A method of using a device for monitoring stability in front of a gas tunnel excavation face

Abstract

The application provides a use method of a device for monitoring stability in front of a gas tunnel excavation face, which comprises a surrounding rock deformation displacement monitoring device, a device for monitoring gas pressure in a borehole, and a data collection and processing terminal; the surrounding rock displacement monitoring device is arranged in a borehole in surrounding rock of the excavation face, and comprises a multi-point displacement meter, an exhaust pipe for exhaust in the borehole, a grouting pipe for grouting, a plurality of displacement meter measuring points on the tunnel surrounding rock, a terminal reading display system for receiving, processing and displaying data, a wireless transmission module for data transmission and a lead-out cable, a sensor for receiving and processing a force bar signal, and a protective displacement sensor casing. The terminal reading display system of the application can realize reading and display of gas pressure in the surrounding rock borehole and displacement deformation of the surrounding rock at multiple points, and can intuitively reflect overall displacement deformation of the surrounding rock of the gas tunnel and gas pressure distribution, and can make an advanced prediction on gas outburst danger of the excavation face of the gas tunnel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel geological disaster monitoring and forecasting, in particular to a use method of a device for monitoring the stability of the front of a gas tunnel excavation face. BACKGROUND

[0002] In recent years, China's modern infrastructure construction has developed rapidly. In addition, China is a mountainous country, and the number of tunnels in China continues to increase rapidly. More and more tunnels pass through various unfavorable geological conditions, especially tunnel projects that pass through harmful gas-containing strata. Not only are there common coal-bearing strata, but there are also more and more tunnels that pass through non-coal-bearing strata. High concentrations of gas in tunnels can easily cause gas disasters, including poisoning and suffocation of construction personnel, gas combustion and explosion, and gas outburst, which directly threaten the safety of construction personnel and project property. At present, the main prevention and treatment measures for tunnel gas-containing strata are advanced strata gas prediction.

[0003] In the advanced prediction of gas tunnels, most gas tunnels use geological analysis as the basis, supplemented by geophysical prospecting methods, to predict disasters in the strata in front of the tunnel excavation face. The existing method for preventing tunnel gas disasters mainly involves manually measuring parameters to obtain various parameters of the strata gas, then classifying the tunnel gas strata, and then predicting the risk level. Since this method only monitors a single parameter, it relies solely on the gas parameter as the basis for prediction data. When measuring the gas parameter, the displacement and deformation of the surrounding rock of the gas stratum under excavation disturbance are not monitored, and it is difficult to obtain multiple position data simultaneously. This method has great limitations in analyzing the gas distribution and surrounding rock stability in front of the tunnel, and improper prediction can easily cause a major gas accident.

[0004] Therefore, a multi-point monitoring device for monitoring the stability of the surrounding rock in front of the excavation face of a gas tunnel and a monitoring method thereof are provided, which can simultaneously monitor the gas distribution of the surrounding rock in front of the excavation face and the deformation and displacement of the surrounding rock under the influence of excavation disturbance and gas pressure. Then, according to the monitoring data analysis, the risk level of the gas disaster in front of the excavation face can be obtained, and appropriate gas prevention measures can be taken quickly according to the data analysis results. The corresponding prevention measures can be adjusted according to the dynamic changes in the monitoring values. This is a method worth studying. SUMMARY

[0005] In order to solve the above problems, the application provides a method for using the device for monitoring the stability of the surrounding rock in front of the excavation face of a gas tunnel, which comprises the following steps: monitoring the gas pressure and the deformation displacement of the surrounding rock in the drilling hole in front of the excavation face and transmitting the data to the data collection processing display terminal in real time; the data collection processing display terminal can intuitively reflect the gas pressure distribution of the surrounding rock and the deformation displacement of the surrounding rock, and provide a scientific basis for further taking corresponding tunnel gas prevention and control measures.

