Tandem point contact under-contact roof height gauge for coal mine strip filling mining and monitoring method

Abstract

The invention relates to a serial point contact under-connected roof height gauge for coal mine strip filling mining, which comprises a plurality of under-connected roof height gauges, a three-way junction box, a driving wire harness, a data acquisition system and a data analysis system, the under-connected roof height gauges are connected with a roadway roof, the driving wire harness is connected with a roadway wall and electrically connected with the data acquisition system, and the data analysis system is electrically connected with the three-way junction box. The data acquisition system is located outside a roadway filling area and is electrically connected with the data analysis system; the monitoring method comprises three steps of equipment layout, real-time monitoring and data summarization. According to the detection device, the undercut roof area in strip filling mining can be detected in a low-cost and easy-to-install mode, information such as the position and the height of the undercut roof area formed after goaf filling can be detected, and three-dimensional information in an invisible filling body can be obtained according to the arrangement mode of the detection device; and follow-up filling slurry filling and safe mining of side coal seams are facilitated.

Description

Technical Field

[0001] The invention relates to a tandem point-contact under-joint top height meter and a monitoring method for coal mine strip filling mining, belonging to the technical field of filling operation. Background Art

[0002] After coal mining using strip and knife-pillar mining methods, the goaf needs to be filled. In the actual filling process, due to the uneven roof, the settlement and accumulation of aggregates in the filling slurry, the seepage of the filling material, the shrinkage of the filling body during maintenance, etc., there are generally large or small under-connected areas in the filling area. If the filling and top connection effect is poor, the exposed area of ​​the mining site roof will be too large, which may easily cause disasters such as roof collapse, surrounding rock slabs, and filling body collapse under dynamic loads, endangering the safety of underground operations. At present, there are two main filling and top connection control technologies, namely, the forced top connection technology for filling operations and the non-settlement-expansion filling and top connection technology. However, the detection of the location and size of the under-connected area is difficult to achieve with existing technologies due to cost and other reasons. For example, during drilling detection, the drilling will cause a certain degree of damage to the original geological structure, which may affect the subsequent stability. Under certain complex geological conditions, the choice of drilling location may be limited and cannot be fully monitored. Borehole observation usually cannot provide real-time data, and it takes a certain amount of time to collect and analyze data. When using geophysical prospecting, the equipment and technology requirements are high. Compared with the borehole observation method, the initial investment and maintenance costs may be higher. The interpretation of data acoustic wave signals requires professional knowledge and experience, and data analysis is relatively complex. External noise may interfere with the acoustic wave signal and affect the accuracy of monitoring.

[0003] Therefore, in view of this problem, it is urgent to develop a coal mine strip filling mining tandem point-contact under-joint top height meter and monitoring method to meet the needs of actual use. Summary of the invention

[0004] In order to address the deficiencies in the prior art, the present invention provides a serial point-contact under-jointed roof height meter and method for strip filling mining in coal mines. The invention can detect the under-jointed roof area in strip filling mining in a low-cost and easy-to-install manner, and can detect the position, height and other information of the under-jointed roof area formed after the goaf is filled. According to the layout of the detection device, three-dimensional information inside the invisible filling body is obtained, which is convenient for subsequent filling of slurry and safe mining of lateral coal seams. The system configuration structure is simple, the adjustment is flexible, and the system expansion capability is strong. It can effectively meet the needs of use in various geological structures and tunnel structure environments, has strong versatility, and is simple and convenient to operate. The monitoring data is convenient to collect and the monitoring data is highly accurate. It can also assist in optimizing the filling process, improve the top connection rate of the filling area, and achieve the purpose of improving the quality and efficiency of the filling operation.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A series point-contact under-jointed top height meter for strip filling mining in coal mines, comprising an under-jointed top height meter, a three-way junction box, a driving harness, a data acquisition system, and a data analysis system, wherein a plurality of under-jointed top height meters are provided, each of which is connected to a tunnel roof and is distributed in a square along the tunnel axis, and at the same time, each of the under-jointed top height meters is connected in parallel with each other, and is electrically connected to the driving harness at the three-way junction box through a wire, at least one driving harness is connected to the tunnel wall and is electrically connected to the data acquisition system, the data acquisition system is located outside the tunnel filling area, and at least one data acquisition system is provided outside each filling area, and is also electrically connected to the data analysis system through a driving harness. The data analysis system is electrically connected, the data analysis system is located on the surface, and establishes data connection with a third-party communication platform through a communication network; the under-connected top altimeter includes an assembly base, a liquid level sensor, and a wiring terminal. The assembly base is in a "T"-shaped structure, and its upper end face is connected to the top of the filling area and is distributed in parallel. At the same time, the lower end face of the assembly base is connected to four liquid level sensors evenly distributed around its axis through a connecting mechanism, and the detection axis of the liquid level sensor is vertically distributed to the upper end face of the assembly base, and each liquid level sensor is electrically connected to the wire through the wiring terminal, the wiring terminal is connected to the outer side of the assembly base, and is electrically connected to the drive wiring harness at the three-way junction box through the wire.

