Rock dynamic crack propagation test device capable of applying initial stress and test method
By designing a rock dynamic crack propagation test device that can apply initial stress, the problem of testing devices and testing methods in the prior art that simulates the burst crack propagation characteristics of rock materials under initial stress conditions is solved, and effective simulation and observation of the initial stress environment of surrounding rocks in underground engineering is achieved, and theoretical basis is provided to provide a theoretical basis for the design of blasting excavation parameters of underground engineering.
Patent Information
- Application Number
- CN202411878076.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-03-14
AI Technical Summary
The existing technology lacks test devices and testing methods that can effectively simulate the expansion characteristics of rock material explosion cracks under initial stress conditions, resulting in a lack of theoretical basis for the design of blasting excavation parameters in underground engineering.
A rock dynamic crack propagation test device that can apply initial stress is designed, including rock specimens, fixing mechanisms and fastening mechanisms. The dynamic crack propagation characteristics of rock specimens under the coupling of initial stress and explosive loads are observed.
The device can be assembled simply and operated easily, simulates the initial stress environment of the surrounding rock of underground engineering, significantly improves work efficiency, and provides a theoretical basis for the design of blasting and excavation parameters of underground engineering.
Smart Images
Figure CN119618870A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of rock dynamics and underground engineering blasting technology, in particular to a rock dynamic crack extension test device and a test method capable of applying initial stress. Background Art
[0002] The surrounding rock of underground engineering is inevitably in a certain geological and structural environment, and will be subjected to initial stresses such as self-weight stress and tectonic stress. The existence of initial stress will affect the mechanical properties of the surrounding rock of underground engineering. Therefore, in order to control the dynamic disasters caused by blasting and excavation of underground engineering, it is necessary to study the dynamic mechanical properties of the surrounding rock under initial geostress, especially the characteristics of explosive crack propagation of surrounding rock under initial geostress, so as to provide a theoretical basis for the precise design of blasting and excavation parameters of underground engineering. At present, there are some relatively complete test devices and test methods for the characteristics and laws of explosive crack propagation of brittle materials such as rocks, such as dynamic photoelastic tests and dynamic caustics tests, but there is still a lack of test devices and test methods for the characteristics of explosive crack propagation of rock materials under initial stress conditions. Based on this, it is necessary to develop a test device and test method with simple structure, easy operation and ability to apply initial stress to rock materials, so as to study the dynamic crack propagation characteristics of rock materials under the coupling of initial stress and explosive load. Summary of the invention
[0003] The purpose of the present invention is to provide a rock dynamic crack extension test device and a test method that can apply initial stress, which can simulate the initial stress environment of the surrounding rock of underground engineering, study the dynamic crack extension characteristics of rock materials under the coupling effect of initial stress and blasting load, and provide a theoretical basis for the precise design of blasting excavation parameters for underground engineering.
[0004] To achieve the above-mentioned purpose, the present invention provides a rock dynamic crack extension test device capable of applying initial stress, comprising a rock sample, a fixing mechanism and a fastening mechanism, wherein the fastening mechanism is connected to the fixing mechanism, the fixing mechanism is connected to the rock sample, a blast hole is arranged in the middle of the rock sample, and explosives are arranged inside the blast hole.
[0005] Preferably, the fixing mechanism comprises an upper clamping plate and a lower clamping plate, and limiting grooves are provided in the lower clamping plate and the upper clamping plate, the limiting grooves are connected to the rock sample, and the upper and lower clamping plates are connected to the fastening mechanism.
[0006] Preferably, the fastening mechanism comprises a positioning screw and a fastening nut, the fastening nut is connected to the positioning screw, and the positioning screw is connected to screw holes provided on the upper clamping plate and the lower clamping plate.
[0007] Preferably, the screw holes are arranged at the ends of the upper clamping plate and the lower clamping plate, and four screw holes are respectively arranged on the upper clamping plate and the lower clamping plate.
[0008] Preferably, the upper clamping plate and the lower clamping plate are both configured as I-shaped structures, and reinforcing ribs are provided on the upper clamping plate and the lower clamping plate.
[0009] Preferably, the tightening nut is subjected to the same torque by a torque wrench, so that the rock sample to be tested is in a uniform initial stress state.