[0006] In order to achieve the above object, the technical scheme provided by the application is as follows:

[0007] The device for monitoring the stability of the surrounding rock in front of the excavation face of a gas tunnel comprises a surrounding rock deformation displacement monitoring device, a device for monitoring the gas pressure in the drilling hole and a data collection processing display terminal 12; the surrounding rock displacement monitoring device is arranged in the surrounding rock drilling hole 23 in the drilling hole 22 in the excavation face, and comprises a multi-point displacement meter, an exhaust pipe 4 for exhausting the drilling hole, a grouting pipe 8 for grouting, a plurality of displacement meter measuring points 10 on the tunnel surrounding rock, a data collection processing display terminal 12 for receiving, processing and displaying data, a deformation displacement sensing anchor head 1 of an anchor displacement meter, a displacement transmission rod 2 for transmitting the deformation of the rock mass, a wireless transmission module 9 for data transmission and a lead-out cable (5), a displacement sensor 7 for receiving and processing the transmission rod signal, and a displacement sensor protection sleeve 3 for protecting the displacement sensor 7 and the wireless transmission module 9.

[0008] The device for monitoring the gas pressure in the drilling hole comprises a sleeve 13 arranged in the surrounding rock drilling hole, three hole sealing rubber air bags 14 arranged on the outer wall of the sleeve 13 at intervals, and three inner gas guide pipes 16 arranged in the sleeve 13; the inner gas guide pipes 16 are connected to the hole sealing rubber air bags 14 respectively, the inner gas guide pipes 16 are connected to a gas pressure meter 17 at the end, the gas pressure meter 17 is connected to a nitrogen gas delivery bottle, a control valve 18 is arranged on each inner gas guide pipe 16, and the control valve 18 is used for controlling the nitrogen gas to be delivered to each hole sealing rubber air bag 14 to make the air bag expand to seal the surrounding rock drilling hole, so that a sealed pressure measuring chamber is formed between two adjacent hole sealing rubber air bags 14; an explosion-proof gas pressure sensor 15 is arranged in each pressure measuring chamber, each explosion-proof gas pressure sensor 15 is connected to a gas pressure guide wire 20, and the outer end of each gas pressure guide wire 20 is connected to a pressure value converter 21 respectively; the other end of each pressure value converter 21 is connected to the data collection processing display terminal 12 through a data optical fiber.

[0009] The deformation displacement sensing anchor head 1, the displacement transmission rod 2 and the displacement sensor 7 are connected in sequence; the displacement transmission rod 2 is wrapped by a displacement transmission rod protection sleeve 6, and the displacement sensor 7 is wrapped by a displacement sensor protection sleeve 3.

[0010] The lead-out cable 5 is a displacement meter lead-out cable, which is connected with the data collection processing display terminal 12;

[0011] The data collection processing display terminal 12 connects signals of multiple lead-out cables 5 or multiple wireless transmission modules 9, the system can record positions of multiple point displacement meter measuring points 10, and convert frequencies output by the cables into deformation amounts for display.

[0012] The wireless transmission module 9 is arranged in the displacement sensor casing 3.

[0013] The nitrogen delivery bottle 19, the pressure value converter 21 and the data collection processing display terminal 12 are arranged at a vault setting position near the excavation face in the tunnel.

[0014] The hole sealing rubber air bag 14 adopts a size specification with a length range of 100mm-200mm, and intervals of the hole sealing rubber rings are 7m-8m.

[0015] The inner gas guide pipe 16 and the gas pressure wire 20 are arranged inside the casing 13, and pass through small holes on the casing to connect the explosion-proof gas pressure sensor 15 and the hole sealing rubber air bag 14.

[0016] The use method of the device for monitoring stability of a front side of a gas tunnel excavation face comprises the following steps:

[0017] a. Determine a monitoring range of the tunnel surrounding rock, and check a drilling position and direction;

[0018] Drill according to a drilling depth and diameter required by sizes of the surrounding rock displacement deformation measuring device and the gas pressure measuring device casing;

[0019] b. After the drilling is completed, flush the hole with clean water and check drilling quality;

