Point load experiment device for measuring rock deformation parameters

Abstract

The invention discloses a point load experiment device for measuring rock deformation parameters, which comprises a device frame, a loading device and a control monitoring system, and the loading device and the control monitoring system are both mounted on the device frame. The device frame is mainly composed of a sectional material, a T-shaped connecting plate, a right-angle connecting piece and a columnar connecting circle. The loading device is mainly composed of a point load upper pressure head, a point load lower pressure head, a receiving disc, a hydraulic jack, a first quick connector, a manual pump, a second quick connector, an unloading valve and a connecting pipe. The control monitoring system is composed of a pressure sensor, a laser distance measuring sensor, a bearing piece, a lead screw, a linear rail, a sliding block, a stable bearing piece, a motor connecting piece, a coupler, a motor, a power source and a control box. The traditional point load experiment is combined with mechanical transmission, hydraulic transmission, a sensor technology, an automatic control technology and the like, so that the determination of the rock point load strength, and the determination of rock deformation parameters and corresponding stress-strain curves under the action of the point load are realized.

Description

Technical Field

[0001] The invention relates to the technical field of rock mechanics experiments, in particular to a point load experiment device for measuring rock deformation parameters, which is specifically designed and applied to measure rock mechanics parameters in point load experiments, including point load strength and point load deformation parameters. Background Art

[0002] The strength and deformation parameters of rocks are the basic mechanical parameters for the development of various mineral resources and mining engineering construction. In the experiment of determining rock mechanical parameters, the point load test can be applied in the laboratory or engineering site because of the small applied load, simple operation and portable equipment. Therefore, the point load test is a more practical, simple, time-saving and economical method to obtain rock mechanical parameters, and it can be carried out on a large number of mining sites to make the test data more representative and reliable. However, the rock mechanical parameters obtained by the point load test are only the point load strength parameters. The rock deformation parameters during the point load application process are not measured and the corresponding stress-strain curves are not recorded. This does not give full play to the advantages of the point load test to a certain extent, which is not conducive to the scientific research of rock mechanical properties under point loads and the guidance of engineering practice, and hinders the further promotion and application of point load tests. Summary of the invention

[0003] The purpose of the present invention is to provide a point load test device for measuring rock deformation parameters to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A point load test device for measuring rock deformation parameters includes a device frame, a loading device and a control and monitoring system, wherein the loading device and the control and monitoring system are installed on the device frame. The device frame is mainly composed of profiles, T-type connecting plate right-angle connectors and columnar connecting circles. The loading device is mainly composed of a point load upper pressure head, a point load lower pressure head, a receiving plate, a hydraulic jack, a first quick connector, a manual pump, a second quick connector, a unloading valve and a connecting pipe. The control and monitoring system is composed of a pressure sensor, a laser ranging sensor, a bearing plate, a screw rod, a linear rail, a slider, a stable bearing plate, a motor connecting plate, a coupling, a motor, a power supply and a control box.

[0006] Preferably, the T-shaped connecting plate is fixedly mounted on the profile at the lower position, the right-angle connecting piece is mounted on the profile at the vertical and horizontal positions, and the columnar connecting circle is mounted on the bottom of the profile at the top position.

[0007] Preferably, the point load upper pressure head is installed at the bottom position of the columnar connecting circle, the hydraulic jack is installed on the profile at the bottom position, the point load lower pressure head is installed at the top position of the hydraulic jack, the receiving plate is also installed on the hydraulic jack, one end of the connecting pipe is docked and installed on the hydraulic jack through a first quick connector, one end of the manual pump is docked and installed on the other end of the connecting pipe through a second quick connector, and the unloading valve is installed on the manual pump.

[0008] Preferably, the pressure sensor is installed at the bottom position of the cylindrical connecting circle, and the pressure sensor is connected to the pressure head on the point load, the laser ranging sensor is installed on the profile at the bottom position, the bearing plate is installed at the bottom of the profile at the top position, the screw rod is inserted in the inner ring of the bearing plate, a linear rail is installed between the profiles at the upper and lower ends, a slider is mounted on the outer ring of the linear rail, a vertical plate is fixedly installed between the upper and lower profiles and at the side position of the linear rail, the stable bearing plate is mounted on the bottom of the outer ring of the screw rod, and the side of the stable bearing plate is fixed on the vertical plate, a motor connecting plate is fixedly installed at the bottom position of the side of the vertical plate, a motor is installed on the top of the profile at the bottom position, and the output shaft of the motor is docked with the screw rod through a coupling.

[0009] Preferably, the power supply is installed at the left side of the front face of the device frame through a fastener structure, and the control box is installed at the right side of the front face of the device frame through a fastener structure.

