A method for monitoring and reconstructing dynamic waste rock filling structure in goaf

Abstract

The present invention discloses a method for monitoring and reconstructing the dynamic gangue filling structure of a goaf. First, different mining and filling sections are delineated, and after each mining and filling section is completed, a plurality of sliding-bar displacement sensors are arranged and gangue filling is carried out. The equivalent gangue filling rate of each mining and filling section is determined by each sliding-bar displacement sensor; and after filling the gangue, the equivalent gangue compaction rate of each mining and filling section during the stress action of the gangue bulk overlying rock is continuously monitored; based on the equivalent gangue filling rate and the equivalent gangue compaction rate of each mining and filling section, the equivalent gangue height of each mining and filling section is calculated; finally, according to the distribution of each equivalent gangue height and the mining and filling step of each mining and filling section, a segmented reconstruction method is used to realize accurate real-time monitoring and reconstruction of the dynamic gangue filling structure of the goaf. The dynamic gangue filling structure of the goaf obtained by the present invention provides the required data support for the evaluation of surrounding rock stability and surface subsidence control in the gangue filling stope, and the control of gas outburst in adjacent layers caused by mining pressure relief.

Description

Technical Field

[0001] The present invention relates to a method for monitoring and reconstructing the dynamic gangue filling structure of a goaf, specifically, a method for reconstructing the dynamic gangue filling structure of a goaf by setting up displacement sensors in different mining and filling sections in a contact monitoring manner, and belongs to the field of green filling mining in coal mines. Background Art

[0002] As part of green mining, goaf filling technology has been widely used in recent years. Filling goaf with coal gangue not only reduces surface waste rock accumulation but also effectively controls the stability of the surrounding rock and mitigates surface subsidence. Furthermore, when the stability of the surrounding rock is controlled, gas outbursts from adjacent coal seams are significantly suppressed.

[0003] The goaf's waste rock filling directly affects the stability of the surrounding rock, which in turn affects the deformation of the surrounding rock, gas outbursts in adjacent coal seams, and the effectiveness of surface subsidence control. On the one hand, during the goaf's waste rock filling process, the filling rate cannot be guaranteed to be consistent at each mining and filling stage due to the limited coal mine waste rock production and the efficiency of waste rock hoisting, transportation, and crushing. On the other hand, the deformation of the bulk waste rock filling in the goaf is time-dependent. In addition, the irregular fracture of the roof causes the overburden stress to act on the bulk waste rock filling at different mining and filling stages, resulting in real-time changes in the dynamic waste rock filling structure of the goaf. Therefore, how to achieve real-time monitoring and reconstruction of the dynamic waste rock filling structure of the goaf at different mining and filling stages has become a top priority for the evaluation of the surrounding rock stability and surface subsidence control of the goaf at different mining and filling stages, and is also an important prerequisite for the subsequent gas outburst assessment of the adjacent coal seam working face. However, due to the unique nature of goaf formation, existing measurement methods make it difficult to conduct on-site measurements of the dynamic goaf fill structure after waste rock filling. Furthermore, existing non-contact measurement methods, such as ultrasonic waves, are significantly affected by the on-site spatial environment, resulting in significant deviations in test results. This currently makes it impossible to accurately monitor and reconstruct the dynamic goaf fill structure in real time. Summary of the Invention

[0004] In response to the problems existing in the above-mentioned prior art, the present invention provides a method for monitoring and reconstructing the dynamic gangue filling structure of the goaf, which can monitor the gangue filling situation in the goaf by contact measurement, and combine specific methods to achieve accurate real-time monitoring and reconstruction of the dynamic gangue filling structure of the goaf.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a method for monitoring and reconstructing the dynamic waste rock filling structure of a goaf, the specific steps of which are as follows:

[0006] Step 1: First determine the coal seam mining height H and the mining and filling step distance L of each mining and filling section P, P is the number of different mining and filling sections, P=1,2,3...; according to the determined mining parameters, coal mining is first carried out in the first mining and filling section. After the mining work in the mining and filling section is completed, multiple sliding rod displacement sensors are set up in a row with a spacing S in the mining and filling section, and the pressure base of each sliding rod displacement sensor is ensured to be vertically fixed to the coal seam floor; finally, each sliding rod displacement sensor is connected to the control end.

[0007] Step 2: Control the pressure plates of the sliding rod displacement sensors to rise and contact the coal seam roof through the control end, and clear the displacement.