[0010] The testing method of the rock dynamic crack extension test device capable of applying initial stress comprises the following steps: S1. Place the rock sample with a blasthole through the center between the upper clamping plate and the lower clamping plate, and clamp the rock sample in the limiting grooves of the upper and lower clamping plates; S2. Pass four positioning screws through the screw holes on the upper and lower clamping plates, and apply a certain pre-tightening force to the entire device by tightening the nuts to eliminate the gap between the rock sample and the upper and lower clamping plates during the assembly process; S3. Use a torque wrench to apply the same torque to the four fastening nuts to put the rock sample in a uniform initial stress state; S4. Load and detonate explosives in the blastholes in the rock sample, and observe the dynamic crack growth characteristics of the rock sample under the coupling effect of initial stress and explosion load; S5. Arrange strain gauges at appropriate locations on the rock sample to be tested or use non-contact DIC digital image correlation technology to obtain the distribution law of the dynamic strain field of the rock sample under the coupling effect of initial stress and explosion load.
[0011] Therefore, the present invention adopts the above-mentioned rock dynamic crack extension test device and test method capable of applying initial stress, which can apply initial stress to rock materials and simulate the initial stress effects such as self-weight stress and structural stress on the surrounding rock of underground engineering. The device is simple to assemble, easy to operate, saves time and effort, improves work efficiency, and is convenient for observing the dynamic crack extension characteristics of rocks under the coupling effect of initial stress and explosion load.
[0012] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a structural schematic diagram of the test device of the present invention; Figure 2 is a side view of the test device of the present invention; Figure 3 It is a schematic diagram of the splint structure of the present invention; Reference numerals 1. Rock sample; 2. Blast hole; 3. Explosive; 4. Upper clamp; 5. Positioning screw; 6. Fastening nut; 7. Lower clamp; 8. Screw hole; 9. Limiting groove. DETAILED DESCRIPTION
[0014] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.
[0015] 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.
[0016] Example See also Figure 1-3 The present invention provides a rock dynamic crack extension test device capable of applying initial stress, comprising a rock sample 1, a fixing mechanism and a fastening mechanism, wherein the fastening mechanism is connected to the fixing mechanism, and the fixing mechanism is connected to the rock sample 1, and the fixing mechanism and the fastening mechanism fix the rock sample 1 to ensure the stability of the rock sample 1 during the test, and a blast hole 2 is arranged in the middle of the rock sample 1, and explosives 3 are arranged inside the blast hole 2.
[0017] The fixing mechanism includes an upper clamping plate 4 and a lower clamping plate 7. The upper clamping plate 4 and the lower clamping plate 7 are both arranged as an I-shaped structure. Limiting grooves 9 are arranged in the lower clamping plate 7 and the upper clamping plate 4. The limiting grooves 9 are connected to the rock sample 1. The limiting grooves 9 can position and fix the rock sample 1 to be tested. Reinforcing ribs are designed on the other side structure of the upper and lower clamping plates to ensure the overall rigidity and prevent the clamping plates from deforming when the initial stress is applied. The upper and lower clamping plates are both connected to the fastening mechanism.
[0018] The fastening mechanism includes a positioning screw 5 and a fastening nut 6, the fastening nut 6 is connected to the positioning screw 5, and the positioning screw 5 is connected to the screw holes 8 provided on the upper clamping plate 4 and the lower clamping plate 7. The screw holes 8 are provided at the ends of the upper clamping plate 4 and the lower clamping plate 7, and four screw holes 8 are provided on the upper clamping plate 4 and the lower clamping plate 7, respectively. Four positioning screws 5 are used to pass through the screw holes 8 of the upper and lower clamping plates, and the upper clamping plate 4 and the lower clamping plate 7 are fixed by the fastening nuts 6.
[0019] The same torque is applied to the tightening nut 6 through a torque wrench to put the rock sample under test in a uniform initial stress state.
[0020] A test method for a rock dynamic crack extension test device capable of applying initial stress is as follows: 1) First, place the rock sample 1 with a blasthole 2 through the center between the upper clamping plate 4 and the lower clamping plate 7, and clamp the rock sample in the limiting grooves 9 of the upper and lower clamping plates.
