Coal rock sample resistivity-acoustic emission combined monitoring device suitable for true triaxial loading and unloading

Abstract

The invention discloses a coal rock sample resistivity-acoustic emission combined monitoring device suitable for true triaxial loading and unloading, which comprises five fixing clamps, the five fixing clamps form a true triaxial clamp structure with an opening at the upper end through a locking assembly, and a coal rock sample is placed among the five fixing clamps. The monitoring sensor assembly is integrally arranged on the side, facing the coal rock sample, of the fixing clamp, and the monitoring sensor assembly is attached to the coal rock sample, it can be ensured that an acoustic emission sensor and an electrode make close contact with the coal rock sample, the signal attenuation degree is reduced, the monitoring precision is improved, and the monitoring accuracy is improved. The integrated channel structure protects the acoustic emission sensor and the electrode, the acoustic emission sensor and the electrode are prevented from being damaged in the loading process, and the acoustic emission and resistivity change characteristics of the coal rock sample can be comprehensively and jointly monitored in the true triaxial loading and unloading process.

Description

Technical Field

[0001] This invention belongs to the field of monitoring technology, specifically relating to a combined monitoring device for resistivity and acoustic emission of coal and rock samples suitable for true triaxial loading and unloading. Background Technology

[0002] The true triaxial loading and unloading coal and rock sample resistivity-acoustic emission joint monitoring device is an experimental system that integrates multi-physics field monitoring technology. It aims to simulate the mechanical response of coal and rock under complex stress conditions and reveal its damage evolution mechanism by synchronously acquiring resistivity and acoustic emission signals.

[0003] In existing coal and rock sample resistivity-acoustic emission joint monitoring devices, the acoustic emission sensor and electrode are not installed stably, the acoustic emission sensor and electrode are not tightly attached to the coal and rock sample, the signal attenuation is serious, the monitoring accuracy is affected, and the monitoring accessories are easily damaged during loading. To address this, we propose a coal and rock sample resistivity-acoustic emission joint monitoring device suitable for true triaxial loading and unloading. Summary of the Invention

[0004] The purpose of this invention is to provide a combined resistivity-acoustic emission monitoring device for coal and rock samples suitable for true triaxial loading and unloading, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a combined resistivity-acoustic emission monitoring device for coal and rock samples suitable for true triaxial loading and unloading, comprising: The fixture is provided in five parts, and the five fixtures are connected by a locking assembly to form a true triaxial fixture structure with an open top. A coal and rock sample, which is placed between the five fixed clamps; A monitoring sensor assembly is integrated on the side of the fixing fixture facing the coal and rock sample, and the monitoring sensor assembly is in contact with the coal and rock sample.

[0006] Preferably, the fixing fixture includes a solid plate and a monitoring sensor mounting plate; The solid plate and the monitoring sensor mounting plate are provided with threaded holes at their four corners, and connecting bolts are provided in the threaded holes.

[0007] Preferably, the locking assembly includes an L-shaped connecting piece and a locking bolt; The adjacent solid plates at the same horizontal level are locked and fixedly connected by the L-shaped connecting piece and the locking bolt.

[0008] Preferably, the outer side of the solid plate at the same horizontal level is provided with a locking thread hole that is compatible with the locking bolt.

[0009] Preferably, the monitoring sensor assembly includes an acoustic emission sensor and electrodes; Each of the monitoring sensor mounting plates has a rectangular array of electrode mounting holes on the side facing the coal and rock sample, and each of the electrode mounting holes is fitted with an electrode that fits into the coal and rock sample. An acoustic emission sensor mounting hole is provided in the middle of the side of the monitoring sensor mounting plate at the bottom facing the coal and rock sample. An acoustic emission sensor mounting hole is provided diagonally on the side of the monitoring sensor mounting plate at the same horizontal height facing the coal and rock sample. The acoustic emission sensor is installed in the acoustic emission sensor mounting hole and is in contact with the coal and rock sample.

