Mining in-situ coal body creep deformation monitoring device
By installing monitoring devices with components such as slotting and axial pressure loading cylinders in situ in the coal seam, the problems of accuracy and stability in monitoring coal creep deformation on site have been solved, achieving high-precision and simple long-term monitoring, supporting the scientific formulation of gas control measures, and ensuring safe mining.
Patent Information
- Application Number
- CN202520016007.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-01-06
AI Technical Summary
Existing technologies for on-site monitoring of coal creep deformation suffer from problems such as low monitoring accuracy, complex operation, and difficulty in achieving long-term stable monitoring, especially in deep coal mining, particularly in high-gas mines, where the coal body may undergo creep deformation under high stress.
Design a mining in-situ coal creep deformation monitoring device, including a slot, an axial pressure loading cylinder, a rigid pressure bearing base, a telescopic fixed support, a pressure sensor, and a stress acquisition device. By excavating a slot in the coal body in situ and setting these components, long-term stable monitoring of coal creep deformation can be achieved.
It provides high-precision and easy-to-use coal creep deformation monitoring, ensuring the integrity and reliability of data acquisition. It can provide real and reliable data support for coal mine gas control, help formulate scientific and reasonable control measures, and ensure safe and efficient mining.
Smart Images
Figure CN223841652U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of coal body monitoring technology, and in particular to an in-situ coal body creep deformation monitoring device for mining. Background Technology
[0002] As shallow coal resources gradually dwindle, mining activities have shifted towards deeper layers. Deep coal resources are situated in more complex geological environments, increasing the difficulty of extraction. Especially in high-gas mines, pre-drainage of gas is necessary to ensure safe production. This process is lengthy and costly, and the coal seam may undergo creep deformation under high stress during this period.
[0003] Current technologies for monitoring coal creep deformation mainly rely on laboratory experiments, which are insufficient for on-site monitoring of coal creep deformation, including problems such as low monitoring accuracy, complex operation, and difficulty in achieving long-term stable monitoring.
[0004] Therefore, it is particularly important to provide a device that can stably monitor the creep deformation of deep coal seams over a long period of time at the coal seam site. Utility Model Content
[0005] To solve the above-mentioned technical problems, this utility model provides an in-situ coal seam creep deformation monitoring device for mining. The technical solution of this utility model is as follows:
[0006] A mining in-situ coal creep deformation monitoring device includes a slot, which is a cubic groove excavated in situ in the coal body to be monitored. An axial pressure loading cylinder is placed on the bottom surface of the slot, and a rigid pressure-bearing base is placed on the top surface of the axial pressure loading cylinder. A coal sample is placed in the middle of the rigid pressure-bearing base, and strain gauges are installed on the sides of the coal sample. A telescopic fixing bracket is installed around the rigid pressure-bearing base, with the top of the telescopic fixing bracket contacting the top surface of the slot. A pressure sensor is placed on the top surface of the coal sample, with the top surface of the pressure sensor contacting the top surface of the slot. The telescopic fixing bracket abuts against the side wall of the pressure sensor. Four through circular holes are opened at the four corners of the rigid pressure-bearing base. All slots are opened at the positions opposite to the circular holes on the bottom surface of the slot. Limit bolts are installed in the corresponding circular holes and slots. A stress acquisition device is installed at the bottom of a borehole near the slot. The stress acquisition device, pressure sensor, and strain gauges are all electrically connected to a pressure control monitoring instrument, which is electrically connected to a display. The axial pressure loading cylinder is connected to a hydraulic pump through a hydraulic pipe.
[0007] Optionally, the telescopic fixing bracket includes a guide cylinder, which is fixedly connected to the top surface of the rigid pressure-bearing base. A weak spring is fixedly connected to the bottom surface of the guide cylinder, with the bottom end of the weak spring fixedly connected to the bottom surface of the guide cylinder. A guide rod is fixedly connected to the top of the weak spring, and the guide rod is slidably connected to the guide cylinder. The top of the guide rod contacts the top surface of the slot. A clamp is fixedly connected to the side of the guide cylinder, and the guide cylinder abuts against the top of the side wall of the pressure sensor. The clamp abuts against the bottom of the side wall of the pressure sensor.
[0008] Optionally, the number of telescopic fixing brackets is four, and the line connecting the four telescopic fixing brackets at the same position forms a square; the line connecting the four circular through holes at the same position forms a square, and the line connecting the four slots at the same position forms a square.
[0009] Optionally, the coal sample is a cylinder with a diameter of 50 mm and a height of 100 mm.
[0010] Optionally, the stress acquisition device, pressure sensor, and strain gauge are all electrically connected to the pressure control monitoring instrument via wires.
