Multifunctional rock dynamic and static loading experiment device and experiment method

Abstract

The application discloses a multifunctional rock dynamic and static loading experiment device and an experiment method, and belongs to the technical field of rock mechanics experiments. The device comprises a lower bearing, a rock heating assembly, a static load applying assembly, a magnetic field generating assembly and an acoustic emission detector. The lower bearing is provided with a dynamic load applying assembly and a controller. The rock heating assembly is used for heating a rock test piece. A pressure head in the static load applying assembly is located directly above the dynamic load applying assembly. The magnetic field generating assembly is used for providing a magnetic field environment for the rock test piece. The acoustic emission detector is used for detecting and analyzing acoustic signals emitted by the rock test piece. The rock heating assembly is used for simulating the influence of the ground temperature of the stratum where the rock test piece is located on the rock test piece. The magnetic field generating assembly is used for providing a magnetic field environment for the rock test piece, so as to simulate the influence of the surrounding magnetic field of the stratum where the rock test piece is located on the rock test piece. The influences of temperature and magnetic field on the rock test piece are comprehensively considered, and the obtained experimental results are more reliable.

Description

TECHNICAL FIELD

[0001] The present application relates to a multifunctional rock dynamic and static loading experiment device and experiment method, and belongs to the technical field of rock mechanics experiment. BACKGROUND

[0002] Nowadays, with the continuous excavation of shallow mineral resources in China, the storage of shallow mineral resources becomes less and less, and mineral resources need to be excavated in the deep underground. However, the problems in the process of deep mineral resource development will become more and more complex. With the mining of deep mineral resources, while excavating the roadway in the deep underground, the temperature will also rise with the deepening of the excavation depth due to the influence of the ground temperature. In many cases, rock will break under the action of temperature stress caused by temperature change in addition to the breakage under the action of external load. Moreover, a certain amount of magnetic minerals are contained in most rocks, so natural rock has a certain magnetism, and these magnetic minerals in the rock will have a certain influence on the stress received by the rock. Therefore, understanding the rock bumping and pressure of rock under the action of high temperature and magnetic field has certain theoretical significance, and has certain experimental value for studying the excavation of roadway in coal mine site and the mining of coal mine.

[0003] The Chinese patent document with publication number CN113075049A discloses a variable frequency and variable intensity dynamic and static combined loading rock mechanics testing machine and test method, which comprises a top beam, a stand column, a dynamic load applying device, a static load applying device, a monitoring device, a base, a loading control system and a signal acquisition device. The top beam is connected to the base through the stand column. The static load applying device is arranged on the base. The dynamic load applying device is arranged on the top beam above the static load applying device. The static load applying device and the dynamic load applying device are both connected to the loading control system. The testing machine is also provided with the monitoring device, which is connected to the signal acquisition device. The structure is simple and reasonable, and the application of static load and dynamic load with different frequencies and intensities is realized, which provides a theoretical basis for the failure mechanism of coal rock under dynamic and static combined load.

[0004] However, under natural conditions, rock in the stratum will be affected by factors such as temperature and magnetic field. The testing machine and test method are used to study the stress of rock under ideal conditions, and the influence of temperature and magnetic field is not considered, which leads to the fact that the test results cannot effectively reflect the real deformation of the rock on site, that is, there is a large deviation between the test results and the actual situation on site. SUMMARY

[0005] To solve the above technical problems, the present application provides a multifunctional rock dynamic and static loading experiment device and experiment method.

[0006] The present application is realized by the following technical solutions:

[0007] Multifunctional rock dynamic and static loading experiment device, including lower carrier, rock heating assembly, static load applying assembly, magnetic field generating assembly and acoustic emission detector, the lower carrier is provided with dynamic load applying assembly and controller, the rock heating assembly is used for heating rock test piece, the indenter in the static load applying assembly is located directly above the dynamic load applying assembly, the magnetic field generating assembly is used for providing magnetic field environment for the rock test piece, and the acoustic emission detector is used for detecting and analyzing the acoustic signal emitted by the rock test piece.

[0008] The dynamic load applying assembly is an exciter, a convex is coaxially arranged on the exciter, and the exciter is electrically connected with the controller; a groove A is arranged on the lower carrier, the cross-sectional shape and size of the groove A are consistent with the cross-sectional shape and size of the lower part of the exciter, and the lower part of the exciter is inserted into the groove A; the bottom of the rock test piece is provided with a groove B with the same shape and size as the convex.

[0009] The static load applying assembly is a press, the indenter is installed on the actuator of the press, and the lower end of the indenter is provided with a pressure sensor, and the press and the pressure sensor are electrically connected with the controller.