[0010] Preferably, the acoustic emission sensor is mounted in the acoustic emission sensor mounting hole via a spring.

[0011] Preferably, the electrode is disposed in the electrode mounting hole by means of a rubber gasket, the rubber gasket having a through hole adapted to the outer diameter of the electrode, and the rubber gasket being fixed to the end face of the monitoring sensor mounting plate by double-sided adhesive.

[0012] Preferably, an electrode wire mounting channel is provided on the outer side of each monitoring sensor mounting plate at the position corresponding to the position of each column of electrode mounting holes. The electrode wire mounting channel is used to install the electrode wires connecting the electrodes to the monitoring system. An acoustic emission signal line mounting channel is provided on the outer side of each monitoring sensor mounting plate at the position corresponding to the position of each acoustic emission sensor mounting hole. The acoustic emission signal line mounting channel is used to install the acoustic emission signal line connecting the acoustic emission sensor to the monitoring system.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, the acoustic emission sensor is set in the acoustic emission sensor mounting hole by a spring, and the electrode is set in the electrode mounting hole by a rubber gasket. The rubber gasket has a through hole that matches the outer diameter of the electrode. The rubber gasket is fixed to the end face of the monitoring sensor mounting plate by double-sided adhesive. The rubber gasket is used to fix the electrode, and plays a role in insulation and noise reduction. It ensures that the acoustic emission sensor and electrode are in close contact with the coal and rock sample, reduces the signal attenuation, and improves the monitoring accuracy. In addition, the monitoring sensor mounting plate has electrode wire mounting channels and acoustic emission signal line mounting channels. The integrated channel structure protects the acoustic emission sensor and electrode and avoids damage to the acoustic emission sensor and electrode during loading. It can realize all-round joint monitoring of the acoustic emission and resistivity change characteristics of the coal and rock sample during true triaxial loading and unloading. 2. The fixing fixture in this invention includes a solid plate and a monitoring sensor mounting plate, which are connected by connecting bolts. It adopts a split structure, which facilitates the deployment of monitoring sensor components. Adjacent solid plates at the same horizontal level are locked and fixedly connected by L-shaped connecting pieces and locking bolts, which improves structural stability and ensures the normal use of the monitoring device. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the upper fixing clamp structure of the present invention; Figure 3 This is a schematic diagram of the bottom fixing clamp structure of the present invention.

