Coal gangue intelligent gob retaining filling method based on roadway mine pressure regulation

Abstract

The application discloses a coal gangue intelligent gob-remaining filling method based on roadway mine pressure regulation and control, and comprises the following steps: I. arranging multiple groups of detectors in the space around the remaining roadway to collect microseismic data in real time, obtaining the stress distribution result around the roadway, and then obtaining the mine pressure distribution around the remaining roadway; II. determining the stress peak value and the stress concentration area position; III. deciding the best filling scheme; and IV. intelligently cooperating with each filling procedure, so that the time used for the whole filling process from the filling start to the filling body reaching self-support is less than the moving period of the filling hydraulic support. The application aims at realizing the gob-remaining, reducing the advanced support workload, and preventing the roadway coal and rock dynamic disaster, fills the gangue in the roadway as a stable support body, reduces the influence of the mining pressure on the remaining roadway, and realizes the organic combination of the gangue treatment and the gob-remaining.

Description

TECHNICAL FIELD

[0001] The present application relates to a coal gangue intelligent gob-remaining filling method based on roadway mine pressure regulation. BACKGROUND

[0002] Gob-remaining is one of the effective methods to relieve the tension of mining and excavation replacement, reduce excavation and support costs. The key to its success is good in-gob support and roadside support. Among them, roadside filling can alleviate the mine pressure of the roadway and is conducive to the stability of the gob-remaining. Therefore, if the roadside filling reduces the impact of the mining pressure on the remaining roadway, it not only prevents coal and rock dynamic disasters caused by stress concentration in the roadway, but also strengthens the stability of the gob-remaining, reduces the workload of the advanced support, and the remaining roadway can serve the next working face. In addition to reducing the excavation and support costs, it also relieves the tension of mining and excavation replacement, making filling more conducive to coal mining. SUMMARY

[0003] In view of the above problems, the present application provides a coal gangue intelligent gob-remaining filling method based on roadway mine pressure regulation, which realizes gob-remaining, reduces the workload of the advanced support, and prevents coal and rock dynamic disasters in the roadway. The underground gangue is filled in the roadside as a stable support body to reduce the impact of the mining pressure on the remaining roadway, realizing the organic combination of gangue treatment and gob-remaining.

[0004] To achieve the above technical purposes and effects, the present application realizes the following technical solutions:

[0005] A coal gangue intelligent gob-remaining filling method based on roadway mine pressure regulation, comprising the following steps:

[0006] Step one, arranging multiple groups of geophones in the space around the remaining roadway to collect microseismic data in real time, inverting the seismic distance and seismic radiation energy according to the collected microseismic data, obtaining the apparent stress distribution results around the roadway, and then obtaining the mine pressure distribution around the remaining roadway;

[0007] Step two, determining the stress peak value and the position of the stress concentration area according to the mine pressure distribution data around the remaining roadway;

[0008] Step three, deciding the best filling scheme according to the position of the stress concentration area;

[0009] Step four, filling according to the decided roadside filling scheme, intelligently cooperating with each filling process, so that the time used for the entire filling process from the start of filling to the self-standing of the filling body is less than the moving period of the filling hydraulic support.

[0010] Preferably, step one specifically comprises the following steps:

[0011] Step 101, arranging multiple groups of geophones in the space around the roadway to collect microseismic data;

[0012] Step 102, selecting data segments of entire P waves and S waves from each geophone record respectively, selecting time windows according to magnitudes and distances, window length being from the beginning of P wave or S wave to attenuation to more than 2 times noise, then removing low frequency components by using band-pass filter, and then performing fast Fourier transform to frequency domain on the processed wave segments, and then performing integration in the frequency domain to obtain seismic velocity power spectrum integral S V and seismic displacement power spectrum integral S D :

[0013] S V = 2∫V 2 (f)df

[0014] S D = 2∫D 2 (f)df

[0015] In the formula, f is the frequency of seismic wave; V(f) is the frequency spectrum of seismic velocity; D(f) is the frequency spectrum of seismic displacement;

[0016] Step 103, calculating the zero frequency limit value Ω0 of seismic wave:

[0017] Ω0 2 = 4S D 3 / 2 S V -1 / 2

[0018] Step 104, obtaining seismic moment M0 and seismic radiation energy E S :

[0019]

[0020] E S = 4πρβS V

[0021] In the formula, β is the wave velocity of S wave; ρ is the medium density;

[0022] Step 105, calculating apparent stress δ of the source area app :

[0023] δ app = μE S / M0

[0024] In the formula, μ is the shear modulus of the medium in the source area; the distribution of the apparent stress of the source area can be obtained to obtain the mine pressure distribution around the roadway.

