Method for monitoring and reconstructing dynamic gangue filling structure in goaf

Abstract

The invention discloses a goaf dynamic gangue filling structure monitoring and reconstruction method, which comprises the following steps: delimiting different mining and filling sections, arranging a plurality of slide bar type displacement sensors after each mining and filling section is completed, filling gangue, and determining the equivalent gangue filling rate of each mining and filling section through each slide bar type displacement sensor; after the gangue is filled, the equivalent gangue compaction rate of each mining and filling section in the process that the gangue bulk body is subjected to the stress action of the overlying strata is continuously monitored; calculating the equivalent gangue height of each mining and filling section based on the equivalent gangue filling rate and the equivalent gangue compaction rate of each mining and filling section; and finally, accurately monitoring and reconstructing the dynamic gangue filling structure of the goaf in real time according to the distribution of each equivalent gangue height in combination with the mining and filling step pitch of each mining and filling section by a segmented reconstruction method. The goaf dynamic gangue filling structure obtained through the method provides required data support for gangue filling stope surrounding rock stability and surface subsidence control evaluation and adjacent layer gas emission treatment caused by mining pressure relief.

Description

Technical Field

[0001] This invention relates to a method for monitoring and reconstructing the dynamic gangue backfill structure in goaf areas. Specifically, it involves reconstructing the dynamic gangue backfill structure in goaf areas by installing displacement sensors in different mining and backfill sections through contact monitoring. This method belongs to the field of green backfill mining in coal mines. Background Technology

[0002] Coal mining generates a large amount of waste coal gangue, causing serious environmental pollution. Goaf backfilling technology, as part of green mining, has been widely used in recent years. Backfilling goafs with coal gangue not only reduces the accumulation of waste gangue on the surface but also effectively controls the stability of the surrounding rock and prevents surface subsidence. Furthermore, when the stability of the surrounding rock is controlled, gas outbursts from adjacent coal seams are significantly suppressed.

[0003] The backfilling of gangue in goaf directly affects the stability of the surrounding rock, which in turn affects the deformation of the surrounding rock, gas outburst from adjacent coal seams, and the control of surface subsidence. On the one hand, during the backfilling process, the backfilling rate cannot be guaranteed to be consistent across all mining and backfilling stages due to limitations in coal mine production and the efficiency of gangue hoisting, transportation, and crushing. On the other hand, the deformation of the backfilled gangue is time-dependent, and the irregular fracture of the roof causes varying degrees of overburden stress acting on the backfilled gangue at different mining and backfilling stages, resulting in real-time changes in the dynamic backfilling structure of the goaf. Therefore, real-time monitoring and reconstruction of the dynamic backfilling structure of the goaf has become crucial for evaluating the stability of the surrounding rock and controlling surface subsidence at different mining and backfilling stages, and is also an important prerequisite for subsequent assessments of gas outburst from adjacent coal seams. However, due to the unique nature of the goaf formation process, it is difficult to conduct on-site measurements of the dynamic gangue backfill structure in the goaf after the gangue backfilling mining has been completed, using existing measurement methods. Furthermore, existing non-contact testing methods, such as ultrasonic testing, are greatly affected by the on-site environment, resulting in significant deviations in the test results. This makes it currently impossible to achieve accurate real-time monitoring and reconstruction of the dynamic gangue backfill structure in the goaf. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for monitoring and reconstructing the dynamic gangue filling structure in goaf areas. This method can monitor the gangue filling situation in goaf areas using contact measurement and, combined with specific methods, achieve accurate real-time monitoring and reconstruction of the dynamic gangue filling structure in goaf areas.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a method for monitoring and reconstructing dynamic gangue filling structures in goaf areas, the specific steps of which are as follows: Step 1: First, determine the coal seam mining height H, and then determine the mining and filling step distance L for each mining and filling section. PP represents the number of different mining and filling sections, P=1,2,3…; according to the determined mining parameters, the first mining and filling section is mined. After the mining of the mining and filling section is completed, multiple sliding rod displacement sensors are installed in the mining and filling section at intervals S and in a row, ensuring that the pressure-bearing base of each sliding rod displacement sensor is vertically fixed to the bottom of the coal seam; finally, each sliding rod displacement sensor is connected to the control terminal.

[0006] Step 2: Control the pressure plate of each sliding rod displacement sensor to rise and contact the top of the coal seam via the control terminal, and then reset the displacement to zero.