[0010] Preferably, a display screen is provided at the front of the control box, operation buttons are provided at the bottom of the front of the control box, and rock samples are placed in the inner cavity of the receiving tray.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. The point load test device for measuring rock deformation parameters combines the traditional point load test with mechanical transmission, hydraulic transmission, sensor technology, automatic control technology, etc., which not only realizes the determination of rock point load strength, but also realizes the determination of rock deformation parameters and corresponding stress-strain curves under point load.

[0013] 2. The point load test device for measuring rock deformation parameters measures the vertical and horizontal deformation of rock specimens through three high-frequency and high-precision laser displacement ranging sensors, and finally realizes the determination of rock point load strength, rock deformation parameters and corresponding stress-strain curves. In addition to the loading process, it realizes automatic control, standardizes the experiment, greatly reduces the influence of human factors on the experiment, and greatly improves and enhances the efficiency and accuracy of the experiment.

[0014] 3. One of the advantages of the point load test device for measuring rock deformation parameters is that the equipment is portable and can be tested on the construction site. However, the traditional point load device is integrated, which is inconvenient during long-distance transportation. The present experimental device realizes modularization of each part, which can be dismantled or assembled, making it easier to transport the parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the present invention;

[0016] Figure 2 A top view of the present invention;

[0017] Figure 3 This is a schematic diagram of the receiving tray structure of the present invention;

[0018] Figure 4 It is the upper and lower pressure heads of the point load of the present invention;

[0019] Figure 5 It is a schematic diagram of the initial state of the present invention;

[0020] Figure 6 This is a schematic diagram of the pre-pressing state of the present invention;

[0021] Figure 7 It is a schematic diagram of the recording state of the present invention.

[0022] In the figure: profile 1, T-type connecting plate 2, right-angle connector 3, cylindrical frustum 4, point load upper pressure head 5, point load lower pressure head 6, receiving plate 7, hydraulic jack 8, first quick connector 9, manual pump 10, second quick connector 11, unloading valve 12, connecting pipe 13, pressure sensor 14, laser ranging sensor 15, bearing plate 16, screw rod 17, linear rail 18, slider 19, stable bearing plate 20, motor connecting plate 21, coupling 22, motor 23, power supply 24, control box 25, display screen 26, operation button 27, rock sample 28. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example: See Figure 1 The present invention provides a technical solution: a point load test device for measuring rock deformation parameters.

[0025] The point load test device mainly consists of three parts: device frame, loading device and control and monitoring system;

[0026] The device frame is the main frame, and all mechanical parts are fixed on the device frame;

[0027] The loading device is the pressure source of the experimental device, which can be used to apply point load to the rock specimen;

[0028] The control and monitoring system realizes automatic real-time monitoring of pressure and deformation parameters, as well as data processing and analysis by connecting the device frame and the loading device.

[0029] The device frame is mainly composed of profile 1, T-shaped connecting plate 2, right-angle connecting piece 3 and columnar connecting circle 4. Figure 1 As shown, the T-shaped connecting plate 2 is fixed on the profile 1 at the lower position, the right-angle connecting piece 3 is installed on the profile 1 at the vertical and bottom horizontal positions, and the columnar connecting circle 4 is installed at the bottom of the profile 1 at the top position. Specifically, the profiles 1 of different lengths are connected and fixed by the right-angle connecting piece 3 and the T-shaped connecting plate 2, and the columnar connecting circle 4 is connected to the profile 1 by screws.

[0030] The loading device applies a point load to the rock specimen. The loading device mainly consists of a point load upper pressure head 5, a point load lower pressure head 6, a receiving plate 7, a hydraulic jack 8, a first quick connector 9, a manual pump 10, a second quick connector 11, a relief valve 12 and a connecting pipe 13. Figure 1 As shown, the point load lower pressure head 6, the receiving tray 7 and the hydraulic jack 8, the point load upper pressure head 5 is connected to the pressure sensor, the hydraulic jack 8 is connected to the profile 1 on the device frame and is located at the bottom, the receiving tray 7 is used to receive the debris after the rock is crushed, the hydraulic jack 8 and the manual pump 10 are both provided with quick connectors, and the pipe 13 is connected to the quick connector to connect the hydraulic jack 8 and the manual pump 10 together.

[0031] The control and monitoring system controls each part, and is composed of a pressure sensor 14, a laser distance sensor 15, a bearing sheet 16, a screw rod 17, a linear rail 18, a slider 19, a stable bearing sheet 20, a motor connecting sheet 21, a coupling 22, a motor 23, a power supply 24 and a control box 25. The lower part of the pressure sensor 14 is connected to the point load upper pressure head 5, and the upper part of the pressure sensor 14 is connected to the columnar connecting truncated table 4. The pressure sensor 14 is used to monitor the applied point load value.

[0032] The linear rail 18 is connected and fixed to the device frame, the upper part of the linear rail 18 is connected to the bearing plate 16 , and the lower part of the linear rail 18 is connected to the motor connecting plate 21 .

