Device and method for monitoring lateral bearing pressure distribution characteristics

Abstract

The invention discloses a monitoring device and method for lateral bearing pressure distribution characteristics, and relates to the technical field of bearing pressure monitoring. The monitoring device comprises an expansion balloon assembly, a surrounding rock monitoring assembly, a radon gas measuring assembly and a hollow steel pipe. The expansion balloon assembly comprises an expansion balloon, an inflation hole and an inflation pump; the surrounding rock monitoring assembly comprises a hydraulic jack assembly and a plurality of surrounding rock stress sensors; the radon gas measuring assembly comprises an activated carbon placing cabin and a radon measuring instrument; the hollow steel pipe comprises a plurality of sections which are in threaded connection, and each section of the hollow steel pipe is correspondingly provided with an expansion balloon, an inflation hole, a hydraulic jack, an oil storage cabin and an activated carbon placement cabin; the top end of the first hollow steel pipe extending into the drill hole is sealed. According to the method, indexes actually measured on site comprise segmented actually measured stress and radon gas concentration, evaluation and analysis indexes are more diversified, and data are more reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of support pressure monitoring, and in particular to a device and method for monitoring lateral support pressure distribution characteristics. Background Art

[0002] In the mining of deep coal resources, geological conditions become more complex and changeable, and strong mine pressure often appears. Since tunnel excavation and face mining will inevitably break the original stress balance state of the coal rock mass, causing stress redistribution, the distribution characteristics of the lateral support pressure are directly related to the stability and safety of the tunnel and the surrounding rock of the mining area. The uneven distribution of lateral support pressure may lead to a decrease in the stability of the surrounding rock and increase the risk of deformation and impact. This uneven distribution of pressure may also lead to excessive load on the tunnel support structure, thereby causing safety accidents such as tunnel roof collapse, which seriously threatens the personal safety of miners and the normal operation of mines. Therefore, accurately grasping the distribution characteristics of the lateral support pressure of the tunnel is of great practical significance for ensuring the safe and efficient mining of deep coal resources.

[0003] At present, the methods for determining the distribution characteristics of lateral support pressure in tunnels mainly include ground stress measurement, numerical simulation analysis, and on-site drilling monitoring. Among them, although ground stress measurement can provide basic data, it is difficult to fully reflect the pressure distribution under complex conditions; although numerical simulation analysis can predict the stress distribution under different conditions, it is limited by the accuracy of the numerical model and the selection of parameters; and on-site drilling monitoring faces problems such as difficulty in equipment installation, susceptibility to operator and environmental influences, and insufficient data real-time and accuracy. These shortcomings limit the efficiency and effectiveness of existing methods in practical applications, especially in dynamically changing deep mining environments.

[0004] Therefore, there is an urgent need to invent a monitoring device and method for lateral support pressure distribution characteristics with strong reliability, high accuracy and easy operation, so as to provide effective protection for mine safety production. Summary of the invention

[0005] In response to the above problems, the present invention discloses a device and method for monitoring the lateral support pressure distribution characteristics. The on-site measured indicators include segmented measured stress and radon gas concentration. The evaluation and analysis indicators are more diverse, the data are more reliable, the accuracy is high, and the operation is convenient.

[0006] According to the purpose of the present invention, a device for monitoring the pressure distribution characteristics of lateral support is provided, comprising an expansion balloon assembly, a surrounding rock monitoring assembly, a radon gas measurement assembly and a hollow steel pipe;

[0007] The inflatable balloon assembly includes an inflatable balloon, an inflation hole, and an inflation pump; the inflatable balloon is wrapped on a hollow steel tube, the inflation hole is opened on the hollow steel tube and is wrapped by the inflatable balloon, and the inflation pump is connected to the inflation hole through an inflation tube;

[0008] The surrounding rock monitoring component includes a hydraulic jack component and a surrounding rock stress sensor, and the hydraulic jack component includes an oil storage tank, a hydraulic jack and a pressure pump; the oil storage tank is annular and is sleeved on the hollow steel pipe in the expansion balloon, and an oil injection hole is opened on the side close to the hollow steel pipe and connected to the hollow steel pipe, and an oil pipeline is connected to the oil injection hole, and is connected to the surrounding rock stress sensor through the oil pipeline and the pressure pump; the hydraulic jack is arranged on the side of the oil storage tank away from the hollow steel pipe, and is evenly distributed along the circumference of the oil storage tank; the pressure pump is used to apply oil pressure to the hydraulic jack to make it fit the hole wall and bear force; the surrounding rock stress sensor is used to monitor the surrounding rock support pressure reflected by the hydraulic jack in real time;

[0009] The radon gas measurement assembly includes an activated carbon placement chamber and a radon detector. The activated carbon placement chamber is sleeved outside the hollow steel pipe and is used to place activated carbon. The upper and lower parts of the activated carbon placement chamber are provided with adsorption holes. The radon detector is used to measure the specific activity of radioactive radon adsorbed by activated carbon and its daughters, and calculate the radon gas concentration.

