Distributed optical fiber monitoring method for internal deformation of coal pillar in close-range multi-coal-seam section

Abstract

The invention provides a distributed optical fiber monitoring method for internal deformation of a coal pillar of a close-range multi-coal-seam section, and the method comprises the steps: carrying out the tunneling of roadways at two sides of the coal pillar of the section based on a to-be-monitored region and the first position information of the coal pillar of the section of a mining region until the tail end of each roadway exceeds the to-be-monitored region; laying optical fibers based on the section coal pillar, and obtaining optical fiber strain distribution in the section coal pillar of the to-be-monitored area through the optical fibers; determining coal pillar deformation characteristics of a lower section based on the section coal pillar; determining a boundary of an elastic partition and a plastic partition in the section coal pillar based on the optical fiber strain distribution to obtain first boundary information; determining a boundary of an elastic partition and a plastic partition in the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information; an elastic partition and a plastic partition are determined based on the first boundary information and the second boundary information. The method solves the problem of low monitoring precision of a section coal pillar monitoring method in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and in particular to a distributed optical fiber monitoring method for internal deformation of coal pillars in a close-range multi-coal seam section and a computer-readable storage medium. Background Art

[0002] Coal is a non-renewable energy basic industry. In recent years, with the continuous exploitation of coal resources, mining areas with multiple coal seams have exhausted most of the shallow coal seams and coal seams with good mining conditions, and gradually developed to the deep. After the mining of the upper mineable coal seams is completed, the overburden structure undergoes a process of collapse, crack development, bending and sinking to stability, resulting in various coal pillars of different angles and widths.

[0003] When mining the underlying coal seams at close range, the overburden structure moves multiple times, the stress field is redistributed, the overlying structure undergoes movements such as sinking, collapse and rotation, and causes abnormal energy release patterns, posing a huge challenge to the mining of the lower coal seam working face and the control of tunnel stability.

[0004] Distributed fiber optic sensing technology is a technology that uses optical fiber as a sensing medium to detect physical quantities (such as temperature, stress, vibration, etc.). It has unique advantages such as long-distance monitoring, high sensitivity, and strong anti-electromagnetic interference ability.

[0005] In the existing technology, there are still many difficulties in laying optical fibers, such as the inaccurate laying position of the optical fibers, loose connections or external interference. In addition, during the coal mining process, it is impossible to accurately monitor the deformation and damage characteristics of the coal pillars based on distributed optical fiber sensing technology, and it is impossible to accurately monitor the internal information of the coal pillars, resulting in low monitoring accuracy. Summary of the invention

[0006] The main purpose of the present application is to provide a distributed optical fiber monitoring method for internal deformation of coal pillars in close-range multi-coal seam segments and a computer-readable storage medium, so as to at least solve the problem of low monitoring accuracy of the segment coal pillar monitoring method in the prior art.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a method for monitoring the internal deformation of coal pillars in a close-range multi-coal seam segment is provided, comprising: based on the first position information of the coal pillars in the monitored area and the mining area, tunnels on both sides of the segment coal pillars are excavated until the end of the tunnel exceeds the monitored area; optical fiber is laid in the segment coal pillar based on the monitored area, and the optical fiber strain distribution inside the segment coal pillar in the monitored area is obtained through the optical fiber; based on the segment coal pillar in the monitored area, the coal pillar deformation characteristics of the lower section of the segment coal pillar are determined; based on the optical fiber strain distribution, the boundary between the elastic partition and the plastic partition inside the segment coal pillar is determined to obtain the first boundary information; based on the coal pillar deformation characteristics, the boundary between the elastic partition and the plastic partition inside the segment coal pillar is determined to obtain the second boundary information; based on the first boundary information and the second boundary information, the elastic partition and the plastic partition are determined.

[0008] Optionally, optical fiber is laid in the section coal pillar of the area to be monitored, including: obtaining drilling parameters, and drilling the area to be monitored according to the drilling parameters to obtain a target borehole; implanting an optical fiber sensor into the target borehole based on the target borehole; and grouting the borehole until the target borehole is closed to complete the optical fiber laying.

[0009] Optionally, the drilling parameters include drilling hole diameter, drilling angle, drilling spacing, drilling starting end height, drilling depth and drilling length.

[0010] Optionally, after drilling the monitored area according to the drilling parameters to obtain a target borehole, the method further includes: when the target borehole penetrates the coal pillar in the section, flushing the target borehole with a water pipe controlled by a preset pressure until the coal slag content in the target borehole is less than or equal to a first threshold value.

[0011] Optionally, implanting the optical fiber sensor into the target borehole based on the target borehole includes: passing the end optical fiber into the target borehole and installing a plug at the terminating end of the target borehole; connecting a PVC pipe based on the target borehole and the plug to fix the optical fiber sensor; implanting the optical fiber sensor in the PVC pipe and coiling the pigtail of the optical fiber sensor.

[0012] Optionally, the borehole is grouted until the target borehole is closed to complete the optical fiber laying, including: installing a grouting elbow in the target borehole; and grouting the target borehole through the grouting elbow until the gap between the grouting elbow and the wall of the target borehole is filled.

[0013] Optionally, determining the boundary between the elastic partition and the plastic partition inside the segmented coal pillar based on the coal pillar deformation characteristics to obtain second boundary information includes: constructing an equilibrium equation of the yield stress of the segmented coal pillar based on the coal pillar deformation characteristics: Among them, σ x is the normal stress in the x direction of the limit equilibrium zone of the coal pillar in the section, τ zx is the shear stress in the x direction of the limit equilibrium zone, is the normal stress in the z direction of the limit equilibrium zone, is the normal stress in the x direction of the limit equilibrium zone, T is the lateral pressure coefficient, M is the mining thickness of the coal seam, is the internal friction angle of the coal body, C is the cohesion of the coal body, and P1 is the resistance of the support to the coal seam; based on the equilibrium equation, the plastic partition width inside the coal pillar in the section is solved: Wherein, K is the stress concentration coefficient, ρ is the average bulk density of the overlying rock strata, and H is the buried depth of the coal seam; the second boundary information is determined based on the plastic zone width.