[0021] 2) Pass four positioning screws 5 through the screw holes 8 on the upper clamping plate 4 and the lower clamping plate 7, and apply a certain pre-tightening force to the entire device through four fastening nuts 6 to eliminate the gap between the rock sample 1 and the upper clamping plate 4 and the lower clamping plate 7 during the assembly process.
[0022] 3) Apply the same torque to the four fastening nuts 6 using a torque wrench to put the rock sample 1 in a uniform initial stress state.
[0023] 4) Explosives 3 are loaded and detonated in the blasthole 2 in the rock sample 1 to observe the dynamic crack growth characteristics of the rock sample under the coupling of initial stress and blast load. At the same time, strain gauges can be arranged at appropriate positions on the rock sample 1 to be measured, or non-contact DIC (digital image correlation technology) measurement can be used to obtain the distribution law of the dynamic strain field of the rock sample under the coupling of initial stress and blast load.
[0024] Therefore, the present invention adopts the above-mentioned rock dynamic crack extension test device and test method capable of applying initial stress, which can apply initial stress to rock materials and simulate the initial stress effects such as self-weight stress and structural stress on the surrounding rock of underground engineering. The device is simple to assemble, easy to operate, saves time and effort, improves work efficiency, and is convenient for observing the dynamic crack extension characteristics of rocks under the coupling effect of initial stress and explosion load.
[0025] 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 rock dynamic crack growth test device capable of applying initial stress, characterized in that: The invention comprises a rock sample, a fixing mechanism and a fastening mechanism, wherein the fastening mechanism is connected to the fixing mechanism, and the fixing mechanism is connected to the rock sample. A blast hole is arranged in the middle of the rock sample, and explosives are arranged inside the blast hole.
2. The rock dynamic crack extension test device capable of applying initial stress according to claim 1, characterized in that: The fixing mechanism comprises an upper clamping plate and a lower clamping plate, wherein the lower clamping plate and the upper clamping plate are both provided with limiting grooves, the limiting grooves are both connected to the rock sample, and the upper and lower clamping plates are both connected to the fastening mechanism.
3. The rock dynamic crack extension test device capable of applying initial stress according to claim 2, characterized in that: The fastening mechanism comprises a positioning screw and a fastening nut, wherein the fastening nut is connected to the positioning screw, and the positioning screw is connected to screw holes arranged on the upper clamping plate and the lower clamping plate.
4. The rock dynamic crack extension test device capable of applying initial stress according to claim 3 is characterized in that: The screw holes are arranged at the ends of the upper clamping plate and the lower clamping plate, and four screw holes are arranged on the upper clamping plate and the lower clamping plate respectively.
5. The rock dynamic crack extension test device capable of applying initial stress according to claim 4, characterized in that: The upper clamping plate and the lower clamping plate are both configured as I-shaped structures, and reinforcing ribs are provided on the upper clamping plate and the lower clamping plate.
6. The rock dynamic crack extension test device capable of applying initial stress according to claim 5, characterized in that: The tightening nut is applied with the same torque through a torque wrench, so that the rock sample to be tested is in a uniform initial stress state.
7. A test method using the rock dynamic crack extension test device capable of applying initial stress according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Place the rock sample with a blasthole through the center between the upper clamping plate and the lower clamping plate, and clamp the rock sample in the limiting grooves of the upper and lower clamping plates; S2. Pass four positioning screws through the screw holes on the upper and lower clamping plates, and apply a certain pre-tightening force to the entire device by tightening the nuts to eliminate the gap between the rock sample and the upper and lower clamping plates during the assembly process; S3. Use a torque wrench to apply the same torque to the four fastening nuts to put the rock sample in a uniform initial stress state; S4. Load and detonate explosives in the blastholes in the rock sample, and observe the dynamic crack growth characteristics of the rock sample under the coupling effect of initial stress and explosion load; S5. Arrange strain gauges at appropriate locations on the rock sample to be tested or use non-contact DIC digital image correlation technology to obtain the distribution law of the dynamic strain field of the rock sample under the coupling effect of initial stress and explosion load.