[0007] Step 3: Fill the first mining section with gangue, ensuring that each sliding rod displacement sensor is within the gangue mass formed by the filling. Then, control the lowering of the bearing plates of each sliding rod displacement sensor via the control terminal, making each bearing plate flush with the top of the gangue mass; and record the displacement of each sliding rod displacement sensor as M at this time. P,1 M P,2 M P,Q Q represents the number of sliding rod displacement sensors installed in the first mining section, from which the gangue filling rate F at each sliding rod displacement sensor can be obtained. P,Q And the equivalent gangue filling rate A of the mining and filling section. P .

[0008] Step 4: Lay pressure equalization sandbags on the upper part of the gangue sludge in the first mining and filling section to ensure that the overburden stress can be evenly applied to the entire gangue sludge during the irregular fracturing of the coal seam roof.

[0009] Step 5: Over time and with the surrounding mining conditions, the roof of the coal seam in the first mining section will fracture, thus applying overburden stress to the equalizing sandbags. At this time, the pressure plates of each sliding rod displacement sensor will be compressed and lowered, continuously monitoring the dynamic displacement at their respective positions, which is N. P,1 N P,2 ,…,N P,Q This allows us to determine the compaction rate Y of the gangue at each sliding displacement sensor. P,Q And the equivalent gangue compaction rate B of the mining and filling section. P .

[0010] Step Six: Repeat steps one through five for each subsequent mining and filling section until the entire coal seam's gangue filling mining is completed, and calculate the equivalent gangue filling rate A for each mining and filling section. P Equivalent gangue compaction rate B P Calculate the equivalent gangue height D in each mining and filling section. P Finally, based on the equivalent gangue height D P The dynamic gangue filling structure of the goaf is reconstructed by combining the mining and filling step distance of each mining and filling section with the segmented reconstruction method.

[0011] Furthermore, the sampling step distance L in different sampling sections in step one... P The step size is much smaller than the period.

[0012] Furthermore, the spacing S in step one must satisfy S≤0.5L P .

[0013] Furthermore, in step three, the gangue filling rate F at each sliding displacement sensor... P,Q And the equivalent gangue filling rate A of the mining and filling section P， The specific calculation formula is as follows: In the formula: .

[0014] Furthermore, in step five, the compaction rate Y of the gangue at each sliding displacement sensor... P,Q And the equivalent gangue compaction rate B in the mining and filling section P , the specific calculation formula is: In the formula: .

[0015] Furthermore, in step six, the equivalent gangue height D P The calculation formula is: .

[0016] Furthermore, the segmented reconstruction method in step six specifically involves maintaining the mining step distance L in each mining and filling section. P The height of the gangue in each mining and filling section remains unchanged, and the equivalent gangue height D of each mining and filling section is determined respectively. P This is used to reconstruct the dynamic gangue filling structure of the goaf.

[0017] Compared with existing technologies, this invention first delineates different mining and filling sections before coal seam mining. After each mining and filling section is completed, multiple sliding rod displacement sensors are deployed to form distributed contact displacement monitoring points. Then, gangue is filled in the goaf section. The gangue filling rate at different locations in each mining and filling section can be determined by the sliding rod displacement sensors, as well as the equivalent gangue filling rate of each mining and filling section. After the gangue is filled in the mining and filling section, the gangue is continuously monitored. This invention calculates the compaction rate of gangue at different locations in each mining and filling section during the stress action of the overlying rock on the loose rock mass, as well as the equivalent gangue compaction rate for each mining and filling section. Based on the equivalent gangue filling rate and compaction rate of each mining and filling section, the equivalent gangue height of each section is calculated. Finally, based on the distribution of each equivalent gangue height and the mining and filling step distance of each section, a segmented reconstruction method is used to achieve accurate real-time monitoring and reconstruction of the dynamic gangue filling structure in the goaf. The dynamic gangue filling structure of the goaf obtained through this invention provides the necessary data support for evaluating the stability of the surrounding rock and controlling surface subsidence in gangue-filled mining areas, as well as for controlling gas outbursts in adjacent layers caused by mining-induced pressure relief. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the dynamic monitoring of the gangue backfilling structure in the goaf area according to the present invention. Figure 2 This is a schematic diagram of the slide bar displacement sensor in this invention; Figure 3 This is a schematic diagram showing the result of reconstructing the dynamic gangue filling structure in the goaf according to the present invention.