[0014] Optionally, determining the boundary between the elastic partition and the plastic partition inside the coal pillar in the section based on the optical fiber strain distribution to obtain the first boundary information includes: determining the Brillouin optical frequency shift value of each point on the optical fiber based on the optical fiber strain distribution, substituting the Brillouin optical frequency shift value into a preset formula to obtain the strain value: in, is the proportional coefficient, ε is the frequency shift value, ν B (ε) is the Brillouin optical frequency shift value ν corresponding to the strain value ε B (0) the Brillouin optical frequency shift value in a free state; and determining the strain value as the first boundary information.

[0015] Optionally, the elastic partition and the plastic partition are determined based on the first boundary information and the second boundary information, including: calibrating the second boundary information with the first boundary information to obtain a strain critical value; determining the area in the second boundary information corresponding to the strain value greater than or equal to the strain critical value as the plastic partition, and determining the area in the second boundary information corresponding to the strain value less than the strain critical value as the elastic partition.

[0016] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed, the method described in any one of the devices where the computer-readable storage medium is located is controlled.

[0017] Applying the technical solution of the present application, in the above-mentioned method for monitoring the internal deformation of coal pillars in a short-range multi-coal seam section, the method includes: based on the first position information of the coal pillars in the area to be monitored and the mining area, excavating the tunnels on both sides of the coal pillars in the above-mentioned section until the end of the tunnel exceeds the above-mentioned area to be monitored; laying optical fibers in the above-mentioned section coal pillar based on the above-mentioned area to be monitored, and obtaining the optical fiber strain distribution inside the above-mentioned section coal pillar in the above-mentioned area to be monitored through the above-mentioned optical fiber; determining the coal pillar deformation characteristics of the lower section of the above-mentioned section coal pillar based on the above-mentioned section coal pillar in the above-mentioned area to be monitored; determining the boundary between the elastic partition and the plastic partition inside the above-mentioned section coal pillar based on the above-mentioned optical fiber strain distribution to obtain the first boundary information; determining the boundary between the above-mentioned elastic partition and the above-mentioned plastic partition inside the above-mentioned section coal pillar based on the above-mentioned coal pillar deformation characteristics to obtain the second boundary information; determining the above-mentioned elastic partition and the above-mentioned plastic partition based on the above-mentioned first boundary information and the above-mentioned second boundary information. This application uses distributed fiber optic sensing technology to lay optical fibers in the monitored area of ​​the segmented coal pillar, monitors physical quantities using optical fibers as sensing media, and divides the boundaries of the elastic-plastic regions inside the coal pillar based on deformation and fiber optic monitoring data, so as to achieve real-time monitoring of the damage and deformation of the segmented coal pillar. The long-distance monitoring, high sensitivity, and strong anti-electromagnetic interference capabilities of fiber optic sensing solve the problem of low monitoring accuracy of the segmented coal pillar monitoring method in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A hardware structure block diagram of a mobile terminal for monitoring internal deformation of coal pillars in a short-range multi-coal seam section according to an embodiment of the present application is shown;

[0019] Figure 2 A schematic flow chart of a method for monitoring internal deformation of coal pillars in close-range multi-coal seam sections provided according to an embodiment of the present application is shown;

[0020] Figure 3 A schematic top view of a distributed optical fiber implantation section coal pillar according to an embodiment of the present application is shown;

[0021] Figure 4 A schematic diagram of a side view of a coal pillar in a distributed optical fiber implantation section provided according to an embodiment of the present application is shown;

[0022] Figure 5 A schematic diagram of optical fiber strain morphology in a normal state of a distributed optical fiber provided in an embodiment of the present application is shown;

[0023] Figure 6 A schematic diagram of optical fiber strain morphology under a distributed optical fiber stretching state provided in accordance with an embodiment of the present application is shown;

[0024] Figure 7A schematic diagram of optical fiber strain morphology under a distributed optical fiber squeezing state provided in accordance with an embodiment of the present application is shown;

[0025] Figure 8 A structural block diagram of a monitoring device for internal deformation of coal pillars in close-range multi-coal seam sections provided according to an embodiment of the present application is shown.

[0026] The above drawings include the following reference numerals:

[0027] 102, processor; 104, memory; 106, transmission device; 108, input and output devices. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] As introduced in the background technology, the existing methods of monitoring through distributed optical fibers have problems such as inaccurate fiber layout positions, loose connections, or external interference, which lead to uncertainties such as the inability to accurately monitor the deformation and damage characteristics of coal pillars, and low monitoring accuracy. In order to solve the problem of low monitoring accuracy of the segmented coal pillar monitoring methods in the existing technology, the embodiments of the present application provide a distributed optical fiber monitoring method for internal deformation of multi-coal seam segmented coal pillars at close range and a computer-readable storage medium.

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0033] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 1 is a hardware structure block diagram of a mobile terminal for a distributed optical fiber monitoring method for internal deformation of coal pillars in a short distance multi-coal seam section according to an embodiment of the present invention. Figure 1 As shown, the mobile terminal may include one or more ( Figure 1 Only one is shown in the figure) a processor 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 and an input / output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the mobile terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations are shown.

[0034] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the display method of device information in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, the above method is implemented. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The transmission device 106 is used to receive or send data via a network. The above-mentioned specific examples of the network may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0035] In this embodiment, a distributed optical fiber monitoring method for internal deformation of coal pillars in close-range multi-coal seam sections is provided, which runs on a mobile terminal, a computer terminal or a similar computing device. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0036] Figure 2 FIG. 1 is a flow chart of a method for distributed optical fiber monitoring of internal deformation of coal pillars in a short-range multi-coal seam section according to an embodiment of the present application. Figure 2 As shown, the method comprises the following steps:

[0037] Step S201, based on the first position information of the coal pillars in the area to be monitored and the mining area, tunneling is performed on both sides of the coal pillars in the above section until the end of the tunnel exceeds the area to be monitored;

[0038] Specifically, based on the area to be monitored in the coal pillar of the mining area section and the opening position of the optical fiber laying, that is, the above-mentioned first position information, tunnels on both sides of the coal pillar of the above-mentioned section are excavated until the end of the tunnel exceeds the scope of the area to be monitored.

[0039] It is understandable that in order to ensure that the optical fiber laying position can reflect the internal state of the coal pillar in the section, to ensure the accuracy and comprehensiveness of the monitoring data, the deformation and damage inside the coal pillar can be effectively monitored.

