Coal rock mass stress flow test platform based on multi-parameter cooperative monitoring

Abstract

The invention relates to the technical field of rock mass mechanics and mining engineering test devices, in particular to a coal rock mass stress flow test platform based on multi-parameter cooperative monitoring. Comprising a rectangular model frame; a first jack is arranged at the lower part of a top beam of the model frame; a rectangular coal-rock similar material is laid on the upper part of the bottom beam, and a roadway is arranged in the coal-rock similar material; the system further comprises a second jack used for supporting a roadway, a stress sensor arranged in a coal rock similar material and a deformation monitoring system. The system further comprises an acoustic emission probe arranged on the coal rock similar material and a data acquisition and processing system. According to the coal rock mass stress flow test platform based on multi-parameter cooperative monitoring, multiple physical parameters can be synchronously obtained in the same test system, stress flow parameters are calculated and verified in a multi-parameter mutual verification mode, and the reliability of stress concentration and fracture evolution judgment can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of rock mechanics and mining engineering test equipment technology, specifically to a coal and rock mass stress flow test platform based on multi-parameter collaborative monitoring. Background Technology

[0002] Stress flow theory, as an important analytical tool for characterizing the stress transmission path, stress concentration, and evolution characteristics within coal and rock masses, plays a significant role in stability studies of underground engineering such as deep rock mechanics and mining engineering. However, existing research on stress flow mainly relies on theoretical derivation or numerical simulation, and its reliability is highly dependent on model assumptions and parameter selection, lacking effective experimental verification methods.

[0003] In experimental research, existing coal and rock mass mechanical tests typically use a single or limited number of physical parameters for monitoring, such as obtaining only stress changes, surface deformation, or acoustic emission information. These methods struggle to simultaneously reflect the intrinsic relationship between stress, deformation, and fracture behavior within the coal and rock mass. In particular, they are difficult to establish the correspondence between stress concentration areas, deformation concentration areas, and fracture locations on spatial and temporal scales, thus limiting the experimental inversion and verification of stress flow-related parameters.

[0004] Therefore, there is an urgent need for a comprehensive experimental platform that can simultaneously acquire multiple physical parameters within the same experimental system and provide an experimental basis for stress flow parameter calculation and verification through mutual verification of multiple parameters. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a multi-parameter collaborative monitoring platform for stress flow in coal and rock masses, comprising a model frame, coal and rock similar materials, a roadway, a stress monitoring system, a deformation monitoring system, and an acoustic emission monitoring system. The model frame is a rectangular frame, including a top beam, a left support column, a bottom beam, and a right support column connected end-to-end. Several first jacks are sequentially installed along the axial direction below the top beam of the model frame. A rectangular coal and rock similar material is laid between the left and right support columns on the upper part of the bottom beam, and a roadway is formed within the coal and rock similar material. The platform also includes a first jack for supporting the roadway. The two jacks are provided with a support column at the rear of the model frame. The top of the support column is connected to a support crossbar pointing towards the roadway. The end of the support crossbar near the support column is connected to the support column, and the end near the roadway has a second jack on its upper, lower, left, and right sides. The stress monitoring system includes stress sensors arranged in the coal-rock similar material. The deformation monitoring system uses a non-contact measurement method based on digital image processing to monitor the deformation process of the coal-rock similar material surface in real time. The acoustic emission monitoring system includes acoustic emission probes arranged in the coal-rock similar material.

[0006] Preferably, the left end of the top beam is connected to the top of the left support column, the right end of the top beam is connected to the top of the right support column, the left end of the bottom beam is connected to the bottom of the left support column, and the right end of the bottom beam is connected to the bottom of the right support column.

[0007] Preferably, the first jacks are fixed to the lower part of the top beam from left to right, the cylinder of the first jack is fixed to the lower end face of the top beam, the telescopic end is provided with a first pressure block of a certain width, the first pressure blocks of adjacent first jacks are adjacent to each other, the left side of the first pressure block of the leftmost first jack is adjacent to the left support column, and the right side of the first pressure block of the rightmost first jack is adjacent to the right support column.

[0008] Preferably, the coal-rock similar material refers to a stratum containing a coal seam and several rock strata; the top surface of the coal-rock similar material is horizontal; and the roadway has a rectangular cross-section.

[0009] Preferably, a pad block is also provided between the top surface of the coal-rock similar material and the bottom surface of the first pressure block of the first jack.

[0010] Preferably, the support column faces the roadway, the cylinders of the four second jacks are fixed on the support column, and the telescopic end is provided with a second pressure block of a certain width, the width of the second pressure block corresponding to the size of the roadway cross section; both the support column and the support column are rectangular cross-section steel columns.