[0007] Furthermore, the assembly base includes a positioning plate, a guide column, a sheath column, a pressure sensor, a spring, and an elastic clamp, wherein the positioning plate is a rectangular plate-like structure, the lower end face of which is connected and coaxially distributed with the guide column, and forms a structure with a "T"-shaped cross-section with the guide column, and the upper end face of the positioning plate is connected and parallelly distributed with the top of the filling area, the guide column is a cylindrical structure, embedded in the sheath column and coaxially distributed between the sheath column, and the guide column and the inner side surface of the sheath column are abutted and slidably connected, and at the same time, a pressure sensor coaxially distributed with the guide column is provided on the lower end face of the guide column, and the pressure sensor is also abutted against the bottom of the sheath column through a spring, and at least four elastic clamps evenly distributed around its axis are provided on the outer side face of the sheath column, and are connected to the liquid level sensor through the elastic clamp, and at least one connecting screw hole is provided on the lower end face of the sheath column, and is connected to an external device through the connecting screw hole, and the pressure sensor is also electrically connected to the wiring terminal.

[0008] Furthermore, the lower end surface of the positioning plate is provided with at least two floating blocks evenly distributed around its axis.

[0009] Further, the liquid level sensor includes a barrel cavity, a liquid level float ball, an annular magnet, a magnetic reed switch, and a seepage net. The barrel cavity is a cylindrical cavity structure with a "冂"-shaped axial cross-section, and its axis is parallel to the axis of the sheath column. The seepage net is coated outside the lower end face of the barrel cavity. The liquid level float ball is embedded in the barrel cavity, abuts against the inner side of the barrel cavity and is slidably connected, and the diameter of the liquid level float ball is not greater than 30% of the height of the barrel cavity. An annular magnet coaxial with it is provided at both the top and bottom of the liquid level float ball. At least three magnetic reed switches are embedded in the side wall of the barrel cavity and are evenly distributed from top to bottom along the axis of the barrel cavity. A magnetic reed switch is provided at both the top and bottom positions of the barrel cavity. At the same time, the magnetic reed switches are connected in parallel and are electrically connected to the terminal block respectively.

[0010] Further, the drive wire harness includes an elastic protective sleeve, a rigid connection sleeve, a traction steel strand, a disc spring, a hook, a bearing keel, a spring piece, a power cable, a communication bus, and a control signal transmission wire. The elastic protective sleeve is a hollow columnar structure with a rectangular axial cross-section. Its front end face and rear end face are both connected to a rigid connection sleeve coaxial with it. At the same time, a number of branch interfaces are evenly distributed on the side wall of the elastic protective sleeve, and each branch interface is connected to a rigid connection sleeve and is vertically distributed. The elastic protective sleeve is connected to and communicates with the three-way junction box through the rigid connection sleeve at the branch interface. There are several bearing keels, which are plate-like structures coaxial with the elastic protective sleeve. An assembly hole coaxial with it is provided on the bearing keel, and at least three wiring grooves are provided around its axis at the edge. The opening of the wiring groove is blocked by a spring piece, and both ends of the spring piece are connected to the outer side of the bearing keel by bolts. A hook coaxial with it is provided at both the front end face and the rear end face of the disc spring, and is connected to at least one traction steel strand through the hook. At the same time, the adjacent two bearing keels are connected to each other through the traction steel strand, and the distance between the adjacent two bearing keels is at least 3 times the maximum width of the bearing keel. At the same time, there is one power cable, one communication bus, and one control signal transmission wire, which are respectively embedded in an independent wiring groove.

[0011] Further, the rigid connection sleeve includes a washer, a guide sheath, and an elastic sealing ring. The upper end face of the washer is connected to the guide sheath and is coaxial. The guide sheath is a cylindrical hollow tubular structure. At the same time, a connection thread and at least one elastic sealing ring coaxial with it are provided on the outer side of the guide sheath. The elastic sealing ring is located between the upper end face of the washer and the connection thread.