[0025] Preferably, step two specifically comprises the following steps:

[0026] Step 201, search the maximum stress value M from the calculated surrounding stress distribution data of the designed roadway, the value of M is the stress peak, and the position of M is recorded as (x m ,y m );

[0027] Step 202, search the stress values greater than σ b1 from the calculated surrounding stress distribution data of the designed roadway, and record them as N1, N2, N3, and so on, and their positions are recorded as (x1, y1), (x2, y2), (x3, y3), and so on, wherein σ b1 is the stress critical value in the slow development stage and stable expansion stage of fissure in coal uniaxial compression experiment;

[0028] Step 203, pre-alarm the positions of M, N1, N2, N3, and so on.

[0029] Preferably, step three specifically includes the following steps:

[0030] Step 301, load the orthogonal combination of filling positions L1, L2, L3, and so on into the FLAC3D three-dimensional numerical model for calculation to obtain the surrounding stress distribution data of the designed roadway under the filling position combination, and establish an empirical knowledge base; wherein the working face is divided into multiple filling areas from the end to the tail, and each adjacent three hydraulic supports are a filling area, recorded as L1, L2, L3, and so on;

[0031] Step 302, according to the positions and sizes of the pre-alarmed M, N1, N2, N3, and so on, find the filling position combination scheme L b1 from the empirical knowledge base, wherein the stress at the position is lower than σ 充 ;

[0032] Step 303, load the filling position, filling height, and filling body strength into the FLAC3D three-dimensional numerical model for calculation to obtain the new surrounding stress distribution data M', N1', N2', N3', and so on of the designed roadway at the positions of M, N1, N2, N3, and so on;

[0033] Step 304, when M', N1', N2', N3', and so on are all less than σ b1 , the filling position combination scheme L 充 is the best filling scheme.

[0034] Preferably, if the best filling scheme is not obtained, re-enter step 302 to obtain a new filling position combination scheme until the best filling scheme is obtained.

[0035] Preferably, step four specifically includes the following steps:

[0036] Step 401, according to the coal seam height, it is divided into φ sections from bottom to top, and each section height is H 模 , respectively recorded as the first L1, L2……L 启 ……L 终 layer, wherein, L 启 = floor (H 活 / H 模 ), floor is the floor function, H 活 is the distance from the bottom of the movable end of the telescopic gangue baffle to the roadway floor;

[0037] Step 402, the gangue is transported to the working face filling transfer machine transition bin by the gangue belt, and the gangue is screened by the vibrating screen before entering the working face filling transfer machine transition bin, the large gangue enters the upper layer of the filling transfer machine transition bin, and the small gangue enters the lower layer of the filling transfer machine transition bin;

[0038] Step 403, initialize Li=1, and enter step 404;

[0039] Step 404, the working face filling transfer machine starts to transfer the large gangue in the transition bin, and enters step 405;

[0040] Step 405, the roadway starts, each support sequentially acts to throw gangue to the rear end, and the gangue is thrown from left to right in a cycle, and the belt speed is gradually reduced until it is filled to the front end, and enters step 406;

[0041] Step 406, it is judged whether the layer laying height is ≥80%*H 模 , if greater, it enters step 407, otherwise it enters step 405;

[0042] Step 407, the working face filling transfer machine starts to transfer the small gangue in the transition bin, and enters step 408;

[0043] Step 408, the roadway starts, each support sequentially acts to throw gangue to the rear end, and the gangue is thrown from left to right in a cycle, and the belt speed is gradually reduced until it is filled to the front end, and enters step 409;

[0044] Step 409, it is judged whether the layer laying height is =H 模 , if equal, it enters step 410, otherwise, it enters step 408;

[0045] Step 410, stop transporting and throwing gangue, start the grouting device to grout, until the cementing agent liquid level ≥10% of the filling height of the next layer, then stop grouting, the value of Li+1, and enter step 411;

[0046] Step 411, it is judged whether Li is greater than or equal to L 启If yes, go to step 412, otherwise go to step 404;

[0047] Step 412, judge whether Li is equal to L 终 If yes, go to step 413, otherwise, the movable end of the telescopic baffle is lifted to 30% of the filling height of the next layer and goes to step 404;