[0011] Preferably, the stress sensor is a stress cell or a strain gauge.

[0012] Preferably, the deformation monitoring system includes: arranging monitoring points on the surface of the coal-rock similar material; setting up a camera system in front of the model frame to monitor and photograph the coal-rock similar material during the test; and processing the acquired photos to obtain displacement and deformation data of each monitoring point of the coal-rock similar material during the test. By acquiring the displacement field information of the model surface, the strain field distribution can be obtained by inversion, and the stress distribution characteristics of the sample surface can be calculated under certain conditions. This allows for mutual verification with the stress data acquired by the stress monitoring system.

[0013] Preferably, the acoustic emission monitoring system is used to capture elastic wave signals released during the initiation, propagation, and penetration of microcracks inside the model; by arranging multiple acoustic emission probes around the model, the time recording and spatial positioning of the model rupture event can be realized, thereby obtaining information on the location and evolution process of the model rupture.

[0014] Preferably, it also includes a data acquisition and processing system for acquiring and processing data from the stress monitoring system, deformation monitoring system, and acoustic emission monitoring system.

[0015] The test method of the coal and rock mass stress flow test platform based on the multi-parameter collaborative monitoring of this invention mainly includes the following steps: S1: Lay out coal and rock similar materials in the model frame to make a model; and arrange stress sensors of the stress monitoring system, monitoring points of the deformation monitoring system, and acoustic emission probes of the primary acoustic emission monitoring system in the coal and rock similar materials; S2: Apply load to the model using the first jack to simulate the pressure of the overlying strata; S3: Excavate the tunnel at the designed location and collect stress, deformation, and acoustic emission data of the model before and throughout the excavation process; S4: The second jack is used to apply pressure to the roadway to simulate the support of the roadway; stress, deformation and acoustic emission data of the model are collected during the support process and under different support pressures; S5: By comprehensively analyzing multi-parameter data such as stress monitoring, deformation monitoring, and acoustic emission monitoring, mutual verification between different physical parameters can be achieved.

[0016] Beneficial technical effects: The coal and rock mass stress flow test platform based on multi-parameter collaborative monitoring of the present invention can realize the simultaneous acquisition of multiple physical parameters in the same test system, and calculate and verify stress flow parameters through the mutual verification of multiple parameters, which can effectively improve the reliability of stress concentration and fracture evolution judgment. Attached Figure Description

[0017] Figure 1 This is a front view of the coal and rock mass stress flow test platform for multi-parameter collaborative monitoring according to the present invention.

[0018] In the diagram: Model frame-1; First jack-2; Coal and rock similar material-3; Pad block-4; Roadway-5; Second jack-6; Acoustic emission probe-7; Stress sensor-8. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, the present invention proposes a multi-parameter collaborative monitoring coal and rock mass stress flow test platform, which includes a model frame 1, coal and rock similar materials 3, roadway 5, stress monitoring system, deformation monitoring system, acoustic emission monitoring system and data acquisition and processing system.

[0021] The model frame 1 is a rectangular frame, including a top beam, a left support column, a bottom beam, and a right support column connected end to end. The left end of the top beam is connected to the top of the left support column, the right end of the top beam is connected to the top of the right support column, the left end of the bottom beam is connected to the bottom of the left support column, and the right end of the bottom beam is connected to the bottom of the right support column. If necessary, several legs (not shown in the figure) can be set at the bottom of the bottom beam to increase the height of the rectangular model frame 1.

[0022] Several first jacks 2 are sequentially installed along the axial direction at the lower part of the top beam of the model frame 1. Specifically, the first jacks 2 are fixed to the lower part of the top beam from left to right. The cylinder of each first jack 2 is fixed to the lower end face of the top beam, and the telescopic end is equipped with a first pressure block of a certain width. The first pressure blocks of adjacent first jacks 2 are adjacent to each other. The left side of the first pressure block of the leftmost first jack 2 is adjacent to the left support column, and the right side of the first pressure block of the rightmost first jack 2 is adjacent to the right support column. The first jacks 2 are used to simulate overburden load, thereby reducing the thickness of the coal-rock similar material 3.