[0012] Further, the data acquisition system is a circuit system based on any one or two of a programmable controller and an FPGA chip. The data analysis system is any one of an industrial computer and a PC computer. At the same time, the data analysis system is also provided with a big data server and a distributed data storage system.

[0013] A method for monitoring under-joint top height of a tandem point-contact under-joint top height meter for strip filling mining in a coal mine comprises the following steps:

[0014] S1, equipment layout, after the filling pipeline is laid out in the area to be filled, install the under-connected top height meter, and lay each under-connected top height meter at the roof 1-2m away from the coal wall on the side away from the filling feeding pipeline, and arrange them in the length direction of the strip, the signal power line is fixed on the roof and connected to the under-connected top height meter by the driving harness fixed on the roof of the coal wall, the under-connected top height meter is connected in series in sequence by the driving harness, and is connected to the data acquisition system set up in the transport lane outside the filling area, the data acquisition system establishes a data connection with the driving harness, and the system configuration can be completed, and after the system configuration is completed, an independent communication address is matched for each under-connected top height meter;

[0015] S2, real-time monitoring. During the filling operation, as the liquid level at the top of the filling slurry continues to rise, it continues to approach the liquid level sensor at the bottom of the under-joint top height gauge. When the top interface of the liquid surface contacts the liquid level sensor, the filling slurry is fully monitored during its rising process. At the same time, the liquid level sensor returns a signal to the data acquisition system based on this. According to the spatial coordinates of the under-joint top height gauge, the filling area slurry top connection situation and the under-joint top height value can be obtained;

[0016] S3, data summary, during the filling and top connection process, the data acquisition system controls and records relevant data, and the data analysis system interpolates the under-connection top height contour map of the filling area according to the plane coordinates (xi, yi) of each under-connection top height meter and the under-connection top height hi (i = 1, 2, ..., n) detected by the liquid level sensor, and displays it in three dimensions; after the filling is completed, data collection and analysis are carried out, including the position, height and other dimensional parameters of the under-connection top area of ​​the filling body; then the detection equipment is used to record various data, analyze the filling effect, and perform subsequent optimization and adjustment based on the data results.

[0017] Furthermore, in the step S1, the distance between two adjacent under-connected top altimeters is 10-50m, and the under-connected top altimeters are installed at any one of the "Z-shaped" and "I-shaped" layout structures according to the strip inclination angle and geometric size factors.

[0018] Furthermore, in the step S2, when performing the filling operation, a layered filling operation is adopted, and the filling height of each layer in the filling area is 0.5-2.0m, and the filling height of the top position of the filling area is 0.3-0.5m; wherein the filling of the top position is divided into two parts: the first stage of material discharge and the second stage of material discharge, and the specific filling steps are as follows:

[0019] The first step is to start the first stage of roof filling by unloading materials from the lower end of the roof; after the first stage of roof filling is completed, start the data acquisition system and data analysis system to solve the contour map of the under-jointed roof height, use the integral method to solve the size of the under-jointed roof space in the designed first stage of roof filling area, and continue to unload materials and fill according to the size of the under-jointed roof space until the roof monitoring system shows that the first stage of roof filling area is completely roofed;

[0020] The second step is to optimize the second stage of material discharge for roof connection and filling, adjust the discharge port, start designing and carry out material discharge for the second stage of roof connection and filling area; after the second stage of material discharge for roof connection and filling is completed, start the data acquisition system and data analysis system, solve the contour map of under-connection height, use the integral method to solve the size of the under-connection space in the designed second stage of roof connection and filling area, and continue to discharge materials and fill according to the size of the under-connection space until the roof connection monitoring system shows that the second stage of roof connection and filling area is completely connected;

[0021] The third step is to repeat the first and second steps until the filling operation of the entire filling area is completed.

[0022] Compared with the prior art, the present invention can detect the under-connected roof area in strip filling mining in a low-cost and easy-to-install manner, and can detect the position, height and other information of the under-connected roof area formed after the goaf is filled, and obtain three-dimensional information inside the invisible filling body according to the layout of the detection device, which is convenient for the subsequent filling of slurry and the safe mining of the lateral coal seams. The system configuration structure is simple, the adjustment is flexible, and the system expansion capability is strong. It can effectively meet the needs of use in various geological structures and tunnel structure environments, has strong versatility, and is simple and convenient to operate. The monitoring data is convenient to collect and the monitoring data is highly accurate. It can also assist in optimizing the filling process, improve the connection rate of the filling area, and achieve the purpose of improving the quality and efficiency of the filling operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments;