[0048] Step 413, the movable end of the telescopic baffle is lifted to 70% of the filling height of the current layer, and the working face filling transfer machine starts to transfer the large gangue in the transition bin, and goes to step 414;

[0049] Step 414, the gangue is thrown to the rear end by the sequential action of each support, and the throwing is circular from left to right, and the belt speed is gradually reduced until the filling is completed to the front end, and goes to step 415;

[0050] Step 415, judge whether the laying height of the layer is greater than or equal to 50%*H 模 If yes, go to step 416, otherwise go to step 414;

[0051] Step 416, the working face filling transfer machine starts to transfer the small gangue in the transition bin, and the gangue is thrown to the rear end until the laying height of the middle and rear end reaches 90% of the laying height of the layer and the gangue leaks out of the front end, the transportation and throwing are stopped, the movable end of the telescopic baffle is lifted to the top end, the grouting device is started to grout, and goes to step 417;

[0052] Step 417, the termination is when the liquid level of the cementing agent reaches the top end and there is overflow at the tail beam gap of the support.

[0053] The beneficial effects of the present application are:

[0054] Firstly, the present application can obtain the distribution of the mine pressure around the roadway by arranging multiple groups of detectors in the space around the roadway to collect microseismic data in real time, inverting the seismic distance and seismic radiation energy according to the collected microseismic data, and obtaining the distribution of the mine pressure around the roadway, thereby warning the position of the stress concentration area, determining the size of the stress peak, and providing a basis for adjusting the filling scheme. Compared with the traditional monitoring means, this method can obtain the distribution law of the mine pressure around the entire roadway, not just a point in the roadway coal body, and the method is not limited by geological conditions and mining conditions. The distribution law of the mine pressure around the roadway analyzed by using apparent stress not only widens the application range of the microseismic monitoring system, but also provides an indirect measurement method for the mine pressure monitoring of the coal mining face.

[0055] Secondly, the application realizes gob-side entry retaining, reduces the workload of advanced support, and prevents coal and rock dynamic disasters in the roadway by filling gangue in the roadway to form a stable support body, reducing the influence of advanced support pressure on the roadway, and realizing the organic combination of gangue treatment and gob-side entry retaining.

[0056] Thirdly, the application can realize intelligent filling by predicting the stress concentration position of the roadway, deciding the best filling scheme, and implementing filling, so as to relieve the stress concentration of the roadway, prevent coal and rock dynamic disasters in the roadway, improve the stability of the roadway, realize gob-side entry retaining, relieve the tension of mining and excavation replacement, reduce the workload of advanced support, reduce the cost of roadway support, realize the intelligentization of the filling process, accurately control each filling process, ensure high-quality filling, and realize the intelligentization of filling equipment and systems. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 is a schematic diagram of the overall arrangement of the application;

[0058] Figure 2 is Figure 1 is a sectional view of I-I in FIG. 1;

[0059] Figure 3 is a structural schematic diagram of the crawler self-moving hydraulic support of the application;

[0060] Figure 4 is a flowchart of a preferred filling embodiment of the application;

[0061] The meanings of the labels of the drawings are as follows:

[0062] 1. coal mining machine; 2. traditional hydraulic support; 3. crawler self-moving hydraulic support; 4. retained roadway; 5. filling body; 6. goaf; 7. top beam; 8. grouting device; 9. multi-angle gangue throwing belt; 10. telescopic gangue blocking plate; 11. support base; 12. lifting crawler; 13. telescopic beam; 14. four-bar linkage mechanism; 15. hydraulic column; 16. bottom-dumping scraper conveyor; 17. binocular synchronous camera; 18. working face filling and transloading machine transition bin; 19. movable end of telescopic gangue blocking plate; 20. carrier roller; 21. baffle; 22. side limit; 23. arc-shaped slide rail; 24. circular rotary base; 25. belt rack. DETAILED DESCRIPTION

[0063] The technical solutions of the present application will be described in further detail below with reference to the drawings and specific examples, so that those skilled in the art can better understand the present application and implement it, but the examples are not intended to limit the present application.