[0015] In the diagram: 1. Fixture; 101. Solid plate; 102. Monitoring sensor mounting plate; 103. Connecting threaded hole; 104. Connecting bolt; 2. Locking assembly; 201. L-shaped connecting piece; 202. Locking bolt; 203. Locking threaded hole; 3. Coal and rock sample; 4. Monitoring sensor assembly; 401. Acoustic emission sensor; 402. Electrode; 5. Electrode mounting hole; 6. Acoustic emission sensor mounting hole; 7. Rubber gasket; 8. Electrode wire mounting channel; 9. Acoustic emission signal line mounting channel. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figures 1-3 The present invention provides a combined resistivity-acoustic emission monitoring device for coal and rock samples suitable for true triaxial loading and unloading, comprising: The fixture 1 has five fixtures, which are connected by locking assembly 2 to form a true triaxial fixture structure with an open top. The fixture 1 includes a solid plate 101 and a monitoring sensor mounting plate 102. The solid plate 101 and the monitoring sensor mounting plate 102 are provided with threaded holes 103 at the four corners. The threaded holes 103 are provided with connecting bolts 104. The locking assembly 2 includes an L-shaped connecting piece 201 and a locking bolt 202. Adjacent solid plates 101 at the same horizontal level are locked and fixedly connected by the L-shaped connecting piece 201 and the locking bolt 202. The outer side of the solid plates 101 at the same horizontal level is provided with locking threaded holes 203 that are adapted to the locking bolts 202. In this invention, the fixing fixture 1 includes a solid plate 101 and a monitoring sensor mounting plate 102, which are connected by connecting bolts 104. It adopts a split structure, which facilitates the installation of the monitoring sensor assembly 4. Adjacent solid plates 101 at the same horizontal height are locked and fixedly connected by L-shaped connecting pieces 201 and locking bolts 202, which improves structural stability and ensures the normal use of the monitoring device. Apply petroleum jelly between the contact surfaces of adjacent fixing clamps 1 to reduce friction; Coal and rock sample 3 is placed between five fixed clamps 1. The monitoring sensor assembly 4 is integrated on the side of the fixed fixture 1 facing the coal and rock sample 3 and is in contact with the coal and rock sample 3. The monitoring sensor assembly 4 includes an acoustic emission sensor 401 and an electrode 402. Each monitoring sensor mounting plate 102 has a rectangular array of electrode mounting holes 5 on the side facing the coal and rock sample 3. Each electrode mounting hole 5 is fitted with an electrode 402 that is in contact with the coal and rock sample 3. The monitoring sensor mounting plate 102 at the bottom has an acoustic emission sensor mounting hole 6 in the middle of the side facing the coal and rock sample 3. The monitoring sensor mounting plate 102 at the same horizontal height has an acoustic emission sensor mounting hole 6 at the diagonal of the side facing the coal and rock sample 3. The acoustic emission sensor 401 is fitted with the coal and rock sample 3 in the acoustic emission sensor mounting hole 6. The acoustic emission sensor 401 is set in the acoustic emission sensor mounting hole 6 by a spring, and the electrode 402 is set in the electrode mounting hole 5 by a rubber gasket 7. The rubber gasket 7 has a through hole that matches the outer diameter of the electrode 402. The rubber gasket 7 is fixed to the end face of the monitoring sensor mounting plate 102 by double-sided adhesive. An electrode wire mounting channel 8 is provided on the outer side of each monitoring sensor mounting plate 102 at the position corresponding to the position of each column of electrode mounting holes 5. The electrode wire mounting channel 8 is used to install the electrode wires connecting the electrode 402 to the monitoring system. An acoustic emission signal line mounting channel 9 is provided on the outer side of each monitoring sensor mounting plate 102 at the position corresponding to the position of each acoustic emission sensor mounting hole 6. The acoustic emission signal line mounting channel 9 is used to install the acoustic emission signal line connecting the acoustic emission sensor 401 to the monitoring system. The inner walls of electrode mounting hole 5, acoustic emission sensor mounting hole 6, electrode wire mounting channel 8, and acoustic emission signal line mounting channel 9 are polished smooth to avoid wear on the wires, signal lines, acoustic emission sensor 401, and electrode 402, effectively protecting the monitoring device. In this invention, the acoustic emission sensor 401 is spring-loaded within the acoustic emission sensor mounting hole 6, and the electrode 402 is mounted within the electrode mounting hole 5 via a rubber gasket 7. The rubber gasket 7 has a through hole that matches the outer diameter of the electrode 402. The rubber gasket 7 is fixed to the end face of the monitoring sensor mounting plate 102 using double-sided adhesive. The rubber gasket 7 serves to fix the electrode 402, providing insulation and noise reduction, ensuring close contact between the acoustic emission sensor 401 and the electrode 402 and the coal and rock sample, reducing signal attenuation, and improving monitoring accuracy. Furthermore, the monitoring sensor mounting plate 102 has an electrode wire mounting channel 8 and an acoustic emission signal line mounting channel 9. This integrated channel structure protects the acoustic emission sensor 401 and the electrode 402, preventing damage during loading. This enables comprehensive monitoring of the acoustic emission and resistivity changes of the coal and rock sample during true triaxial loading and unloading. (The monitoring process of the acoustic emission sensor 401 and the electrode 402, as well as the signal transmission with the monitoring system, are existing technologies and will not be elaborated upon here.)

