Intelligent monitoring and control method for dynamic deformation of deep high-stress tunnels

Abstract

The present invention discloses a method for intelligently monitoring and controlling dynamic deformation in deep, high-stress tunnels. The method comprises the following steps: A) using anchor rods and cables for active support on both sides and the top of the surrounding rock mass in the deep, high-stress tunnel; B) arranging stress monitoring sections every 15-25 meters, starting from the front support section of the working face, in the sensitive section of the mining-induced stress change ahead of the working face; C) configuring dynamic pressure regulating mechanisms for all stress-monitoring anchor rods and cables; and D) intelligently controlling the dynamic deformation of the tunnel. This method not only achieves comprehensive monitoring but also automatically regulates the pressure of the anchor rods and cables based on the monitoring results, shifting stress from high-stress areas to adjacent low-stress areas, achieving a uniform distribution and reducing local deformation of the surrounding rock under high-stress conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of surrounding rock deformation control, and in particular to a method for monitoring dynamic deformation of a tunnel under deep, high-stress and complex conditions. Background Art

[0002] Since the surrounding rock in deep mining areas is subject to higher ground stress and complex geological environment, its deformation characteristics are very different from those in shallow areas. The application of deformation control methods and monitoring systems for surrounding rock in deep mining areas is one of the important measures to ensure safe mining of deep working faces.

[0003] Domestic and foreign experts have conducted some research on the deformation of deep high-stress tunnels. Although it has provided theoretical guidance and technical support for the deformation control of deep high-stress tunnels to a certain extent, there are still some shortcomings. The main problems are: the internal support strength of the tunnel is not enough; the sensor layout is unreasonable, and the deformation of the tunnel sides and bottom plate is not monitored, and the monitoring data is relatively simple; only the internal support strength of the tunnel is improved, and the automatic pressure adjustment of anchor rods and cables is not involved. Summary of the Invention

[0004] The present invention aims to provide a method for monitoring the dynamic deformation of tunnels under deep, high-stress and complex conditions, which can not only achieve comprehensive monitoring, but also automatically adjust the pressure of anchor rods and cables according to the monitoring results, so that the stress in high-stress areas is transferred to adjacent low-stress areas and transformed into a uniform distribution, thereby reducing local deformation of the surrounding rock under high-stress conditions.

[0005] To this end, the technical solution adopted by the present invention is: a method for intelligent monitoring and control of dynamic deformation of deep high-stress tunnels, comprising the following steps:

[0006] Step A: Actively support the sides and top of the deep, high-stress roadway surrounding rock using anchor rods and cables; wherein the top plate of the roadway surrounding rock is supported by a combination of high-strength anchor rods and prestressed anchor cables, and both the mined and unmined sides are supported by high-strength anchor rods, with the upper and lower spacing of the high-strength anchor rods in the mined side being greater than that in the unmined side;

[0007] Step B: In a section sensitive to mining stress changes ahead of the working face, a stress monitoring section is arranged every 15-25 meters starting from the outside of the advance support section of the working face drift. Fiber Bragg grating stress sensors are embedded in high-strength anchor rods in the middle of the two sides of the roadway and the middle of the roof, as well as in prestressed anchor cables in the middle of the roadway roof, to monitor mining stress. The high-strength anchor rods in the middle of the two sides of the roadway and the middle of the roof, as well as the prestressed anchor cables in the middle of the roadway roof, are collectively referred to as stress monitoring anchor rods and anchor cables.

[0008] Step C: equip all stress monitoring anchor rods and cables with dynamic pressure regulating mechanisms;

[0009] A hollow jack and an anchor cable prestress monitoring element are installed between the tray and the rock wall of each stress monitoring anchor cable, and the outer side of the tray is locked with a nut. A metal safety net is installed at the position of the stress monitoring anchor cable outside the rock wall. All hollow jacks are connected to the same multi-channel oil source control system through their corresponding high-pressure oil pipes. The multi-channel oil source control system is connected to the built-in human-machine interface through the built-in program controller. The anchor cable prestress monitoring element is connected to the anchor cable prestress monitoring display element.