[0064] A coal gangue intelligent gob-filling method based on roadway mine pressure regulation, comprising the following steps:

[0065] Step one, a plurality of geophones are arranged in the space around the reserved roadway 4 to collect microseismic data in real time, and the seismic distance and seismic radiation energy are inverted according to the collected microseismic data, so as to obtain the apparent stress distribution result of the roadway and further obtain the mine pressure distribution around the reserved roadway 4, and the preferred step one specifically comprises the following steps:

[0066] Step 101, a plurality of geophones are arranged in the space around the reserved roadway 4 to collect microseismic data;

[0067] Step 102, the data segments of the entire P wave (seismic longitudinal wave) and S wave (seismic transverse wave) are selected from the records of each geophone respectively, the time window is selected according to the magnitude and distance, the window length is determined according to the P wave or S wave starting from the attenuation to more than 2 times the noise, then the low-frequency component is removed by using a band-pass filter, and the wave segment after processing is subjected to fast Fourier transform (FFT) to the frequency domain, and integration is performed in the frequency domain to obtain the seismic velocity power spectrum integral S V and the seismic displacement power spectrum integral S D :

[0068] S V = 2∫V 2 (f)df

[0069] S D = 2∫D 2 (f)df

[0070] In the formula, f is the frequency of the seismic wave; V(f) is the frequency spectrum of the seismic velocity; and D(f) is the frequency spectrum of the seismic displacement;

[0071] Step 103, the zero-frequency limit value Ω0 of the seismic wave is calculated:

[0072] Ω0 2 = 4S D 3 / 2 S V -1 / 2

[0073] Step 104, the seismic distance M0 and the seismic radiation energy E S are obtained:

[0074]

[0075] E S= 4πρβS V

[0076] Wherein: β is the wave velocity of S wave; ρ is the medium density;

[0077] Step 105, calculating the apparent stress δ of the seismic source area app :

[0078] δ app = μE S / M0

[0079] Wherein: μ is the shear modulus of the medium of the seismic source area; the distribution of the apparent stress of the seismic source area can be obtained to obtain the mine pressure distribution around the reserved roadway 4.

[0080] Step two, according to the mine pressure distribution data around the reserved roadway 4, the size of the stress peak value is determined, the position of the stress concentration area is warned, preferably, step two specifically includes the following steps:

[0081] Step 201, searching for the maximum stress value M from the calculated mine pressure distribution data around the reserved roadway 4, the value of M is the stress peak value, and the position of M is recorded as (x m ,y m );

[0082] Step 202, searching for the stress value greater than σ b1 from the calculated mine pressure distribution data around the reserved roadway 4, and recording as N1, N2, N3......, and the positions corresponding to (x1, y1), (x2, y2), (x3, y3)......, wherein σ b1 is the stress critical value in the slow development stage and the stable expansion of the crack of the coal uniaxial compression experiment, when the internal stress of the coal is less than σ b1 , new cracks are generated in the coal body and show a non-impact dangerous state;

[0083] Step 203, warning the positions of M, N1, N2, N3.......

[0084] Step three, according to the position of the stress concentration area warned, the best filling scheme is decided, preferably, step three specifically includes the following steps:

[0085] Step 301, taking the orthogonal combination of the filling positions L1, L2, L3...... as input, loading into the FLAC3D three-dimensional numerical model for calculation, obtaining the mine pressure distribution data around the reserved roadway 4 under the filling position combination, and establishing an experience knowledge base; wherein, the working face is divided into multiple filling areas from the end to the end, and each adjacent 3 filling hydraulic supports are a filling area, recorded as L1, L2, L3.......

[0086] FLAC 3D(Fast Lagrangian Analysis of Continua) is a simulation calculation software developed by ITASCA company in the United States, which can simulate the stress characteristics of three-dimensional structures of soil, rock and other materials and analyze plastic flow.

[0087] Step 302, according to the pre-warning M, N1, N2, N3... position and size, find the filling position combination scheme L from the experience knowledge base, which should be less than σ b1 ; 充 ;

[0088] Step 303, taking the filling position, filling height and filling body strength as input, loading into the FLAC3D three-dimensional numerical model for calculation, obtaining the new mine pressure distribution data M', N1', N2', N3' around the M, N1, N2, N3... positions of the set roadway 4;

[0089] Among them, the filling height and the filling body strength are fixed values, the filling height is equal to the mining height of the coal seam, and the filling body strength is the material itself characteristics, the application requires the filling body to realize self-standing in a short time and can support the roof to a certain strength. Considering comprehensively, the method of cementing gangue is used for filling, and the cement water glass solution or the mixed solution of water glass solution and calcium chloride solution with the characteristics of high bonding strength, good heat resistance, strong acid resistance and short setting time is used as the filling material.