[0040] In the specific implementation, tunnel excavation mainly includes: tunnel location confirmation, tunnel excavation design, tunnel excavation construction, tunnel support, tunnel equipment installation and other steps, the purpose is to ensure the smooth progress of the tunnel excavation process and the safety of personnel when in the internal area of ​​the section coal pillar. On-site construction mainly includes drilling excavation, fiber optic sensor implantation and drilling grouting.

[0041] Step S202, laying optical fibers in the above-mentioned section coal pillar based on the above-mentioned area to be monitored, and obtaining the optical fiber strain distribution inside the above-mentioned section coal pillar in the above-mentioned area to be monitored through the above-mentioned optical fibers;

[0042] Specifically, optical fibers are laid in the above-mentioned coal pillar sections in the monitored area, and the strain conditions in the area are monitored in real time using distributed optical fiber sensing technology, and the internal strain distribution data of the coal pillar sections in the monitored area are obtained through optical fibers.

[0043] It is understandable that the deformation and stress information inside the coal pillar can be obtained by monitoring the strain distribution of the optical fiber. Under normal conditions, the strain distribution of the optical fiber will show a certain pattern, and when subjected to external forces such as compression or tension, the strain distribution of the optical fiber will change. By analyzing the changes in the distributed optical fiber strain under normal conditions and under compression and tension, the internal damage of the coal pillar can be judged.

[0044] Step S203, determining the coal pillar deformation characteristics of the lower section of the above-mentioned section coal pillar based on the above-mentioned section coal pillar of the above-mentioned area to be monitored;

[0045] Specifically, the deformation characteristics of the coal pillars in the lower section of the above-mentioned coal pillar section in the above-mentioned area to be monitored are determined, and the possible conditions of the lower coal pillars are inferred by monitoring the deformation of the upper coal pillars, so as to further analyze the overall stability of the coal pillar system.

[0046] Step S204, determining the boundary between the elastic partition and the plastic partition inside the coal pillar in the above section based on the above optical fiber strain distribution, and obtaining first boundary information;

[0047] Specifically, by analyzing the optical fiber strain distribution data, the boundary between the elastic zone and the plastic zone inside the segment coal pillar is determined to obtain the first boundary information. It can be understood that the elastic zone of the coal pillar refers to the reversible deformation of the coal pillar when subjected to an external load, that is, after the load is removed, the coal pillar can return to its original shape. The plastic zone of the coal pillar refers to the irreversible plastic deformation of the coal pillar when the external load exceeds the bearing limit of the coal pillar, that is, after the load is removed, the coal pillar cannot completely return to its original shape.

[0048] Step S205, determining the boundary between the elastic partition and the plastic partition inside the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information;

[0049] Specifically, by analyzing the deformation characteristics of the coal pillar, the boundary between the elastic zone and the plastic zone inside the segment coal pillar is determined to obtain the second boundary information.

[0050] Step S206: determining the elastic partition and the plastic partition based on the first boundary information and the second boundary information.

[0051] Specifically, the elastic partition and plastic partition inside the coal pillar are determined through the first boundary information and the second boundary information in combination with the deformation characteristics of the coal pillar and the monitoring data.

[0052] Through this embodiment, based on the first position information of the coal pillars in the area to be monitored and the mining area, the tunnels on both sides of the coal pillars in the above-mentioned sections are excavated until the end of the tunnel exceeds the above-mentioned area to be monitored; based on the above-mentioned area to be monitored, optical fiber is laid for the coal pillars in the above-mentioned section, and the optical fiber strain distribution inside the coal pillars in the above-mentioned section of the area to be monitored is obtained through the above-mentioned optical fiber; based on the coal pillars in the above-mentioned section of the area to be monitored, the deformation characteristics of the coal pillars in the lower section of the coal pillars in the above-mentioned section are determined; based on the above-mentioned optical fiber strain distribution, the boundary between the elastic partition and the plastic partition inside the coal pillars in the above-mentioned section is determined to obtain the first boundary information; based on the above-mentioned coal pillar deformation characteristics, the boundary between the above-mentioned elastic partition and the above-mentioned plastic partition inside the coal pillars in the above-mentioned section is determined to obtain the second boundary information; based on the above-mentioned coal pillar deformation characteristics, the elastic partition and the above-mentioned plastic partition are determined to obtain the second boundary information; based on the above-mentioned first boundary information and the above-mentioned second boundary information, the elastic partition and the above-mentioned plastic partition are determined. This application uses distributed fiber optic sensing technology to lay optical fibers in the monitored area of ​​the segmented coal pillar, monitors physical quantities using optical fibers as sensing media, and divides the boundaries of the elastic-plastic regions inside the coal pillar based on deformation and fiber optic monitoring data, so as to achieve real-time monitoring of the damage and deformation of the segmented coal pillar. The long-distance monitoring, high sensitivity, and strong anti-electromagnetic interference capabilities of fiber optic sensing solve the problem of low monitoring accuracy of the segmented coal pillar monitoring method in the prior art.

[0053] In order to lay optical fibers in the above-mentioned coal pillar section in the monitoring area, the above-mentioned step S202 includes:

[0054] Step S2021, obtaining drilling parameters, and drilling the area to be monitored according to the drilling parameters to obtain a target borehole;

[0055] Specifically, according to the preset drilling parameters, drilling operations are performed on the monitored area to obtain a target borehole that meets the requirements.

[0056] In one embodiment, the drilling parameters include drilling hole diameter, drilling angle, drilling spacing, drilling start end height, drilling depth and drilling length.

[0057] Step S2022, implanting an optical fiber sensor into the target borehole based on the target borehole;

[0058] Specifically, the optical fiber sensor is implanted into the target borehole through the target borehole so that the optical fiber sensor is accurately arranged at the position required for monitoring.

[0059] Step S2023, grouting is performed on the above-mentioned drill hole until the above-mentioned target drill hole is closed to complete the above-mentioned optical fiber laying.

[0060] Specifically, during the grouting process of the target borehole, a specific slurry is injected into the hole to fill the hole until the target borehole is completely closed, thereby ensuring that the layout position of the optical fiber sensor is fixed and protected, and completing the laying of the optical fiber.

[0061] In order to prevent residual cinders in the borehole from interfering with the optical fiber implantation operation, in an optional implementation, after drilling the above-mentioned area to be monitored according to the above-mentioned drilling parameters to obtain the target borehole, the above-mentioned method further includes:

[0062] Step S301, when the target borehole passes through the coal pillar in the section, flushing the target borehole with a water pipe controlled by a preset pressure until the coal slag content in the target borehole is less than or equal to a first threshold value.