[0010] Step D: Intelligent control of tunnel dynamic deformation;

[0011] The built-in human-machine interface receives the anchor bolt and cable stress signals monitored by the fiber Bragg grating stress sensor in real time, and dynamically adjusts the prestress of the anchor bolt and cable; the mining stress increase threshold is set by the built-in program controller to determine whether the received data exceeds the threshold. If it exceeds the threshold, the prestress of the anchor bolt and cable in the stress increase section is automatically increased during the mining stress increase section. The built-in program controller drives the multi-channel oil source control system to supply pressure to the hollow jack, and the prestress of the anchor bolt and cable in the high stress area is increased through the stroke control of the hollow jack. Axial prestress is directly applied to the anchor bolt and cable without radial torque conversion, so that the applied prestress can be maintained for a long time during the use of the anchor bolt and cable; the automatic pressure regulation function can transfer the stress in the high stress area to the adjacent low stress area and transform it to a uniform distribution, thereby reducing local deformation of the surrounding rock under high stress state.

[0012] As a preferred embodiment of the above scheme, water supply, compressed air, fire protection and drainage pipelines are installed from top to bottom on the side without mining, and a ditch is set at the bottom of the side without mining.

[0013] It is further preferred that the specification of the high-strength anchor rods is φ20×2400mm, the spacing between high-strength anchor rods on the tunnel surrounding rock top plate is 1200×1000mm, the spacing between high-strength anchor rods on the mining side is 800×1000mm, and the spacing between high-strength anchor rods on the non-mining side is 1600×1000mm; the specification of the prestressed anchor cable is φ22×6000mm, and the spacing between rows is 1300×2900mm.

[0014] Further preferably, fiber Bragg grating displacement sensors are installed near the roof, floor, and middle of the two sides of the roadway to monitor the displacement of the roof and floor of the roadway and the two sides; fiber Bragg grating surrounding rock pressure sensors, fiber Bragg grating embedded strain sensors, and fiber Bragg grating temperature sensors are installed in series in the coal body drill holes at the lower middle of the two sides and at the junction of the roof and floor plates and the coal wall; the roof and floor plate drill holes are distributed diagonally in the roadway to monitor the dynamic pressure of the roof and floor plates of the roadway during mining; and instead of using one drilling depth for mining, three different drilling depths are used at intervals along the longitudinal direction of the mining side;

[0015] An array of fiber grating surrounding rock pressure sensors, fiber grating embedded strain sensors, and fiber grating temperature sensors are connected in series and then connected in parallel with fiber grating displacement sensors. The sensors are connected to a fiber grating signal management host via optical cables. The fiber grating signal management host is connected to a fiber grating sensor network analyzer via cables. The fiber grating sensor network analyzer is connected to a computer equipped with a three-dimensional mining field dynamic pressure and deformation monitoring system via a local area network, thus forming a three-dimensional mining field dynamic pressure and deformation monitoring system based on LabVIEW and intelligent fiber optic sensors. Based on the monitoring data of mining stress in the adjacent working face, the intelligent fiber optic sensors are arranged in the mining stress increased area outside the advance support of the mining field, with the monitoring points spaced 20m apart.

[0016] The beneficial effects of the present invention are: the applied prestress can be maintained for a longer period of time during the use of anchor rods and anchor cables; through the automatic pressure regulation function, the stress in the high stress area can be transferred to the adjacent low stress area and transformed into a uniform distribution, thereby reducing local deformation of the surrounding rock under high stress conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the layout location of the fiber Bragg grating sensor in the tunnel.

[0018] Figure 2 Schematic diagram of the dynamic pressure-regulating anchor rod structure.

[0019] Figure 3 This is the flow chart of intelligent control of dynamic deformation of tunnel.

[0020] Figure 4 Schematic diagram of the three-dimensional mining site dynamic pressure and deformation monitoring system based on LabVIEW and intelligent fiber optic sensors.

[0021] Figure 5 This is the flow chart of the three-dimensional stope dynamic pressure and deformation platform based on LabVIEW.

[0022] Figure 6 This is the layout location of sensors in the three-dimensional stope dynamic pressure and deformation monitoring system.

