Large-size artificial false bottom bearing test device under mining influence

Abstract

The utility model relates to the field of mining, in particular to a large-size artificial false bottom bearing test device under mining influence, which comprises a downward pressurizing assembly, a mold assembly and an upward pressurizing assembly which are sequentially arranged from top to bottom, the mold assembly comprises a monitoring type limiting plate, a functional type limiting plate and bearing horizontal plates which are of a rectangular frame structure and are arranged in a stacked mode, a slurry filling space is formed in the middle of the mold assembly, and the bearing horizontal plates arranged adjacently form a bottom plate of the slurry filling space. And the upward pressurizing assembly is used for controlling the displacement of the bearing horizontal plate. According to the scheme, indoor large-scale simulation research on the stability of the artificial false bottom under the influence of layered mining of a downward stope is realized by adopting an upward pressurizing device, the device adopts a modular layered structure, is simple to assemble and easy to operate, and performs multi-dimensional comprehensive detection on the artificial false bottom through multiple monitoring means; the method is of great significance to guidance of on-site actual safe and efficient production.

Description

Technical Field

[0001] The utility model relates to the field of mining, in particular to a large-scale artificial false bottom bearing test device under the influence of mining. Background Art

[0002] With the development of mining engineering technology, backfill mining has been widely used in underground mines and occupies a key position in my country's nonferrous metal and gold underground mining. Downward layered backfilling has been widely used as an important mining method to control confining pressure deformation and ground pressure manifestation, and to improve resource recovery rates. In a fractured ore body, the artificial false bottom formed by the backfill provides stable support for the mining of the lower layer, effectively improving the stress environment of the surrounding rock and reducing the risk of mining disasters such as roof falls and spalling. It is a key factor influencing the safe and efficient mining of complex ore bodies. Analyzing and studying the load-bearing capacity and deformation and failure patterns of the artificial false bottom is an important reference for guiding mine safety production.

[0003] For many years, both domestic and international researchers have analyzed the stability of artificial false bottoms through long-term on-site monitoring. However, due to the complex and variable mechanical behavior of fill in mining projects, on-site monitoring lags behind project progress. Furthermore, monitoring methods are relatively limited, assessing only local parameters and lacking a comprehensive analysis of the overall mechanical behavior of the artificial false bottom. While indoor simulation tests offer advantages such as multivariable and repeatable performance, existing traditional equipment is still inadequate in simulating and testing the bearing capacity of artificial false bottoms under mining conditions. Some instruments primarily use small models with similar scale conversions for simulation dimensions, which are subject to significant size effects compared to actual on-site projects, and their foresight and comprehensiveness in construction guidance remain insufficient. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, the utility model provides a large-scale artificial false bottom bearing test device under the influence of mining, which can effectively simulate the downward layered excavation process while reducing the influence of the simulated specimen size effect, detect the stress distribution and deformation damage of the artificial false bottom under static load conditions, record the monitoring data in real time, facilitate the multi-dimensional comprehensive analysis of failure nodes, construct a physical and mechanical model of the artificial false bottom under the influence of mining, and guide mine safety production.

[0005] To achieve the above object, a large-size artificial false bottom bearing test device under mining influence disclosed by the utility model includes a test mechanism. The test mechanism includes a downward pressure applying component, a mold component, and an upward pressure applying component sequentially arranged from top to bottom. The mold component includes a monitoring type limiting plate and a functional type limiting plate with a rectangular frame structure, and further includes a supporting horizontal plate. The monitoring type limiting plate and the functional type limiting plate are stacked, and a slurry filling space is formed in the middle. The functional type limiting plate is arranged in the middle layer, and the monitoring type limiting plate is arranged in the uppermost layer and the lowermost layer, or the monitoring type limiting plate is arranged in the uppermost layer, the lowermost layer, and the middle layer. Several adjacent arranged supporting horizontal plates form the lower bottom plate of the slurry filling space. The downward pressure applying component is used to apply a downward pressure to the mortar filling body, and the upward pressure applying component is used to control the displacement of the supporting horizontal plate.

[0006] Further, it further includes a data acquisition and control system.

[0007] Further, it further includes a support mechanism arranged outside the test mechanism. The support mechanism includes an upper reaction force plate and a bottom plate arranged in parallel, and further includes several support columns arranged between the upper reaction force plate and the bottom plate. The downward pressure applying component is fixedly installed on the upper reaction force plate, and the upward pressure applying component is fixedly installed on the bottom plate.

