A cylindrical charge blasting model test device

Abstract

The utility model relates to the technical field of mine engineering technology test equipment, and specifically discloses a columnar charge blasting model test device, which comprises a test piece, the test piece is in the shape of a cuboid, a vertical blast hole is arranged through the geometric center of the test piece, the vertical blast hole is used for loading explosive columns, one side of the test piece is provided with a high-speed camera, and the test piece is positioned in a restraint. The utility model is in conformity with the stress condition under columnar charge as a whole, is convenient to operate, and is convenient for shooting the strain field evolution and crack propagation process of the complete surface around the vertical blast hole.

Description

Technical Field

[0001] This utility model relates to the field of mining engineering technology testing equipment, and in particular to a test device for a columnar charge blasting model. Background Technology

[0002] The depth of boreholes for on-site drilling and blasting is generally several meters or more, which falls under the condition of columnar charges. In order to study the crack propagation and stress wave propagation law in the near zone of the borehole under columnar charge conditions, similar model tests are often carried out using cylindrical explosive charges of the same length as detonating cord. Deformation or stress measurement is achieved by using strain or stress sensors built in during casting; or deformation measurement is obtained through non-contact means. For example, Chinese patent application number CN202110107006.9 discloses an experimental method for quantitative analysis of principal stress in the entire field of explosive stress wave propagation, but it does not consider the influence of columnar charge conditions on the test results. The application of columnar charge blasting load should meet the following requirements: (1) The load generated by the explosion of the explosive in contact with the medium should be along the direction perpendicular to the borehole axis, that is, this part of the medium is completely within the range of columnar stress wave action; (2) It should not affect the propagation of cracks and deformation on the surface of the captured medium; (3) It should be easy to operate, the method should be safe and reliable, and it should meet the requirements of laboratory management.

[0003] Similar model tests were conducted using long cylindrical explosives such as detonating cords. However, the model tests were large and inconvenient to operate, and it was impossible to obtain full-field deformation observations of the rock around the vertical borehole.

[0004] (2) The crack propagation and deformation failure processes obtained by related non-contact measurement methods are not strictly the result of cylindrical stress wave action. In summary, the existing model test charge blasting method has not achieved full-field observation of rock deformation and crack propagation under strict cylindrical charge blasting load.

[0005] To address these issues, we propose a cylindrical charge blasting model test device. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a cylindrical charge blasting model test device.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A cylindrical charge blasting model test device includes a specimen, which is rectangular in shape. A vertical borehole is provided through the geometric center of the specimen, and the interior of the vertical borehole is used to fill the explosive charge. A high-speed camera is positioned on one side of the specimen, and the specimen is positioned within a constraint member.

[0009] Preferably, the surface of the specimen is treated with a smoothing process and a speckle treatment.

[0010] Preferably, the explosive charge includes a detonator and an explosive body. The detonator is positioned on the side of the specimen facing away from the high-speed camera and is inserted into the explosive body. The explosive body includes a thin-walled glass tube, which is filled with the explosive body and placed inside a vertical borehole. The length of the thin-walled glass tube is longer than the thickness of the specimen. Both ends of the thin-walled glass tube extend out of the two sides of the specimen, and a first steel sleeve and a second steel sleeve are respectively fitted onto the two protruding ends of the thin-walled glass tube. The length of the first steel sleeve is longer than the length of the second steel sleeve, and the detonator is also inserted into the first steel sleeve.

[0011] Preferably, the test piece is fitted with pads on both sides corresponding to the two ends of the vertical borehole. One pad has a slot, through which a first steel sleeve can pass. The two ends of the first steel sleeve are connected. The other pad has a groove, through which a second steel sleeve can be inserted. The end of the second steel sleeve near the inside of the groove is sealed.

[0012] Preferably, foam material is used to fill the space between the edge of the specimen and the pad.

[0013] Preferably, the constraint member includes two constraint plates, which are fixedly connected by four screws. Each of the four corners of the two constraint plates is provided with a round hole that matches the screw. The screw is threaded with a nut. The specimen is clamped and placed between the two constraint plates. The four screws pass through the corresponding round holes on the two constraint plates and are tightened with the four nuts respectively, which can fix the two constraint plates and the specimen between them.