[0010] The rock heating assembly comprises a heating element and a temperature detecting element, and the temperature detecting element and the heating element are electrically connected with the controller.

[0011] The heating element comprises two electric heaters or two electric heating sheets, the two electric heaters are symmetrically arranged with respect to the center of the dynamic load applying assembly and are installed on the lower carrier, and the two electric heating sheets are respectively installed at the top end and the bottom end of the rock test piece; the temperature detecting element is an industrial infrared thermometer.

[0012] The device further comprises a U-shaped baffle, a U-shaped groove is arranged on the lower carrier, the U-shaped baffle is partially inserted into the U-shaped groove, and a fixing bolt A is threadedly connected to the lower carrier at a position corresponding to the U-shaped baffle; a camera is installed on the U-shaped baffle.

[0013] The magnetic field generating assembly is a hoof-shaped magnet, and the projection of the dynamic load applying assembly on the lower carrier is located inside the projection of the hoof-shaped magnet on the lower carrier.

[0014] A U-shaped groove is arranged on the inner side wall of the U-shaped baffle along the length direction thereof, an iron sheet is arranged on the bottom surface of the U-shaped groove, and the hoof-shaped magnet is inserted into the U-shaped groove.

[0015] The magnetic field generating assembly comprises a coil, a resistance box and a power supply connected in series to form a loop, and the resistance box is electrically connected with the controller.

[0016] The acoustic emission detector comprises an acoustic emission sensor, a preamplifier, a data acquisition and processing system, and a recording, analyzing, and displaying system, the data acquisition and processing system is electrically connected with the acoustic emission sensor through the preamplifier, and the recording, analyzing, and displaying system is electrically connected with the data acquisition and processing system; the recording, analyzing, and displaying system comprises a computer and an acoustic emission software installed on the computer.

[0017] The experimental method of the multifunctional rock dynamic and static loading experimental device comprises the following steps:

[0018] A, selecting a rock to be tested, and processing a rock sample;

[0019] B, installing the rock sample on the dynamic load applying assembly, fixing the acoustic emission sensor on the side of the rock sample through adhesive tape, and applying coupling agent between the acoustic emission sensor and the rock sample;

[0020] C, connecting the camera with the computer in the recording, analyzing, and displaying system;

[0021] D, heating the rock sample through the rock heating assembly to simulate the influence of the formation temperature of the formation where the rock sample is located on the rock sample;

[0022] E, generating a magnetic field through the magnetic field generating assembly to simulate the influence of the surrounding magnetic field of the formation where the rock sample is located on the rock sample;

[0023] F, when the temperature of the rock sample rises to the target temperature, the static load applying assembly acts to apply a static load to the rock sample, and the dynamic load applying assembly acts to apply a dynamic load to the rock sample until the rock sample is destroyed;

[0024] G, stopping the collection of various data and arranging the experimental data.

[0025] The rock heating assembly is used for heating the rock sample to simulate the influence of the formation temperature of the formation where the rock sample is located on the rock sample, i.e., to simulate the influence of temperature stress on the rock sample; the magnetic field generating assembly is used for providing a magnetic field environment for the rock sample to simulate the influence of the surrounding magnetic field of the formation where the rock sample is located on the rock sample; then the static load applying assembly is used for applying a static load to the rock sample, and the dynamic load applying assembly is used for applying a dynamic load to the rock sample, so that the dynamic and static loading experiment on the rock sample can be started; since the influences of the formation temperature and the magnetic field of the formation where the rock sample is located on the rock sample are comprehensively considered, the experimental result is closer to the real situation and has higher reliability. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present application;

[0027] Figure 2Assembling structure schematic diagram of U-shaped baffle, camera and hoof-shaped magnet of the present application;

[0028] Figure 3 Assembling structure schematic diagram of U-shaped baffle and iron sheet of the present application;

[0029] Figure 4 Explosion view of U-shaped baffle, lower carrier and fixing bolt A of the present application;

[0030] Figure 5 Structure schematic diagram of U-shaped baffle before inserting into lower carrier of the present application;

[0031] Figure 6 Assembling structure schematic diagram of lower carrier, dynamic load applying assembly and rock test piece of the present application.

[0032] In the figure: 1-U-shaped baffle, 2-camera, 3-hoof-shaped magnet, 4-electric heater, 5-dynamic load applying assembly, 51-protrusion, 6-lower carrier, 60-U-shaped groove, 7-fixing bolt A, 8-indenter, 9-acoustic emission sensor, 10-rock test piece, 11-fixing bolt B, 12-front amplifier, 13-data acquisition and processing system, 14-recording, analyzing and displaying system, 15-temperature detecting piece, 16-wire, 17-iron sheet. DETAILED DESCRIPTION

[0033] The technical solutions of the present application are further described below, but the scope of protection is not limited to the description.