[0010] The hollow steel pipe is a plurality of sections connected by threads, and each section of the hollow steel pipe is provided with an expansion balloon, an inflation hole, a hydraulic jack, an oil storage tank and an activated carbon placement tank; the top end of the first section of the hollow steel pipe extending into the drill hole is sealed.

[0011] Preferably, both ends of each section of the hollow steel pipe are provided with external threads, and two adjacent sections of the hollow steel pipe are connected by nut sleeves; a longitudinal partition is provided inside the hollow steel pipe to divide the inside of the hollow steel pipe into an oil pipeline laying channel and an inflation channel.

[0012] Preferably, the inflation tube is a special-shaped inflation tube, which is compatible with the inflation channel in the hollow steel tube.

[0013] Preferably, each output end of the hydraulic jack is provided with an arc-shaped rubber block.

[0014] Preferably, the activated carbon storage cabin is formed by splicing two semi-circular cabins, and the interfaces are connected by magnetic buckles; the inner wall of the activated carbon storage cabin that contacts the hollow steel pipe is provided with an anti-slip coating.

[0015] The present invention further discloses a method for monitoring lateral support pressure distribution characteristics using the above monitoring device, comprising the following steps:

[0016] Step 1: Select the test point in the tunnel according to the actual situation, and estimate the approximate range of the lateral support pressure distribution based on experience and the measured conditions of the adjacent tunnels, and perform drilling operations at 1.2 times the estimated range;

[0017] Step 2: Place equal amounts of activated carbon into the activated carbon placement cabin and fix them on the hollow steel pipe. At the same time, according to the depth of the borehole, use nuts to overlap the threads on the hollow steel pipe and number them in sequence. Place multiple hollow steel pipes into the borehole, and lay the oil pipeline in each section of the hollow steel pipe on the same side.

[0018] Step 3: According to the numbering of the hollow steel pipes, a number of surrounding rock stress sensors are numbered, and the end of the oil pipeline connected to the oil storage tank on each section of the hollow steel pipe is connected to the surrounding rock stress sensor with the corresponding number through a three-way valve in turn. The other end of the three-way valve is connected to the booster pump, and the oil stop valve screw on the three-way valve is opened to form a passage between the booster pump oil filling port on the three-way valve and the oil pipeline. The booster pump is used to pressurize the corresponding hydraulic jack until the reading on the surrounding rock stress sensor is equal to the original rock stress of the formation, and then the oil stop valve screw is tightened and the booster pump is removed;

[0019] Step 4: According to the pressurization steps in step 3, pressurize the hydraulic jacks of each section in turn, and debug the surrounding rock stress sensor;

[0020] Step 5: Connect the inflation tube on the inflation pump to the inflation channel of the last section of the hollow steel pipe, turn on the inflation pump, and allow the gas to pass through the inflation tube, the inflation channel and the inflation hole to reach the inside of the expansion balloon. The expansion balloon expands and clings to the hole wall, dividing the borehole into multiple radon gas absorption areas, and starting the on-site measurement of the lateral support pressure;

[0021] Step 6: Maintain the above state for five days to allow the activated carbon to fully absorb the radon gas leaking from the cracks in the borehole and the hole wall. During this period, the surrounding rock stress sensor and the air pump remain in working condition;

[0022] Step 7: After five days, use a collector to collect monitoring data from each surrounding rock stress sensor, take out the activated carbon from each section of the measured location, and use a radon detector to determine the radon gas concentration value of each section;

[0023] Step 8: Draw a corresponding relationship diagram based on the monitoring data of the surrounding rock stress sensor and the radon gas concentration values ​​of each section by linear fitting, and analyze the distribution characteristics of the lateral support pressure at the experimental site.

[0024] Preferably, in step one, the drill hole is arranged at a position 1.5 m above the ground on the side of the coal wall and inclined upward at an angle of 5°.