[0014] Preferably, the constraint plate is made of high-strength transparent resin material, and the opposite side of the two constraint plates can abut against the two pads respectively. The pad near the high-speed camera is also made of high-strength transparent resin material, and one constraint plate is provided with a round hole through which the first steel sleeve can pass.

[0015] Preferably, the constraint further includes a rectangular frame and four pads. Jacks are installed on both sides of one corner inside the rectangular frame, allowing the specimen to be placed inside the rectangular frame. The four pads are respectively abutted against the four sides of the specimen. Two of the pads abut against the telescopic ends of two jacks, and the other two pads abut against the two sides of another corner inside the rectangular frame. Each telescopic end of the jack is fixed with a stop block.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] This invention provides a vertical borehole, detonator, and explosives that are designed to work with the test specimen. It also includes a pad and restraints to ensure that the test specimen meets the stress conditions under a cylindrical charge. This design allows for smaller model tests, easier operation, and effective observation of the full-field deformation of the rock surrounding the vertical borehole. The crack propagation and deformation failure processes obtained by the related non-contact measurement methods are strictly the result of cylindrical stress wave action. This makes it convenient to photograph the strain field evolution and crack propagation process of the intact surface surrounding the vertical borehole. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an isometric view of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the test piece and the two pads of this utility model;

[0021] Figure 3 This is a separation diagram of the specimen and the two pads of this utility model;

[0022] Figure 4 This is a schematic diagram of the vertical borehole structure of this utility model;

[0023] Figure 5 This is a schematic diagram of the detonator, explosive, and first steel sleeve of this utility model;

[0024] Figure 6 This is a structural diagram of the rectangular frame, jack, and pad block of this utility model.

[0025] In the figure: 1. Specimen; 2. Vertical borehole; 3. Detonator; 4. Explosive body; 5. Pad; 6. Foam material; 7. Constraint plate; 8. Screw; 9. First steel sleeve; 10. Nut; 11. Slot; 12. Rectangular frame; 13. Jack; 14. Pad block; 15. Second steel sleeve; 16. Groove; 17. Round hole. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around" and other terms indicating orientation or positional relationship are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0028] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 as well as Figure 6 A cylindrical charge blasting model test device includes a specimen 1, which is rectangular in shape and made of rock. The thickness of the specimen 1 is much smaller than its length and width. A vertical borehole 2 is provided through the geometric center of the specimen 1. The interior of the vertical borehole 2 is used to fill the explosive charge. A high-speed camera is positioned on one side of the specimen 1, which is the imaging surface. The specimen 1 is positioned within a constraint.

[0029] As a technical optimization of this utility model, the surface of specimen 1 is subjected to flattening and speckle treatment.

[0030] The surface smoothing process involves using fine sandpaper to sand the surface of rock specimen 1, removing any loose dust, and then spraying a layer of white matte paint over the surface, ensuring it is not too thick. After the white primer dries, randomly apply black dots with a marker, creating a speckled effect. The size and density of the dots should be such that they are easily processed by DIC software when photographing the entire surface of specimen 1 with a high-speed camera, clearly reflecting its deformation.

[0031] For the above examples, those skilled in the art should understand that DIC software processing, or DIC technology, is used when implementing the above technical solutions. Digital image correlation (DIC) is currently a commonly used non-contact deformation testing method. It uses images of the specimen 1 captured by a high-speed camera during the deformation process to calculate the deformation at different locations on the surface based on the relative position changes of speckles during the deformation process, thus obtaining the surface strain field.

[0032] As a technical optimization of this utility model, the explosive charge includes a detonator 3 and an explosive body 4. The detonator 3 is located on the side of the test piece 1 away from the high-speed camera. The detonator 3 is inserted into the explosive body 4. The explosive body 4 includes a thin-walled glass tube, and the explosive body 4 is filled inside the thin-walled glass tube. The explosive charge includes a detonator 3 and an explosive body 4. The detonator 3 is located on the side of the test piece 1 away from the high-speed camera. The detonator 3 is inserted into the explosive body 4. The explosive body 4 includes a thin-walled glass tube, and the explosive body 4 is filled inside the thin-walled glass tube. The thin-walled glass tube is placed inside the vertical borehole 2. The length of the thin-walled glass tube is longer than the thickness of the test piece 1. The two ends of the thin-walled glass tube extend out of the two sides of the test piece 1, and the two ends of the thin-walled glass tube are respectively fitted with a first steel sleeve 9 and a second steel sleeve 15. The length of the first steel sleeve 9 is longer than the length of the second steel sleeve 15. The detonator 3 is also inserted into the first steel sleeve 9.