[0034] As Figures 1 to 6As shown, the multifunctional rock dynamic and static loading experiment device comprises a lower carrier 6, a rock heating assembly, a static load applying assembly, a magnetic field generating assembly and an acoustic emission detector, the lower carrier 6 is provided with a dynamic load applying assembly 5 and a controller (not shown in the figure), the rock heating assembly is used for heating a rock test piece 10, a pressure head 8 in the static load applying assembly is located directly above the dynamic load applying assembly 5, the magnetic field generating assembly is used for providing a magnetic field environment for the rock test piece 10, and the acoustic emission detector is used for detecting and analyzing acoustic signals emitted by the rock test piece 10.In use, the rock heating assembly is used for heating the rock test piece 10 to simulate the influence of the temperature of the formation where the rock test piece 10 is located on the rock test piece 10, that is, to simulate the influence of temperature stress on the rock test piece 10; the magnetic field generating assembly is used for providing a magnetic field environment for the rock test piece 10 to simulate the influence of the surrounding magnetic field of the formation where the rock test piece 10 is located on the rock test piece 10; then the static load applying assembly is used for applying a static load to the rock test piece 10, and the dynamic load applying assembly 5 is used for applying a dynamic load to the rock test piece 10, so that the dynamic and static loading experiment on the rock test piece 10 can be started, and since the influences of the temperature and the magnetic field of the formation where the rock test piece 10 is located on the rock test piece 10 are comprehensively considered, the obtained experimental result is closer to the actual situation and has higher reliability.

[0035] The dynamic load applying assembly 5 is a vibration exciter, a protrusion 51 is coaxially arranged on the vibration exciter, and the vibration exciter is electrically connected with the controller; the lower carrier 6 is processed with a groove A, the cross-sectional shape and size of the groove A are consistent with the cross-sectional shape and size of the lower part of the vibration exciter, and the lower part of the vibration exciter is inserted into the groove A; the bottom of the rock test piece 10 is processed with a groove B having a shape and size consistent with those of the protrusion 51.In use, the model of the vibration exciter is HEV-20, the vibration exciter is electrically connected with the controller, so as to facilitate the adjustment of the frequency and the exciting force of the vibration exciter.The radial and axial lower ends of the vibration exciter are limited by the groove A on the lower carrier 6; the axial lower end of the rock test piece 10 is limited by the vibration exciter, and the radial direction of the rock test piece 10 is limited by the protrusion 51 on the vibration exciter, so that the rock test piece 10 is convenient, fast and efficient to install.

[0036] The static load applying assembly is a press (not shown in the figure), the pressure head 8 is installed on the execution element of the press, and a pressure sensor is installed at the lower end of the pressure head 8, and the press and the pressure sensor are electrically connected with the controller.

[0037] The rock heating assembly comprises a heating piece and a temperature detection piece 15, and the temperature detection piece 15 and the heating piece are electrically connected with the controller.

[0038] The heating member comprises two electric heaters 4 or two electric heating sheets, the two electric heaters 4 are symmetrically arranged relative to the center of the dynamic load applying assembly 5 and are installed on the lower carrier 6, and the two electric heating sheets (not shown in the figure) are respectively installed on the top end and the bottom end of the rock sample 10; the temperature detecting member 15 is an industrial infrared temperature detector.

[0039] The device further comprises a U-shaped baffle 1, a U-shaped groove 60 is formed on the lower carrier 6, the U-shaped baffle 1 is partially inserted into the U-shaped groove 60, and the lower carrier 6 is threadedly connected with a fixing bolt A7 at a position corresponding to the U-shaped baffle 1; the U-shaped baffle 1 is installed with a camera 2. In use, the U-shaped baffle 1 plays a shielding and protecting role to avoid the flying stones from hurting the experimental personnel after the rock sample 10 is broken. After the lower end of the U-shaped baffle 1 is inserted into the U-shaped groove 60, the U-shaped baffle 1 is locked and fixed by the fixing bolt A7. The camera 2 is connected with the display screen of the computer, and the screen of the rock sample 10 can be displayed in real time during the experiment.

[0040] The magnetic field generating assembly is a hoof-shaped magnet 3, and the projection of the dynamic load applying assembly 5 on the lower carrier 6 is located on the inner side of the projection of the hoof-shaped magnet 3 on the lower carrier 6.