[0024] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0025] Figure 2 It is a schematic diagram of the local structure of the under-connected top altimeter;

[0026] Figure 3 It is a schematic diagram of the partial structure of the liquid level sensor in cross section;

[0027] Figure 4 It is a schematic diagram of the partial structure of the drive harness;

[0028] Figure 5 This is a schematic diagram of the main structure of the load-bearing keel;

[0029] Figure 6 It is a schematic diagram of the local structure of the hard connection casing;

[0030] Figure 7 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0031] In order to facilitate the construction of the technical means, creative features, objectives and effects achieved by the present invention, the present invention is further described below in conjunction with specific implementation methods.

[0032] like Figure 1-Figure 6 As shown, a serial point-contact under-jointed top height meter for strip filling mining in coal mines comprises an under-jointed top height meter 1, a three-way junction box 2, a drive harness 3, a data acquisition system 4, and a data analysis system 5, wherein there are a plurality of under-jointed top height meters 1, each of which is connected to the tunnel roof and is distributed in a square along the tunnel axis, while each of the under-jointed top height meters 1 is connected in parallel to each other, and is electrically connected to the drive harness 3 at the three-way junction box 2 through a wire, at least one drive harness 3 is connected to the tunnel wall and is electrically connected to the data acquisition system 4, the data acquisition system 4 is located outside the tunnel filling area, and at least one data acquisition system 4 is provided outside each filling area, and is electrically connected to the data analysis system 5 through the drive harness 3, the data analysis system 5 is located on the surface, and establishes a data connection with a third-party communication platform through a communication network.

[0033] In this embodiment, the under-connected top altimeter 1 includes an assembly base 11, a liquid level sensor 12, and a wiring terminal 13. The assembly base 11 is in a "T"-shaped structure, and its upper end face is connected to the top of the filling area and distributed in parallel. At the same time, the lower end face of the assembly base 11 is connected to four liquid level sensors 12 evenly distributed around its axis through a connecting mechanism. The liquid level sensor 12 is vertically distributed between the detection axis and the upper end face of the assembly base 11, and each liquid level sensor 12 is electrically connected to the 13 wires through the wiring terminal, and the wiring terminal is connected to the outer side surface of the 13 assembly base 11, and is electrically connected to the drive harness 3 through the wire at the three-way junction box 2.

[0034] In this embodiment, the assembly base 11 includes a positioning plate 111, a guide column 112, a sheath column 113, a pressure sensor 114, a spring 115, and an elastic clamp 116, wherein the positioning plate 111 is a rectangular plate-like structure, the lower end surface of which is connected to and coaxially distributed with the guide column 112, and forms a structure with a "T"-shaped cross section with the guide column 112, and the upper end surface of the positioning plate 111 is connected to and parallel to the top of the filling area, the guide column 112 is a cylindrical structure, embedded in the sheath column 113 and coaxially distributed with the sheath column 113, and the guide column 112 and the sheath The inner side surfaces of the columns 113 are abutted against each other and slidably connected. At the same time, a pressure sensor 114 coaxially distributed therewith is provided on the lower end surface of the guide column 112. The pressure sensor 114 is also abutted against the bottom of the sheath column 113 through a spring 115. The outer side surface of the sheath column 113 is also provided with at least four elastic clamps 116 evenly distributed around its axis, and is connected to the liquid level sensor 12 through the elastic clamps 116. At least one connecting screw hole 117 is also provided on the lower end surface of the sheath column 113, and is connected to an external device through the connecting screw hole. At the same time, the pressure sensor 114 is also electrically connected to the wiring terminal 13.

[0035] The sliding connection structure between the guide column and the sheath column can, on the one hand, flexibly adjust the equipment structure according to the needs of use, and on the other hand, enable the positioning plate to float synchronously with the slurry liquid level during the grouting process, thereby improving the work quality and efficiency of the grouting operation. At the same time, when the positioning plate floats up or down, the pressure sensor can be used to detect the force condition of the positioning plate, thereby indirectly judging the pressure value of the grouting slurry filling the working surface, thereby facilitating improving the accuracy of the grouting operation control.

[0036] For further optimization, the lower end surface of the positioning plate 111 is provided with at least two floating blocks 118 evenly distributed around its axis.

[0037] The provided floating block can help to improve the flexibility of the positioning plate in floating adjustment along with the grouting slurry liquid level.