[0023] In the lower part of the model frame 1, i.e., above the bottom beam, a rectangular coal-rock similar material 3 is laid from bottom to top between the left and right support columns, meaning the top surface of the coal-rock similar material 3 is horizontal. A roadway 5 is provided within the coal-rock similar material 3, which is excavated at a predetermined location after the coal-rock similar material 3 is laid. In this embodiment, the roadway 5 has a rectangular cross-section. A pad block 4 is also provided between the top surface of the coal-rock similar material 3 and the bottom surface of the first pressure block of the first jack 2. The pad block 4 can reduce the damage to the coal-rock similar material 3 caused by the first pressure block of the first jack 2. The coal-rock similar material 3 refers to a stratum containing coal seams and several rock strata.

[0024] It also includes second jacks 6 for supporting tunnel 5. At the rear of the model frame 1, a support column (not shown in the figure) is positioned directly opposite tunnel 5. The top of the support column is connected to a support crossbar (not shown in the figure) pointing towards tunnel 5. One end of the support crossbar is connected to the support column, and the other end, near tunnel 5, has a second jack 6 positioned on its top, bottom, left, and right sides. The cylinders of the four second jacks 6 are fixed to the support crossbar, and their telescopic ends are equipped with second pressure blocks of a certain width, the width of which corresponds to the dimensions of the corresponding tunnel cross-section. The second jacks 6 are used to simulate the support device for tunnel 5. In this embodiment, both the support column and the support crossbar are rectangular cross-section steel columns.

[0025] The stress monitoring system includes a stress sensor 8 arranged in the coal-rock similar material 3. The stress sensor 8 can be a stress cell or a strain gauge. The strain value measured by the strain gauge and the stress-strain relationship are converted into stress. The stress monitoring system is used to acquire stress change information of the model during the experiment.

[0026] The deformation monitoring system employs a non-contact measurement method based on digital image correlation to monitor the surface deformation process of the coal-rock similar material 3 in real time. For example, monitoring points are arranged on the surface of the coal-rock similar material 3, and a camera system (not shown in the figure) is set up in front of the model frame 1 to monitor and photograph the coal-rock similar material 3 during the test. The acquired photos are processed to obtain the displacement and deformation data of each monitoring point (a black dot of uniform size and spacing on the model surface) of the coal-rock similar material 3 during the test. By obtaining the displacement field information of the model surface, the strain field distribution can be further inverted, and the stress distribution characteristics of the sample surface can be calculated under certain conditions; thus, it can be cross-validated with the stress data obtained by the stress monitoring system.

[0027] The acoustic emission monitoring system includes acoustic emission probes 7 arranged in the coal-rock similar material 3 to capture elastic wave signals released during the initiation, propagation, and penetration of microcracks inside the model. By arranging multiple acoustic emission probes 7 around the model, the time recording and spatial positioning of model rupture events can be realized, thereby obtaining information on the location and evolution process of model rupture. The acoustic emission monitoring results are used to characterize the damage and rupture behavior inside the model and to compare and analyze them with stress and deformation information.

[0028] The data acquisition and processing system is used to acquire and process data from the stress monitoring system, deformation monitoring system, and acoustic emission monitoring system.

[0029] The test method of the coal and rock mass stress flow test platform based on the multi-parameter collaborative monitoring of this invention mainly includes the following steps: S1: Lay out coal and rock similar material 3 in the model frame 1 to make a model; and arrange stress sensor 8, deformation monitoring point and acoustic emission probe 7 of primary acoustic emission monitoring system in the coal and rock similar material 3. S2: Apply load to the model using the first jack 2 to simulate the pressure of the overlying strata; S3: Excavate tunnel 5 at the designed location and collect stress, deformation, and acoustic emission data of the model before and throughout the excavation process; S4: Use the second jack 6 to apply pressure to roadway 5 to simulate the support of roadway 5; collect stress, deformation and acoustic emission data of the model during the support process and under different support pressures; S5: By comprehensively analyzing multi-parameter data such as stress monitoring, deformation monitoring, and acoustic emission monitoring, cross-verification between different physical parameters can be achieved. Specifically, high deformation regions and dense acoustic emission event regions are spatially consistent, and stress concentration regions and rupture locations correspond in both time and space. Through multi-parameter superposition analysis, the reliability of judging stress concentration and rupture evolution can be effectively improved, providing credible experimental evidence for the calculation of stress flow parameters.