[0008] Further, the downward pressure applying component includes a downward pressure applying cylinder and a pressure plate arranged at the telescopic end of the downward pressure applying cylinder. The pressure plate applies a downward pressure to the mortar filling body under the drive of the downward pressure applying cylinder.

[0009] Further, the upward pressure applying component is an upward pressure applying cylinder. The number of the upward pressure applying cylinders is the same as that of the supporting horizontal plates, and the positions correspond one by one. The telescopic end of the upward pressure applying cylinder can control the lifting of the supporting horizontal plate.

[0010] Further, the mold component further includes a limiting plate positioning column. Installation holes for the limiting plate positioning column to pass through are opened at the corners of the monitoring type limiting plate and the functional type limiting plate. The limiting plate positioning column is a stud, and the installation and fixation of the monitoring type limiting plate and the functional type limiting plate are realized through positioning nuts.

[0011] Further, several acoustic emission positioning holes facing the slurry filling space are opened on the monitoring type limiting plate. The acoustic emission positioning holes are used for installing acoustic emission probes.

[0012] Further, several steel bar positioning holes facing the slurry filling space are opened on the functional type limiting plate. The steel bar positioning holes are used for passing steel bars to form a steel bar mesh in the slurry filling space. Several fiber Bragg grating sensors are distributed on the horizontal and longitudinal bars of the steel bar mesh.

[0013] Further, it also includes an earth pressure cell stress monitoring device, which is laid in the filling slurry in a layered and regular manner during the mortar filling process.

[0014] Further, the support column is a stud, and the upper reaction plate is limited by a fastening nut.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] The large-size artificial false bottom bearing test device under mining influence proposed by the present utility model realizes the indoor large-scale simulation research on the stability of the artificial false bottom under the influence of downward stope sublevel mining by using the upward pressure device. The device adopts a modular layered structure, is simple to assemble, easy to operate, adapts to various artificial false bottom laying and sublevel mining modes, and conducts multi-dimensional comprehensive detection of the artificial false bottom through various monitoring means, which is of great significance for guiding the actual safe and efficient production on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a three-dimensional schematic diagram of the overall structure of the test device of the present utility model;

[0018] Figure 2 is the front view of the test device of the present utility model;

[0019] Figure 3 is a schematic diagram of the structure of the mold assembly of the present utility model;

[0020] Figure 4 is a schematic diagram of the structure of the mold assembly with a steel mesh of the present utility model.

[0021] In the figure, 1. upper reaction plate; 2. downward pressure cylinder; 3. pressure plate; 4. monitoring type limiting plate; 401. acoustic emission positioning hole; 5. functional type limiting plate; 501. steel bar positioning hole; 6. supporting horizontal plate; 7. upward pressure cylinder; 8. bottom plate; 9. support column; 10. limiting plate positioning column; 11. positioning nut; 12. fastening nut; 13. data acquisition and control system; 14. steel bar; 15. steel mesh; 16. earth pressure cell stress monitoring device; 17. fiber Bragg grating sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following describes the principles and features of the present utility model in conjunction with the attached Figure 1 to the attached Figure 4 The principles and features of the present utility model are described, and the examples given are only used to explain the present utility model and are not intended to limit the scope of the present utility model.

[0023] Large-size artificial false bottom bearing test device under mining influence, including a support mechanism, a test mechanism, and a data acquisition and control system 13. The support mechanism is the outer frame structure of the test mechanism, playing the role of overall support. The test mechanism is located in the internal space of the support mechanism. The data acquisition and control system 13 is used for the overall automatic control of the system and the acquisition, processing, and analysis of data. Specifically, the data acquisition and control system 13 is used to collect acoustic emission signals, earth pressure cell stress signals, and fiber Bragg grating sensor stress and strain signals.

[0024] The support mechanism includes an upper reaction plate 1 and a bottom plate 8 arranged in parallel, and also includes a number of support columns 9 arranged between the upper reaction plate 1 and the bottom plate 8. The downward pressure application assembly is fixedly installed on the upper reaction plate 1, and the upward pressure application assembly is fixedly installed on the bottom plate 8. The support column 9 is a stud, and its upper end is limited by a fastening nut 12 to the upper reaction plate 1, and its lower end is installed at the preset positioning point on the bottom plate 8. Specifically, the lower end of the support column 9 is screwed and installed with the screwed hole preset on the bottom plate 8.