[0090] Step 304, when M', N1', N2', N3'... are all less than σ b1 , the filling position combination scheme L 充 is the best filling scheme.

[0091] Preferably, if the best filling scheme is not obtained, the new filling position combination scheme is obtained again in step 302 until the best filling scheme is obtained.

[0092] Step four, as shown in Figures 1-4 , wherein the coal mining machine 1 forms a goaf 6 in the coal mining process, the gangue is transported to the working face filling transfer machine transition bin 18 by the gangue belt, when the gangue in the working face filling transfer machine transition bin 18 meets the filling condition (such as the weight is greater than 30 kg), the filling transfer machine starts to transport the gangue to the bottom discharge type scraper conveyor 16 to start filling.

[0093] To achieve intelligent backfilling of coal gangue, this invention employs a combination of traditional hydraulic supports 2 and tracked self-propelled hydraulic supports 3. This provides a safe backfilling operation space without altering the existing supports at the working face, and eliminates the need for personnel to enter the goaf for temporary or reinforcement support. Backfilling is performed using the tracked self-propelled hydraulic supports 3, forming a backfill body 5 that meets the requirements for gangue processing while providing excellent overburden control and exhibiting a high degree of mechanization.

[0094] like Figure 3 As shown, the tracked self-propelled hydraulic support 3 includes a top beam 7, a hydraulic column 15, a support base 11, a lifting track 12, a bottom-discharge scraper conveyor 16, a gangue throwing device (multi-angle gangue throwing belt 9), a four-bar linkage mechanism 14, and a binder grouting device 8, etc.

[0095] The hydraulic column 15 is responsible for raising and lowering the top beam, and the lifting cylinder is responsible for raising and lowering the lifting track 12. During frame relocation, the hydraulic column 15 is retracted first, the top beam 7 is lowered, and then the lifting cylinder lowers the lifting track 12. The pneumatic motor drives the track to achieve frame relocation. During support, the lifting track 12 is raised first, then the hydraulic column 15 is raised, and the top beam 7 supports the top plate. Movable side guards can be installed on the left and right sides of the top beam 7 to adjust the support width. Telescopic beams 13 can be installed at the front and rear of the top beam to extend the support distance.

[0096] The grouting device (8) consists of several nozzles with spraying function.

[0097] The multi-angle waste rock throwing belt 9 has adjustable speed idlers 20 at both ends. The belt speed of the multi-angle waste rock throwing belt 9 is adjusted by the idlers 20, which are fixed on the belt frame 25. Four telescopic hydraulic columns are arranged below the belt frame 25. The first two telescopic hydraulic columns are arranged on the arc-shaped slide rail 23 of the support base 11, and the last two telescopic hydraulic columns are arranged on the circular rotating base 24 of the support base 11. This allows the multi-angle waste rock throwing belt 9 to be adjusted vertically by adjusting the height of each telescopic hydraulic column, and to be adjusted horizontally by adjusting the position of each telescopic hydraulic column on the slide rail. A baffle 21 is provided at one end of the multi-angle waste rock throwing belt 9. The diameter of most mine waste rock is concentrated between 10-20 cm. Through experiments, the correspondence between the speed of the multi-angle waste rock throwing belt 9 and the throwing position can be measured.

[0098] The filling is carried out according to the determined roadside filling plan, and the filling process is intelligently coordinated so that the time taken for the entire filling process from the start of filling to the filling body reaching self-support is less than the moving cycle of the filling hydraulic support.

[0099] Preferably, step four specifically includes the following steps:

[0100] Step 401, according to the coal seam height, it is divided into φ segments from bottom to top, and each segment height is H 模 , respectively recorded as the first L1, L2……L 启 ……L 终 layer, wherein, L 启 =floor(H 活 / H 模 ), floor is the floor function, H 活 is the distance from the bottom of the telescopic gangue baffle movable end 19 to the roadway floor, the telescopic gangue baffle 10 is arranged at the tail of the support base 11, and drives the telescopic gangue baffle movable end 19 to move up and down.