[0020] c. Surrounding rock displacement deformation measuring device assembly: assemble the deformation displacement sensing anchor head 1, the displacement force bar 2 and the displacement sensor 7, and wrap the displacement force bar 2 and the displacement sensor 7 with the displacement force bar casing 6 and the displacement sensor casing 3 respectively for protection, set a support disc to ensure relative stability of the displacement force bar 2, and lead out data transmission cables; gas pressure measuring device assembly: assemble the explosion-proof gas pressure sensor 15, the gas pressure wire 20 passes through a wire hole on a surface of the displacement sensor casing 3, and connects the explosion-proof gas pressure sensor 15 and the pressure value converter 21 through the displacement sensor casing 3, and an inner ring of the hole sealing rubber air bag 14 is adhered to a surface of the metal casing through an anti-corrosion glue;

[0021] d. Place the assembled displacement meter and the gas pressure measuring device into the excavation face drilling 22 and the surrounding rock drilling 23, and place firmly;

[0022] e, insert the grouting pipe 8 and the exhaust pipe 4 into the surrounding rock displacement deformation measuring device borehole, the grouting pipe 8 needs to be inserted to the hole bottom; grouting is carried out from the grouting pipe 8, the grouting pipe 8 and the exhaust pipe 4 are slowly pulled out step by step while grouting, and grouting is completed when the slurry reaches the bottom of the displacement sensor casing 3;

[0023] f, after the slurry solidifies, ensure that the deformation displacement sensing anchor head 1 is integrated with the hole wall anchor;

[0024] g, the displacement meter of the multipoint displacement meter measuring point 10 is connected to the data collection processing display terminal 12 through the wireless transmission module 9 or the wired lead-out cable 5;

[0025] h, control the valve 18 of the nitrogen delivery bottle 19 of the gas pressure measuring device, inflate the hole sealing rubber air bag 14 according to the set appropriate pressure, fill the whole borehole space with the hole sealing rubber air bag 14, realize the closure of the gas pressure measuring chamber, and connect the pressure value converter 21 and the data collection processing display terminal 12 through the transmission line;

[0026] i, the data collection processing display terminal 12 is connected with multiple surrounding rock displacement deformation measuring devices and gas pressure measuring devices, processes the transmitted data and outputs the overall deformation of the surrounding rock of the tunnel and the dynamic change of the borehole gas pressure on the display.

[0027] Active beneficial effects: 1, the surrounding rock displacement measuring device with a terminal display system and the surrounding rock borehole gas pressure monitoring device in the application can simultaneously monitor the surrounding rock deformation displacement and gas pressure of multiple monitoring points, and can directly reflect the stability change of the surrounding rock in front of the tunnel excavation face under the influence of excavation disturbance and gas pressure. 2, the application realizes the closure of the gas pressure monitoring chamber by bonding multiple rubber air bags on the metal casing of the gas pressure monitoring device and using nitrogen for fixed air inflation, and the adjacent two gas pressure monitoring chambers are separated by rubber air bags, so that the stratum gas pressure under two different surrounding rock distances can be independently monitored; nitrogen delivery bottles are used as pressure sources and connected with pressure gauges, so that the rubber air bags can be accurately inflated, and the rubber air bags can be prevented from being broken due to excessive pressure or not being completely closed due to insufficient pressure. 3, the data collection processing display terminal can be set in the open position near the excavation face, so that the real-time dynamic monitoring of the surrounding rock deformation displacement and the stratum gas pressure of multiple positions can be realized, the accuracy of the measured information is high, the data acquisition terminal can more accurately and quickly transmit data for analysis and realize linear dynamic processing, and the stability of the gas stratum in front of the tunnel excavation face and the excavation risk can be evaluated. In summary, the application is also widely applied to the surrounding rock stability monitoring and risk prediction of the gas tunnel in the coal stratum and the non-coal stratum. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the structure of the applicationFigure 1 ;

[0029] Figure 2 Figure is the structural schematic diagram of the present application Figure 2 ;

[0030] Figure 3 Figure is the partial enlarged structural schematic diagram of the drilling hole outside of the gas pressure monitoring device;

[0031] Figure 4 Figure is the partial enlarged structural schematic diagram of the drilling hole inside of the gas pressure monitoring device;

[0032] Figure 5 Figure is the overall layout schematic diagram of the tunnel excavation face surrounding rock of the present device;

