Testing device and method for researching dynamic crack propagation characteristics of rock material

Abstract

The invention discloses a test device and method for researching the dynamic crack propagation characteristics of a rock material, and relates to the technical field of rock dynamics and blasting engineering.The test device comprises a base, a positioning mechanism and a fixing mechanism, the fixing mechanism is arranged on the upper portion of the base, and the side end of the base is connected with the positioning mechanism; the positioning mechanism comprises transverse rods, vertical rods and round clamps, the round clamps are connected with the transverse rods, the transverse rods are connected with the vertical rods, and the vertical rods are connected with the base through bolts. According to the test device and method for researching the dynamic crack growth characteristics of the rock material, the axis of the electronic detonator and the axis of the blast hole can be coaxial by adjusting the positions of the cross rod and the vertical rod, so that the detonator is located in the center of the blast hole, and on the basis, different blast hole diameters can be set to realize a non-coupling charging structure; the problem that the electronic detonator is eccentric in the blast hole of the rock sample is solved, the test steps are convenient and simple, and the explosion crack propagation characteristics of a rock material under a non-coupling charging structure are convenient to research.

Description

Technical Field

[0001] The invention relates to the technical field of rock dynamics and blasting engineering, and in particular to a test device and method for studying dynamic crack extension characteristics of rock materials. Background Art

[0002] At present, the excavation method of rock slopes and mountain tunnels is still mainly based on drilling and blasting. In order to reduce the damage to the retained rock mass outside the excavation area, the blast holes near the contour surface of the excavation area often use uncoupled charging structures to weaken the peak value of the explosive blast load and prolong its action time to improve the forming quality of the excavation contour surface. Therefore, studying the characteristics of explosive crack propagation in rock materials under uncoupled charging conditions is the key to revealing its dynamic crushing mechanism, which can provide a theoretical basis for the precise design of blasting excavation parameters in rock engineering. At present, the main experimental research methods for the dynamic crack growth law and characteristics of rock materials under explosive loads include dynamic photoelastic test, dynamic caustic test and rock material explosion model test. Among them, the dynamic photoelastic test and dynamic caustic test have expensive test system equipment, complex test process and high cost. For the rock material explosion model test, most of them adopt the method of drilling first, then charging, and then detonating the explosive to apply the explosive load. Under the condition of uncoupled charging, it is difficult to keep the explosive and the blast hole coaxial, which makes the explosive easy to be eccentric in the blast hole, causing uneven distribution of the explosion load on the blast hole wall, thus affecting the accurate analysis of the explosion crack growth law and characteristics of rock materials. Based on this, it is necessary to develop a test device that is easy to operate and can ensure the coaxiality of the explosive and the blast hole, and design the corresponding test method to study the dynamic crack growth characteristics of rock materials under the condition of uncoupled charging. Summary of the invention

[0003] The purpose of the present invention is to provide a test device for studying the dynamic crack growth characteristics of rock materials, which can ensure that the explosive is coaxial with the blast hole during the test and improve the accuracy of the test results, so as to study the explosive crack growth characteristics of rock materials under uncoupled charge coefficients.

[0004] To achieve the above-mentioned purpose, the present invention provides a test device and method for studying the dynamic crack extension characteristics of rock materials, comprising a base, a positioning mechanism and a fixing mechanism, wherein the fixing mechanism is arranged on the upper part of the base, and the side end of the base is connected to the positioning mechanism;

[0005] The positioning mechanism comprises a cross bar, a vertical bar and a circular clamp, wherein the circular clamp is connected to the cross bar, the cross bar is connected to the vertical bar, and the vertical bar is connected to the base through bolts.

[0006] Preferably, the fixing mechanism comprises a card slot and a U-shaped card buckle, the U-shaped card buckle is connected to the card slot, the card slot is arranged on the base, and the card slot is arranged along the end of the base.

[0007] Preferably, four U-shaped buckles are provided, and the upper parts of the four U-shaped buckles are connected to screws.

[0008] Preferably, scale lines are provided on the base, the base is connected to the object to be tested, and blast holes are provided in the center of the object to be tested and the base.

[0009] Preferably, scale lines are provided on the vertical rod and the horizontal rod, a convex tube is provided at one end of the horizontal rod, the convex tube is slidably connected to the vertical rod, a threaded hole is opened on one side of the convex tube, and the threaded hole is connected to a locking bolt.

[0010] Preferably, the upper portion of the circular clamp is connected to the vertical pole, the upper portion of the vertical pole is connected to the horizontal pole through the convex tube, and the lower portion of the circular clamp is connected to the electronic detonator.

[0011] Preferably, the inner diameter of the circular clamp is smaller than the diameter of the electronic detonator.