[0018] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A combined resistivity-acoustic emission monitoring device for coal and rock samples suitable for true triaxial loading and unloading, characterized in that, include: The five fixed clamps (1) are provided, and the five fixed clamps (1) form a true triaxial clamp structure with an open top by means of locking assembly (2); A coal and rock sample (3) is placed between five of the fixing clamps (1); The monitoring sensor assembly (4) is integrated on the side of the fixed clamp (1) facing the coal and rock sample (3) and is in contact with the coal and rock sample (3).

2. The resistivity-acoustic emission combined monitoring device for coal and rock samples suitable for true triaxial loading and unloading as described in claim 1, characterized in that: The fixing fixture (1) includes a solid plate (101) and a monitoring sensor mounting plate (102). The solid plate (101) and the monitoring sensor mounting plate (102) are provided with connecting threaded holes (103) at their four corners, and connecting bolts (104) are provided in the connecting threaded holes (103).

3. The resistivity-acoustic emission combined monitoring device for coal and rock samples suitable for true triaxial loading and unloading as described in claim 2, characterized in that: The locking assembly (2) includes an L-shaped connecting piece (201) and a locking bolt (202); The adjacent solid plates (101) located at the same horizontal level are locked and fixedly connected by the L-shaped connecting piece (201) and the locking bolt (202).

4. The resistivity-acoustic emission combined monitoring device for coal and rock samples suitable for true triaxial loading and unloading as described in claim 3, characterized in that: The outer side of the solid plate (101) located at the same horizontal level is provided with a locking thread hole (203) that is compatible with the locking bolt (202).

5. A combined resistivity-acoustic emission monitoring device for coal and rock samples suitable for true triaxial loading and unloading, as described in claim 2, is characterized in that: The monitoring sensor assembly (4) includes an acoustic emission sensor (401) and an electrode (402). Each of the monitoring sensor mounting plates (102) has a rectangular array of electrode mounting holes (5) on the side facing the coal and rock sample (3), and each of the electrode mounting holes (5) has an electrode (402) that fits against the coal and rock sample (3). An acoustic emission sensor mounting hole (6) is provided in the middle of the side of the monitoring sensor mounting plate (102) at the bottom facing the coal and rock sample (3). An acoustic emission sensor mounting hole (6) is provided diagonally on the side of the monitoring sensor mounting plate (102) at the same horizontal height facing the coal and rock sample (3). The acoustic emission sensor (401) is installed in the acoustic emission sensor mounting hole (6) and is in contact with the coal and rock sample (3).

6. The resistivity-acoustic emission combined monitoring device for coal and rock samples suitable for true triaxial loading and unloading as described in claim 5, characterized in that: The acoustic emission sensor (401) is mounted in the acoustic emission sensor mounting hole (6) by means of a spring.

7. The resistivity-acoustic emission combined monitoring device for coal and rock samples suitable for true triaxial loading and unloading as described in claim 5, characterized in that: The electrode (402) is set in the electrode mounting hole (5) by a rubber gasket (7). The rubber gasket (7) has a through hole that matches the outer diameter of the electrode (402). The rubber gasket (7) is fixed to the end face of the monitoring sensor mounting plate (102) by double-sided adhesive.

8. A combined resistivity-acoustic emission monitoring device for coal and rock samples suitable for true triaxial loading and unloading, as described in claim 5, is characterized in that: An electrode wire mounting channel (8) is provided on the outer side of each monitoring sensor mounting plate (102) at the position corresponding to each column of electrode mounting holes (5). The electrode wire mounting channel (8) is used to install the electrode wires connecting the electrode (402) to the monitoring system. An acoustic emission signal line mounting channel (9) is provided on the outer side of each monitoring sensor mounting plate (102) at the position corresponding to each acoustic emission sensor mounting hole (6). The acoustic emission signal line mounting channel (9) is used to install the acoustic emission signal line connecting the acoustic emission sensor (401) to the monitoring system.

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