[0019] In the diagram: 1-Coal seam roof, 2-Coal seam, 3-Coal seam floor, 4-Mining and filling section, 5-Equalizing sandbag, 6-Sliding rod displacement sensor, 6-1-Pressure plate, 6-2-Pressure base, 6-3-Telescopic sliding rod, 6-4-Sensor housing, 6-5-Upper contact electrode, 6-6-Lower contact electrode, 6-7-Power supply line, 6-8-Signal transmission line, 7-Control terminal. Detailed Implementation

[0020] The present invention will be further described below.

[0021] like Figure 1 As shown, the specific steps of this invention are as follows: Step 1: First, determine the mining height H of coal seam 2, and determine the mining and filling step distance L of each mining and filling section 4. P P represents the number of different mining and filling sections 4, P=1,2,3…; and the mining and filling step distance L P The step distance is much smaller than the period; according to the determined mining parameters, the first mining and filling section 4 is mined first. After the mining of the mining and filling section 4 is completed, multiple sliding rod displacement sensors 6 are installed in the mining and filling section 4 at intervals S and in a row. The interval S must satisfy S≤0.5L.P And ensure that the pressure-bearing base 6-2 of each sliding rod displacement sensor 6 is vertically fixed to the coal seam bottom plate 3; finally, connect each sliding rod displacement sensor 6 to the control terminal 7.

[0022] Step 2: Control the pressure plate 6-1 of each sliding displacement sensor 6 to rise and contact the coal seam roof 1 through the control terminal 7, and reset the displacement to zero.

[0023] Step 3: Fill the first mining section 4 with gangue and ensure that each sliding rod displacement sensor 6 is within the gangue mass formed by the filling. Then, control the pressure plate 6-1 of each sliding rod displacement sensor 6 to descend through the control terminal 7, so that each pressure plate 6-1 is flush with the upper end of the gangue mass; and record the displacement of each sliding rod displacement sensor 6 at this time as M. P,1 M P,2 M P,Q Q represents the number of sliding rod displacement sensors 6 installed in the first mining section 4, from which the gangue filling rate F at each sliding rod displacement sensor 6 can be obtained. P,Q And the equivalent gangue filling rate A of the mining and filling section. P , the specific calculation formula is: In the formula: .

[0024] Step 4: Lay pressure equalization sandbags 5 on the upper end of the gangue sludge in the first mining and filling section 4 to ensure that the overburden stress can be evenly applied to the entire gangue sludge during the irregular fracture of the coal seam roof 1.

[0025] Step 5: As time progresses and the surrounding mining conditions change, the roof 1 of the first mining section 4 will fracture, thus applying overburden stress to the equalizing sandbags 5. At this time, the pressure plates 6-1 of each sliding rod displacement sensor 6 will be compressed and lowered, continuously monitoring the dynamic displacement of their respective positions, which is N. P,1 N P,2 ,…,N P,Q This allows us to determine the compaction rate Y of the gangue at each of the six sliding displacement sensors. P,Q And the equivalent gangue compaction rate B of the mining section 4. P The specific calculation formula is as follows.

[0026] In the formula: .

[0027] Step Six: Repeat Steps One through Five for each subsequent mining and filling section 4 until the entire coal seam 2 is mined with gangue. Then, based on the equivalent gangue filling rate A of each mining and filling section 4... P Equivalent gangue compaction rate BP Calculate the equivalent gangue height D for each mining and filling section 4. P , the specific calculation formula is: .

[0028] Finally, based on maintaining the mining step distance L in each mining section 4... P The height of the gangue in each mining and filling section 4 remains unchanged, and the equivalent gangue height D of each mining and filling section 4 is determined respectively. P This is used to reconstruct the dynamic gangue filling structure of the goaf, such as Figure 3 As shown.

[0029] The aforementioned slider-type displacement sensor 6 is an existing component, such as... Figure 2 As shown, it includes a pressure plate 6-1, a pressure base 6-2, a telescopic slide rod 6-3, a sensor housing 6-4, an upper contact electrode 6-5, a lower contact electrode 6-6, a power supply line 6-7, and a signal transmission line 6-8. The sensor housing 6-4 is mounted on the upper part of the pressure base 6-2. One end of the telescopic slide rod 6-3 extends into the sensor housing 6-4 from above. The pressure plate 6-1 is mounted on the other end of the telescopic slide rod 6-3. The upper contact electrode 6-5 is mounted on the upper part of the sensor housing 6-4 and contacts the side of the telescopic slide rod 6-3. The lower contact electrode 6-6 is mounted on one end of the telescopic slide rod 6-3. When the telescopic slide rod 6-3 moves up and down inside the sensor housing 6-4, it can adjust the distance between the upper contact electrode 6-5 and the lower contact electrode 6-6, thereby changing the current signal and transmitting it to the control terminal 7 through the signal transmission line 6-8. The displacement of the telescopic slide rod 6-3 is recorded according to the change in the current signal. The control terminal 7 supplies power to the slide rod displacement sensor 6 through the power supply line 6-7.