[0025] The test mechanism includes a downward pressure application assembly, a mold assembly, an upward pressure application assembly, and a limit plate positioning assembly arranged in sequence from top to bottom. The mold assembly is used to fill the test slurry to form a filling body, which can also be called an artificial prosthesis. The downward pressure application assembly is used to apply downward pressure to the mortar filling body. The upward pressure application assembly plays a role in supporting the mortar filling body. The limit plate positioning assembly is used for the support and positioning of the mold assembly.

[0026] The mold assembly includes a monitoring type limit plate 4 and a functional type limit plate 5 with a rectangular frame structure, and also includes a supporting horizontal plate 6. The monitoring type limit plate 4 and the functional type limit plate 5 are stacked, and a slurry filling space is formed in the middle. A number of adjacent supporting horizontal plates 6 can slide inside the slurry filling space to form the lower bottom plate of the slurry filling space. The monitoring type limit plate 4 and the functional type limit plate 5 can both be stacked in several layers. In one embodiment, the functional type limit plate 5 is arranged in the middle layer, and the monitoring type limit plate 4 is arranged in the topmost layer and the bottommost layer, or the monitoring type limit plate 4 is arranged in the topmost layer, the bottommost layer, and the middle layer. In one embodiment, six supporting horizontal plates 6 are provided, and they are arranged in three rows and two columns adjacent to each other at the bottom of the slurry filling space.

[0027] A number of acoustic emission positioning holes 401 facing the slurry filling space are opened on the monitoring type limit plate 4. The acoustic emission positioning holes 401 are used to install acoustic emission probes. The acoustic emission probes are electrically connected to the data acquisition and control system 13 through data wires, and are used to monitor parameters such as the position, ringdown count, and intensity of the acoustic emission signals of the filling body, and to locate and identify the model rupture points. During the test, the acoustic emission probes smeared with vaseline are placed into the acoustic emission positioning holes 401 and adhered tightly to the filling body.

[0028] On the functional limiting plate 5, a number of steel bar positioning holes 501 facing the slurry filling space are provided. The steel bar positioning holes 501 are used to pass through steel bars 14 to form a steel bar mesh 15 in the slurry filling space. A number of fiber Bragg grating sensors 17 are distributed on the horizontal and vertical longitudinal bars of the steel bar mesh 15. The fiber Bragg grating sensors 17 are electrically connected to the data acquisition and control system 13 through data wires, and are used to collect the stress and strain data generated by the force deformation of the steel bar mesh 15 during the test of the filling body. During the test, the fiber Bragg grating sensors 17 are pasted onto the steel bar mesh 15 in advance. During the mortar filling process, a number of earth pressure cell stress monitoring devices 16 can also be regularly laid in layers in the filling slurry. The earth pressure cell stress monitoring device 16 is an earth pressure cell probe, and the earth pressure cell probe is electrically connected to the data acquisition and control system 13 through a data wire, and is used to monitor the vertical stress change of each point of the filling body during the test. The fiber Bragg grating sensors 17 are connected to the steel bar mesh 15 in a uniformly arranged manner, and the earth pressure cell stress monitoring devices 16 are also uniformly arranged in the filling body. In addition, according to the needs of detection, the fiber Bragg grating sensors 17 and the earth pressure cell stress monitoring devices 16 can be arranged in other regular arrangements.

[0029] The modularly layered monitoring limiting plate 4 and the functional limiting plate 5 are devices for restricting the horizontal displacement of the filling body. They are flexible to install and disassemble, and their quantity can also be set according to needs, improving the flexibility of the test. Such a design not only plays a positioning role for the filling of test materials, but also simulates the laying forms of different steel bar densities through the preset steel bar positioning holes 501 and acoustic emission positioning holes 401, and can also measure artificial false bottoms with different layered combinations according to needs.

[0030] The limiting plate positioning assembly includes a limiting plate positioning column 10 and a positioning nut 11. Installation holes are provided at the four corners of the monitoring limiting plate 4 and the functional limiting plate 5 for the limiting plate positioning column 10 to pass through. The limiting plate positioning column 10 is a stud, and the lower end is installed at the preset positioning points on the bottom plate 8. Specifically, the lower end of the limiting plate positioning column 10 is screwed and installed with the screwed holes preset on the bottom plate 8, and the upper end is installed and fixed to the monitoring limiting plate 4 and the functional limiting plate 5 through the positioning nut 11 and the height is adjusted to maintain accurate positioning between the mold assembly and the downward pressing device, so as to ensure the positioning and structural stability of the mold assembly when it is necessary to change the number of limiting plate layers or add different limiting plate modules.