[0023] Figure 7 It is a three-dimensional stope dynamic pressure and deformation monitoring system. DETAILED DESCRIPTION

[0024] The present invention will be further described below by way of examples and in conjunction with the accompanying drawings:

[0025] A method for intelligently monitoring and controlling dynamic deformation of deep high-stress tunnels comprises the following steps:

[0026] Step A: Figure 1As shown in the figure, anchor rods and cables are used for active support on both sides and the top of the deep high-stress tunnel surrounding rock; among them, the top plate of the tunnel surrounding rock is jointly supported by high-strength anchor rods and prestressed anchor cables, and both the mined and unmined sides are supported by high-strength anchor rods, and the upper and lower spacing of the high-strength anchor rods in the mined side is greater than the upper and lower spacing of the high-strength anchor rods in the unmined side.

[0027] Preferably, the specification of high-strength anchor rods is φ20×2400mm, the spacing between high-strength anchor rods on the tunnel surrounding rock top plate is 1200×1000mm, the spacing between high-strength anchor rods on the mining side is 800×1000mm, and the spacing between high-strength anchor rods on the non-mining side is 1600×1000mm; the specification of the prestressed anchor cable is φ22×6000mm, and the spacing between rows is 1300×2900mm.

[0028] In addition, water supply, compressed air, fire extinguishing and drainage pipelines are installed from top to bottom on the side without mining, and a ditch is set at the bottom of the side without mining.

[0029] Step B: In the mining stress change sensitive section in front of the working face, a stress monitoring section is arranged every 15-25 meters starting from the advance support section of the working face. The fiber grating stress sensor is embedded in the high-strength anchor rods in the middle of the two sides of the roadway and the middle of the roof, as well as the prestressed anchor cable in the middle of the roadway roof. Figure 1 The ① shown in the figure is a fiber Bragg grating stress sensor, which monitors the mining stress. The high-strength anchor rods in the middle of the two sides of the tunnel and the middle of the roof, as well as the prestressed anchor cables in the middle of the tunnel roof are collectively referred to as stress monitoring anchor rods and cables.

[0030] Step C: equip all stress monitoring anchor rods and cables with dynamic pressure regulating mechanisms.

[0031] like Figure 2 As shown, a hollow jack 3 and an anchor cable prestress monitoring element 4 are installed between the tray 2 of each stress monitoring anchor cable 1 and the rock wall, and the outer side of the tray 2 is locked by a nut 5, and a metal safety net 6 and a steel belt 7 are installed at the position of the stress monitoring anchor cable outside the rock wall; all hollow jacks 3 are connected to the same multi-channel oil source control system 9 through their respective corresponding high-pressure oil pipes 8, and the multi-channel oil source control system 9 is connected to the built-in human-machine interface 11 through the built-in program controller 10, and the anchor cable prestress monitoring element 4 is connected to the anchor cable prestress monitoring display element 12.

[0032] Step D: Intelligent control of dynamic deformation of laneway.

[0033] like Figure 3As shown, the built-in human-machine interface receives the anchor bolt and cable stress signals monitored by the fiber Bragg grating stress sensor in real time and dynamically adjusts the prestress of the anchor bolt and cable; the mining stress increase threshold is set by the built-in program controller to determine whether the received data exceeds the threshold. If it exceeds the threshold, the prestress of the anchor bolt and cable in the stress increase section is automatically increased during the mining stress increase section. The built-in program controller drives the multi-channel oil source control system to supply pressure to the hollow jack, and the prestress of the anchor bolt and cable in the high stress area is increased by controlling the stroke of the hollow jack. Axial prestress is directly applied to the anchor bolt and cable without radial torque conversion, so that the applied prestress can be maintained for a long time during the use of the anchor bolt and cable; the automatic pressure regulation function can transfer the stress in the high stress area to the adjacent low stress area and convert it to a uniform distribution, thereby reducing local deformation of the surrounding rock under high stress state.

[0034] like Figure 4 As shown, the three-dimensional mining site dynamic pressure and deformation monitoring system based on LabVIEW and intelligent fiber optic sensors includes a series of fiber grating surrounding rock pressure sensors 9, fiber grating embedded strain sensors 10, and fiber grating temperature sensors 11. Each series group is then connected in parallel with a fiber grating displacement sensor 8, connected to a fiber grating signal management host 6 via an optical cable 7, and the fiber grating signal management host 6 is connected to a fiber grating sensor network analyzer 4 via a cable 5. The fiber grating sensor network analyzer 4 is connected to a computer 1 equipped with a three-dimensional mining site dynamic pressure and deformation monitoring system 2 via a local area network 3. The flowchart of the three-dimensional mining site dynamic pressure and deformation platform based on LabVIEW is shown below. Figure 5 shown.