[0025] Compared with the prior art, the device and method for monitoring lateral support pressure distribution characteristics disclosed in the present invention have the following advantages:

[0026] (1) The present invention enriches the diversity of methods for measuring the lateral support pressure distribution characteristics of a tunnel.

[0027] (2) The indicators measured on site in the present invention include segmented measured stress and radon gas concentration, the evaluation and analysis indicators are more diverse, and the data are more reliable.

[0028] (3) The design of the monitoring device in the present invention takes portability and ease of operation into consideration, so that it can be quickly deployed and used in various complex environments. It has high on-site fit and high reliability, which greatly improves the efficiency of the measurement work. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 Schematic diagram of the structure of the monitoring device for lateral support pressure distribution characteristics.

[0031] Figure 2 This is a schematic diagram of the structure of the special-shaped inflation tube of the inflation pump.

[0032] Figure 3 It is a schematic diagram of the structure of the lower perspective of the annular hydraulic jack assembly.

[0033] Figure 4 This is a schematic diagram of the activated carbon placement cabin structure.

[0034] Figure 5 This is a schematic diagram of underground measurements of the lateral support pressure distribution characteristics.

[0035] Figure 6 This is the corresponding relationship diagram between the stress of each section and the radon gas concentration measured on site.

[0036] In the figure: 1-hollow steel pipe; 2-expansion balloon; 3-inflation hole; 4-activated carbon placement cabin; 5-adsorption hole; 6-magnetic buckle; 7-hydraulic jack; 8-arc rubber block; 9-oil pipeline; 10-oil storage tank; 11-radon detector; 12-inflation pump; 13-boosting pump; 14-surrounding rock stress sensor; 15-external thread; 16-nut sleeve; 17-steel ball; 18-inflation tube; 19-rubber tube; 20-special-shaped blocking block; 21-oil filling hole; 22-longitudinal partition. DETAILED DESCRIPTION

[0037] The specific implementation of the present invention is briefly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0038] Figure 1-Figure 6 The preferred embodiments of the present invention are shown and analyzed in detail.

[0039] like Figure 1 The device shown is used for monitoring the lateral support pressure distribution characteristics, including an expansion balloon assembly, a surrounding rock monitoring assembly, a radon gas measurement assembly and a hollow steel pipe 1.

[0040] Among them, the hollow steel pipe 1 is a multi-section threaded connection, each section is 1 meter long, and each section of the hollow steel pipe 1 is provided with an expansion balloon 2 and an inflation hole 3 in the expansion balloon assembly, a hydraulic jack 7 in the surrounding rock monitoring assembly, an oil storage tank 10, and an activated carbon placement tank 4 in the radon gas measurement assembly. External threads 15 are provided at both ends of each hollow steel pipe 1, and two adjacent hollow steel pipes 1 are connected by a nut sleeve 16, and the top of the first hollow steel pipe 1 inserted into the borehole is sealed. A longitudinal partition 22 is provided inside the hollow steel pipe 1, dividing the inside of the hollow steel pipe 1 into two parts: an oil pipeline laying channel and an inflation channel.

[0041] The expansion balloon assembly includes an expansion balloon 2, an inflation hole 3, and an inflation pump 12. The expansion balloon 2 is made of rubber and is usually in a deflated state. It is wrapped around the hollow steel pipe 1. The two ends of the expansion balloon 2 tightly wrap the hollow steel pipe 1. The inflation hole 3 is opened on the hollow steel pipe 1 and is wrapped by the expansion balloon 2. The inflation pump 12 is an integrated inflation pump 12 for mining, which is connected to the inflation hole 3 through an inflation pipe 18. Figure 2 As shown, the inflation tube 18 is a special-shaped inflation tube 18, including a rubber tube 19 and a special-shaped blocking block 20. The rubber tube 19 is inserted into the special-shaped blocking block 20. The special-shaped blocking block 20 is a semi-conical rubber block that is adapted to the shape of the inflation channel in the hollow steel tube 1 and can perfectly block the inflation channel so that the inflation pump 12 can inflate the inflation channel through the rubber tube 19 to provide sufficient expansion force for the inflation balloon 2.