[0033] For the above examples, those skilled in the art should know that when implementing the above technical solutions, the explosive body 4 can be RDX explosive in a thin-walled glass tube, or the explosive body 4 can be replaced with a detonating cord, and the detonator 3 can be inserted into the explosive body 4 or connected to the detonating cord.

[0034] The detonating cord or the RDX explosive body 4, which is filled in a thin-walled glass tube, penetrates the specimen 1 through the vertical borehole 2 and is detonated from the back of the shooting face using a detonator 3.

[0035] As a technical optimization of this utility model, the test piece 1 is fitted with pads 5 on both sides corresponding to the two ends of the vertical borehole 2. One pad 5 is provided with a slot 11, through which a first steel sleeve 9 can pass. The two ends of the first steel sleeve 9 are connected. The other pad 5 is provided with a groove 16, through which a second steel sleeve 15 can be inserted. The end of the second steel sleeve 15 near the inside of the groove 16 is sealed.

[0036] The first steel sleeve 9 and the second steel sleeve 15 serve to counteract the explosion at both ends of the explosive body 4, so that some of the explosive energy inside the specimen 1 can be effectively applied to the specimen 1 during the explosion.

[0037] The first part should also be placed inside the sleeve (the sleeve is mainly for protection). The length that extends out needs to be compared with the front pad. It can be inserted without passing through the pad.

[0038] As a technical optimization of this utility model, foam material 6 is filled between the edge of the side of the specimen 1 and the pad 5. The foam material 6 is used to reduce the tensile effect of stress wave reflection.

[0039] As a technical optimization of this utility model, the constraint component includes two constraint plates 7, which are fixedly connected by four screws 8. Each of the four corners of the two constraint plates 7 has a round hole matching the screw 8. Nuts 10 are threaded onto the screws 8. The specimen 1 is clamped between the two constraint plates 7. The four screws 8 pass through the corresponding round holes on the two constraint plates 7 and are tightened with the four nuts 10, thus fixing the two constraint plates 7 and the specimen 1 located between them. The constraint component effectively positions and constrains the specimen 1, compressing the two constraint plates 7 and the specimen 1 located between them through the threaded connection of the four screws 8 and the two nuts 10.

[0040] As a technical optimization of this utility model, the constraint plate 7 is made of high-strength transparent resin. The opposite sides of the two constraint plates 7 can respectively abut against the two pads 5. The pad 5 near the high-speed camera is also made of high-strength transparent resin. The high-strength transparent resin material enables the high-speed camera to effectively capture the strain field evolution and crack propagation process of the intact surface surrounding the vertical borehole 2. Furthermore, one constraint plate 7 has a circular hole 17 through which the first steel sleeve 9 can pass, facilitating the installation of the detonator 3.

[0041] Specific reference Figure 6 The constraint components also include a rectangular frame 12 and four pads 14. Jacks 13 are installed on both sides of one corner inside the rectangular frame 12, allowing the specimen 1 to be placed inside the rectangular frame 12. The four pads 14 are respectively positioned against the four sides of the specimen 1. Two of the pads 14 also abut against the telescopic ends of the two jacks 13, and the other two pads 14 abut against the two sides of another corner inside the rectangular frame 12. Each telescopic end of the jacks 13 is fixed with a stop block. This device enables the positioning and installation of the specimen 1. During positioning and installation, the two pads 5 and the constraint plate 7 are installed on the front and rear sides of the specimen 1. Furthermore, during positioning and installation, the vertical bore 2 is positioned with both ends horizontally, allowing a high-speed camera positioned on one side to perform direct shooting.