[0035] Fiber Bragg grating displacement sensor 8, fiber Bragg grating surrounding rock pressure sensor 9, fiber Bragg grating embedded strain sensor 10 and fiber Bragg grating temperature sensor 11 are used to measure roof separation, surrounding rock deformation, and monitor the pressure, strain and temperature inside the surrounding rock. Design appropriate sensor locations. The sensor location diagram is shown in the figure below. Figure 6As shown in the figure, ① is the installation location of the fiber Bragg grating displacement sensor, and ② is the installation location of the fiber Bragg grating surrounding rock pressure sensor, fiber Bragg grating embedded strain sensor, and fiber Bragg grating temperature sensor. The fiber Bragg grating displacement sensor is installed near the middle of the roadway roof, floor, and two sides to monitor the displacement of the roadway roof, floor, and two sides. The fiber Bragg grating surrounding rock pressure sensor, fiber Bragg grating embedded strain sensor, and fiber Bragg grating temperature sensor are installed in series in coal boreholes located slightly below the middle of the two sides and at the junction of the roof, floor, and coal wall. The roof and floor boreholes are distributed diagonally in the roadway to monitor the dynamic pressure of the roadway roof and floor during mining. The fiber Bragg grating surrounding rock pressure sensor, fiber Bragg grating embedded strain sensor, and fiber Bragg grating temperature sensor installed on both sides of the roadway are located in the coal boreholes located slightly below the middle of the roadway. This arrangement is designed to minimize the impact of the drilling on the displacement sensor in the middle of the roadway and facilitate on-site deployment by workers. Placing the remaining sensors in the lower middle of the roadway, close to the displacement sensor, facilitates analysis combined with the data monitored by the displacement sensor. Because the mining side of a roadway is significantly affected by mining stress, to ensure more accurate monitoring of dynamic pressure, instead of using a single drilling depth, three different drilling depths are used at intervals along the longitudinal axis. During installation, the optical cable should be protected with a protective device to prevent damage from excessive pulling force. Based on monitoring data from mining stress in the adjacent working face, intelligent fiber optic sensors were deployed in areas of increased mining stress outside the advance support of the tunnel, with monitoring points spaced 20 meters apart.

[0036] The length mark and tunnel position of the fiber optic Bragg grating are marked at the sensor layout in the tunnel. This is to facilitate the scientific and efficient management of monitoring data and to facilitate the maintenance of the sensor by the staff.

[0037] Based on LabVIEW and the optimization algorithm of intelligent fiber Bragg grating sensor, a three-dimensional stope dynamic pressure and deformation monitoring system is established. Figure 7 The system shown in the figure consists of four related subsystems: sensor system, data acquisition system, data transmission system, and three-dimensional stope dynamic pressure and deformation remote monitoring system.

[0038] Data acquisition system: The system first records the analog signal after being transformed by the sensor and amplified by the amplifier, and then records the digital quantity after analog-to-digital conversion. The data acquisition work of this system is mainly completed by the fiber Bragg grating sensor network analyzer.

[0039] Data transmission system: realizes the function of real-time monitoring, transmits monitoring data to the control room through wired and wireless means, displays it on the computer screen, and finally stores it in the monitoring database.

[0040] 3D remote monitoring system for dynamic pressure and deformation in stopes: This system integrates the characteristics of the monitored targets to efficiently and effectively store stress, strain, and temperature data for anchor bolts and cables in a management system. This management system conveniently acquires data from the data measurement system and allows different users to easily access data, reducing the accumulation of invalid data and ensuring the reliability of essential information storage.