[0041] A U-shaped groove is formed on the inner side wall of the U-shaped baffle 1 along the length direction thereof, an iron sheet 17 is installed on the bottom surface of the U-shaped groove, and the hoof-shaped magnet 3 is inserted into the U-shaped groove. In use, the rock sample 10 is also located on the inner side of the hoof-shaped magnet 3. After the hoof-shaped magnet 3 is inserted into the U-shaped groove, the hoof-shaped magnet 3 is kept fixed by the mutual attraction with the iron sheet 17, and the hoof-shaped magnet 3 is convenient and fast to install. When the magnetic field strength needs to be changed, the hoof-shaped magnet 3 can be replaced.

[0042] The magnetic field generating assembly comprises a coil, a resistance box and a power supply connected in series to form a loop, and the resistance box is electrically connected with a controller. In use, the coil is placed on the dynamic load applying assembly 5 and is sleeved on the rock sample 10, and is used to provide a magnetic field for the rock sample 10. The resistance value in the loop can be changed through the resistance box, so as to adjust the current size, and further to adjust the size of the electromagnetic field. The resistance box is electrically connected with the controller, and the controller can calculate the size of the electromagnetic field in combination with the resistance value of the resistance connected in series into the loop in the resistance box.

[0043] The acoustic emission detector comprises an acoustic emission sensor 9, a preamplifier 12, a data acquisition and processing system 13 and a recording, analysis and display system 14, the data acquisition and processing system 13 is electrically connected with the acoustic emission sensor 9 through the preamplifier 12, and the recording, analysis and display system 14 is electrically connected with the data acquisition and processing system 13; the recording, analysis and display system 14 comprises a computer and acoustic emission software installed on the computer.

[0044] The experimental method of the multifunctional rock dynamic and static loading experimental device comprises the following steps:

[0045] A, select the rock to be measured, and process the rock to obtain a rock test piece 10;

[0046] B, install the rock test piece 10 on the dynamic load applying assembly 5, fix the acoustic emission sensor 9 to the side surface of the rock test piece 10 through the adhesive tape, and apply the coupling agent between the acoustic emission sensor 9 and the rock test piece 10;

[0047] C, connect the camera 2 with the computer in the recording, analysis and display system 14;

[0048] D, heat the rock test piece 10 through the rock heating assembly to simulate the influence of the formation temperature on the rock test piece 10;

[0049] E, generate a magnetic field through the magnetic field generating assembly to simulate the influence of the surrounding magnetic field of the formation on the rock test piece 10;

[0050] F, when the temperature of the rock test piece 10 rises to the target temperature, the static load applying assembly acts to apply a static load to the rock test piece 10, and the dynamic load applying assembly 5 acts to apply a dynamic load to the rock test piece 10 until the rock test piece 10 is destroyed;

[0051] G, stop collecting various data and organize the experimental data.

[0052] The multifunctional rock dynamic and static loading experimental device has the working principle as follows:

[0053] After the rock sample 10 is installed on the exciter, the rock sample 10 is heated by the two electric heaters 4 or the two electric heating sheets to simulate the influence of the ground temperature of the formation where the rock sample 10 is located on the rock sample 10, that is, to simulate the influence of the temperature stress on the rock sample 10; the rock sample 10 is provided with a magnetic field environment by the hoof-shaped magnet 3 or the energized coil to simulate the influence of the surrounding magnetic field of the formation where the rock sample 10 is located on the rock sample 10; then the static load is applied to the rock sample 10 by the press head 8 driven by the press, and the dynamic load is applied to the rock sample 10 by the exciter, so that the dynamic and static loading experiment on the rock sample 10 can be started.

[0054] During the experiment, the real-time picture of the rock sample 10 is taken by the camera 2 and transmitted to the display screen of the computer for display; the size of the static load is detected by the pressure sensor and transmitted to the controller; the temperature of the rock sample 10 is detected in real time by the industrial infrared temperature measuring instrument and transmitted to the controller. The acoustic signal emitted by the rock sample 10 is converted into an electric signal by the acoustic emission sensor 9 and then transmitted to the preamplifier 12, the preamplifier 12 amplifies the received electric signal and transmits it to the data acquisition and processing system 13, the data acquisition and processing system 13 converts the received electric signal into a digital signal and transmits it to the software in the computer for calculation and analysis, and then the required experimental parameters or results are displayed on the display screen, including amplitude, ringing count, duration, rise time, event, etc.

[0055] Since the influence of the temperature and magnetic field of the formation where the rock sample 10 is located on the rock sample 10 is comprehensively considered in the experiment, the obtained experimental results are closer to the actual situation and have higher reliability.

