Mine roof stress-rotation angle synchronous monitoring device

Abstract

The utility model discloses a mine roof stress-rotation angle synchronous monitoring device, and belongs to the technical field of mine roof rock stratum movement monitoring. The device comprises a plurality of monitoring sensors and connecting rods, the monitoring sensors are sequentially connected end to end, and every two adjacent monitoring sensors are connected through the corresponding connecting rod; the monitoring sensor comprises a pipe body, and a strain rosette used for collecting stress data is arranged on the outer surface of the pipe body. A three-way angle meter used for collecting angle data is arranged in the pipe body. Hole sealing rings are arranged in the circumferential directions of the head end and the tail end of the pipe body; a grouting module is further arranged on the pipe body, and grout in the grouting module can flow to the outer surface of the sensor pipe body, the inner wall of the monitoring drill hole and the closed space between the two hole sealing rings through the liquid drainage holes; and after the slurry is solidified, the device and the rock stratum are integrated. According to the utility model, the stress and the rotation angle of each rock stratum of the roof can be monitored accurately, continuously and synchronously in real time, and more detailed rock stratum information is provided for prevention and control of mine disasters.

Description

TECHNICAL FIELD

[0001] The utility model relates to mine roof stratum movement monitoring technical field, concretely relates to a mine roof stress-rotation angle synchronous monitoring device. BACKGROUND

[0002] The coal seam mining process destroys the balance state of the original rock stress field, causes stress redistribution, and forms an advanced support pressure in front of the working face, which has a significant impact on the mine pressure behavior of the transportation roadway and the air return roadway, specifically, the roof local caving, roadway spalling, and floor heaving are prone to occur. With the continuous advancement of the working face, the mined-out space continuously increases, and the length of the overlying roof stratum in a suspended state without support also continuously increases. When the roof suspension reaches the limit span, the roof stratum breaks and rotates, the working face roof sharply subsides, and the pressure comes. The initial pressure is relatively strong, which is easy to cause roof accidents. The advanced support pressure and the broken pressure caused by the movement of the overburden rock are important factors inducing roof disasters and rock burst disasters, so the mine pressure monitoring and early warning is an important part of mine disaster prevention and control work and plays an important role in safe mining.

[0003] At present, the monitoring of the roof during the mining process mainly focuses on the static test of the original rock stress, and the stress evolution monitoring caused by the mining disturbance is relatively less, and the dynamic change of the stress is crucial for evaluating the safety of the mine mining. At present, there is no effective means for monitoring the movement of the overburden rock in the goaf, and most of the existing projects use the monitoring of the working resistance of the hydraulic support and the roof subsidence to reflect the roof state and infer the pressure situation. The monitoring of the working resistance of the hydraulic support can provide some information, but this method cannot directly obtain the deformation and breaking of the rock stratum. Although the monitoring of the roof subsidence can reflect the displacement change of the roof, it cannot accurately judge the internal structure change of the rock stratum. These monitoring methods can provide some reference information to a certain extent, but still have obvious limitations. Moreover, the current monitoring of the roof stratum in the roadway and the goaf is independent, the monitoring information lacks continuity, and the whole process characteristics of the roof mine pressure behavior in the whole area of the roadway and the goaf cannot be reflected. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a mine roof stress-rotation angle synchronous monitoring device to monitor the stress evolution and movement of the roof stratum in real time, accurately and continuously, and realize the whole process monitoring from the roadway to the goaf.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is as follows:

[0006] A mine roof stress-rotation angle synchronous monitoring device comprises a plurality of monitoring sensors and connecting rods, the plurality of monitoring sensors are connected in sequence, and the adjacent two monitoring sensors are connected through the connecting rods.

[0007] The monitoring sensor comprises a pipe body, a strain gauge for collecting stress data is arranged on the outer surface of the pipe body, and a three-way angle gauge for collecting angle data is arranged in the interior of the pipe body;

[0008] A sealing ring is arranged on the circumference of the leading end and the trailing end of the pipe body, and when the pipe body is inserted into the inner wall of the monitoring borehole, the sealing ring closely adheres to the pipe body and the inner wall of the monitoring borehole, so that a sealed space is formed between the pipe body, the inner wall of the monitoring borehole and the sealing rings at the leading end and the trailing end of the pipe body;

[0009] A grouting module for grouting into the sealed space is further arranged on the pipe body.