[0042] The surrounding rock monitoring assembly includes a hydraulic jack assembly and a surrounding rock stress sensor 14, and the hydraulic jack assembly includes an oil storage tank 10, a hydraulic jack 7 and a pressure pump 13. Figure 3As shown, the oil storage tank 10 is annular and is sleeved on the hollow steel pipe 1 in the expansion balloon 2 to avoid the inflation hole 3, providing oil pressure for the hydraulic jack 7. The oil storage tank 10 is provided with an oil filling hole 21 near the hollow steel pipe 1 and connected to the hollow steel pipe 1. The oil filling hole 21 is connected to the oil delivery pipe 9, and is connected to the surrounding rock stress sensor 14 through the oil delivery pipe 9 and the pressure pump 13. The hydraulic jack 7 is arranged on the side of the oil storage tank 10 away from the hollow steel pipe 1, and there are six of them evenly distributed along the circumference of the oil storage tank 10. Each output end of the hydraulic jack 7 is provided with an arc-shaped rubber block 8. The arc-shaped rubber block 8 can be pressed against the hole wall in the pressurized state. The arc-shaped rubber block 8 and the hydraulic jack 7 are connected by a steel ball 17, and the arc-shaped rubber block 8 can rotate freely. The pressure pump 13 is a small handheld pressure pump 13, which is used to apply oil pressure to the hydraulic jack 7 so that it fits the hole wall and is stressed. The surrounding rock stress sensor 14 is a GYW25 type mining stress sensor, which is set in multiple sections corresponding to the hollow steel pipes 1, and is used to monitor the surrounding rock support pressure reflected by each section of the annular hydraulic jack 7 in real time. The surrounding rock stress sensor 14 can convert the pressure into an electrical signal, and finally convert it into a numerical value and store it in each surrounding rock stress sensor 14. The data is automatically saved every two hours. At the end of the corresponding oil pipeline 9 on each hollow steel pipe 1 is a three-way valve, which is respectively connected to the surrounding rock stress sensor 14 and the booster pump 13; in addition, there is also an oil stop valve screw on the three-way valve. When tightened, the oil pipeline 9 and the surrounding rock stress sensor 14 form an oil pressure passage. When loosened, the booster pump 13, the oil pipeline 9 and the surrounding rock stress sensor 14 form an oil pressure passage.

[0043] The radon gas measurement assembly includes an activated carbon storage compartment 4 and a radon detector 11. The activated carbon storage compartment 4 is sleeved outside the hollow steel pipe 1 and is used to store activated carbon. Figure 4 As shown, the activated carbon storage compartment 4 is composed of two semi-circular compartments spliced ​​together, and the interface is connected by a magnetic buckle 6. The upper and lower parts of the activated carbon storage compartment 4 are provided with adsorption holes 5. The inner wall of the activated carbon storage compartment 4 that contacts the hollow steel pipe 1 is provided with an anti-slip coating. The radon detector 11 is a BH-1324 environmental gamma spectrometer, which is used to measure the specific activity of radioactive radon adsorbed by activated carbon and its daughters, and calculate the radon concentration.

[0044] like Figure 5 As shown, the present invention further discloses a method for monitoring lateral support pressure distribution characteristics using the above monitoring device, comprising the following steps:

[0045] Step 1: According to the actual situation, select the experimental point in the tunnel, and estimate the approximate range of the lateral support pressure distribution based on experience and the measured conditions of the adjacent tunnels, and perform drilling operations according to 1.2 times the estimated range as the drilling depth. The drilling hole is arranged 1.5m above the ground on the side of the coal wall, with an upward angle of 5°. The diameter of the drilling hole is larger than the outer diameter of the activated carbon placement cabin 4, and smaller than the outer diameter of the expansion balloon 2 when it is expanded.

[0046] Step 2: 5g of activated carbon is placed in the activated carbon placement chamber 4 and fixed on the hollow steel pipe 1. At the same time, according to the depth of the borehole, the nut sleeve 16 is used to overlap and number the hollow steel pipes 1 in sequence through the thread on the hollow steel pipe 1. Each hollow steel pipe 1 has the expansion balloon 2 at the bottom and the activated carbon placement chamber 4 at the top. Multiple hollow steel pipes 1 are placed in the same direction. The top of the first hollow steel pipe 1 extending into the borehole is sealed, and the oil pipeline 9 in each hollow steel pipe 1 is uniformly arranged on the same side.

[0047] Step three: According to the numbering of the hollow steel pipes 1, several surrounding rock stress sensors 14 are numbered, and the ends of the oil pipeline 9 connected to the oil storage tank 10 on each section of the hollow steel pipe 1 are connected to the surrounding rock stress sensors 14 with corresponding numbers through three-way valves in turn, and the other end of the three-way valve is connected to the pressure pump 13. The oil stop valve screw on the three-way valve is opened to form a passage between the oil filling port of the pressure pump 13 on the three-way valve and the oil pipeline 9. The pressure pump 13 is used to pressurize the corresponding hydraulic jack 7 until the reading on the surrounding rock stress sensor 14 is equal to the original rock stress of the local formation, and then the oil stop valve screw is tightened to remove the pressure pump 13.