[0012] A method for using a test device for studying dynamic crack growth characteristics of rock materials comprises the following steps:

[0013] S1. Prepare rock samples with a thickness of 10 mm;

[0014] S2, drilling a blast hole in the center of the rock sample, the blast hole passing through the entire rock sample;

[0015] S3. Place the rock sample in the center of the base according to the scale lines on the base;

[0016] S4. Move the U-shaped buckle to the center of each end of the rock sample, clamp the rock sample, and tighten the screws;

[0017] S5. Clamp one end of the electronic detonator connecting leg wire with a circular clamp, keep it vertical, move the locking bolt to make the detonator axis coaxial with the blast hole axis, ensure that the detonator is in the center of the blast hole, and then tighten the locking bolt to lock the horizontal bar and the vertical bar;

[0018] S6. Detonate the electronic detonator with the detonator, collect the loaded rock samples, and observe the expansion law and characteristics of the explosion cracks.

[0019] Therefore, the present invention adopts the above-mentioned test device and method for studying the dynamic crack propagation characteristics of rock materials. By adjusting the positions of the horizontal bar and the vertical bar, the axis of the electronic detonator can be made coaxial with the axis of the blasthole to ensure that the detonator is in the center of the blasthole. On this basis, different blasthole diameters can be set to achieve an uncoupled charging structure, which solves the problem of eccentricity of the electronic detonator in the blasthole of the rock sample. The test steps are convenient and simple, which is convenient for studying the explosion crack propagation characteristics of rock materials under the uncoupled charging structure.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a test device for studying dynamic crack propagation characteristics of rock materials according to the present invention;

[0022] Figure 2 A top view of a test device for studying dynamic crack propagation characteristics of rock materials according to the present invention;

[0023] Reference numerals

[0024] 1. Base; 2. Screws; 3. U-shaped buckle; 4. Vertical rod; 5. Horizontal rod; 6. Locking bolt; 7. Convex tube; 8. Vertical rod; 9. Round clamp; 10. Rock sample; 11. Blast hole; 12. Slot; 13. Electronic detonator. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0026] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] Example

[0028] See also Figure 1-2 The present invention provides a test device for studying the dynamic crack extension characteristics of rock materials, including a base 1, a positioning mechanism and a fixing mechanism, wherein the fixing mechanism is arranged on the upper part of the base, and the side end of the base 1 is connected to the positioning mechanism.

[0029] The positioning mechanism includes a crossbar 5, a vertical bar 4 and a circular clamp 9, the circular clamp 9 is connected to the crossbar 5, the crossbar 5 is connected to the vertical bar 4, and the vertical bar 4 is connected to the base 1 through bolts. Graduation lines are provided on the vertical bar 4 and the crossbar 5, so as to facilitate the adjustment of the position of the convex tube 7 and the crossbar 5 according to actual conditions. A convex tube 7 is provided at one end of the crossbar 5, and the convex tube 7 is slidably connected to the vertical bar 4. The crossbar 5 can rotate with the vertical bar 4 as the center of the circle. The crossbar 5 can be rotated or the vertical bar 4 can be moved according to actual conditions to adjust the position of the circular clamp 9. A threaded hole is provided on one side of the convex tube 7, and the threaded hole is connected to the locking bolt 6, and the position of the crossbar 5 is fixed by the locking bolt 6.

[0030] The upper part of the circular clamp 9 is connected to the vertical pole 8, and the upper part of the vertical pole 8 is connected to the cross bar 5 through the convex tube 7. The position of the vertical pole 8 and the circular clamp 9 is fixed by the locking bolt 6 to keep it vertical. The lower part of the circular clamp 9 is connected to the electronic detonator 13. The foot line end of the electronic detonator 13 is clamped with the circular clamp 9, and the position of the convex tube 7 and the vertical pole 8 is moved to make the axis of the electronic detonator 13 coaxial with the axis of the blast hole 11, ensuring that the detonator is in the center of the blast hole 11, and then tighten the locking bolt 6 to achieve the locking of the cross bar 5 and the vertical pole 8. The inner diameter of the circular clamp 9 is smaller than the diameter of the electronic detonator 13 to ensure that the electronic detonator 13 is clamped.

[0031] The fixing mechanism includes a slot 12 and a U-shaped clip 3. The U-shaped clip 3 is connected to the slot 12. The slot 12 is arranged on the base 1. The slot 12 is arranged along the end of the base 1, and the slot 12 is arranged in a circle. There are four U-shaped clips 3. The upper parts of the four U-shaped clips 3 are connected to the screws 2. The U-shaped clips 3 are fixed by the screws 2. One end of the U-shaped clip 3 is stuck in the slot 12. The U-shaped clip 3 can move freely in the slot 12.