[0010] Preferably, the grouting module comprises a slurry chamber, the slurry chamber is filled with slurry in the interior thereof, the slurry chamber is arranged in the interior of the pipe body, a drainage hole is arranged on the pipe wall of the pipe body and at a position corresponding to the slurry chamber, a sliding block is arranged at one end of the slurry chamber, and the sliding block is connected with a pulling rope for extruding the slurry in the slurry chamber; when the sliding block extrudes the slurry in the slurry chamber, the slurry enters the sealed space through the drainage hole.

[0011] Preferably, a fixing block is arranged in the interior of the pipe body, and the sliding block, the fixing block and the pipe wall of the pipe body jointly enclose the slurry chamber;

[0012] A pulley block is further arranged in the interior of the pipe body, the pulley block comprises a first pulley, a second pulley and a third pulley, the first pulley is arranged on one side of the fixing block, the second pulley and the third pulley are respectively arranged on the upper side and the lower side of the trailing end of the pipe body, and the first pulley is connected with the sliding block through a connecting rope.

[0013] One end of the pulling rope is connected with the second pulley or the third pulley, and the other end of the pulling rope passes through the first pulley and the third pulley, or the first pulley and the second pulley and then extends out of the monitoring borehole.

[0014] Preferably, a plurality of drainage holes are arranged, and the drainage holes are arranged in a ring shape and are spaced apart along the pipe wall of the pipe body; the drainage holes are arranged at the end of the slurry chamber which first extends into the monitoring borehole.

[0015] Preferably, three groups of strain gauges are arranged on each pipe body, the three groups of strain gauges are spaced apart by an angle of 120°, and the three groups of strain gauges are arranged in a ring shape and are spaced apart along the outer surface of the pipe body.

[0016] Preferably, the connecting rod and the pipe body are both made of hard material, and the sealing ring is made of soft material, and the pulling rope passes through the space between the sealing ring and the pipe body.

[0017] Preferably, the synchronous monitoring device further comprises a data acquisition unit, the data acquisition unit is connected with the three-way angle gauge and the strain gauges through signal cables, and the two ends of the pipe body are provided with threading holes or are in a semi-closed state, and the signal cables pass through the pipe body and the connecting rod.

[0018] The beneficial technical effects of the utility model are as follows:

[0019] (1) The mine roof stress-rotation angle synchronous monitoring device can monitor the evolution process of the roadway roof stress, that is, with the advance of the coal seam working face, the stress and movement parameters of the goaf roof stratum can be synchronously monitored; and the synchronous monitoring device comprises a plurality of monitoring sensors which are distributed at different positions of the mine roof, so that comprehensive monitoring can be realized.

[0020] (2) The mine roof stress-rotation angle synchronous monitoring device can realize real-time multi-point monitoring of the mine roof stratum, that is, the stress and rotation angle of each stratum of the roof can be synchronously monitored in real time, accurately and continuously, and the whole cycle and large range of the coal seam roof from the advanced area to the goaf are monitored, so that more detailed stratum information can be provided for the mine pressure, stratum control and rock burst disaster prevention and control.

[0021] (3) The mine roof stress-rotation angle synchronous monitoring device has a simple structure, fewer components, is convenient to process and manufacture, and has a relatively low cost, so that the investment cost of the mine monitoring can be reduced.

[0022] (4) Based on the stress, rotation angle and other data measured by the mine roof stress-rotation angle synchronous monitoring device, the pressure step distance can be obtained without complex calculation, the accurate prediction of the mine roof pressure can be realized, and the method is simple and fast. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural principle schematic view of the mine roof stress-rotation angle synchronous monitoring device of the utility model embodiment;

[0024] Figure 2 is a construction layout section schematic view of the mine roof stress-rotation angle synchronous monitoring device of the utility model embodiment;

[0025] Figure 3 is a construction layout plane schematic view of the mine roof stress-rotation angle synchronous monitoring device of the utility model embodiment.