[0048] Step 4: According to the pressurization steps in step 3, pressurize the hydraulic jacks 7 of each section in turn, and debug the surrounding rock stress sensor 14.

[0049] Step 5: Connect the inflation port on the inflation pump 12 to the inflation channel of the last section of the hollow steel pipe 1 through the rubber tube 19 and the special-shaped blocking block 20, turn on the inflation pump 12, and allow the gas to pass through the rubber tube 19, the inflation channel and the inflation hole 3 to reach the inside of the expansion balloon 2. The expansion balloon 2 expands and fits tightly against the hole wall, dividing the borehole into multiple radon gas absorption areas of one meter each, and start on-site measurement of the lateral support pressure.

[0050] Step 6: Maintain the above state for five days to allow the activated carbon to fully absorb the radon gas leaking from the cracks in the borehole and the hole wall. During this period, the surrounding rock stress sensor 14 and the air pump 12 remain in working condition to prevent leakage of components from causing inaccurate radon gas measurement concentrations in each segment.

[0051] Step 7: After five days, use a collector to collect monitoring data from each surrounding rock stress sensor 14, take out the activated carbon in each section of the measured location, and use a radon detector 11 to determine the radon gas concentration value of each section.

[0052] Step 8: Draw a corresponding relationship diagram based on the monitoring data of the surrounding rock stress sensor 14 and the radon gas concentration values ​​of each section by linear fitting, and analyze the distribution characteristics of the lateral support pressure at the experimental site. Figure 6As shown in the figure, it can be seen that areas Ⅰ and Ⅱ are lateral support pressure decompression areas, Ⅲ and Ⅳ are lateral support pressure pressure increase areas, and Ⅴ is the original rock stress area, where x1 is the lateral support pressure peak position and x4 is the lateral support pressure influence range; the above analysis can provide a reliable basis for the stability control of the tunnel surrounding rock. If you want to obtain the reliability of multiple sets of data enhancement results, you can drill a hole every 10m and repeat the above steps.

[0053] The above description of the disclosed embodiments enables those skilled in the art to implement and use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit and scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A device for monitoring lateral support pressure distribution characteristics, characterized in that: It comprises an expansion balloon component, a surrounding rock monitoring component, a radon gas measurement component and a hollow steel pipe (1); The inflatable balloon assembly comprises an inflatable balloon (2), an inflation hole (3) and an inflation pump (12); the inflatable balloon (2) is wrapped on the hollow steel tube (1), the inflation hole (3) is opened on the hollow steel tube (1) and is wrapped by the inflatable balloon (2), and the inflation pump (12) is connected to the inflation hole (3) via an inflation tube (18); The surrounding rock monitoring assembly comprises a hydraulic jack assembly and a surrounding rock stress sensor (14); the hydraulic jack assembly comprises an oil storage tank (10), a hydraulic jack (7) and a pressure pump (13); the oil storage tank (10) is annular and is sleeved on a hollow steel pipe (1) in an expansion balloon (2); an oil injection hole (21) is provided on the side close to the hollow steel pipe (1) and is connected to the hollow steel pipe (1); the oil injection hole (21) is connected to an oil delivery pipe (9) and is connected to the hollow steel pipe (1). The hydraulic jack (7) is connected to the surrounding rock stress sensor (14) through an oil pipeline (9) and a pressure pump (13); the hydraulic jack (7) is arranged on a side of the oil storage tank (10) away from the hollow steel pipe (1), and is a plurality of hydraulic jacks evenly distributed along the circumference of the oil storage tank (10); the pressure pump (13) is used to apply oil pressure to the hydraulic jack (7) so that it fits the hole wall and is stressed; the surrounding rock stress sensor (14) is used to monitor in real time the size of the surrounding rock support pressure reflected by the hydraulic jack (7); The radon gas measurement assembly comprises an activated carbon storage compartment (4) and a radon detector (11). The activated carbon storage compartment (4) is sleeved outside the hollow steel pipe (1) and is used to store activated carbon. The upper and lower parts of the activated carbon storage compartment (4) are provided with adsorption holes (5). The radon detector (11) is used to measure the specific activity of radioactive radon adsorbed by the activated carbon and its progeny, and calculate the radon gas concentration. The hollow steel pipe (1) is a plurality of sections connected by threads, and each section of the hollow steel pipe (1) is provided with an expansion balloon (2), an inflation hole (3), a hydraulic jack (7), an oil storage tank (10) and an activated carbon storage tank (4); the top end of the first section of the hollow steel pipe (1) extending into the drilled hole is sealed.