Claims

1. A multifunctional rock dynamic and static loading experimental device, characterized in that: The device comprises a lower carrier (6), a rock heating assembly, a static load applying assembly, a magnetic field generating assembly and an acoustic emission detector, the lower carrier (6) is provided with a dynamic load applying assembly (5) and a controller, the rock heating assembly is used for heating a rock test piece (10), a pressure head (8) in the static load applying assembly is located directly above the dynamic load applying assembly (5), the magnetic field generating assembly is used for providing a magnetic field environment for the rock test piece (10), and the acoustic emission detector is used for detecting and analyzing acoustic signals emitted by the rock test piece (10); The dynamic load applying assembly (5) is an exciter, a protrusion (51) is coaxially arranged on the exciter, and the exciter is electrically connected with the controller; the lower carrier (6) is provided with a groove A, the cross-sectional shape and size of the groove A are consistent with the cross-sectional shape and size of the lower part of the exciter, and the lower part of the exciter is inserted into the groove A; the bottom of the rock test piece (10) is provided with a groove B with a shape and size consistent with those of the protrusion (51); The magnetic field generating assembly is a hoof-shaped magnet (3), and the projection of the dynamic load applying assembly (5) on the lower carrier (6) is located on the inner side of the projection of the hoof-shaped magnet (3) on the lower carrier (6); A U-shaped groove is arranged on the inner side wall of the U-shaped baffle (1) along the length direction of the U-shaped baffle (1), an iron sheet (17) is arranged on the bottom surface of the U-shaped groove, and the hoof-shaped magnet (3) is inserted into the U-shaped groove; The magnetic field generating assembly comprises a coil, a resistance box and a power supply connected in series to form a loop, and the resistance box is electrically connected with the controller; The acoustic emission detector comprises an acoustic emission sensor (9), a preamplifier (12), a data acquisition and processing system (13) and a recording, analyzing and displaying system (14), the data acquisition and processing system (13) is electrically connected with the acoustic emission sensor (9) through the preamplifier (12), and the recording, analyzing and displaying system (14) is electrically connected with the data acquisition and processing system (13); the recording, analyzing and displaying system (14) comprises a computer and acoustic emission software installed on the computer. 2.The multifunctional rock dynamic and static loading experiment device of claim 1, wherein: The static load applying assembly is a press, the pressure head (8) is installed on an execution element of the press, and the lower end of the pressure head (8) is provided with a pressure sensor, and the press and the pressure sensor are electrically connected with the controller. 3.The multifunctional rock dynamic and static loading experiment device of claim 1, wherein: The rock heating assembly comprises a heating element and a temperature detection element (15), and the temperature detection element (15) and the heating element are electrically connected with the controller.

4. The multifunctional rock dynamic and static loading experiment device according to claim 3, characterized in that: The heating element comprises two electric heaters (4) or two electric heating sheets, the two electric heaters (4) are symmetrically arranged with respect to the center of the dynamic load applying assembly (5) and are installed on the lower carrier (6), and the two electric heating sheets are respectively installed on the top end and the bottom end of the rock test piece (10); the temperature detection element (15) is an industrial infrared temperature detector.

5. The multifunctional rock dynamic and static loading experiment device according to claim 1, characterized in that: The device further comprises a U-shaped baffle (1), the lower carrier (6) is provided with a U-shaped groove (60), the U-shaped baffle (1) is partially inserted into the U-shaped groove (60), and the lower carrier (6) is threadedly connected with a fixing bolt A (7) at a position corresponding to the U-shaped baffle (1); a camera (2) is installed on the U-shaped baffle (1).

6. The experimental method of the multifunctional rock dynamic and static loading experimental device according to any one of claims 1 to 5, characterized in that: The device comprises the following steps: A, selecting a rock to be tested to obtain a rock test piece (10); B, install the rock sample (10) to the dynamic load applying assembly (5), fix the acoustic emission sensor (9) to the side of the rock sample (10) through the adhesive tape, and apply the coupling agent between the acoustic emission sensor (9) and the rock sample (10); C, connect the camera (2) with the computer in the recording analysis display system (14); D, heat the rock sample (10) through the rock heating assembly, so as to simulate the influence of the formation temperature on the rock sample (10); E, generate the magnetic field through the magnetic field generating assembly, so as to simulate the influence of the surrounding magnetic field on the rock sample (10); F, when the temperature of the rock sample (10) rises to the target temperature, the static load applying assembly acts to apply the static load to the rock sample (10), and the dynamic load applying assembly (5) acts to apply the dynamic load to the rock sample (10) until the rock sample (10) is destroyed; G, stop collecting various data, and arrange the experimental data.

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