[0063] Specifically, before drilling through the coal pillar and laying the optical fiber, in order to prevent residual coal slag and other substances in the borehole from affecting the optical fiber implantation process, the present application provides for cleaning the borehole through a water pipe until the coal slag and other residues are flushed away.

[0064] In one embodiment, the flushing process lasts for 2-3 minutes.

[0065] In order to complete the optical fiber laying work, in an optional implementation, the above step S2022 includes:

[0066] Step S20221, inserting the end optical fiber into the target borehole, and installing a plug at the terminal end of the target borehole;

[0067] Specifically, in the process of passing the end optical fiber into the above-mentioned target borehole and installing a plug at the terminal end of the above-mentioned target borehole, it is necessary to ensure that the layout and connection of the optical fiber are accurate and reliable. The correct passage of the end optical fiber into the target borehole can ensure the accurate transmission and collection of the monitoring signal, and the installation of the plug is to effectively isolate the internal environment of the borehole from the external environment.

[0068] Step S20222, connecting the PVC pipe according to the target drilling hole and the plug to fix the optical fiber sensor;

[0069] Specifically, a PVC tube is connected to the target borehole and the plug to fix the optical fiber sensor, and the PVC tube is connected to the target borehole and the plug to protect the optical fiber sensor from external factors other than strain, thereby reducing the risk of mechanical damage to the optical fiber sensor.

[0070] Step S20223, implant the optical fiber sensor in the PVC tube, and coil the pigtail of the optical fiber sensor.

[0071] Specifically, the optical fiber sensor is implanted in the PVC tube, and the pigtail of the optical fiber sensor is coiled.

[0072] It can be understood that by implanting the optical fiber sensor into the PVC tube, the optical fiber sensor can be effectively protected from the influence and damage of the external environment, and the pigtail of the optical fiber sensor is coiled in the PVC tube to facilitate subsequent maintenance and management.

[0073] In order to perform grouting on the above-mentioned borehole, in an optional implementation manner, the above-mentioned S2023 includes:

[0074] Step S20231, installing a grouting elbow in the target borehole;

[0075] Specifically, a grouting elbow is installed in the target borehole to provide waterproof and dustproof protection, while preparing for grouting into the target borehole.

[0076] Step S20232, grouting is performed into the target borehole through the grouting elbow until the gap between the grouting elbow and the wall of the target borehole is filled.

[0077] Specifically, grouting is performed into the target borehole based on the grouting elbow until the gap between the grouting elbow and the hole wall of the target borehole is completely filled.

[0078] In order to obtain the second boundary information, the above step S205 includes:

[0079] Step S2051, constructing a yield stress equilibrium equation of the above section coal pillar based on the above coal pillar deformation characteristics;

[0080]

[0081]

[0082] Among them, σ x is the normal stress in the x direction of the limit equilibrium zone of the coal pillar in the above section, τ zx is the shear stress in the x direction in the above limit equilibrium zone, is the normal stress in the z direction of the above limit equilibrium zone, is the normal stress in the x direction of the limit equilibrium zone, T is the lateral pressure coefficient, M is the mining thickness of the coal seam, is the friction inner angle of coal body, C is the cohesion of coal body, and P1 is the resistance of support to coal seam;

[0083] Specifically, the yield stress equilibrium equation is constructed based on known parameters and combined with the theory of elastic mechanics, and the following is obtained:

[0084]

[0085] Furthermore, we can know that:

[0086] Step S2052, solving the plastic zone width inside the coal pillar in the above section based on the above equilibrium equation;

[0087]

[0088] Among them, K is the stress concentration coefficient, ρ is the average bulk density of the overlying rock layer, and H is the burial depth of the coal seam;

[0089] Specifically, Among them, there are:

[0090]

[0091] Step S2053, taking the to-be-monitored area of ​​the above-mentioned section coal pillar as a reference, and determining the above-mentioned second boundary information based on the above-mentioned plastic zone width.

[0092] Specifically, the second boundary information is determined according to the width of the above-mentioned plastic zone.

[0093] In order to obtain the first boundary information, in an optional implementation manner, the above step S204 includes:

[0094] Step S2041, determining the Brillouin optical frequency shift value of each point of the optical fiber based on the optical fiber strain distribution, substituting the Brillouin optical frequency shift value into a preset formula to obtain a strain value:

[0095]

[0096] in, is the proportional coefficient, ε is the frequency shift value, ν B (ε) is the Brillouin optical frequency shift value ν corresponding to the strain value ε B (0) the above Brillouin optical frequency shift value in the free state;

[0097] Specifically, based on the frequency shift caused by Brillouin scattering when light waves propagate in the medium, the optical fiber strain will affect the value and distribution of the Brillouin light frequency shift. Then, based on the monitored Brillouin light frequency shift value, the optical fiber strain value is converted.

[0098] It is understandable that optical fiber strain will cause the refractive index of the optical fiber to change, thereby affecting the transmission characteristics of light in the optical fiber. When the optical fiber is strained, the value of the Brillouin optical frequency shift will change, and the distribution of the optical frequency shift will also be affected.

[0099] Step S2042: determining the strain value as the first boundary information.

[0100] Specifically, the first boundary information is determined according to the above strain value.

[0101] In order to determine the elastic partition and the plastic partition based on the first boundary information and the second boundary information, in an optional implementation, the step S206 includes:

[0102] Step S2061: calibrate the second boundary information based on the first boundary information to obtain a strain critical value.

[0103] Specifically, the second boundary information of the section coal pillar is determined based on the second boundary information, and is matched with the first boundary information, so as to determine the strain value of the distributed optical fiber corresponding to the first boundary information and obtain the strain critical value.

[0104] Step S2062: Determine the region in the second boundary information where the strain value is greater than or equal to the strain critical value as the plastic partition, and determine the region in the second boundary information where the strain value is less than the strain critical value as the elastic partition.

[0105] Specifically, according to the second boundary information, the area with strain value greater than or equal to the strain critical value is determined as the plastic partition, that is, the area where plastic deformation occurs in the coal pillar; the area with strain value less than the strain critical value is determined as the elastic partition, that is, the area where plastic deformation does not occur in the coal pillar.