[0042] In this invention, the working principle of the device is as follows:

[0043] After the surface of the cuboid specimen 1 is smoothed, speckle treatment is applied. A vertical borehole 2 is left at the geometric center of the back of specimen 1, penetrating specimen 1. A detonating cord or RDX explosive body 4, filled in a thin-walled glass tube, penetrates specimen 1, with the portion protruding from specimen 1 placed inside the first steel sleeve 9. A detonator 3 is used to detonate from the back of the imaging surface. The RDX explosive charge in the thin-walled glass tube protruding from the imaging surface is relatively small, with radial coupling charge on the back. The detonator 3 is inserted into the explosive body 4 or connected to the detonating cord to simulate a columnar charge environment, and a restraint is used to constrain specimen 1. Foam material 6 is filled between the side of specimen 1 and the pad 5 to reduce the tensile effect of stress wave reflection, and the specimen is constrained at the front and back by a high-strength transparent resin restraint plate 7. The strain field evolution and crack propagation process of the intact surface around the vertical borehole 2 are obtained using a high-speed camera, and the entire strain field evolution process is obtained by combining it with DIC technology.

[0044] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A test apparatus for a cylindrical charge explosion model, comprising a test specimen (1), characterized in that, The specimen (1) is rectangular in shape, and a vertical blast hole (2) is provided through the geometric center of the specimen (1). The interior of the vertical blast hole (2) is used to fill explosive charge. A high-speed camera is located on one side of the specimen (1), and the specimen (1) is positioned within the constraint.

2. The cylindrical charge blasting model test device according to claim 1, characterized in that, The surface of the specimen (1) was treated with smoothing and speckle treatment.

3. The cylindrical charge blasting model test device according to claim 1, characterized in that, The explosive charge includes a detonator (3) and an explosive body (4). The detonator (3) is placed on the side of the test piece (1) away from the high-speed camera. The detonator (3) is inserted into the explosive body (4). The explosive body (4) includes a thin-walled glass tube. The explosive body (4) is filled in the thin-walled glass tube. The thin-walled glass tube is placed inside the vertical borehole (2). The length of the thin-walled glass tube is longer than the thickness of the test piece (1). The two ends of the thin-walled glass tube extend out of the two sides of the test piece (1). The two ends of the thin-walled glass tube are respectively fitted with a first steel sleeve (9) and a second steel sleeve (15). The length of the first steel sleeve (9) is longer than the length of the second steel sleeve (15). The detonator (3) is also inserted into the first steel sleeve (9).

4. The cylindrical charge blasting model test device according to claim 3, characterized in that, The specimen (1) is fitted with pads (5) on both sides corresponding to the two ends of the vertical blast hole (2). One pad (5) has a slot (11) through which a first steel sleeve (9) can pass. The two ends of the first steel sleeve (9) are connected. The other pad (5) has a groove (16) through which a second steel sleeve (15) can be inserted. The end of the second steel sleeve (15) near the inside of the groove (16) is sealed.

5. The cylindrical charge blasting model test device according to claim 4, characterized in that, Foam material (6) is filled between the edge of the side of the specimen (1) and the pad (5).

6. The cylindrical charge blasting model test device according to claim 5, characterized in that, The constraint component includes two constraint plates (7), which are fixedly connected by four screws (8). Each of the four corners of the two constraint plates (7) is provided with a round hole that matches the screw (8). The screw (8) is threaded with a nut (10). The specimen (1) is clamped between the two constraint plates (7). The four screws (8) pass through the corresponding round holes on the two constraint plates (7) and tighten the four nuts (10) respectively, which can fix the two constraint plates (7) and the specimen (1) between them.

7. The cylindrical charge blasting model test device according to claim 6, characterized in that, The constraint plate (7) is made of high-strength transparent resin. The opposite sides of the two constraint plates (7) can abut against the two pads (5) respectively. The pad (5) near the high-speed camera is also made of high-strength transparent resin. One constraint plate (7) is provided with a round hole (17) through which the first steel sleeve (9) can pass.

8. The cylindrical charge blasting model test device according to claim 7, characterized in that, The constraint also includes a rectangular frame (12) and four pads (14). Jacks (13) are installed on the two sides of one corner inside the rectangular frame (12). The specimen (1) can be placed inside the rectangular frame (12). The four pads (14) are respectively placed against the four sides of the specimen (1). Two of the pads (14) are also placed against the telescopic ends of the two jacks (13). The other two pads (14) are respectively placed against the two sides of another corner inside the rectangular frame (12). The telescopic ends of the jacks (13) are all fixed with abutments.

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