[0038] Meanwhile, the liquid level sensor 12 includes a barrel cavity 121, a liquid level float 122, an annular magnet 123, a magnetic reed switch 124, and a seepage net 125. The barrel cavity 121 is a cylindrical cavity structure with a "冂"-shaped axial cross-section, and its axis is parallel to the axis of the sheath column 113. The seepage net 125 is coated outside the lower end face of the barrel cavity 121. The liquid level float 122 is embedded in the barrel cavity 121, abuts against the inner side surface of the barrel cavity 121 and is slidably connected, and the diameter of the liquid level float 122 is not greater than 30% of the height of the barrel cavity 121. An annular magnet 123 is provided at both the top and bottom of the liquid level float 122 and is coaxially distributed therewith. At least three magnetic reed switches 124 are embedded in the side wall of the barrel cavity 121 and are evenly distributed along the axis of the barrel cavity from top to bottom. A magnetic reed switch 124 is provided at both the top and bottom positions of the barrel cavity 121. At the same time, the magnetic reed switches 124 are connected in parallel and are respectively electrically connected to the terminal block 13.

[0039] Specifically, the drive wire harness 3 includes an elastic protective sleeve 31, a rigid connection sleeve 32, a traction steel strand 33, a disc spring 34, a hook 35, a load-bearing keel 36, a spring piece 37, a power cable 38, a communication bus 39, and a control signal transmission wire 30. The elastic protective sleeve 31 is a hollow columnar structure with a rectangular axial cross-section. Its front end face and rear end face are both connected to a rigid connection sleeve 32 coaxially distributed therewith. At the same time, a number of branch interfaces 301 are evenly distributed on the side wall of the elastic protective sleeve 31, and each branch interface 301 is connected to a rigid connection sleeve 32 and is vertically distributed. The elastic protective sleeve 31 is connected to and communicates with the three-way junction box 2 through the rigid connection sleeve 32 at the branch interface 301. There are a number of load-bearing keels 36, which are plate-like structures coaxially distributed with the elastic protective sleeve 31. An assembly hole 302 coaxially distributed therewith is provided on the load-bearing keel 36, and at least three wiring grooves 303 are provided around its axis at the edge. The opening of the wiring groove 303 is blocked by a spring piece 37, and both ends of the spring force 37 are connected to the outer side surface of the load-bearing keel 36 through bolts. A hook 35 coaxially distributed therewith is provided at both the front end face and the rear end face of the disc spring 34, and is connected to at least one traction steel strand 33 through the hook 35. At the same time, the adjacent two load-bearing keels 36 are connected to each other through the traction steel strand 33, and the distance between the adjacent two load-bearing keels 36 is at least 3 times the maximum width of the load-bearing keel 36. At the same time, there is one power cable 38, one communication bus 39, and one control signal transmission wire 30, which are respectively embedded in an independent wiring groove 303.

[0040] At the same time, the hard connecting sleeve 32 includes a gasket 321, a guide sleeve 322, and an elastic sealing ring 323, wherein the upper end face of the gasket 321 is connected to the guide sleeve 322 and is coaxially distributed, and the guide sleeve 322 is a cylindrical hollow tubular structure, and the outer side of the guide sleeve 322 is provided with a connecting thread and at least one elastic sealing ring coaxially distributed therewith, and the elastic sealing ring 323 is located between the upper end face of the gasket 321 and the connecting thread.

[0041] In this embodiment, the data acquisition system 4 is a circuit system based on any one of a programmable controller and an FPGA chip or a combination of both, and the data analysis system 5 is any one of an industrial computer and a PC computer. At the same time, the data analysis system 5 is also equipped with a big data server and a distributed data storage system.

[0042] like Figure 7 As shown, a method for monitoring the under-joint top height of a tandem point-contact under-joint top height meter for strip filling mining in a coal mine comprises the following steps:

[0043] S1, equipment layout, after the filling pipeline is laid out in the area to be filled, install the under-connected top height meter, and lay each under-connected top height meter at the roof 1-2m away from the coal wall on the side away from the filling feeding pipeline, and arrange them in the length direction of the strip, the signal power line is fixed on the roof and connected to the under-connected top height meter by the driving harness fixed on the roof of the coal wall, the under-connected top height meter is connected in series in sequence by the driving harness, and is connected to the data acquisition system set up in the transport lane outside the filling area, the data acquisition system establishes a data connection with the driving harness, and the system configuration can be completed, and after the system configuration is completed, an independent communication address is matched for each under-connected top height meter;