[0011] Optionally, the dimensions of the slot are 300mm × 300mm × 300mm.
[0012] Optionally, the pressure sensor and the axial pressure loading cylinder are symmetrical about their positions relative to the coal sample.
[0013] All of the above-mentioned optional technical solutions can be combined arbitrarily, and this utility model does not provide a detailed description of the structure after each combination.
[0014] The beneficial effects of this utility model through the above solution are as follows:
[0015] By excavating a slot in situ within the coal seam to be monitored, and installing a structure within the slot including an axial pressure loading cylinder, a rigid pressure-bearing base, a telescopic fixing bracket, a pressure sensor, limit bolts, a coal sample, and a stress acquisition device, a device is provided for long-term, stable monitoring of deep coal seam creep deformation in the field, ensuring the integrity and reliability of data acquisition. The entire device is structurally stable, ensuring the accuracy of test results. The locally acquired coal sample further enhances the accuracy of the monitoring results. This invention offers advantages such as high monitoring accuracy, simple operation, and the ability to achieve long-term stable monitoring, providing more accurate and reliable data support for coal mine gas control and contributing to the development of more scientific and rational gas control measures.
[0016] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the composition structure of this utility model.
[0018] Figure 2 This is a top view of the rigid pressure-bearing base in this utility model.
[0019] Figure 3 This is a structural schematic diagram of the telescopic fixed bracket in this utility model.
[0020] The attached figures are labeled as follows: 1. Coal sample, 2. Stress acquisition device, 3. Telescopic fixed bracket, 4. Rigid bearing base, 5. Axial pressure loading cylinder, 6. Pressure sensor, 7. Strain gauge, 8. Limit bolt, 9. Wire, 10. Pressure control monitoring instrument, 11. Display, 12. Hydraulic pump, 13. Hydraulic pipe, 14. Weak spring, 15. Guide rod, 16. Guide cylinder, 17. Clamp, 18. Groove. Detailed Implementation
[0021] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0022] like Figures 1 to 3 As shown in the embodiment of this utility model, the in-situ coal creep deformation monitoring device includes a slot 18, which is a cubic groove excavated in situ in the coal body to be monitored. An axial pressure loading cylinder 5 is placed on the bottom surface of the slot 18, and a rigid pressure-bearing base 4 is placed on the top surface of the axial pressure loading cylinder 5. A coal body sample 1 is placed in the middle of the rigid pressure-bearing base 4, and strain gauges 7 are installed on the side of the coal body sample 1. A telescopic fixing bracket 3 is installed around the rigid pressure-bearing base 4, and the top of the telescopic fixing bracket 3 contacts the top surface of the slot 18. A pressure sensor 6 is placed on the top surface of the coal body sample 1, and the top surface of the pressure sensor 6 contacts the top surface of the slot 18. The top surface of the slot 18 is in contact with the telescopic fixed bracket 3, which abuts against the side wall of the pressure sensor 6. Four through circular holes are opened at the four corners of the rigid pressure-bearing base 4. All slots are opened at the positions opposite to the circular through holes on the bottom surface of the slot 18. Limit bolts 8 are installed in the corresponding circular through holes and slots. A stress collector 2 is installed at the bottom of the drill hole near the slot 18. The stress collector 2, pressure sensor 6 and strain gauge 7 are all electrically connected to the pressure control monitor 10 through wires 9. The pressure control monitor 10 is electrically connected to a display 11. The axial pressure loading cylinder 5 is connected to a hydraulic pump 12 through a hydraulic pipe 13.
[0023] Preferably, the number of telescopic fixing brackets 3 is four, and the line connecting the four telescopic fixing brackets 3 at the same position is a square; the line connecting the four circular through holes at the same position is a square, and the line connecting the four slots at the same position is a square.
[0024] The coal sample 1 was directly sampled and processed on-site, preserving as much of the original physical and mechanical properties as possible to improve the accuracy and representativeness of the monitoring data. The surface of the coal sample 1 is smooth and free of obvious cracks to ensure the accuracy of the test results. Preferably, the dimensions of the slot 18 are 300mm × 300mm × 300mm, and the coal sample 1 is cylindrical with a diameter of 50mm and a height of 100mm.