[0030] This invention is not limited to the preferred embodiments described above. Anyone can derive other methods in various forms under the guidance of this invention. Any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A test platform for multi-parameter collaborative monitoring of stress flow in coal and rock masses, characterized in that, The system includes a model frame, coal-rock similar materials, roadways, a stress monitoring system, a deformation monitoring system, and an acoustic emission monitoring system. The model frame is a rectangular frame, comprising a top beam, a left support column, a bottom beam, and a right support column connected end-to-end. Several first jacks are sequentially installed along the axial direction of the lower part of the top beam. A rectangular coal-rock similar material is laid between the left and right support columns on the upper part of the bottom beam, and a roadway is formed within the coal-rock similar material. The system also includes second jacks for supporting the roadway. Support columns are installed at the rear of the model frame, with a support crossbeam connecting to the top of each column, pointing towards the roadway. The crossbeam is connected to the support column at one end near the support column, and a second jack is arranged on its upper, lower, left, and right sides at the end near the roadway. The stress monitoring system includes stress sensors arranged within the coal-rock similar material. The deformation monitoring system uses a non-contact measurement method based on digital image processing to monitor the surface deformation process of the coal-rock similar material in real time. The acoustic emission monitoring system includes acoustic emission probes arranged within the coal-rock similar material.

2. The coal and rock mass stress flow test platform according to claim 1, characterized in that, The left end of the top beam is connected to the top of the left support column, the right end of the top beam is connected to the top of the right support column, the left end of the bottom beam is connected to the bottom of the left support column, and the right end of the bottom beam is connected to the bottom of the right support column.

3. The coal and rock mass stress flow test platform according to claim 1, characterized in that, The first jacks are fixed to the lower part of the top beam from left to right. The cylinder of the first jack is fixed to the lower end face of the top beam. The telescopic end is provided with a first pressure block of a certain width. The first pressure blocks of adjacent first jacks are adjacent to each other. The left side of the first pressure block of the leftmost first jack is adjacent to the left support column, and the right side of the first pressure block of the rightmost first jack is adjacent to the right support column.

4. The coal and rock mass stress flow test platform according to claim 1, characterized in that, The coal-rock similar material refers to a stratum that includes a coal seam and several rock strata; the top surface of the coal-rock similar material is horizontal; the roadway has a rectangular cross-section; and a pad block is also provided between the top surface of the coal-rock similar material and the bottom surface of the first pressure block of the first jack.

5. The coal and rock mass stress flow test platform according to claim 1, characterized in that, The support column faces the tunnel, and the cylinders of the four second jacks are fixed on the support column. The telescopic end is equipped with a second pressure block of a certain width, the width of which corresponds to the size of the tunnel cross section. Both the support column and the support column are rectangular steel columns.

6. The coal and rock mass stress flow test platform according to claim 1, characterized in that, The stress sensor is a stress cell or strain gauge.

7. The coal and rock mass stress flow test platform according to claim 1, characterized in that, The deformation monitoring system includes: arranging monitoring points on the surface of the coal-rock similar material; setting up a camera system in front of the model frame to monitor and photograph the coal-rock similar material during the test; and processing the acquired photos to obtain displacement and deformation data of each monitoring point of the coal-rock similar material during the test. By obtaining the displacement field information of the model surface, the strain field distribution can be obtained by inversion, and the stress distribution characteristics of the sample surface can be deduced under certain conditions. This allows for cross-verification with stress data acquired by the stress monitoring system.

8. The coal and rock mass stress flow test platform according to claim 7, characterized in that, The acoustic emission monitoring system is used to capture elastic wave signals released during the initiation, propagation, and penetration of microcracks inside the model. By arranging multiple acoustic emission probes around the model, the time recording and spatial positioning of model rupture events can be achieved, thereby obtaining information on the location and evolution process of model rupture.

9. The coal and rock mass stress flow test platform according to claim 8, characterized in that, It also includes a data acquisition and processing system, which is used to acquire and process data from the stress monitoring system, deformation monitoring system, and acoustic emission monitoring system.

10. A test method based on the multi-parameter collaborative monitoring coal and rock mass stress flow test platform according to any one of claims 1-9, characterized in that, Includes the following steps: S1: Lay out coal and rock similar materials in the model frame to make a model; and arrange stress sensors of the stress monitoring system, monitoring points of the deformation monitoring system, and acoustic emission probes of the primary acoustic emission monitoring system in the coal and rock similar materials; S2: Apply load to the model using the first jack to simulate the pressure of the overlying strata; S3: Excavate the tunnel at the designed location and collect stress, deformation, and acoustic emission data of the model before and throughout the excavation process; S4: The second jack is used to apply pressure to the roadway to simulate the support of the roadway; stress, deformation and acoustic emission data of the model are collected during the support process and under different support pressures; S5: By comprehensively analyzing multi-parameter data from stress monitoring, deformation monitoring, and acoustic emission monitoring, mutual verification between different physical parameters can be achieved.

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