[0106] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0107] In another embodiment, the above embodiment is described by taking a mining process of a certain mine as an example.

[0108] Assume that the mining of 1-2 coal in a certain mine has been completed, and the main mining of 2-2 coal has begun. The coal seam is a nearly horizontal coal seam. The thickness of the overlying rock layer of 2-2 coal is 82 to 139m, the coal seam inclination is 1 to 3°, the coal seam thickness is 4.2 to 4.4m, the average is 4.3m, and the inclination is 1 to 3°. The working face is under the overlying 1-2 coal leftover goaf. The working face adopts a double-lane layout, and there are a large number of oblique leftover coal pillars. A 15m wide section coal pillar is set between the return air chute and the transport chute of the 2-2 coal working face, and part of the coal pillar is under the leftover coal pillar in the overlying goaf.

[0109] Based on the internal area of ​​the coal pillar in the multi-coal seam mining section, tunnel excavation is carried out on both sides of the section coal pillar to ensure on-site construction to achieve internal monitoring of the section coal pillar;

[0110] The above-mentioned on-site construction operations include drilling excavation, fiber optic sensor implantation and borehole grouting.

[0111] In a specific implementation, an example of the implantation position of the optical fiber sensor is as follows: Figure 3 and Figure 4 As shown, Figure 3 This is a top view of the coal pillar in the distributed optical fiber implantation section. Figure 4 This is a schematic diagram of the side of the coal pillar in the distributed optical fiber implantation section.

[0112] Furthermore, according to the deformation and failure characteristics of the coal pillar in the lower section of the remaining coal pillar, the stress distribution of the coal pillar in the lower coal seam section is analyzed, and the elastic-plastic zoning of the coal pillar in the section is reasonably calculated based on the stress distribution.

[0113] The equilibrium equation of yield stress is established based on the theory of elastic mechanics, based on the formula:

[0114]

[0115] K is the stress concentration factor, which is taken as 3; ρ is the average bulk density of the overlying rock layer, which is taken as 25KN / m 3 ; H is the depth of coal seam, 130m; M = 4.3m, T = 0.58, K=3,ρ=25KN / m 3 , H=130m; C=2MPa; P1=0.75MPa.

[0116] Solving according to the above parameters, we can get x0=3m.

[0117] Based on the principle of distributed optical fiber monitoring, the strain distribution of optical fiber under different conditions is analyzed and corresponds to the site. The calculation of the strain value of a distributed optical fiber point includes:

[0118]

[0119] It can be understood that when the optical fiber is implanted into the coal pillar at an angle α along the coal pillar inclination, when the working face is not mined, the rock formation integrity is good, the optical fiber is subjected to balanced force, and there is no obvious change, such as Figure 5 As shown in the figure, when one side of the coal pillar is mined, the stress concentration of the overlying rock strata increases on the mined side, and the coal rock mass will undergo a transition from elastic to plastic, forming a stress disturbance zone. The rock mass in the disturbance zone is deformed by the crushing and expansion of the coal rock mass, causing the optical fiber to be deformed by force. The optical fiber within the corresponding damage range is pulled as a whole, and the strain is positive, as shown in the figure. Figure 6 As shown; if the optical fiber is in a squeezed state as a whole, the strain is negative as shown Figure 7 shown.

[0120] Based on the above calculation results, the elastic partition and the plastic partition are divided, that is, x0 is 3m, which corresponds to the distributed optical fiber strain value of 450με. The boundaries on both sides of the coal pillar are not considered. When the strain value is less than 450με, it is in the elastic zone, and when it is greater than 450με, it is in the plastic zone. The strain curve can be used to judge the internal changes of the coal pillar.

[0121] The embodiment of the present application also provides a monitoring device for the internal deformation of a coal pillar in a close-range multi-coal seam section. It should be noted that the monitoring device for the internal deformation of a coal pillar in a close-range multi-coal seam section in the embodiment of the present application can be used to execute the monitoring method for the internal deformation of a coal pillar in a close-range multi-coal seam section provided in the embodiment of the present application. The device is used to implement the above-mentioned embodiments and preferred implementation modes, and those that have been explained will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware for a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0122] The following is an introduction to a monitoring device for internal deformation of coal pillars in a close-range multi-coal seam section provided in an embodiment of the present application.

[0123] Figure 8 1 is a structural block diagram of a monitoring device for internal deformation of coal pillars in a close-range multi-coal seam section according to an embodiment of the present application. Figure 8 As shown, the device comprises:

[0124] The first control unit 10 is used to excavate the tunnels on both sides of the coal pillars in the section based on the first position information of the area to be monitored and the section coal pillars in the mining area, until the end of the tunnel exceeds the area to be monitored;

[0125] A second control unit 20 is used to lay optical fibers in the above-mentioned section coal pillar based on the above-mentioned area to be monitored, and obtain the optical fiber strain distribution inside the above-mentioned section coal pillar in the above-mentioned area to be monitored through the above-mentioned optical fibers;

[0126] A first determining unit 30 is used to determine the coal pillar deformation characteristics of the lower section of the above-mentioned section coal pillar based on the above-mentioned section coal pillar of the above-mentioned area to be monitored;

[0127] A second determination unit 40 is used to determine the boundary between the elastic partition and the plastic partition inside the coal pillar in the above section based on the above optical fiber strain distribution to obtain first boundary information;

[0128] A third determining unit 50 is used to determine the boundary between the elastic partition and the plastic partition inside the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information;

[0129] The fourth determining unit 60 is used to determine the elastic partition and the plastic partition based on the first boundary information and the second boundary information.