[0033] In the figure: deformation displacement sensing anchor head 1, displacement transmission rod 2, displacement sensor casing 3, exhaust pipe 4, lead-out cable 5, displacement transmission rod casing 6, displacement sensor 7, grouting pipe 8, wireless transmission module 9, displacement meter measuring point 10, excavation face 11, data collection processing display terminal 12, casing 13, hole sealing rubber air bag 14, explosion-proof gas pressure sensor 15, inner gas guide pipe 16, gas pressure gauge 17, control valve 18, nitrogen delivery bottle 19, gas pressure lead 20, pressure value converter 21, excavation face drilling hole 22, surrounding rock drilling hole 23, optical fiber 24. DETAILED DESCRIPTION

[0034] The present application will be described in detail below in combination with the drawings and examples. Example 1

[0035] As shown in Figure 1 , Figure 2 , a device for monitoring the stability in front of the gas tunnel excavation face, comprising a surrounding rock deformation displacement monitoring device, a device for monitoring the gas pressure in the drilling hole, and a data collection processing display terminal 12; the surrounding rock displacement monitoring device is arranged in the surrounding rock drilling hole 23 in the excavation face drilling hole 22, and the surrounding rock displacement monitoring device comprises a multi-point displacement meter, an exhaust pipe 4 for exhaust in the drilling hole, a grouting pipe 8 for grouting, and Figure 5 As shown in

[0036] The device for monitoring the gas pressure of the borehole comprises a casing 13 arranged in the borehole of the surrounding rock, three sealing rubber air bags 14 are arranged on the outer wall of the casing 13 at intervals, three inner gas pipes 16 are arranged in the casing 13, the inner gas pipes 16 are connected with the sealing rubber air bags 14 respectively, as shown in the figure, the end of the inner gas pipe 16 is connected with a gas pressure gauge 17, the gas pressure gauge 17 is connected with a nitrogen delivery bottle, a control valve 18 is arranged on each inner gas pipe 16, which is used for controlling the nitrogen to deliver gas to the sealing rubber air bags 14 to make the air bags expand to seal the borehole of the surrounding rock, as shown in the figure, so that a closed pressure measuring chamber is formed between two adjacent sealing rubber air bags 14, an explosion-proof gas pressure sensor 15 is arranged in each pressure measuring chamber, each explosion-proof gas pressure sensor 15 is connected with a gas pressure lead wire 20, the outer end of each gas pressure lead wire 20 is connected with a pressure value converter 21, the other end of each pressure value converter 21 is connected with the data collection processing display terminal 12 through a data optical fiber. Figure 3 Figure 4

[0037] The displacement sensing anchor head 1, the displacement transmission rod 2 and the displacement sensor 7 are connected in sequence, the displacement transmission rod 2 is wrapped by the displacement transmission rod protection pipe 6, and the displacement sensor 7 is wrapped by the displacement sensor protection cylinder 3.

[0038] The lead cable 5 is a displacement meter lead cable, which can be connected with the data collection processing display terminal 12.

[0039] The data collection processing display terminal 12 connects the signals of multiple lead cables 5 or multiple wireless transmission modules 9, the system can record the positions of multiple point displacement meter measuring points 10, and convert the frequencies transmitted by the cables into deformation amounts for display.

[0040] The wireless transmission module 9 is arranged in the displacement sensor protection cylinder 3.

[0041] The nitrogen delivery bottle 19, the pressure value converter 21 and the data collection processing display terminal 12 are arranged at the invert setting position near the excavation face in the tunnel.

[0042] The inner gas pipe 16 and the gas pressure lead wire 20 are arranged inside the casing 13, and are connected with the explosion-proof gas pressure sensor 15 and the sealing rubber air bag 14 through small holes on the casing.

[0043] In the above embodiment, the sealing rubber air bag 14 is selected to have a length range of 100-200 mm. The interval between two adjacent sealing rubber air bags is determined according to actual needs. If the gas pressure of the surrounding rock in the range of 5 m-20 m in front of the excavation face is to be measured, a range of 7 m-8 m can be used.