[0031] The downward pressing assembly includes a downward pressing cylinder 2 and a pressure plate 3 arranged at the telescopic end of the downward pressing cylinder 2. The downward pressing cylinder 2 can be a hydraulic cylinder, and the pressure plate 3 applies a downward pressure to the mortar filling body under the drive of the downward pressing cylinder 2. The downward pressing cylinder 2 is fixedly installed on the lower end surface of the upper reaction plate 1. Through the adjustment of the height of the mold assembly by the limiting plate positioning assembly, it is ensured that the pressure plate 3 is in close contact with the filling body.

[0032] The upward pressure component is an upward pressure cylinder 7, which can be a hydraulic cylinder. The number of upward pressure cylinders 7 is the same as the number of supporting plates 6, and their positions correspond one to one. The telescopic ends of the upward pressure cylinders 7 control the raising and lowering of the supporting plates 6. By coordinating the supporting plates 6 with the upward pressure cylinders 7, during testing, the upward pressure cylinders 7 control the downward displacement of different supporting plates 6, ending their support function at corresponding positions in the backfill, fully simulating the mining environment of the next layer and ensuring the credibility of the test results.

[0033] The downward pressurizing assembly and the upward pressurizing assembly group are both connected to the servo hydraulic system to control the loading and unloading process, and are equipped with pressure sensors connected to the data acquisition and control system 13.

[0034] When the test device of the utility model is installed:

[0035] First, place the bottom plate 8 at the bottom and assemble the support columns 9 at the four preset points at the corners of the bottom plate 8. After screwing the fastening nuts 12 into the upper parts of the four support columns 9 to horizontally position them, insert the upper reaction plate 1 and screw the fastening nuts 12 into the upper part of the upper reaction plate 1 to ensure that it does not slide when subjected to force.

[0036] Then, assemble the limit plate positioning column 10 and the upward pressure cylinder 7 to the preset position on the upper surface of the base plate 8, and screw the positioning nut 11 into the horizontal position on the limit plate positioning column 10, assemble the supporting horizontal plate 6 to the telescopic end of the upward pressure cylinder 7, and set the monitoring limit plate 4 and the functional limit plate 5 on the limit plate positioning column 10 as needed, and adjust the position;

[0037] Finally, the downward pressure cylinder 2 is assembled and fixed to a preset position on the lower surface of the upper reaction plate 1 , and the pressure plate 3 is positioned and assembled to the telescopic end of the downward pressure cylinder 2 .

[0038] The test process of the test device of the utility model is as follows:

[0039] S1, assemble the entire test device. When assembling the mold assembly, ensure that the uppermost and lowermost layers of the layered structure are both monitoring limit plates 4;

[0040] S2, control the upward pressure cylinder 7 to make the supporting horizontal plate 6 and the lowest monitoring limit plate 4 level;

[0041] S3, passing the steel bars 14 through the steel bar positioning holes 501 according to the designed distribution position, and weaving the steel mesh 15 in the fixed layer;

[0042] S4, regularly distribute the fiber Bragg grating sensors 17 on the horizontal and vertical bars of the steel mesh 15, and extend the data wires along the vacant steel bar positioning holes 501 and connect to the data acquisition and control system 13;

[0043] S5. Cover the outer surfaces of the monitoring limit plate 4, the functional limit plate 5, and the supporting horizontal plate 6 with a soft film to prevent the filling slurry from leaking.

[0044] S6. Pour the prepared filling slurry into the slurry filling space. During the pouring process, lay the earth pressure cell stress monitoring device 16 in the filling slurry in a layered pattern, and extend the data wire out along the empty steel bar positioning hole 501 and connect it to the data acquisition and control system 13.

[0045] S7. After curing, tear off the soft film, fix the acoustic emission probe to the periphery of the filling body through the acoustic emission positioning hole 401, and connect the data wire to the data acquisition and control system 13.

[0046] S8. Press the pressure plate 3 against the filling body by controlling the downward pressure cylinder 2 according to the design.