[0033] The screw rod 17 is connected with the bearing sheet 16 and the stable bearing sheet 20. The slider 19 connects the screw rod 17 and the linear rail 18 together.

[0034] The lower part of the motor 23 is connected and fixed to the device frame, the upper part of the motor 23 is connected to the motor connecting piece 21, and the coupling 22 connects the screw rod 17 to the motor 23.

[0035] There are three laser distance measuring sensors 15, which are fixed at the lower part of the device frame to monitor the position of the receiving plate 7, so as to determine the deformation of the rock specimen in the vertical direction under the point load. The laser distance measuring sensors 15 are respectively connected to the sliders on the left and right sides to monitor the deformation of the rock specimen in the horizontal direction (or vertical loading direction) under the point load.

[0036] The power supply 24 is fixed on the device frame to provide power for the entire experimental device.

[0037] The control box 25 is fixed on the device frame. The surface of the control box 25 is provided with a display screen 26 and an operation button 27. The programmable controller and the motor driver are fixed inside the control box 25. The display screen 26 is used to display the applied load value, stress-strain curve, point load intensity parameter and deformation parameter (in vertical and horizontal directions) in real time. The pressure sensor 14 monitors the applied point load value and inputs the analog value into the programmable controller inside the control box 25. The laser ranging sensor 15 monitors the deformation value of the rock and inputs the analog value into the programmable controller inside the control box 25.

[0038] The specific measurement principle is:

[0039] The initial state is Figure 5 As shown, the preload state is Figure 6 As shown, the loading status is as follows Figure 7 As shown. In the initial state (returning to the initial state after each experiment), the distance between the two laser distance sensors 15 in the horizontal direction is w1, the height from the point load upper pressure head 5 to the upper part of the device frame is h1, the height from the lower laser distance sensor 15 to the receiving plate 7 is h2, the height between the point load upper pressure head 5 and the point load lower pressure head 6 is h3, and the height from the two laser distance sensors 15 measuring points in the horizontal direction to the upper part of the device frame is h4.

[0040] In the pre-stressing state (tightening the rock specimen), the height from the lower laser distance sensor 15 to the receiving plate 7 is h6, and the size of the specimen in the vertical direction is h=h3-(h6-h2), and the two laser distance sensors 15 in the horizontal direction are lowered by a distance h5 (aimed at the middle of the specimen in the vertical direction), h5=h1+0.5[h3-(h6-h2)]-h4, and at this time, the left and right laser distance sensors 15 in the horizontal direction can measure the distances from the surface of the rock specimen to be w2 and w3 respectively, and the size of the rock specimen in the horizontal direction is w=w1-w2-w3. h5 can be controlled by controlling the running time t of the motor 23. If the lead of the screw rod is p and the speed of the motor 23 is n, t=h5 / pn is calculated according to h5=pnt.

[0041] Under the loading state (if the applied point load is Pi), the distance from the lower laser distance sensor 15 to the receiving plate becomes hi6'. At this time, the distances from the left and right laser distance sensors 15 to the surface of the rock specimen in the horizontal direction can be measured as wi2' and wi3' respectively. Then the deformation of the rock specimen in the vertical direction is Δhi=hi6'-h6, and the strain is εi z =Δhi / h. The deformation of the rock specimen in the horizontal direction is Δwi=w2-wi2'+w3-wi3', and the strain is εi x =Δwi / w. This experimental device is for standard cylindrical specimens, and the applied load can be converted into applied stress. The calculation formula is:

[0042]

[0043] Record and plot the load stress σi and strain εi at different points z The relationship curve between the two can be used to obtain the stress-strain curve of the rock under the point load. If the rock is damaged, that is, the applied point load is Pimax, then the corresponding σimax is the point load strength Is(50) = σimax. At the same time, it can be found that when the applied point load is 50% Pimax (50% of the maximum applied load), the point load stress is 50% σimax, and the strain in the vertical direction is ε z50 , the horizontal strain is ε x50 , then the deformation modulus of rock under point load (the ratio of stress to strain when half of the maximum applied load) is E = 50% σimax / ε z50 , Poisson's ratio of rock under point load (ratio of strain in horizontal direction to strain in vertical direction when half of the maximum applied load) μ = ε x50 / ε z50 .

[0044] The test steps of the point load device for measuring rock deformation parameters are as follows:

[0045] ①Assemble and connect the various parts of the device.

[0046] ② Turn on the experiment start / end button, the entire experimental device starts, the initial state is as follows Figure 5 shown.

[0047] ③Install the rock specimen and operate the manual pump to complete the preloading of the rock specimen (generally, the load applied to the rock specimen is 0 to 0.5KN to complete the preloading).