[0101] Step 402, the gangue is transported to the working face filling transfer machine transition bin by the gangue belt, and the gangue is screened by the vibrating screen before entering the working face filling transfer machine transition bin, the large gangue enters the upper layer of the filling transfer machine transition bin, and the small gangue enters the lower layer of the filling transfer machine transition bin;

[0102] Step 403, initializing Li=1, and entering step 404;

[0103] Step 404, the working face filling transfer machine starts to transfer the large gangue in the transition bin, and enters step 405;

[0104] Step 405, the side of the roadway starts, each support sequentially acts to throw gangue to the rear end, and the throwing is circular from left to right, and the belt speed is gradually reduced until the filling is to the front end, and step 406 is entered;

[0105] During the filling process, the belt speed and angle of the multi-angle gangue throwing belt 9 are adjusted to make the gangue uniformly cover the filling area, and the side limits 22 can be set on the left and right sides of the filling area using U-shaped steel and waterproof shed materials to shape and prevent leakage.

[0106] Step 406, it is judged whether the layer laying height is greater than or equal to 80%*H 模 , if greater, step 407 is entered, otherwise step 405 is entered;

[0107] Step 407, the working face filling transfer machine starts to transfer the small gangue in the transition bin, and enters step 408;

[0108] Step 408, the side of the roadway starts, each support sequentially acts to throw gangue to the rear end, and the throwing is circular from left to right, and the belt speed is gradually reduced until the filling is to the front end, and step 409 is entered;

[0109] Step 409, it is judged whether the layer laying height is equal to H 模 , if equal, step 410 is entered, otherwise, step 408 is entered;

[0110] Step 410, stop transporting and throwing gangue, and start the grouting device to conduct grouting (when the gangue accumulates to a certain height, the gangue cementing agent grouting device 8 is started to cement the bulk gangue to improve its strength to support the roof and reduce the side pressure of the gangue filling body to the side support structure of the gob-side entry retaining), until the cementing agent liquid surface is greater than or equal to 10% of the filling height of the next layer, the grouting is stopped, the value of Li is increased by 1, and step 411 is entered;

[0111] Step 411, whether Li is greater than or equal to L 启 , if yes, step 412 is entered, otherwise step 404 is entered;

[0112] Step 412, whether Li is equal to L 终 , if yes, step 413 is entered, otherwise, the movable end of the telescopic baffle is lifted to 30% of the filling height of the next layer and step 404 is entered;

[0113] Step 413, the movable end of the telescopic baffle is lifted to 70% of the filling height of the current layer, and the face filling transfer machine starts to transfer the large gangue in the transition bin, and step 414 is entered;

[0114] Step 414, the gangue is thrown to the rear end by the sequential action of each support from left to right in a cycle, and the belt speed is gradually reduced until the filling is completed to the front end, and step 415 is entered;

[0115] Step 415, whether the laying height of the layer is greater than or equal to 50%*H 模 , if yes, step 416 is entered, otherwise, step 414 is entered;

[0116] Step 416, the face filling transfer machine starts to transfer the small gangue in the transition bin, and the gangue is thrown to the rear end until the laying height of the middle and rear end reaches 90% of the laying height of the layer and the gangue leaks out of the front end, the transporting and throwing of the gangue are stopped, the movable end of the telescopic baffle is lifted to the top end, the grouting device is started to conduct grouting, and step 417 is entered;

[0117] Step 417, the grouting is terminated when the cementing agent liquid surface reaches the top end and there is overflow at the tail beam gap of the support, and the nozzle is retracted into the tail beam after grouting.

[0118] The above distance measuring device is one or a combination of an infrared range finder, a binocular synchronous camera 17, and a laser scanning device.

[0119] In order to achieve the coordination of mining and filling, and realize that the front coal mining and the rear filling do not affect each other, the self-standing time T 充 of the filling body should be less than the next moving period T 周 of the crawler self-moving hydraulic support, that is, T 充 ≤T 周By optimizing the design of the crawler self-moving hydraulic support 3, installing the gangue throwing device and the gangue cement grouting device, safe, efficient and intelligent filling is realized. In addition, the installed gangue throwing device has the advantages of long throwing distance, adjustable throwing angle, good gangue top connection effect, no need to hang filling bags or set filling molds, and filling process is not affected by coal mining moving support, small disturbance to coal mining, suitable for multi-cutting and one-filling mode (i.e. more cutting and one filling), and can achieve the coordinated state of normal coal mining in front and normal filling in back.