[0044] ​​In the above embodiment, the diameter of the gas pressure measuring borehole is determined by the diameter of the inflated sealing rubber air bag 14, for example, in the range of 70mm-110mm; and the depth of the gas pressure measuring borehole is in the range of 10-25m according to the number of sealing rubber air bags 14 and the range of the surrounding rock to be measured.

[0045] In the above embodiment, the data collection and processing display terminal 12 is a mobile computer, and the computer is installed with relevant data processing software to collect and process the gas pressure data and the surrounding rock deformation displacement data in real time, and the processed data is outputted to the professional drawing software to obtain the gas pressure and surrounding rock deformation displacement data curve, and the longitudinal deformation displacement of the surrounding rock in front of the tunnel excavation face and the change rule of the surrounding rock gas pressure are displayed intuitively.

[0046] In the above embodiment, the data collection and processing display terminal 12 and the gas pressure value converter 21 are placed in the empty position of the tunnel inverted arch, and a simple operation table is arranged for terminal operation.

[0047] The use method of the device for monitoring the stability of the front of the gas tunnel excavation face comprises the following steps:

[0048] a. Determine the monitoring range of the surrounding rock of the tunnel, and check the position and direction of the borehole;

[0049] According to the drilling depth and diameter required by the size of the surrounding rock displacement deformation measuring device and the gas pressure measuring device, the drilling operation is performed;

[0050] b. After the drilling is completed, the hole is flushed with clean water and the drilling quality is checked;

[0051] c. Surrounding rock displacement deformation measuring device assembly: assemble the deformation displacement sensing anchor head 1, the displacement transmission rod 2 and the displacement sensor 7, and wrap the displacement transmission rod 2 and the displacement sensor 7 with the displacement transmission rod protection pipe 6 and the displacement sensor protection cylinder 3 respectively for protection, set the support disc to ensure the relative stability of the displacement transmission rod 2, and lead out the data transmission cable; gas pressure measuring device assembly: assemble the explosion-proof gas pressure sensor 15, the gas pressure lead 20 passes through the wire hole on the surface of the displacement sensor protection cylinder 3, the explosion-proof gas pressure sensor 15 and the pressure value converter 21 are connected through the inside of the displacement sensor protection cylinder 3, and the inner ring of the sealing rubber air bag 14 is adhered to the surface of the metal protection cylinder through the anti-corrosion glue;

[0052] d. Place the assembled displacement meter and gas pressure measuring device into the excavation face borehole 22 and the surrounding rock borehole 23, and place it firmly;

[0053] e. Insert the grouting pipe 8 and the vent pipe 4 into the borehole of the surrounding rock displacement deformation measuring device. The grouting pipe 8 needs to be inserted to the bottom of the hole. Grouting is carried out from the grouting pipe 8. At the same time as grouting, the grouting pipe 8 and the vent pipe 4 are slowly pulled out step by step. Grouting is completed when the grout reaches the bottom of the displacement sensor casing 3.

[0054] f. After the grout solidifies, ensure that the deformation displacement sensing anchor head 1 is integrated with the hole wall anchor.

[0055] g. The displacement gauges of the multi-point displacement gauge measuring points 10 are connected to the data collection, processing and display terminal 12 via either a wireless transmission module 9 or a wired lead-out cable 5.

[0056] h. The control valve 18 of the nitrogen delivery cylinder 19 of the gas pressure measuring device inflates the sealing rubber airbag 14 according to the set appropriate pressure, so that the sealing rubber airbag 14 fills the entire drilling space and realizes the sealing of the gas pressure measuring chamber; the pressure value converter 21 and the data collection, processing and display terminal 12 are connected through the transmission line.

[0057] i. The data collection, processing, and display terminal 12 connects to multiple surrounding rock displacement and deformation measuring devices and gas pressure measuring devices, processes the transmitted data, and outputs the overall deformation of the tunnel surrounding rock and the dynamic changes in borehole gas pressure on the display.