[0026] In the figure: 1. three-way angle gauge, 2. pipe body, 3. connecting rod, 4. strain gauge, 5. pulley block, 6. hole sealing ring, 7. sliding block, 8. slurry chamber, 9. liquid discharge hole, 10. pull rope, 11. return air roadway, 12. transportation roadway, 13. connecting roadway, 14. monitoring drill hole, 15. goaf, 16. monitoring sensor. DETAILED DESCRIPTION

[0027] The utility model discloses a kind of mine roof stress-rotation angle synchronous monitoring devices and pressure prediction method, to monitor the stress evolution and movement situation of roof strata in real time, accurately, continuously, realize the whole process monitoring from roadway to gob, predict the pressure step distance of roof strata.

[0028] The utility model is further described below with reference to the drawings and specific embodiments.

[0029] As Figure 1 As shown in a kind of mine roof stress-rotation angle synchronous monitoring device, including several monitoring sensors 16 and connecting rod 3, several monitoring sensors 16 are sequentially connected head to tail, and the connecting rod 3 is connected between adjacent two monitoring sensors 16.The monitoring sensor 16 includes pipe body 2, and strain gauge 4 is arranged on the outer surface of pipe body 2 to collect stress data.In the inside of pipe body 2, there is three-way angle gauge 1 to collect angle data.Three-way angle gauge 1 is used to measure the relative angle of the pipe body where the angle gauge is located.This angle is used to calculate the rotation angle of the roof strata where the monitoring sensor is located.The strain gauge 4 is used to measure and calculate three-dimensional stress state.The first end and the tail end of pipe body are both provided with sealing ring 6, when pipe body 2 is inserted into monitoring drill hole 14 or said through-hole drill hole inner wall, sealing ring 6 is tightly attached to pipe body 2 and monitoring drill hole 14 inner wall, so that sealed space is formed between pipe body 2, monitoring drill hole 14 inner wall and the first end and tail end sealing ring 6 of pipe body 2.

[0030] Slipper 7 is provided at one end of slurry chamber 8, and pull rope 10 for pulling slipper 7 to extrude slurry in slurry chamber 8 is connected to slipper 7.When slipper 7 extrudes slurry in slurry chamber 8, slurry enters the above-mentioned sealed space through drain hole 9.

[0031] The three-way angle gauge used in the utility model is also commonly known as a three-dimensional motion attitude measurement system, or an attitude sensor, which includes three-axis gyroscope, three-axis accelerometer, three-axis electronic compass and other motion sensors.

[0032] Due to the inclusion of multiple monitoring sensors 16, the synchronous monitoring device of the utility model can be placed in multiple points in one hole to monitor the movement of multiple overlying rock layers.When installing, several monitoring sensor pipes are sequentially connected head to tail, and the connecting rod is connected between adjacent two pipes.

[0033] As further design of the utility model, three groups of strain flowers 4 are arranged on each pipe body 2, and the three groups of strain flowers 4 are arranged at intervals of 120 ° along the outer surface of the pipe body 2. In order to standardize the installation of the device, one group of strain flowers 4 is arranged on the intersection line of the plane where the x-z axis of the three-way goniometer is located and the pipe body 2. When the synchronous monitoring device is installed in the monitoring borehole 14, the group of strain flowers is at the uppermost position. The plane where the x-z axis of the three-way goniometer is located has two intersection lines with the pipe body 2, and one group of strain flowers 4 is arranged on one of the intersection lines, and when the synchronous monitoring device is installed in the monitoring borehole, the group of strain flowers faces upward and is at the uppermost position. The three groups of strain flowers are used to measure the three-dimensional in-situ stress state of the rock stratum where the pipe body is located.

[0034] Furthermore, a fixed block is arranged in the interior of the pipe body 2, and the sliding block 7, the fixed block and the pipe wall of the pipe body jointly form a slurry chamber 8. The interior of the pipe body 2 is also provided with a pulley block 5. Specifically, the pulley block 5 includes a first pulley, a second pulley and a third pulley, wherein the first pulley is located on one side of the fixed block, and the second pulley and the third pulley are respectively installed on the upper and lower sides of the end of the pipe body; the first pulley is connected with the sliding block 7 through a connecting rope. One end of the pull rope 10 is connected with the second pulley or the third pulley, and the other end of the pull rope 10 is wound around the first pulley and the third pulley, or the first pulley and the second pulley and then extends outward from the monitoring borehole 14. The first pulley is a movable pulley, and the second pulley and the third pulley are both fixed pulleys. The slurry chamber 8 of each pipe body 2 is equipped with one pull rope 10.