[0130] Through this embodiment, the first control unit excavates the tunnels on both sides of the coal pillars in the above-mentioned section based on the first position information of the coal pillars in the area to be monitored and the mining area, until the end of the tunnel exceeds the above-mentioned area to be monitored; the second control unit lays optical fibers for the above-mentioned coal pillars in the section based on the above-mentioned area to be monitored, and obtains the optical fiber strain distribution inside the above-mentioned coal pillars in the above-mentioned section of the area to be monitored through the above-mentioned optical fiber; the first determination unit determines the deformation characteristics of the coal pillars in the lower section of the above-mentioned coal pillars in the above-mentioned section based on the above-mentioned coal pillars in the above-mentioned area to be monitored; the second determination unit determines the boundary between the elastic partition and the plastic partition inside the above-mentioned coal pillar in the section based on the above-mentioned optical fiber strain distribution, and obtains the first boundary information; the third determination unit determines the boundary between the above-mentioned elastic partition and the above-mentioned plastic partition inside the above-mentioned coal pillar in the section based on the above-mentioned coal pillar deformation characteristics, and obtains the second boundary information; the fourth determination unit determines the above-mentioned elastic partition and the above-mentioned plastic partition based on the above-mentioned first boundary information and the above-mentioned second boundary information. This application uses distributed fiber optic sensing technology to lay optical fibers in the monitored area of ​​the segmented coal pillar, monitors physical quantities using optical fibers as sensing media, and divides the boundaries of the elastic-plastic regions inside the coal pillar based on deformation and fiber optic monitoring data, so as to achieve real-time monitoring of the damage and deformation of the segmented coal pillar. The long-distance monitoring, high sensitivity, and strong anti-electromagnetic interference capabilities of fiber optic sensing solve the problem of low monitoring accuracy of the segmented coal pillar monitoring method in the prior art.

[0131] In order to lay optical fibers in the above-mentioned coal pillar section of the monitoring area, the above-mentioned second control unit includes:

[0132] The first control subunit acquires drilling parameters, and drills the area to be monitored according to the drilling parameters to obtain a target borehole;

[0133] A second control subunit, implanting an optical fiber sensor into the target borehole based on the target borehole;

[0134] The third control subunit performs grouting on the above-mentioned borehole until the above-mentioned target borehole is closed to complete the above-mentioned optical fiber laying.

[0135] In order to prevent residual cinders in the borehole from interfering with the optical fiber implantation operation, in an optional embodiment, the above-mentioned device further includes:

[0136] The third control unit is used to drill the above-mentioned monitored area according to the above-mentioned drilling parameters to obtain a target borehole, and when the above-mentioned target borehole penetrates the coal pillar in the above-mentioned section, flush the above-mentioned target borehole with a preset pressure controlled water pipe until the coal slag content in the above-mentioned target borehole is less than or equal to the first threshold value.

[0137] In order to complete the optical fiber laying work, in an optional implementation manner, the second control subunit includes:

[0138] A first control module is used to pass the end optical fiber into the target borehole and install a plug at the terminal end of the target borehole;

[0139] A second control module is used to connect the PVC pipe according to the target drilling and the plug to fix the optical fiber sensor;

[0140] The third control module is used to implant the optical fiber sensor in the PVC tube and coil the pigtail of the optical fiber sensor.

[0141] In order to perform grouting on the above-mentioned borehole, in an optional embodiment, the above-mentioned third processing subunit includes:

[0142] A fourth control module is used to install a grouting elbow in the target borehole;

[0143] The fifth control module is used to inject grout into the target borehole through the grouting elbow until the gap between the grouting elbow and the wall of the target borehole is filled.

[0144] In order to obtain the second boundary information, the third determining unit includes:

[0145] A first calculation subunit is used to construct a balance equation of the yield stress of the above-mentioned section coal pillar based on the above-mentioned coal pillar deformation characteristics;

[0146]

[0147]

[0148] Among them, σ x is the normal stress in the x direction of the limit equilibrium zone of the coal pillar in the above section, τ zx is the shear stress in the x direction in the above limit equilibrium zone, is the normal stress in the z direction of the above limit equilibrium zone, is the normal stress in the x direction of the limit equilibrium zone, T is the lateral pressure coefficient, M is the mining thickness of the coal seam, is the friction inner angle of coal body, C is the cohesion of coal body, and P1 is the resistance of support to coal seam;

[0149] The second calculation subunit is used to solve the plastic partition width inside the coal pillar in the above section based on the above equilibrium equation;

[0150] Specifically,

[0151] Among them, K is the stress concentration coefficient, ρ is the average bulk density of the overlying rock layer, and H is the burial depth of the coal seam;

[0152] The first determination subunit is used to determine the second boundary information based on the plastic partition width.

[0153] In order to obtain the first boundary information, in an optional implementation manner, the fourth control unit includes:

[0154] The third calculation subunit is used to determine the Brillouin optical frequency shift value of each point of the optical fiber based on the optical fiber strain distribution, and substitute the Brillouin optical frequency shift value into a preset formula to obtain a strain value:

[0155]

[0156] in, is the proportional coefficient, ε is the frequency shift value, ν B (ε) is the Brillouin optical frequency shift value ν corresponding to the strain value ε B (0) the above Brillouin optical frequency shift value in the free state;

[0157] The second determining subunit is used to determine the strain value as the first boundary information.

[0158] In order to determine the elastic partition and the plastic partition based on the first boundary information and the second boundary information, in an optional implementation manner, the fourth determining unit includes:

[0159] The calibration subunit is used to calibrate the second boundary information based on the first boundary information to obtain a strain critical value.

[0160] The third determination subunit is used to determine the area in the second boundary information corresponding to the strain value greater than or equal to the strain critical value as the plastic partition, and determine the area in the second boundary information corresponding to the strain value less than the strain critical value as the elastic partition.

[0161] The above-mentioned monitoring device for internal deformation of coal pillars in a close-range multi-coal seam section includes a processor and a memory, and the above-mentioned first control unit, second control unit, first determination unit, second determination unit, third determination unit and fourth determination unit are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize corresponding functions. The above-mentioned modules are all located in the same processor; or, the above-mentioned modules are located in different processors in the form of any combination.

[0162] The processor includes a kernel, which calls the corresponding program unit from the memory. One or more kernels can be set, and the accuracy of elastic-plastic region division can be improved by adjusting kernel parameters.

[0163] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0164] An embodiment of the present application provides a computer-readable storage medium, which includes a stored program, wherein when the program is run, the device where the computer-readable storage medium is located is controlled to execute the above-mentioned method for monitoring the internal deformation of coal pillars in a close-range multi-coal seam section.