[0058] 1. This invention is based on a surrounding rock displacement measuring device with a terminal display system and a surrounding rock borehole gas pressure monitoring device. It simultaneously performs dynamic monitoring of surrounding rock deformation displacement and gas pressure at multiple monitoring points, directly reflecting the stability changes of the surrounding rock ahead of the tunnel excavation face under the influence of excavation disturbance and gas pressure. 2. This invention achieves the sealing of the gas pressure monitoring chamber by bonding multiple rubber airbags to the metal casing of the gas pressure monitoring device and using nitrogen for fixed-rate inflation. Adjacent gas pressure monitoring chambers are separated by rubber airbags, allowing independent monitoring of formation gas pressure at two different surrounding rock distances. Using a nitrogen delivery cylinder as the pressure source and connecting it to a pressure gauge enables precise inflation of the rubber airbags, avoiding excessive pressure leading to bursting or insufficient pressure leading to incomplete sealing. 3. This invention, by setting up a data collection, processing, and display terminal in an open location near the excavation face, enables real-time dynamic monitoring of surrounding rock deformation and displacement and stratum gas pressure at multiple locations simultaneously. The measurement information is highly accurate, allowing the data acquisition terminal to transmit and analyze multiple data points more accurately and rapidly, achieving linear dynamic processing and assessing the stability of the gas-bearing strata ahead of the tunnel excavation face and the excavation risk. In summary, this invention is also widely applicable to the monitoring and risk prediction of surrounding rock stability in coal-bearing and non-coal-bearing gas tunnels.

[0059] The above detailed description of the specific embodiments of the present application has been given to understand the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for using a device for monitoring the stability ahead of a gas tunnel excavation face, characterized in that, Includes the following steps: Determine the monitoring range of the surrounding rock of the tunnel and verify the location and direction of the boreholes; carry out drilling operations according to the required borehole depth and diameter based on the size requirements of the casing of the surrounding rock displacement deformation measuring device and the gas pressure measuring device; b. After drilling is completed, rinse the hole with clean water and check the drilling quality; c. Assembly of the surrounding rock displacement deformation measuring device: Assemble the deformation displacement sensing anchor head (1), displacement transmission rod (2) and displacement sensor (7), and wrap the displacement transmission rod (2) and displacement sensor (7) with the displacement transmission rod protective tube (6) and displacement sensor protective tube (3) respectively for protection. Set up a support plate to ensure the relative stability of the displacement transmission rod (2) and lead out the data transmission cable; Assembly of the gas pressure measuring device: Assemble the explosion-proof gas pressure sensor (15), the gas pressure wire (20) passes through the wire hole on the surface of the displacement sensor protective tube (3), and connects the explosion-proof gas pressure sensor (15) and pressure value converter (21) through the inside of the displacement sensor protective tube (3). The inner ring of the sealing rubber air bag (14) is bonded to the surface of the metal protective tube with anti-corrosion adhesive; d. Place the assembled displacement gauge and gas pressure measuring device into the borehole (22) at the excavation face and the surrounding rock borehole (23) and place them securely; e. Insert the grouting pipe (8) and the exhaust pipe (4) into the borehole of the surrounding rock displacement deformation measuring device. The grouting pipe (8) needs to be inserted to the bottom of the hole. Grouting is carried out from the grouting pipe (8). At the same time as grouting, the grouting pipe (8) and the exhaust pipe (4) are slowly pulled out step by step. Grouting is completed when the grout reaches the bottom of the displacement sensor casing (3). f. After the grout solidifies, ensure that the deformation displacement sensing anchor head (1) is integrated with the hole wall anchor. g. The displacement gauges of the multi-point displacement gauge measuring points (10) are connected to the data collection, processing and display terminal (12) by either a wireless transmission module (9) or a wired lead cable (5). h. The control valve (18) of the nitrogen delivery cylinder (19) of the gas pressure measuring device inflates the sealing rubber airbag (14) according to the set appropriate pressure, so that the sealing rubber airbag (14) fills the entire drilling space and realizes the sealing of the gas pressure measuring chamber; the pressure value converter (21) and the data collection, processing and display terminal (12) are connected through the transmission line. i. Data collection, processing and display terminal (12) connects to multiple surrounding rock displacement and deformation measuring devices and gas pressure measuring devices, processes the transmitted data and outputs the overall deformation of the surrounding rock of the tunnel and the dynamic changes of borehole gas pressure on the display.

Images