[0044] S2, real-time monitoring. During the filling operation, as the liquid level at the top of the filling slurry continues to rise, it continues to approach the liquid level sensor at the bottom of the under-joint top height gauge. When the top interface of the liquid surface contacts the liquid level sensor, the filling slurry is fully monitored during its rising process. At the same time, the liquid level sensor returns a signal to the data acquisition system based on this. According to the spatial coordinates of the under-joint top height gauge, the filling area slurry top connection situation and the under-joint top height value can be obtained;

[0045] S3, data summary. During the filling and capping process, the data acquisition system controls and records relevant data. The data analysis system interpolates the contour map of the under-joint height of the filling area according to the plane coordinates (xi, yi) of each under-joint height meter and the under-joint height hi (i=1, 2,…, n) detected by the liquid level sensor, and displays it in three dimensions. After the filling is completed, data collection and analysis are carried out, including the position, height and other dimensional parameters of the under-joint area of ​​the filling body. Then, the detection equipment is used to record various data, analyze the filling effect, and perform subsequent optimization and adjustment based on the data results.

[0046] Furthermore, in the step S1, the spacing between two adjacent under-connected top altimeters is 10-50m, and the under-connected top altimeters are installed in any of the "Z-shaped" and "I-shaped" layout structures according to the strip inclination angle and geometric size factors. At the same time, when the local roof fluctuation changes greatly in the area, the number of installations can be appropriately increased.

[0047] Furthermore, in the step S2, when performing the filling operation, a layered filling operation is adopted, and the filling height of each layer in the filling area is 0.5-2.0m, and the filling height of the top position of the filling area is 0.3-0.5m; wherein the filling of the top position is divided into two parts: the first stage of material discharge and the second stage of material discharge, and the specific filling steps are as follows:

[0048] The first step is to start the first stage of roof filling by unloading materials from the lower end of the roof; after the first stage of roof filling is completed, start the data acquisition system and data analysis system to solve the contour map of the under-jointed roof height, use the integral method to solve the size of the under-jointed roof space in the designed first stage of roof filling area, and continue to unload materials and fill according to the size of the under-jointed roof space until the roof monitoring system shows that the first stage of roof filling area is completely roofed;

[0049] The second step is to optimize the second stage of material discharge for roof connection and filling, adjust the discharge port, start designing and carry out material discharge for the second stage of roof connection and filling area; after the second stage of material discharge for roof connection and filling is completed, start the data acquisition system and data analysis system, solve the contour map of under-connection height, use the integral method to solve the size of the under-connection space in the designed second stage of roof connection and filling area, and continue to discharge materials and fill according to the size of the under-connection space until the roof connection monitoring system shows that the second stage of roof connection and filling area is completely connected;

[0050] The third step is to repeat the first and second steps until the filling operation of the entire filling area is completed.

[0051] Compared with the prior art, the present invention can detect the under-connected roof area in strip filling mining in a low-cost and easy-to-install manner, and can detect the position, height and other information of the under-connected roof area formed after the goaf is filled, and obtain three-dimensional information inside the invisible filling body according to the layout of the detection device, which is convenient for the subsequent filling of slurry and the safe mining of the lateral coal seams. The system configuration structure is simple, the adjustment is flexible, and the system expansion capability is strong. It can effectively meet the needs of use in various geological structures and tunnel structure environments, has strong versatility, and is simple and convenient to operate. The monitoring data is convenient to collect and the monitoring data is highly accurate. It can also assist in optimizing the filling process, improve the connection rate of the filling area, and achieve the purpose of improving the quality and efficiency of the filling operation.

[0052] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A tandem point-contact under-joint top height meter for coal mine strip filling mining, characterized in that: The serial point-contact under-jointed top height meter for strip filling mining in coal mines comprises an under-jointed top height meter, a three-way junction box, a drive harness, a data acquisition system, and a data analysis system, wherein there are a plurality of under-jointed top height meters, each of which is connected to the top plate of the tunnel and is distributed in a square along the axis of the tunnel, and at the same time, each of the under-jointed top height meters is connected in parallel to each other, and is electrically connected to the drive harness at the three-way junction box through a wire, at least one of the drive harnesses is connected to the tunnel wall and is electrically connected to the data acquisition system, the data acquisition system is located outside the tunnel filling area, and at least one data acquisition system is provided outside each filling area, and is also electrically connected to the data analysis system through a drive harness The data analysis system is located on the surface and establishes a data connection with a third-party communication platform through a communication network; the under-connected top altimeter includes an assembly base, a liquid level sensor, and a wiring terminal. The assembly base is in a "T"-shaped structure, and its upper end face is connected to the top of the filling area and is distributed in parallel. At the same time, the lower end face of the assembly base is connected to four liquid level sensors evenly distributed around its axis through a connecting mechanism. The detection axis of the liquid level sensor is vertically distributed between the upper end face of the assembly base, and each liquid level sensor is electrically connected to the wire through a wiring terminal. The wiring terminal is connected to the outer side of the assembly base, and is electrically connected to the drive harness at the three-way junction box through the wire.