[0008] Step 3: Fill the first mining section with gangue and ensure that each slide-type displacement sensor is in the gangue bulk formed by the filled gangue. Then, control the pressure plate of each slide-type displacement sensor 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-type 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 and filling section P .

[0009] Step 4: Lay equalizing sandbags on the upper end of the loose gangue in the first mining and filling 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.

[0010] Step 5: The coal seam roof of the first mining section will break over time and with the surrounding mining conditions, which will then apply overburden stress to the equalizing sandbags. 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 slide bar displacement sensor can be obtained P,Q , and the equivalent gangue compaction rate B of the mining and filling section P .

[0011] Step 6: Repeat steps 1 to 5 for each subsequent mining and filling 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 and filling 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 using the segmented reconstruction method combined with the mining and filling step distance of each mining and filling section.

[0012] Furthermore, the filling step distance L of different filling sections in step 1 is P Both are much smaller than the periodic pressure step.

[0013] Furthermore, the spacing S in step 1 must satisfy S≤0.5L P .

[0014] Furthermore, the gangue filling rate F at each sliding rod displacement sensor in step 3 is P,Q And the equivalent gangue filling rate A of the mining and filling section P， The specific calculation formula is:

[0015]

[0016] Where: , , .

[0017] Furthermore, the gangue compaction rate Y at each sliding rod displacement sensor in step 5 is P,Q And the equivalent gangue compaction rate B of the mining and filling section P , the specific calculation formula is:

[0018]

[0019] Where: , , .

[0020] Furthermore, the equivalent gangue height D in step 6 P The calculation formula is:

[0021] .

[0022] Furthermore, the segmented reconstruction method in step 6 is specifically: maintaining the sampling and filling step 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.

[0023] Compared with the existing technology, the present invention first demarcates different mining and filling sections before coal seam mining, and after each mining and filling section is completed, a plurality of sliding rod displacement sensors are arranged to form a distributed contact displacement monitoring point, and then gangue filling is carried out in the goaf section. Through each sliding rod displacement sensor, the gangue filling rate at different positions of each mining and filling section and the equivalent gangue filling rate of each mining and filling section can be determined; and the gangue filling rate is continuously monitored after the mining and filling section is filled with gangue. The method is to calculate the waste rock compaction rate at different positions of each mining section during the stress action of the overburden of the boulders, as well as the equivalent waste rock compaction rate of each mining section; finally, the equivalent waste rock height of each mining section is calculated based on the equivalent waste rock filling rate and equivalent waste rock compaction rate of each mining section, and finally, according to the distribution of each equivalent waste rock height and the mining step of each mining section, a segmented reconstruction method is used to achieve accurate real-time monitoring and reconstruction of the dynamic waste rock filling structure of the goaf. The dynamic waste rock filling structure of the goaf obtained by the present invention provides the required data support for the evaluation of the surrounding rock stability and surface subsidence control of the waste rock filling mine, and the control of gas outburst in the adjacent layer caused by mining unloading. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of dynamic monitoring of the goaf gangue filling structure of the present invention.

[0025] Figure 2 Schematic diagram of the structure of the sliding bar displacement sensor in the present invention.

[0026] Figure 3 This is a schematic diagram of the results of reconstructing the dynamic gangue filling structure of the goaf according to the present invention.

[0027] In the figure: 1-coal seam roof, 2-coal seam, 3-coal seam floor, 4-mining and filling section, 5-equalizing pressure 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 end. DETAILED DESCRIPTION

[0028] The present invention will be further described below.

[0029] like Figure 1 As shown, the specific steps of the present invention are:

[0030] Step 1: First determine the mining height H of the coal seam 2 and the mining and filling step distance L of each mining and filling section 4 P , P is the number of different sampling and filling sections 4, P = 1, 2, 3...; and the sampling and filling step distance L Pare much smaller than the periodic pressure step; according to the determined mining parameters, the first mining and filling section 4 is mined first. After the mining work of the mining and filling section 4 is completed, multiple sliding rod displacement sensors 6 are set up in a row with a spacing S in the mining and filling section 4. The spacing S must meet S≤0.5L P and ensure that the pressure base 6-2 of each sliding rod displacement sensor 6 is fixed vertically to the coal seam floor 3; finally, each sliding rod displacement sensor 6 is connected to the control end 7.