2. A device for monitoring lateral support pressure distribution characteristics according to claim 1, characterized in that: Both ends of each section of the hollow steel pipe (1) are provided with external threads (15), and two adjacent sections of the hollow steel pipe (1) are connected via nut sleeves (16); a longitudinal partition (22) is provided inside the hollow steel pipe (1) to divide the inside of the hollow steel pipe (1) into an oil pipeline laying channel and an air charging channel.

3. A device for monitoring lateral support pressure distribution characteristics according to claim 2, characterized in that: The inflation tube (18) is a special-shaped inflation tube (18) adapted to the inflation channel in the hollow steel tube (1).

4. The device for monitoring lateral support pressure distribution characteristics according to claim 1, characterized in that: Each output end of the hydraulic jack (7) is provided with an arc-shaped rubber block (8).

5. The device for monitoring lateral support pressure distribution characteristics according to claim 1, characterized in that: The activated carbon storage compartment (4) is formed by splicing two semi-circular compartments, and the interfaces are connected by magnetic buckles (6); the inner wall of the activated carbon storage compartment (4) in contact with the hollow steel pipe (1) is provided with an anti-slip coating.

6. A method for monitoring lateral support pressure distribution characteristics using the device for monitoring lateral support pressure distribution characteristics according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Select the test point in the tunnel according to the actual situation, and estimate the approximate range of the lateral support pressure distribution based on experience and the measured conditions of the adjacent tunnels, and perform drilling operations at 1.2 times the estimated range; Step 2: Place equal amounts of activated carbon into the activated carbon storage chamber (4) and fix them on the hollow steel pipe (1). At the same time, according to the depth of the borehole, overlap and number them in sequence through the threads on the hollow steel pipe (1) using nut sleeves (16). Place multiple hollow steel pipes (1) into the borehole, and uniformly lay the oil pipeline (9) in each section of the hollow steel pipe (1) on the same side. Step 3: According to the numbering of the hollow steel pipe (1), a number of surrounding rock stress sensors (14) are numbered, and the end of the oil pipeline (9) connected to the oil storage tank (10) on each section of the hollow steel pipe (1) is connected to the surrounding rock stress sensor (14) with the corresponding number through a three-way valve in turn, and the other end of the three-way valve is connected to the pressure pump (13), and the stop valve screw on the three-way valve is opened to form a passage between the oil filling port of the pressure pump (13) on the three-way valve and the oil pipeline (9), and the pressure pump (13) is used to pressurize the corresponding hydraulic jack (7) until the reading on the surrounding rock stress sensor (14) is equal to the original rock stress of the formation, and then the stop valve screw is tightened and the pressure pump (13) is removed; Step 4: According to the pressurization step in step 3, pressurize the hydraulic jacks (7) of each section in turn, and debug the surrounding rock stress sensor (14); Step 5: Connect the inflation tube (18) on the inflation pump (12) to the inflation channel of the last section of the hollow steel pipe (1), turn on the inflation pump (12), and allow the gas to pass through the inflation tube (18), the inflation channel and the inflation hole (3) to reach the inside of the expansion balloon (2). The expansion balloon (2) expands and clings to the hole wall, dividing the borehole into multiple radon gas absorption areas, and starting to conduct on-site measurement of the lateral support pressure; Step 6: Maintain the above state for five days to allow the activated carbon to fully absorb the radon gas leaking from the borehole and the cracks in the borehole wall, during which the surrounding rock stress sensor (14) and the air pump (12) remain in working condition; Step 7: After five days, use a collector to collect monitoring data from each surrounding rock stress sensor (14), take out the activated carbon in each section of the measured location, and use a radon detector (11) to determine the radon gas concentration value of each section; Step 8: Perform linear fitting based on the monitoring data of the surrounding rock stress sensor (14) and the radon gas concentration values ​​of each section to draw a corresponding relationship diagram, and analyze the distribution characteristics of the lateral support pressure at the experimental site.

7. The method according to claim 6, characterized in that In step one, the drilling hole is arranged at the side of the coal wall 1.5m above the ground and inclined upward at an angle of 5°.

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