2. A tandem point-contact under-joint top height meter for coal mine strip filling mining according to claim 1, characterized in that: The assembly base includes a positioning plate, a guide column, a sheath column, a pressure sensor, a spring, and an elastic clamp, wherein the positioning plate is a rectangular plate-like structure, the lower end face of which is connected and coaxially distributed with the guide column, and forms a "T"-shaped structure with the guide column, and the upper end face of the positioning plate is connected and parallelly distributed with the top of the filling area, the guide column is a cylindrical structure, embedded in the sheath column and coaxially distributed with the sheath column, and the guide column and the inner side of the sheath column are abutted and slidably connected, and at the same time, a pressure sensor coaxially distributed with the guide column is provided on the lower end face of the guide column, and the pressure sensor is also abutted against the bottom of the sheath column through a spring, and at least four elastic clamps evenly distributed around its axis are provided on the outer side face of the sheath column, and are connected to the liquid level sensor through the elastic clamp, and at least one connecting screw hole is provided on the lower end face of the sheath column, and is connected to an external device through the connecting screw hole, and the pressure sensor is also electrically connected to the wiring terminal.

3. A tandem point-contact under-joint top height meter for coal mine strip filling mining according to claim 2, characterized in that: The lower end surface of the positioning plate is provided with at least two floating blocks evenly distributed around its axis.

4. A tandem point-contact under-joint top height meter for coal mine strip filling mining according to claim 1 or 2, characterized in that: The liquid level sensor includes a barrel cavity, a liquid level float ball, an annular magnet, a magnetic reed switch, and a seepage net. The barrel cavity is a cylindrical cavity structure with a "冂”-shaped axial cross-section, and its axis is parallel to the axis of the sheath column. The seepage net is wrapped outside the lower end face of the barrel cavity. The liquid level float ball is embedded in the barrel cavity, abuts against the inner side of the barrel cavity and is slidably connected, and the diameter of the liquid level float ball is not greater than 30% of the height of the barrel cavity. An annular magnet coaxial with it is provided at the top and bottom of the liquid level float ball. At least three magnetic reed switches are embedded in the side wall of the barrel cavity and are evenly distributed from top to bottom along the axis of the barrel cavity. A magnetic reed switch is provided at the top and bottom positions of the barrel cavity. At the same time, the magnetic reed switches are connected in parallel and are electrically connected to the terminal block respectively.

5. The tandem point-contact under-joint top height meter for coal mine strip filling mining according to claim 1 is characterized in that: The drive wire harness includes an elastic protective sleeve, a rigid connection sleeve, a traction steel strand, a disc spring, a hook, a load-bearing keel, a spring piece, a power cable, a communication bus, and a control signal transmission wire. The elastic protective sleeve is a hollow columnar structure with a rectangular axial cross-section. Its front end face and rear end face are both connected to a rigid connection sleeve coaxial with it. At the same time, several branch interfaces are evenly distributed on the side wall of the elastic protective sleeve, and each branch interface is connected to a rigid connection sleeve and is vertically distributed. The elastic protective sleeve is connected to and communicates with a three-way junction box through the rigid connection sleeve at the branch interface. There are several load-bearing keels, which are plate-like structures coaxial with the elastic protective sleeve. An assembly hole coaxial with it is provided on the load-bearing keel, and at least three wire grooves are provided around its axis at the edge. The opening of the wire groove is blocked by a spring piece, and both ends of the spring piece are connected to the outer side of the load-bearing keel through bolts. A hook coaxial with it is provided at the front end face and rear end face of the disc spring, and is connected to at least one traction steel strand through the hook. At the same time, the adjacent load-bearing keels are connected to each other through the traction steel strand, and the distance between the adjacent load-bearing keels is at least 3 times the maximum width of the load-bearing keel. At the same time, there is one power cable, one communication bus, and one control signal transmission wire, which are respectively embedded in an independent wire groove.

