closed structure cylinder (4) is hollow inside.

7. The protective layer blasting shaped charge cushioning device of claim 1, wherein: The cavity thin-shell closed structure cylinder (4) is filled with low-wave impedance granular material inside.

8. The protective layer blasting shaped charge cushioning device of claim 1, wherein: ​

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