[0035] The above-mentioned drainage holes 9 are arranged at intervals along the pipe wall of the pipe body 2. The drainage holes 9 are arranged at the end of the slurry chamber which first extends into the monitoring borehole. Since the slurry has a certain viscosity, and when the pipe body 2 is inclined and inserted into the monitoring borehole 14, the drainage holes 9 are located at the obliquely upper position of the slurry chamber 8, so the slurry will not flow out of the drainage holes 9 before the slurry chamber 8 is extruded.

[0036] Further, the connecting rod 3 comprises a cylindrical rod body, the ends of which are provided with flared ends into which the ends of the pipe body 2 are inserted. The connecting rod 3 and the pipe body 2 are both made of hard material, and a plurality of pipe bodies 2 are connected end to end, and two adjacent pipe bodies 2 are connected by the connecting rod 3, so as to ensure that the device can be pushed to the designated position when installed at multiple points in one hole. Of course, the pipe body 2 made of hard material can also protect the internal three-way angle gauge, so that it is not damaged during monitoring. The circumferential end of each monitoring sensor pipe body is provided with at least one sealing ring 6, which is made of soft material such as rubber, so as to tightly fit the pipe body 2 and the inner wall of the monitoring borehole. That is, the pipe body 2 and the inner wall of the monitoring borehole are sealed by the sealing ring 6, so as to form a sealed space between the pipe body 2, the inner wall of the monitoring borehole and the two sealing rings 6. When the grouting module is grouted and fixed, the sliding block 7 is pulled by the pulley and the pull rope 10 to extrude the grout in the grout chamber, and the extruded grout enters the above-mentioned sealed space through the drainage hole 9. After the grout solidifies, the grout fixes the pipe body 2 and the roof strata as a whole. In this way, the pipe body 2 migrates and rotates with the roof strata. The sealing ring 6 is used to confine the grout in the closed space outside the circumferential direction of the pipe body 2, so as to avoid the outflow of the grout, and the pull rope 10 passes between the sealing ring 6 and the pipe body 2.

[0037] Further, the synchronous monitoring device further comprises a data acquisition unit, which is located in the transport roadway 12. The data acquisition unit connects the three-way angle gauge 1 and the strain gauge 4 through a signal cable, and is used to collect angle data through the three-way angle gauge 1 and stress data through the strain gauge 4. The two ends of the pipe body 2 are provided with a wire hole or are in a semi-closed state, and the connecting rod 3 is hollow inside, and the signal cable passes through the pipe body 2 and the connecting rod 3.

[0038] The mine roof stress-rotation angle synchronous monitoring device as described above can be used for mine roof pressure prediction, and the specific method comprises the following steps:

[0039] Step 1, drill holes in the entity coal roof strata in the transport roadway 12 or the air return roadway 11 of the working face to form monitoring boreholes 14, as shown in Figure 2 , Figure 3 The drilling depth should reach the key layer.

[0040] Step 2, assemble the pipe body 2 and the connecting rod 3 according to the height of each stratum of the roof, so that each stratum has a monitoring sensor 16. A spatial coordinate system is established with the vertical upward direction as the z-axis positive direction and the direction of the roadway axis as the y-axis, which is used to judge the rotation angle after the stratum breaks. Inject the adhesive grout which acts as a fixing device into the grout chamber 8 of the pipe body 2, and then push the sequentially connected pipe body 2 and connecting rod 3 into the monitoring borehole 14, and the sealing ring 6 is attached to the outer surface of the pipe body and the inner wall of the monitoring borehole.

[0041] Step 3, grouting fixation by grouting module. After pushing the device to the predetermined position, the sliding block 7 is moved by pulling the pull rope 10 through the pulley block 5, extruding the adhesive slurry in the slurry chamber 8, so that the slurry flows out of the sensor tube through the drainage hole 9. The surface of the sealing space between the borehole inner wall and the two sealing holes.

[0042] Step 4, after the slurry solidifies, the device becomes one with the rock stratum. Real-time acquisition of angle data measured by the three-way angle gauge 1 in each monitoring sensor, stress data measured by the strain gauge 4, and then the real-time horizontal and vertical positions and stress state of the tube body of any monitoring sensor are obtained.