[0047] S9. After the monitoring parameters are stable, control the upward pressure cylinder 7 to move downward through the data acquisition and control system 13, and then complete the movement of different supporting horizontal plates 6 to simulate the mining dynamics behavior of the artificial false bottom under different drift widths in the next layer.

[0048] S10. Collect the test data through the data acquisition and control system 13, and conduct processing and analysis to complete the comprehensive monitoring of the mechanical behavior of the large-size artificial false bottom under mining influence.

[0049] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Large-size artificial false bottom bearing test device under mining influence, including a test mechanism, the test mechanism includes a downward pressure component, a mold component and an upward pressure component arranged in sequence from top to bottom, and is characterized in that, The mold assembly includes a monitoring type limit plate (4) and a functional type limit plate (5) with a rectangular frame structure, and also includes a supporting horizontal plate (6). The monitoring type limit plate (4) and the functional type limit plate (5) are stacked, and a slurry filling space is formed in the middle. The functional type limit plate (5) is arranged in the middle layer, and the monitoring type limit plate (4) is arranged in the uppermost layer and the lowermost layer, or the monitoring type limit plate (4) is arranged in the uppermost layer, the lowermost layer and the middle layer. A plurality of adjacent arranged supporting horizontal plates (6) constitute the lower bottom plate of the slurry filling space. The downward pressing assembly is used to apply a downward pressure to the mortar filling body, and the upward pressing assembly is used to control the displacement of the supporting horizontal plate (6).

2. The large-size artificial false bottom bearing test device under mining influence according to claim 1, characterized in that, It also includes a data acquisition and control system (13).

3. The large-size artificial false bottom bearing test device under mining influence according to claim 1, wherein It also includes a support mechanism arranged outside the test mechanism. The support mechanism includes an upper reaction force plate (1) and a bottom plate (8) arranged in parallel, and also includes a plurality of support columns (9) arranged between the upper reaction force plate (1) and the bottom plate (8). The downward pressing assembly is fixedly installed on the upper reaction force plate (1), and the upward pressing assembly is fixedly installed on the bottom plate (8).

4. The large-size artificial false bottom bearing test device under mining influence according to claim 1, wherein, The downward pressing assembly includes a downward pressing cylinder (2) and a pressure plate (3) arranged at the telescopic end of the downward pressing cylinder (2). The pressure plate (3) applies a downward pressure to the mortar filling body under the drive of the downward pressing cylinder (2).

5. The large-size artificial false bottom bearing test device under mining influence according to claim 4, wherein, The upward pressing assembly is an upward pressing cylinder (7). The number of the upward pressing cylinders (7) is the same as that of the supporting horizontal plates (6), and the positions correspond one by one. The telescopic end of the upward pressing cylinder (7) can control the lifting of the supporting horizontal plate (6).

6. The large-size artificial false bottom bearing test device under mining influence according to claim 1, characterized in that, The mold assembly also includes a limit plate positioning column (10). The corners of the monitoring type limit plate (4) and the functional type limit plate (5) are provided with mounting holes for the limit plate positioning column (10) to pass through. The limit plate positioning column (10) is a stud, and the installation and fixation of the monitoring type limit plate (4) and the functional type limit plate (5) are realized through positioning nuts (11).

7. The large-size artificial false bottom bearing test device under mining influence according to claim 2, wherein A plurality of acoustic emission positioning holes (401) facing the slurry filling space are opened on the monitoring type limit plate (4). The acoustic emission positioning holes (401) are used for installing acoustic emission probes.

8. The large-size artificial false bottom bearing test device under mining influence according to claim 2, characterized in that, A plurality of steel bar positioning holes (501) facing the slurry filling space are opened on the functional type limit plate (5). The steel bar positioning holes (501) are used for threading steel bars (14) to form a steel bar mesh (15) in the slurry filling space. A plurality of fiber Bragg grating sensors (17) are distributed on the horizontal and longitudinal bars of the steel bar mesh (15).

9. The large-size artificial false bottom bearing test device under mining influence according to claim 8, characterized in that, It also includes an earth pressure cell stress monitoring device (16). The earth pressure cell stress monitoring device (16) is regularly laid in layers in the filling slurry during the mortar filling process.

10. The large-size artificial false bottom bearing test device under mining influence according to claim 3, characterized in that, The support column (9) is a stud, and the limit of the upper reaction force plate (1) is realized through a fastening nut (12).

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