Claims

1. A method for intelligent monitoring and control of dynamic deformation of deep high-stress tunnels, characterized in that: The following steps are involved: Step A: Actively support the sides and top of the deep, high-stress roadway surrounding rock using anchor rods and cables; wherein the top plate of the roadway surrounding rock is supported by a combination of high-strength anchor rods and prestressed anchor cables, and both the mined and unmined sides are supported by high-strength anchor rods, with the upper and lower spacing of the high-strength anchor rods in the mined side being greater than that in the unmined side; Step B: In a section sensitive to mining stress changes ahead of the working face, a stress monitoring section is arranged every 15-25 meters starting from the outside of the advance support section of the working face drift. Fiber Bragg grating stress sensors are embedded in high-strength anchor rods in the middle of the two sides of the roadway and the middle of the roof, as well as in prestressed anchor cables in the middle of the roadway roof, to monitor mining stress. The high-strength anchor rods in the middle of the two sides of the roadway and the middle of the roof, as well as the prestressed anchor cables in the middle of the roadway roof, are collectively referred to as stress monitoring anchor rods and anchor cables. Step C: equip all stress monitoring anchor rods and cables with dynamic pressure regulating mechanisms; A hollow jack and an anchor cable prestress monitoring element are installed between the tray and the rock wall of each stress monitoring anchor cable, and the outer side of the tray is locked with a nut. A metal safety net is installed on the rock wall at the position corresponding to the stress monitoring anchor cable. All hollow jacks are connected to the same multi-channel oil source control system through their corresponding high-pressure oil pipes. The multi-channel oil source control system is connected to the built-in human-machine interface through the built-in program controller. The anchor cable prestress monitoring element is connected to the anchor cable prestress monitoring display element. Step D: Intelligent control of tunnel dynamic deformation; The built-in human-machine interface receives the anchor bolt and cable stress signals monitored by the fiber Bragg grating stress sensor in real time and dynamically adjusts the prestress of the anchor bolt and cable. The built-in program controller sets the mining stress increase threshold to determine whether the received data exceeds the threshold. If so, the prestress of the anchor bolt and cable in the stress increase section is automatically increased during the mining stress increase section. The built-in program controller drives the multi-channel oil source control system to supply pressure to the hollow jack, and the prestress of the anchor bolt and cable in the high stress area is increased by controlling the stroke of the hollow jack. Axial prestress is directly applied to the anchor bolt and cable without radial torque conversion, so that the applied prestress can be maintained for a longer time during the use of the anchor bolt and cable. The automatic pressure regulation function can transfer the stress in the high stress area to the adjacent low stress area and convert it to a uniform distribution, thereby reducing local deformation of the surrounding rock under high stress conditions. Fiber Bragg grating (FBG) displacement sensors are installed near the roadway roof, floor, and the middle of the two sides to monitor their displacement. Fiber Bragg grating (FBG) surrounding rock pressure sensors, embedded FBG strain sensors, and FBG temperature sensors are installed in series in coal boreholes located slightly below the middle of the two sides and at the junction of the roof, floor, and coal wall. The roof and floor boreholes are distributed diagonally in the roadway to monitor the dynamic pressure of the roadway roof and floor during mining. A single drilling depth is used for non-mining, while three different drilling depths are used at intervals along the longitudinal direction of the mining side. An array of fiber grating surrounding rock pressure sensors, fiber grating embedded strain sensors, and fiber grating temperature sensors are connected in series and then connected in parallel with fiber grating displacement sensors. The sensors are connected to a fiber grating signal management host via optical cables. The fiber grating signal management host is connected to a fiber grating sensor network analyzer via cables. The fiber grating sensor network analyzer is connected to a computer equipped with a three-dimensional mining field dynamic pressure and deformation monitoring system via a local area network, thus forming a three-dimensional mining field dynamic pressure and deformation monitoring system based on LabVIEW and intelligent fiber optic sensors. Based on the monitoring data of mining stress in the adjacent working face, the intelligent fiber optic sensors are arranged in the mining stress increased area outside the advance support of the mining field, with the monitoring points spaced 20m apart.

2. The method for intelligent monitoring and control of dynamic deformation in deep high-stress tunnels according to claim 1, characterized in that: Water supply, compressed air, fire extinguishing and drainage pipelines are installed from top to bottom on the side without mining, and a ditch is set at the bottom of the side without mining.

3. The method for intelligent monitoring and control of dynamic deformation in deep high-stress tunnels according to claim 1, characterized in that: The specifications of the high-strength anchor rods are φ20×2400mm, the spacing between high-strength anchor rods on the tunnel surrounding rock top plate is 1200×1000mm, the spacing between high-strength anchor rods on the mining side is 800×1000mm, and the spacing between high-strength anchor rods on the non-mining side is 1600×1000mm; the specifications of the prestressed anchor cable are φ22×6000mm, and the spacing between rows is 1300×2900mm.

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