[0043] When the measurement area is located in the roadway area, the monitoring sensor mainly monitors the stress data of the roof at the advanced area of the roadway. As the working face recovers and the area to be measured enters the goaf, the rock stress-rotation angle will be monitored synchronously, and the roof pressure step distance will be predicted by the real-time rotation angle and stress measured by the tube body of each monitoring sensor.

[0044] That is, when the coal seam under the installation position has not been mined, the roof stress state can be monitored in real time to provide accurate data for the support scheme of the roadway. After mining, the rotation angle and pressure step distance of the roof rock stratum are predicted by the real-time horizontal and vertical positions and stress of the tube body of each monitoring sensor, and the pressure prediction is completed.

[0045] The above specific embodiments further illustrate the purpose, technical scheme and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A synchronous monitoring device for stress-rotation angle on the top slab of a mine, characterized in that: The monitoring device comprises a plurality of monitoring sensors and connecting rods, the monitoring sensors are connected in sequence, and the adjacent two monitoring sensors are connected through the connecting rods. The monitoring sensor comprises a pipe body, a strain rosette for collecting stress data is arranged on the outer surface of the pipe body, and a three-way angle gauge for collecting angle data is arranged in the pipe body. A hole sealing ring is arranged on the circumferential direction of the head end and tail end of the pipe body, and the hole sealing ring is tightly attached to the pipe body and the inner wall of the monitoring borehole after the pipe body is inserted into the monitoring borehole, so that a sealed space is formed between the pipe body, the inner wall of the monitoring borehole and the hole sealing rings at the head end and tail end of the pipe body. A grouting module for grouting into the sealed space is further arranged on the pipe body.

2. The mine roof stress-rotation angle synchronous monitoring device according to claim 1, characterized in that: The grouting module comprises a slurry chamber, the slurry chamber is filled with slurry, the slurry chamber is arranged in the pipe body, a drainage hole is arranged on the pipe wall of the pipe body and at a position corresponding to the slurry chamber, a sliding block is arranged at one end of the slurry chamber, and the sliding block is connected with a pulling rope for extruding the slurry in the slurry chamber, when the sliding block extrudes the slurry in the slurry chamber, the slurry enters the sealed space through the drainage hole.

3. The mine roof stress-rotation angle synchronous monitoring device according to claim 2, characterized in that: A fixing block is arranged in the pipe body, the sliding block, the fixing block and the pipe wall of the pipe body jointly form the slurry chamber. A pulley block is further arranged in the pipe body, the pulley block comprises a first pulley, a second pulley and a third pulley, the first pulley is arranged on one side of the fixing block, the second pulley and the third pulley are respectively arranged on the upper and lower sides of the end of the pipe body, and the first pulley is connected with the sliding block through a connecting rope. One end of the pulling rope is connected with the second pulley or the third pulley, and the other end of the pulling rope passes through the first pulley and the third pulley or the first pulley and the second pulley and then extends out of the monitoring borehole.

4. The mine roof stress-rotation angle synchronous monitoring device according to claim 2, characterized in that: A plurality of drainage holes are arranged on the pipe wall of the pipe body and are circumferentially and spacedly arranged, and the drainage holes are arranged at the end of the slurry chamber which is firstly inserted into the monitoring borehole.

5. The mine roof stress-rotation angle synchronous monitoring device according to claim 1, characterized in that: Three groups of strain rosettes are arranged on each pipe body, the three groups of strain rosettes are circumferentially and spacedly arranged on the outer surface of the pipe body and are spaced by an angle of 120°.

6. The mine roof stress-rotation angle synchronous monitoring device according to claim 1, characterized in that: The connecting rods and the pipe body are made of hard materials, the hole sealing rings are made of soft materials, and the pulling rope passes through the hole sealing rings and the pipe body.

7. The mine roof stress-rotation angle synchronous monitoring device according to claim 1, characterized in that: The synchronous monitoring device further comprises a data acquisition unit, the data acquisition unit is connected with the three-way angle gauge and the strain rosette through a signal cable, and the two ends of the pipe body are provided with threading holes or are in a semi-closed state, and the signal cable passes through the pipe body and the connecting rods.

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