[0165] Specifically, a method for monitoring internal deformation of coal pillars in a close-range multi-coal seam section includes:

[0166] Step S201, based on the first position information of the coal pillars in the area to be monitored and the mining area, tunneling is performed on both sides of the coal pillars in the above section until the end of the tunnel exceeds the area to be monitored;

[0167] Step S202, laying optical fibers in the above-mentioned section coal pillar based on the above-mentioned area to be monitored, and obtaining the optical fiber strain distribution inside the above-mentioned section coal pillar in the above-mentioned area to be monitored through the above-mentioned optical fibers;

[0168] Step S203, determining the coal pillar deformation characteristics of the lower section of the above-mentioned section coal pillar based on the above-mentioned section coal pillar of the above-mentioned area to be monitored;

[0169] Step S204, determining the boundary between the elastic partition and the plastic partition inside the coal pillar in the above section based on the above optical fiber strain distribution, and obtaining first boundary information;

[0170] Step S205, determining the boundary between the elastic partition and the plastic partition inside the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information;

[0171] Step S206: determining the elastic partition and the plastic partition based on the first boundary information and the second boundary information.

[0172] An embodiment of the present invention provides a processor, which is used to run a program, wherein the program, when running, executes the above-mentioned method for monitoring the internal deformation of coal pillars in a close-range multi-coal seam section.

[0173] Specifically, a method for monitoring internal deformation of coal pillars in a close-range multi-coal seam section includes:

[0174] Step S201, based on the first position information of the coal pillars in the area to be monitored and the mining area, tunneling is performed on both sides of the coal pillars in the above section until the end of the tunnel exceeds the area to be monitored;

[0175] Step S202, laying optical fibers in the above-mentioned section coal pillar based on the above-mentioned area to be monitored, and obtaining the optical fiber strain distribution inside the above-mentioned section coal pillar in the above-mentioned area to be monitored through the above-mentioned optical fibers;

[0176] Step S203, determining the coal pillar deformation characteristics of the lower section of the above-mentioned section coal pillar based on the above-mentioned section coal pillar of the above-mentioned area to be monitored;

[0177] Step S204, determining the boundary between the elastic partition and the plastic partition inside the coal pillar in the above section based on the above optical fiber strain distribution, and obtaining first boundary information;

[0178] Step S205, determining the boundary between the elastic partition and the plastic partition inside the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information;

[0179] Step S206: determining the elastic partition and the plastic partition based on the first boundary information and the second boundary information.

[0180] An embodiment of the present invention provides a monitoring system for internal deformation of coal pillars in a close-range multi-coal seam section. The monitoring system includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, at least the following steps are implemented:

[0181] Step S201, based on the first position information of the coal pillars in the area to be monitored and the mining area, tunneling is performed on both sides of the coal pillars in the above section until the end of the tunnel exceeds the area to be monitored;

[0182] Step S202, laying optical fibers in the above-mentioned section coal pillar based on the above-mentioned area to be monitored, and obtaining the optical fiber strain distribution inside the above-mentioned section coal pillar in the above-mentioned area to be monitored through the above-mentioned optical fibers;

[0183] Step S203, determining the coal pillar deformation characteristics of the lower section of the above-mentioned section coal pillar based on the above-mentioned section coal pillar of the above-mentioned area to be monitored;

[0184] Step S204, determining the boundary between the elastic partition and the plastic partition inside the coal pillar in the above section based on the above optical fiber strain distribution, and obtaining first boundary information;

[0185] Step S205, determining the boundary between the elastic partition and the plastic partition inside the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information;

[0186] Step S206: determining the elastic partition and the plastic partition based on the first boundary information and the second boundary information.

[0187] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program for initializing at least the following method steps:

[0188] Step S201, based on the first position information of the coal pillars in the area to be monitored and the mining area, tunneling is performed on both sides of the coal pillars in the above section until the end of the tunnel exceeds the area to be monitored;

[0189] Step S202, laying optical fibers in the above-mentioned section coal pillar based on the above-mentioned area to be monitored, and obtaining the optical fiber strain distribution inside the above-mentioned section coal pillar in the above-mentioned area to be monitored through the above-mentioned optical fibers;

[0190] Step S203, determining the coal pillar deformation characteristics of the lower section of the above-mentioned section coal pillar based on the above-mentioned section coal pillar of the above-mentioned area to be monitored;

[0191] Step S204, determining the boundary between the elastic partition and the plastic partition inside the coal pillar in the above section based on the above optical fiber strain distribution, and obtaining first boundary information;

[0192] Step S205, determining the boundary between the elastic partition and the plastic partition inside the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information;

[0193] Step S206: determining the elastic partition and the plastic partition based on the first boundary information and the second boundary information.

[0194] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0195] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0196] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0197] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0198] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0199] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0200] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0201] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0202] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity or device including the element.

[0203] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0204] 1) A method for monitoring the internal deformation of coal pillars in a short-range multi-coal seam section of the present application comprises: based on the first position information of the coal pillars in the area to be monitored and the mining area, tunnels on both sides of the coal pillars in the above-mentioned section are excavated until the end of the tunnel exceeds the above-mentioned area to be monitored; optical fiber is laid in the above-mentioned coal pillars in the above-mentioned section based on the above-mentioned area to be monitored, and the optical fiber strain distribution inside the coal pillars in the above-mentioned section of the area to be monitored is obtained through the above-mentioned optical fiber; based on the above-mentioned coal pillars in the above-mentioned area to be monitored, the deformation characteristics of the coal pillars in the lower section of the above-mentioned coal pillars are determined; based on the above-mentioned optical fiber strain distribution, the boundary between the elastic partition and the plastic partition inside the above-mentioned coal pillars in the above-mentioned section is determined to obtain the first boundary information; based on the above-mentioned coal pillar deformation characteristics, the boundary between the above-mentioned elastic partition and the above-mentioned plastic partition inside the above-mentioned coal pillars in the above-mentioned section is determined to obtain the second boundary information; based on the above-mentioned first boundary information and the above-mentioned second boundary information, the elastic partition and the above-mentioned plastic partition are determined. This application uses distributed fiber optic sensing technology to lay optical fibers in the monitored area of ​​the segmented coal pillar, monitors physical quantities using optical fibers as sensing media, and divides the boundaries of the elastic-plastic regions inside the coal pillar based on deformation and fiber optic monitoring data, so as to achieve real-time monitoring of the damage and deformation of the segmented coal pillar. The long-distance monitoring, high sensitivity, and strong anti-electromagnetic interference capabilities of fiber optic sensing solve the problem of low monitoring accuracy of the segmented coal pillar monitoring method in the prior art.