[0025] In the specific implementation, firstly, a cut 18 with dimensions of 300mm × 300mm × 300mm is excavated at a suitable location on both sides of the roadway. The location of the cut 18 should not affect underground operations such as construction and transportation. The top and bottom surfaces of the cut 18 need to be cut flat, and the extracted coal sample is processed into a cylindrical coal body sample 1 with a diameter of 50mm and a height of 100mm. Then, a hole (10m to 20m deep) is drilled at a distance of no more than 1m from the cut 18, and a stress acquisition device 2 is installed at the bottom of the hole. The stress acquisition device 2 is connected to the pressure control monitoring instrument 10 through the wire 9. Next, the axial pressure loading cylinder 5 is placed on the bottom surface of the cut 18 and connected to the hydraulic pump 12 using a hydraulic pipe 13. Four sets of equally spaced slots are drilled around the axial pressure loading cylinder 5 on the bottom surface of the cut 18. A rigid pressure-bearing base 4 is installed directly above the axial pressure loading cylinder 5, with the surfaces of the two tightly fitted. Four limiting bolts 8 are inserted into the circular through hole and slots. Subsequently, the coal sample 1 is placed on the rigid pressure-bearing base 4, and the telescopic fixing bracket 3 is adjusted to ensure that the bottom surface of the pressure sensor 6 is in close contact with the coal sample 1, and the top surface is in close contact with the top surface of the slot 18. The side of the coal sample 1 is in contact with the strain gauge 7, and the strain gauge 7 and the pressure sensor 6 are connected to the pressure control monitoring instrument 10 through the wires 9. After checking that all the wires 9 and hydraulic pipes 13 are properly connected, the display 11 is turned on to view the internal stress value of the coal seam recorded by the stress acquisition device 2. The hydraulic pump 12 is started to inject hydraulic oil into the axial pressure loading cylinder 5 until the reading on the display 11 reaches the internal stress value of the coal seam recorded by the stress acquisition device 2, at which point the oil injection is stopped. At this time, the axial pressure loading cylinder 5 achieves pressure balance with the stress acquisition device 2 through the hydraulic pipe 13. Finally, the position of the rigid pressure-bearing base 4 is fixed with a nut, and the creep deformation (determined based on the data collected by the strain gauge 7) and stress change (determined based on the data collected by the pressure sensor 6) of the coal sample 1 are recorded by the pressure control monitoring instrument 10.
[0026] The top surface of coal sample 1 is in close contact with the bottom surface of pressure sensor 6, and the bottom surface is in close contact with the top surface of rigid pressure-bearing base 4, ensuring uniform stress on coal sample 1. The bottom of limiting bolt 8 is firmly connected to the bottom surface of slot 18, ensuring the stability of the entire device. The top surface of coal sample 1 is in close contact with the bottom surface of pressure sensor 6, the bottom surface is in close contact with the top surface of rigid pressure-bearing base 4, and the side surface is in contact with strain gauge 7, ensuring the accuracy of stress and strain measurements. The top surface of axial pressure loading cylinder 5 is close to the bottom surface of rigid pressure-bearing base 4, and the bottom surface is close to the bottom surface of slot 18, ensuring uniform and stable applied pressure.
[0027] In one specific embodiment, the telescopic fixing bracket 3 includes a guide cylinder 16, which is fixedly connected to the top surface of the rigid pressure-bearing base 4. A weak spring 14 is fixedly connected to the bottom surface of the inner side of the guide cylinder 16, with its bottom end fixedly connected to the bottom surface of the inner side of the guide cylinder 16. A guide rod 15 is fixedly connected to the top of the weak spring 14, and the guide rod 15 is slidably connected to the guide cylinder 16. The top of the guide rod 15 contacts the top surface of the slot 18. A clamp 17 is fixedly connected to the side of the guide cylinder 16, abutting against the top of the side wall of the pressure sensor 6, and the clamp 17 abutting against the bottom of the side wall of the pressure sensor 6. Specifically, the clamp 17 is a square rod-shaped or cylindrical structure. The abutting between the top of the side wall of the guide cylinder 16 and the bottom contact between the clamp 17 and the side wall of the pressure sensor 6 ensures effective fixation and support for the coal sample 6. The weak spring 14 provides soft support for the axial pressure loading process of the axial pressure loading cylinder 5.
[0028] In one specific embodiment, the pressure sensor 6 and the axial pressure loading cylinder 5 are symmetrically positioned relative to the coal sample 1 to ensure uniform stress on the coal sample 1 and accuracy of the pressure test results.
[0029] This utility model has the following advantages:
[0030] 1. With a moderate size and convenient operation, it allows multiple monitoring points to be set up in the same mining area for synchronous recording and on-site data collection. It can not only continuously monitor the creep deformation of coal in coal seam roadways for a long time, ensuring the integrity and reliability of data collection, but also obtain the common deformation of coal based on the data records of multiple monitoring points.
[0031] 2. The device employs robust structural components such as a rigid pressure-bearing base 4 and a telescopic fixing bracket 3 to ensure optimal operation even in complex underground environments. The use of limit bolts 8 further enhances the overall stability of the device, guaranteeing the accuracy of test results even under high ground stress conditions.