[0032] The base 1 is provided with scale lines, the base is connected to the object to be tested, and a blast hole 11 is provided in the center of the object to be tested and the base 1. The diameter of the blast hole 11 changes with the change of the uncoupling coefficient. The blast hole 11 can be set at any position of the rock sample 10, and the device can fix the electronic detonator 13 at any position of the rock sample 10 by moving the U-shaped buckle 3, the cross bar 5 and the vertical bar 4.

[0033] A method for using a test device for studying dynamic crack growth characteristics of rock materials comprises the following steps:

[0034] S1. Prepare rock sample 10 with a thickness of 10 mm;

[0035] S2, drilling a blast hole 11 in the center of the rock sample 10, the blast hole 11 passing through the entire rock sample 10;

[0036] S3. Place the rock sample 10 in the center of the base 1 according to the scale lines on the base 1;

[0037] S4, move the U-shaped buckle 3 to the center of each end of the rock sample, clamp the rock sample 10, and tighten the screw 2 on the U-shaped buckle 3 to fix it;

[0038] S5, the circular clamp 9 clamps one end of the connecting leg line of the electronic detonator 13, keeps it vertical, moves the locking bolt 6, makes the axis of the detonator coaxial with the axis of the blast hole 11, ensures that the detonator is in the center of the blast hole 11, and then tightens the locking bolt 6 to achieve the locking of the cross bar 5 and the vertical bar 4;

[0039] S6. Detonate the electronic detonator 13 through the detonator, collect the loaded rock sample 10, and observe the expansion law and characteristics of the explosion crack.

[0040] Therefore, the present invention adopts the above-mentioned test device and method for studying the dynamic crack propagation characteristics of rock materials. By adjusting the positions of the horizontal bar and the vertical bar, the axis of the electronic detonator can be made coaxial with the axis of the blasthole to ensure that the detonator is in the center of the blasthole. On this basis, different blasthole diameters can be set to achieve an uncoupled charging structure, which solves the problem of eccentricity of the electronic detonator in the blasthole of the rock sample. The test steps are convenient and simple, which is convenient for studying the explosion crack propagation characteristics of rock materials under the uncoupled charging structure.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A test device for studying the dynamic crack growth characteristics of rock materials, characterized by: It comprises a base, a positioning mechanism and a fixing mechanism, wherein the fixing mechanism is arranged on the upper part of the base, and the side end of the base is connected to the positioning mechanism; The positioning mechanism comprises a cross bar, a vertical bar and a circular clamp, wherein the circular clamp is connected to the cross bar, the cross bar is connected to the vertical bar, and the vertical bar is connected to the base through bolts.

2. The test device for studying dynamic crack growth characteristics of rock materials according to claim 1, characterized in that: The fixing mechanism comprises a clamping slot and a U-shaped clamping buckle, the U-shaped clamping buckle is connected to the clamping slot, the clamping slot is arranged on the base, and the clamping slot is arranged along the end of the base.

3. The test device for studying dynamic crack growth characteristics of rock materials according to claim 2, characterized in that: The U-shaped buckles are provided with four, and the upper parts of the four U-shaped buckles are connected with screws.

4. The test device for studying dynamic crack growth characteristics of rock materials according to claim 3, characterized in that: The base is provided with scale lines, the base is connected to the object to be tested, and blast holes are provided in the center of the object to be tested and the base.

5. The test device for studying dynamic crack growth characteristics of rock materials according to claim 4, characterized in that: Graduation lines are arranged on the vertical rod and the horizontal rod, a convex tube is arranged at one end of the horizontal rod, the convex tube is slidably connected with the vertical rod, a threaded hole is opened on one side of the convex tube, and the threaded hole is connected with a locking bolt.

6. The test device for studying dynamic crack growth characteristics of rock materials according to claim 5, characterized in that: The upper part of the circular clamp is connected to the vertical rod, the upper part of the vertical rod is connected to the horizontal rod through the convex tube, and the lower part of the circular clamp is connected to the electronic detonator.

7. The test device for studying dynamic crack growth characteristics of rock materials according to claim 6, characterized in that: The inner diameter of the circular clamp is smaller than the diameter of the electronic detonator.

8. A method for using a test device for studying dynamic crack growth characteristics of rock materials according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Prepare rock samples with a thickness of 10 mm; S2, drilling a blast hole in the center of the rock sample, the blast hole passing through the entire rock sample; S3. Place the rock sample in the center of the base according to the scale lines on the base; S4. Move the U-shaped buckle to the center of each end of the rock sample, clamp the rock sample, and tighten the screws; S5. Clamp one end of the electronic detonator connecting leg wire with a circular clamp, keep it vertical, move the locking bolt to make the detonator axis coaxial with the blast hole axis, ensure that the detonator is in the center of the blast hole, and then tighten the locking bolt to lock the horizontal bar and the vertical bar; S6. Detonate the electronic detonator with the detonator, collect the loaded rock samples, and observe the expansion law and characteristics of the explosion cracks.

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