[0205] 2) A monitoring device for internal deformation of coal pillars in a short-range multi-coal seam section of the present application, the first control unit excavates the tunnels on both sides of the above-mentioned section coal pillars based on the first position information of the section coal pillars in the area to be monitored and the mining area, until the end of the tunnel exceeds the above-mentioned area to be detected and monitored; the second control unit lays optical fibers for the above-mentioned section coal pillars based on the above-mentioned area to be detected and monitored, and obtains the optical fiber strain distribution inside the above-mentioned section coal pillars in the above-mentioned area to be monitored through the above-mentioned optical fibers; the first determination unit determines the deformation characteristics of the coal pillars in the lower section of the above-mentioned section coal pillars based on the above-mentioned section coal pillars in the above-mentioned area to be monitored; the second determination unit determines the boundary between the elastic partition and the plastic partition inside the above-mentioned section coal pillar based on the above-mentioned optical fiber strain distribution, and obtains the first boundary information; the third determination unit determines the boundary between the above-mentioned elastic partition and the above-mentioned plastic partition inside the above-mentioned section coal pillar based on the above-mentioned coal pillar deformation characteristics, and obtains the second boundary information; the fourth determination unit determines the above-mentioned elastic partition and the above-mentioned plastic partition based on the above-mentioned first boundary information and the above-mentioned second boundary information. This application uses distributed fiber optic sensing technology to lay optical fibers in the monitored area of ​​the segmented coal pillar, monitors physical quantities using optical fibers as sensing media, and divides the boundaries of the elastic-plastic regions inside the coal pillar based on deformation and fiber optic monitoring data, so as to achieve real-time monitoring of the damage and deformation of the segmented coal pillar. The long-distance monitoring, high sensitivity, and strong anti-electromagnetic interference capabilities of fiber optic sensing solve the problem of low monitoring accuracy of the segmented coal pillar monitoring method in the prior art.

[0206] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. 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 monitoring internal deformation of coal pillars in close-range multi-coal seam sections, characterized in that: include: Based on the first position information of the coal pillars in the area to be monitored and the mining area, tunnels on both sides of the coal pillars in the section are excavated until the end of the tunnel exceeds the area to be monitored; Arranging optical fibers in the section coal pillar based on the area to be monitored, and obtaining the optical fiber strain distribution inside the section coal pillar in the area to be monitored through the optical fibers; Determine the coal pillar deformation characteristics of the lower section of the section coal pillar based on the section coal pillar of the area to be monitored; Determine the boundary between the elastic partition and the plastic partition inside the coal pillar of the section based on the optical fiber strain distribution to obtain first boundary information; Determine the boundary between the elastic partition and the plastic partition inside the section coal pillar based on the deformation characteristics of the coal pillar to obtain second boundary information; The elastic partition and the plastic partition are determined based on the first boundary information and the second boundary information.

2. The method according to claim 1, characterized in that: The optical fiber is laid out in the section coal pillar based on the area to be monitored, including: Acquire drilling parameters, and drill the area to be monitored according to the drilling parameters to obtain a target borehole; implanting an optical fiber sensor into the target borehole based on the target borehole; The borehole is grouted until the target borehole is closed to complete the optical fiber laying.

3. The method according to claim 2, characterized in that The drilling parameters include drilling hole diameter, drilling angle, drilling spacing, drilling starting end height, drilling depth and drilling length.

4. The method according to claim 2, characterized in that: After drilling the area to be monitored according to the drilling parameters to obtain a target borehole, the method further includes: In the case that the target borehole passes through the coal pillar of the section, the target borehole is flushed by controlling the water pipe with a preset pressure until the coal slag content in the target borehole is less than or equal to a first threshold value.

5. The method according to claim 2, characterized in that: Implanting an optical fiber sensor into the target borehole based on the target borehole includes: Passing the end optical fiber into the target borehole, and installing a plug at the terminal end of the target borehole; Connecting a PVC pipe based on the target borehole and the plug to fix the optical fiber sensor; The optical fiber sensor is implanted in the PVC tube, and the pigtail of the optical fiber sensor is coiled.

6. The method according to claim 2, characterized in that Grouting is performed on the borehole until the target borehole is closed to complete the optical fiber laying, including: Installing a grouting elbow in the target borehole; Grouting is performed into the target borehole through the grouting elbow until the gap between the grouting elbow and the wall of the target borehole is filled.

7. The method according to claim 1, characterized in that Determining the boundary between the elastic partition and the plastic partition inside the coal pillar of the section based on the deformation characteristics of the coal pillar to obtain second boundary information includes: Based on the deformation characteristics of the coal pillar, the equilibrium equation of the yield stress of the section coal pillar is constructed: Among them, σ x is the normal stress in the x direction of the limit equilibrium zone of the coal pillar in the section, τ zx is the shear stress in the x direction of the limit equilibrium zone, is the normal stress in the z direction of the limit equilibrium zone, is the normal stress in the x direction of the limit equilibrium zone, T is the lateral pressure coefficient, M is the mining thickness of the coal seam, is the friction inner angle of coal body, C is the cohesion of coal body, and P1 is the resistance of support to coal seam; The plastic partition width inside the coal pillar in the section is solved based on the equilibrium equation: Among them, K is the stress concentration coefficient, ρ is the average bulk density of the overlying rock layer, and H is the burial depth of the coal seam; The second boundary information is determined based on the plastic partition width.

8. The method according to claim 1, characterized in that Determining the boundary between the elastic partition and the plastic partition inside the coal pillar of the section based on the optical fiber strain distribution to obtain first boundary information includes: The Brillouin optical frequency shift value of each point of the optical fiber is determined based on the optical fiber strain distribution, and the Brillouin optical frequency shift value is substituted into a preset formula to obtain a strain value: in, is the proportional coefficient, ε is the frequency shift value, ν B (ε) is the Brillouin optical frequency shift value ν corresponding to the strain value ε B (0) the Brillouin optical frequency shift value in the free state; The strain value is determined as the first boundary information.

9. The method according to claim 8, characterized in that Determining the elastic partition and the plastic partition based on the first boundary information and the second boundary information includes: Calibrate the second boundary information based on the first boundary information to obtain a strain critical value; The region in the second boundary information corresponding to the strain value greater than or equal to the strain critical value is determined as the plastic partition, and the region in the second boundary information corresponding to the strain value less than the strain critical value is determined as the elastic partition.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

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