[0032] 3. Coal sample 1 was directly sampled and processed on-site, realizing on-site sampling, preserving the original physical and mechanical properties of the sample as much as possible, reducing sample damage, and being in the original rock stress environment consistent with the actual geological conditions for a long time, providing more real and reliable data for coal mine gas control, and helping to formulate more scientific and reasonable gas control measures.
[0033] 4. It can be adjusted according to different site conditions. For example, the position of the slot 18 and the stress acquisition device 2 can be adjusted, and the axial force applied by the axial pressure loading cylinder 5 can be adjusted. It is suitable for monitoring the creep deformation and stress changes of coal body in coal seam roadways at different times, providing reliable data support for optimizing gas control measures, thereby ensuring safe and efficient mining.
[0034] In summary, this utility model aims to address the adverse effects of coal creep deformation on gas control during long-term static storage in deep coal seams. It designs a simple, easy-to-operate, and long-term applicable in-situ coal creep deformation monitoring device, overcoming many shortcomings of existing technologies in on-site monitoring of coal creep deformation, such as low monitoring accuracy, complex operation, and difficulty in achieving long-term stable monitoring. This provides reliable data support for optimizing gas control measures, thereby ensuring safe and efficient mining.
[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A mining in-situ coal seam creep deformation monitoring device, characterized in that, The system includes a slot (18), which is a cubic groove excavated in situ in the coal body to be monitored. An axial pressure loading cylinder (5) is placed on the bottom surface of the slot (18), and a rigid pressure-bearing base (4) is placed on the top surface of the axial pressure loading cylinder (5). A coal body sample (1) is placed in the middle of the rigid pressure-bearing base (4), and strain gauges (7) are installed on the side of the coal body sample (1). A telescopic fixing bracket (3) is installed around the rigid pressure-bearing base (4), and the top of the telescopic fixing bracket (3) contacts the top surface of the slot (18). A pressure sensor (6) is placed on the top surface of the coal body sample (1), and the top surface of the pressure sensor (6) contacts the top surface of the slot (18). The fixed bracket (3) abuts against the side wall of the pressure sensor (6). Four through circular holes are opened at the four corners of the rigid pressure base (4). All slots are opened at the positions opposite to the circular holes on the bottom surface of the slot (18). Limit bolts (8) are installed in the corresponding circular holes and slots. A stress collector (2) is installed at the bottom of the drill hole near the slot (18). The stress collector (2), pressure sensor (6) and strain gauge (7) are electrically connected to the pressure control monitor (10). The pressure control monitor (10) is electrically connected to the display (11). The axial pressure loading cylinder (5) is connected to the hydraulic pump (12) through the hydraulic pipe (13).
2. The in-situ coal seam creep deformation monitoring device according to claim 1, characterized in that, The telescopic fixed bracket (3) includes a guide cylinder (16), which is fixedly connected to the top surface of the rigid pressure base (4). A weak spring (14) is fixedly connected to the bottom surface of the guide cylinder (16). The bottom end of the weak spring (14) is fixedly connected to the bottom surface of the guide cylinder (16). A guide rod (15) is fixedly connected to the top end of the weak spring (14). The guide rod (15) is slidably connected to the guide cylinder (16). The top end of the guide rod (15) contacts the top surface of the slot (18). A clamp (17) is fixedly connected to the side of the guide cylinder (16). The guide cylinder (16) abuts against the top of the side wall of the pressure sensor (6). The clamp (17) abuts against the bottom of the side wall of the pressure sensor (6).
3. The in-situ coal seam creep deformation monitoring device for mining according to claim 1 or 2, characterized in that, The number of telescopic fixing brackets (3) is four, and the line connecting the four telescopic fixing brackets (3) at the same position is a square; the line connecting the four circular through holes at the same position is a square, and the line connecting the four slots at the same position is a square.
4. The in-situ coal seam creep deformation monitoring device for mining according to claim 1, characterized in that, The coal sample (1) is a cylinder with a diameter of 50 mm and a height of 100 mm.
5. The in-situ coal seam creep deformation monitoring device for mining according to claim 1, characterized in that, The stress acquisition device (2), pressure sensor (6) and strain gauge (7) are all electrically connected to the pressure control monitoring instrument (10) via wires (9).
6. The in-situ coal seam creep deformation monitoring device for mining according to claim 1, characterized in that, The dimensions of the slot (18) are 300mm×300mm×300mm.
7. The in-situ coal seam creep deformation monitoring device for mining according to claim 1, characterized in that, The pressure sensor (6) and the axial pressure loading cylinder (5) are symmetrical in position relative to the coal sample (1).