[0120] The beneficial effects of the present application are:

[0121] Firstly, the present application arranges multiple groups of detectors in the space around the retained roadway to collect microseismic data in real time, inverses the seismic distance and seismic radiation energy according to the collected microseismic data, obtains the mine pressure distribution around the roadway, thereby early warns the position of stress concentration area, determines the size of stress peak value, and provides basis for adjusting the filling scheme. Compared with the traditional monitoring means, this method can obtain the mine pressure distribution law around the entire roadway, not only a certain point in the roadway coal body, and the method is not limited by geological conditions and mining conditions. Using apparent stress to analyze the distribution law of mine pressure around the roadway not only widens the application range of the microseismic monitoring system, but also provides an indirect measurement method for coal mine stope mine pressure monitoring.

[0122] Secondly, the present application aims to realize gob-side entry retaining, reduce the workload of advance support, and prevent roadway coal and rock dynamic disasters, fills gangue in the roadway side as a stable support body in the underground, reduces the influence of stope advance support pressure on the retained roadway, and realizes the organic combination of gangue treatment and gob-side entry retaining. Through the present application, in-situ green intelligent filling of coal gangue can be realized, which not only can reduce carbon dioxide emission caused by gangue ground accumulation spontaneous combustion, reduce unit output energy resource consumption, form an effective carbon emission control valve at the source of production, but also can use gangue filling to control roadway mine pressure to realize gob-side entry retaining, relieve mining replacement tension, prevent roadway coal and rock dynamic disasters, reduce the workload of advance support, and realize green and low-carbon intelligent mining of coal.

[0123] Thirdly, according to the real-time distribution of mine pressure around the retained roadway, the present application early warns the stress concentration position of the roadway, decides the best filling scheme to implement filling, can relieve the stress concentration of the roadway after filling in the roadway side, prevent roadway coal and rock dynamic disasters, improve the stability of the roadway, realize gob-side entry retaining, relieve mining replacement tension, reduce the workload of advance support, reduce the cost of roadway support, realize the intelligentization of filling process, accurately control each filling process, ensure high-quality filling, and realize the intelligentization of filling equipment and system.

[0124] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application, and any equivalent structure or equivalent process conversion, or direct or indirect application in other related technical fields, which is made by using the content of the present application specification and drawings, is also included in the patent protection scope of the present application.

Claims

1. A method for intelligent roadway retention and backfilling of coal gangue based on roadway pressure control, characterized in that, Includes the following steps: Step 1: Arrange multiple sets of geophones in the space around the reserved roadway to collect microseismic data in real time. Based on the collected microseismic data, perform inversion of seismic distance and seismic radiation energy to obtain the apparent stress distribution around the roadway and thus obtain the mine pressure distribution around the reserved roadway. Step 2: Based on the mine pressure distribution data around the reserved roadway, determine the magnitude of the stress peak and warn of the location of the stress concentration area; Step 3: Determine the optimal filling scheme based on the location of the stress concentration area identified in the early warning. Step 4: Fill the alleyway according to the determined backfilling plan, and intelligently coordinate each backfilling process so that the time taken for the entire backfilling process from the start of backfilling to the backfill body becoming self-supporting is less than the moving cycle of the backfilling hydraulic support. Step one specifically includes the following steps: Step 101: Arrange multiple sets of geophones in the space surrounding the reserved tunnel to collect microseismic data; Step 102: Select the entire P-wave and S-wave data segments from each detector record, and select time windows according to different magnitudes and distances. The window length is based on the start of the P-wave or S-wave until it decays to more than twice the noise level. Then, use bandpass filtering to remove low-frequency components, perform a fast Fourier transform on the processed band to the frequency domain, and integrate in the frequency domain to obtain the ground velocity power spectrum integral S. V The power spectrum integral S of ground displacement D : S V =2∫V 2 (f)df S D =2∫D 2 (f)df In the formula, f is the seismic wave frequency; V(f) is the spectrum of the ground velocity; and D(f) is the spectrum of the ground displacement. Step 103: Calculate the zero-frequency limit value Ω0 of the seismic wave: Ω0 2 =4S D 3 / 2 S V -1 / 2 Step 104: Calculate the seismic distance M0 and the seismic radiation energy E. S : E S =4prβS V In the formula: β is the wave velocity of the S-wave; ρ is the density of the medium; Step 105: Calculate the apparent stress δ in the seismic source region. app : d app =μE S / M0 In the formula: μ is the shear modulus of the medium in the source area; the distribution of mine pressure around the roadway can be obtained by the apparent stress distribution law in the source area; Step two specifically includes the following steps: Step 201: Search for the maximum stress value M from the calculated surrounding mine pressure distribution data of the reserved roadway. The value of M is the stress peak value, and the position of M is denoted as (x... m ,y m ); Step 202: Search for values ​​greater than σ from the calculated surrounding mine pressure distribution data of the reserved roadway. b1 The stress values ​​are denoted as N1, N2, N3, ..., and their corresponding positions are denoted as (x1, y1), (x2, y2), (x3, y3), ..., where σ b1 This represents the critical stress value for the slow development stage and stable propagation stage of cracks in the uniaxial compressive strength test of coal. Step 203: Location of warning numbers M, N1, N2, N3...; Step three specifically includes the following steps: Step 301: Using the orthogonal combination of filling locations L1, L2, L3... as input, load it into the FLAC3D three-dimensional numerical model for calculation to obtain the mine pressure distribution data around the reserved roadway under the filling location combination, and establish an experience knowledge base; wherein, the working face is divided into multiple filling areas from end to end, and every 3 adjacent filling hydraulic supports constitute 1 filling area, denoted as L1, L2, L3...; Step 302: Based on the location and magnitude of the warning values ​​M, N1, N2, N3..., search the experience knowledge base to find locations where the stress is always lower than σ. b1 Filling location combination scheme L 充 ; Step 303: Using the filling location, filling height, and filling strength as input quantities, load them into the FLAC3D three-dimensional numerical model for calculation to obtain new mine pressure distribution data M', N1', N2', N3', ... around the reserved roadway at locations M, N1, N2, N3... Step 304: When M', N1', N2', N3'... are all less than σ b1 When, the filling location combination scheme L 充 This is the optimal filling scheme.