[0048] ④ Turn on the experiment button, the control monitoring system first controls the rotation time t of the motor 23 to make the two laser distance sensors 15 in the horizontal direction drop by a distance h5, then the display screen displays "Formal Experiment", and then operates the manual pump to load the specimen according to the experimental requirements until the rock specimen is destroyed. During the loading process, the screen will display in real time the applied point load Pi and stress σi, the deformation Δhi and strain εi of the rock specimen in the vertical direction z , the deformation Δwi and strain εi of the rock specimen in the horizontal direction x , and record and draw the load stress σi and strain εi at different points in real time z After the rock specimen is destroyed, the maximum applied load Pimax, point load strength Is(50)=σimax, rock deformation modulus E under point load, and rock Poisson's ratio μ under point load will be displayed.

[0049] ⑤ Turn on the next set of experimental buttons, the device will return to the initial state. Figure 5 As shown, the previous set of experimental data will be saved (the data can be exported), and then the unloading valve will be opened to restore the hydraulic jack to its initial state.

[0050] ⑥ After cleaning the experimental device, you can proceed to the next set of experiments. If you turn on the experiment start / end button again, the entire device will be shut down. If you do not want to conduct experiments anymore, you can also disassemble the device to facilitate long-distance transportation.

[0051] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A point load test device for measuring rock deformation parameters, comprising a device frame, a loading device and a control and monitoring system, characterized in that: The loading device and the control and monitoring system are both installed on a device frame. The device frame is mainly composed of a profile (1), a T-shaped connecting plate (2), a right-angle connecting piece (3) and a columnar connecting circle. The loading device is mainly composed of a point load upper pressure head (5), a point load lower pressure head (6), a receiving plate (7), a hydraulic jack (8), a first quick connector (9), a manual pump (10), a second quick connector (11), a unloading valve (12) and a connecting pipe (13). The control and monitoring system is composed of a pressure sensor (14), a laser distance sensor (15), a bearing plate (16), a screw rod (17), a linear rail (18), a slider (19), a stable bearing plate (20), a motor connecting plate (21), a coupling (22), a motor (23), a power supply (24) and a control box (25).

2. A point load test device for measuring rock deformation parameters according to claim 1, characterized in that: The T-shaped connecting plate (2) is fixedly mounted on the profile (1) at the lower position, the right-angle connecting piece (3) is mounted on the profile (1) at the vertical and horizontal positions, the columnar connecting circle (4) is mounted on the bottom of the profile (1) at the top position, the point load pressure head (6) is mounted on the top position of the hydraulic jack (8), and the receiving plate (7) is also mounted on the hydraulic jack (8).

3. A point load test device for measuring rock deformation parameters according to claim 1, characterized in that: The point load upper pressure head (5) is installed at the bottom position of the columnar connecting circle (4), the hydraulic jack (8) is installed on the profile (1) at the bottom position, one end of the connecting pipe (13) is connected to the hydraulic jack through a first quick connector (9), one end of the manual pump (10) is connected to the other end of the connecting pipe (13) through a second quick connector (11), and the unloading valve (12) is installed on the manual pump (10).

4. A point load test device for measuring rock deformation parameters according to claim 1, characterized in that: The pressure sensor (14) is installed at the bottom position of the columnar connecting circle (4), and the pressure sensor (14) is connected to the pressure head (5) on the point load, the laser distance sensor (15) is installed on the profile (1) at the bottom position, and the bearing plate (16) is installed at the bottom of the profile (1) at the top position.

5. The point load test device for measuring rock deformation parameters according to claim 1, characterized in that: The power supply (24) is installed at the left side of the front of the device frame through a fastener structure, and the control box (25) is installed at the right side of the front of the device frame through a fastener structure.

6. A point load test device for measuring rock deformation parameters according to claim 1, characterized in that: A display screen (26) is arranged at the front of the control box (25), an operation button (27) is arranged at the bottom of the front of the control box (25), and a rock sample (28) is placed in the inner cavity of the receiving tray (7).

7. The point load test device for measuring rock deformation parameters according to claim 1, characterized in that: The screw rod (17) is inserted into the inner ring of the bearing plate (16), and a linear rail (18) is installed between the profiles (1) at the upper and lower ends.

8. The point load test device for measuring rock deformation parameters according to claim 1, characterized in that: The stabilizing bearing sheet (20) is sleeved on the bottom of the outer ring of the screw rod (17), and the side of the stabilizing bearing sheet (20) is fixed on the vertical plate, a motor connecting sheet (21) is fixedly installed at the bottom position of the side of the vertical plate, a motor (23) is installed on the top of the profile (1) at the bottom position, and the output shaft of the motor (23) is docked and installed with the screw rod (17) through a coupling (22).

9. A point load test device for measuring rock deformation parameters according to claim 7, characterized in that: A slider (19) is mounted on the outer ring of the linear rail (18), and a vertical plate is fixedly installed between the upper and lower profiles (1) and at the side of the linear rail (18).

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