[0031] Step 2: Control the pressure plate 6 - 1 of each sliding rod displacement sensor 6 to rise and contact the coal seam roof 1 through the control terminal 7 , and clear the displacement.

[0032] Step 3: Fill the first mining and filling section 4 with gangue and ensure that each slide-type displacement sensor 6 is in the gangue bulk formed by the filled gangue. Then, control the pressure plate 6-1 of each slide-type 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 bulk. The displacement of each slide-type displacement sensor 6 at this time is recorded as M. P,1 , M P,2 ,…,M P,Q , Q is the number of slide-rod displacement sensors 6 installed in the first mining and filling section 4, and then the gangue filling rate F at each slide-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:

[0033]

[0034] Where: , , .

[0035] Step 4: laying equalizing sandbags 5 on the upper end of the loose gangue in the first mining and filling section 4 to ensure that the overburden stress can be evenly applied to the entire loose gangue during the irregular breaking of the coal seam roof 1.

[0036] Step 5: The coal seam roof 1 of the first mining and filling section 4 will break over time and under the surrounding mining conditions, which will then apply overburden stress to the equalizing sandbag 5. At this time, the pressure plates 6-1 of each sliding rod displacement sensor 6 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 slide bar displacement sensor 6 can be obtained P,Q , and the equivalent gangue compaction rate B of the mining and filling section 4 P , the specific calculation formula is:

[0037]

[0038] Where: , , .

[0039] Step 6: Repeat steps 1 to 5 for each subsequent mining and filling section 4 until the gangue filling mining of the entire coal seam 2 is completed, and based on the equivalent gangue filling rate A of each mining and filling section 4 P Equivalent gangue compaction rate B P Calculate the equivalent gangue height D of each mining and filling section 4 P , the specific calculation formula is: .

[0040] Finally, according to the filling step L of each filling section 4, P The gangue height of each mining and filling section 4 is determined as the equivalent gangue height D of each mining and filling section 4. P , in order to reconstruct the dynamic gangue filling structure of the goaf. Figure 3 shown.

[0041] The above-mentioned sliding bar 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 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 6-3 extends into the interior of the sensor housing 6-4 from the top, the pressure plate 6-1 is mounted on the other end of the telescopic slide 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 6-3, and the lower contact electrode 6-6 is mounted on one end of the telescopic slide 6-3. When the telescopic slide 6-3 moves up and down in the sensor housing 6-4, the distance between the upper contact electrode 6-5 and the lower contact electrode 6-6 can be adjusted, thereby changing the current signal and transmitting it to the control terminal 7 through the signal transmission line 6-8, and recording the displacement of the telescopic slide 6-3 according to the change of the current signal; the control terminal 7 supplies power to the slide displacement sensor 6 through the power supply line 6-7.

[0042] 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 and filling step distance L of each mining and filling section P , P is the number of different mining and filling sections; according to the determined mining parameters, coal mining is first carried out in the first mining and filling section. After the mining work in the mining and filling section is completed, multiple sliding rod displacement sensors are set up in a row with a spacing S in the mining and filling section, and the pressure base of each sliding rod displacement sensor is ensured to be 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 the sliding rod displacement sensors to rise and contact 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-type displacement sensor is in the gangue bulk formed by the filled gangue. Then, control the pressure plate of each slide-type displacement sensor 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-type 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 and filling section P , the specific calculation formula is: ； Where: , , ; Step 4: Lay equalizing sandbags on the upper end of the loose gangue in the first mining and filling section to ensure that the overburden stress can be evenly applied to the entire loose gangue during the irregular fracture of the coal seam roof; Step 5: The coal seam roof of the first mining section will break over time and with the surrounding mining conditions, which will then apply overburden stress to the equalizing sandbags. 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 slide bar displacement sensor can be obtained P,Q , and the equivalent gangue compaction rate B of the mining and filling section P， The specific calculation formula is: ； Where: , , ; Step 6: Repeat steps 1 to 5 for each subsequent mining and filling 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 and filling section P Equivalent gangue compaction rate B P Calculate the equivalent gangue height D of each mining and filling section P , the specific calculation formula is: ; Finally, according to the equivalent gangue height D P The dynamic waste rock filling structure of the goaf is reconstructed by using the segmented reconstruction method combined with the mining and filling step distance of each mining and filling section.

2. The method for monitoring and reconstructing dynamic waste rock 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 periodic 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 specific segmented reconstruction method in step 6 is: keep the sampling and filling step 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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