6. A tandem point-contact under-joint top height meter for coal mine strip filling mining according to claim 5, characterized in that: The rigid connection sleeve includes a washer, a guide sheath, and an elastic sealing ring. The upper end face of the washer is connected to the guide sheath and is coaxial. The guide sheath is a cylindrical hollow tubular structure. At the same time, a connection thread and at least one elastic sealing ring coaxial with it are provided on the outer side of the guide sheath. The elastic sealing ring is located between the upper end face of the washer and the connection thread.

7. The tandem point-contact under-joint top height meter for coal mine strip filling mining according to claim 1 is characterized in that: The data acquisition system is a circuit system based on any one or two of a programmable controller and an FPGA chip. The data analysis system is any one of an industrial computer and a PC computer. At the same time, the data analysis system is additionally provided with a big data server and a distributed data storage system.

8. A method for monitoring under-joint top height based on the tandem point-contact under-joint top height meter for coal mine strip filling mining according to claim 1, characterized in that: The undercut height monitoring includes the following steps: S1, equipment layout, after the filling pipeline is laid out in the area to be filled, install the under-connected top height meter, and lay each under-connected top height meter at the roof 1-2m away from the coal wall on the side away from the filling feeding pipeline, and arrange them in the length direction of the strip, the signal power line is fixed on the roof and connected to the under-connected top height meter by the driving harness fixed on the roof of the coal wall, the under-connected top height meter is connected in series in sequence by the driving harness, and is connected to the data acquisition system set up in the transport lane outside the filling area, the data acquisition system establishes a data connection with the driving harness, and the system configuration can be completed, and after the system configuration is completed, an independent communication address is matched for each under-connected top height meter; S2, real-time monitoring. During the filling operation, as the liquid level at the top of the filling slurry continues to rise, it continues to approach the liquid level sensor at the bottom of the under-joint top height gauge. When the top interface of the liquid surface contacts the liquid level sensor, the filling slurry is fully monitored during its rising process. At the same time, the liquid level sensor returns a signal to the data acquisition system based on this. According to the spatial coordinates of the under-joint top height gauge, the filling area slurry top connection situation and the under-joint top height value can be obtained; S3, data summary. During the filling and capping process, the data acquisition system controls and records relevant data. The data analysis system interpolates the contour map of the under-joint height of the filling area according to the plane coordinates (xi, yi) of each under-joint height meter and the under-joint height hi (i=1, 2,…, n) detected by the liquid level sensor, and displays it in three dimensions. After the filling is completed, data collection and analysis are carried out, including the position, height and other dimensional parameters of the under-joint area of ​​the filling body. Then, the detection equipment is used to record various data, analyze the filling effect, and perform subsequent optimization and adjustment based on the data results.

9. The under-joint top height monitoring method based on the tandem point-contact under-joint top height meter for strip filling mining in coal mines according to claim 8 is characterized in that: In the step S1, the distance between two adjacent under-connected top altimeters is 10-50m, and the under-connected top altimeters are arranged in a "Z-shaped" or "Linear" layout structure according to the strip inclination angle and geometric size factors.

10. The under-joint top height monitoring method based on the tandem point-contact under-joint top height meter for strip filling mining in coal mines according to claim 8, characterized in that: In the step S2, when performing the filling operation, a layered filling operation is adopted, and the filling height of each layer in the filling area is 0.5-2.0m, and the filling height of the top position of the filling area is 0.3-0.5m; wherein the filling of the top position is divided into two parts: the first stage of material discharge and the second stage of material discharge, and the specific filling steps are as follows: The first step is to start the first stage of roof filling by unloading materials from the lower end of the roof; after the first stage of roof filling is completed, start the data acquisition system and data analysis system to solve the contour map of the under-jointed roof height, use the integral method to solve the size of the under-jointed roof space in the designed first stage of roof filling area, and continue to unload materials and fill according to the size of the under-jointed roof space until the roof monitoring system shows that the first stage of roof filling area is completely roofed; The second step is to optimize the second stage of material discharge for roof connection and filling, adjust the discharge port, start designing and carry out material discharge for the second stage of roof connection and filling area; after the second stage of material discharge for roof connection and filling is completed, start the data acquisition system and data analysis system, solve the contour map of under-connection height, use the integral method to solve the size of the under-connection space in the designed second stage of roof connection and filling area, and continue to discharge materials and fill according to the size of the under-connection space until the roof connection monitoring system shows that the second stage of roof connection and filling area is completely connected; The third step is to repeat the first and second steps until the filling operation of the entire filling area is completed.

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