[0030] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for monitoring and reconstructing dynamic gangue filling structure in goaf, characterized in that: The specific steps are: Step 1: First determine the coal seam mining height H and the mining step distance L of each mining section P , P is the number of different mining and filling sections; according to the determined mining parameters, the first mining and filling section is first mined, and when the mining work of the mining and filling section is completed, multiple sliding rod displacement sensors are set up in a row with a spacing of S in the mining and filling section, and the pressure base of each sliding rod displacement sensor is vertically fixed to the coal seam floor; finally, each sliding rod displacement sensor is connected to the control end; Step 2: Control the pressure plates of each sliding rod displacement sensor to rise and contact with the coal seam roof through the control end, and clear the displacement; Step 3: Fill the first mining section with gangue and ensure that each slide-rod displacement sensor is in the gangue bulk formed by the filled gangue. Then, the pressure plates of each slide-rod displacement sensor are controlled to descend through the control end so that each pressure plate is flush with the upper end of the gangue bulk. The displacement of each slide-rod displacement sensor at this time is recorded as M. P,1 , M P,2 , …, M P,Q , Q is the number of sliding rod displacement sensors installed in the first mining and filling section, and then the gangue filling rate F at each sliding rod displacement sensor can be obtained P,Q , and the equivalent gangue filling rate A of the mining section P ; Step 4: lay pressure-equalizing sandbags on the upper end of the loose gangue in the first mining section to ensure that the overburden stress can be evenly applied to the entire loose gangue during the irregular breaking of the coal seam roof; Step 5: The coal seam roof of the first mining section will break over time and due to the surrounding mining conditions, and then exert overburden stress on the equalizing sandbag. At this time, the pressure plates of each sliding rod displacement sensor are pressed down, and the dynamic displacement of each position is continuously monitored, which are N P,1 , N P,2 ,…,N P,Q , and then the gangue compaction rate Y at each sliding rod displacement sensor can be obtained P,Q , and the equivalent gangue compaction rate B of the mining and filling section P ; Step 6: Repeat steps 1 to 5 for each subsequent mining section until the gangue filling mining of the entire coal seam is completed, and based on the equivalent gangue filling rate A of each mining section P Equivalent gangue compaction rate B P Calculate the equivalent gangue height D of each mining and filling section P Finally, according to the equivalent gangue height D P The dynamic waste rock filling structure of the goaf is reconstructed by the segmented reconstruction method combined with the mining and filling step size of each mining and filling section.

2. The method for monitoring and reconstructing dynamic gangue filling structure in goaf according to claim 1, characterized in that: The filling step distance L of different filling sections in step 1 P Both are much smaller than the cycle pressure step.

3. The method for monitoring and reconstructing dynamic waste rock filling structure in goaf according to claim 1, characterized in that: The spacing S in step 1 must satisfy S≤0.5L P .

4. The method for monitoring and reconstructing dynamic waste rock filling structure in goaf according to claim 1, characterized in that: The gangue filling rate F at each sliding rod displacement sensor in step 3 P,Q And the equivalent gangue filling rate A of the mining and filling section P， The specific calculation formula is: Where: .

5. The method for monitoring and reconstructing dynamic waste rock filling structure in goaf according to claim 1, characterized in that: The gangue compaction rate Y at each sliding rod displacement sensor in step 5 P,Q And the equivalent gangue compaction rate B of the mining and filling section P , the specific calculation formula is: Where: .

6. The method for monitoring and reconstructing dynamic waste rock filling structure in goaf according to claim 1, characterized in that: The equivalent gangue height D in step 6 P The calculation formula is: 。 7. The method for monitoring and reconstructing dynamic waste rock filling structure in goaf according to claim 1, characterized in that: The specific segmented reconstruction method in step 6 is: keep the sampling and filling step length L of each sampling and filling section P The gangue height of each mining and filling section is determined as the equivalent gangue height D of each mining and filling section. P , in order to reconstruct the dynamic gangue filling structure of the goaf.

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