2. The intelligent coal gangue retention and backfilling method based on roadway mine pressure control according to claim 1, characterized in that, If the optimal filling scheme is not obtained, proceed to step 302 to obtain a new combination of filling positions until the optimal filling scheme is obtained.

3. The intelligent coal gangue retention and backfilling method based on roadway mine pressure control according to claim 1, characterized in that, Step four specifically includes the following steps: Step 401: Based on the coal seam mining height, divide it into equal segments φ from bottom to top, with each segment having a height of H. 模 Let them be denoted as L1, L2...L1 respectively. 启 ...L 终 Layer, where L 启 =floor(H 活 / H 模 ), floor is the floor function, H 活 The distance between the bottom of the movable end of the telescopic rock-blocking plate and the roadway floor. Step 402: The excavated gangue is transported to the transition bin of the backfilling transfer machine via a gangue conveyor belt. Before entering the transition bin, the gangue is screened by a vibrating screen. Large pieces of gangue enter the upper layer of the backfilling transfer machine transition bin, and small pieces of gangue enter the lower layer of the backfilling transfer machine transition bin. Step 403: Initialize Li = 1, proceed to step 404; Step 404: The working face filling and transfer machine begins transferring large pieces of gangue from the transition bin, proceeding to step 405; Step 405: Starting from the side of the alley, each support moves sequentially to throw the rock to the rear end, cyclically throwing from left to right, and gradually reducing the belt speed until it is filled to the front end, then proceed to step 406. Step 406: Determine if the laying height of this layer is ≥80%*H 模 If it is greater than , proceed to step 407; otherwise, proceed to step 405. Step 407: The working face filling and transfer machine begins transferring small pieces of gangue from the transition bin, proceeding to step 408; Step 408: Starting from the side of the alley, each support moves sequentially to throw the rock to the rear end, cyclically throwing from left to right, and gradually reducing the belt speed until it is filled to the front end, then proceed to step 409; Step 409: Determine if the laying height of this layer is equal to H. 模 If it equals, proceed to step 410; otherwise, proceed to step 408. Step 410: Stop transportation and dumping of waste rock, start the grouting device to grout until the cementitious liquid level is ≥ 10% of the filling height of the next layer, then stop grouting, increment the value of Li by 1, and proceed to step 411. Step 411: Determine if Li is greater than or equal to L. 启 If yes, proceed to step 412; otherwise, proceed to step 404. Step 412: Determine if Li is equal to L 终 If yes, proceed to step 413; otherwise, raise the movable end of the telescopic baffle to 30% of the next layer's filling height and proceed to step 404. Step 413: The movable end of the telescopic baffle is raised to 70% of the filling height of this layer, and the working face filling and transfer machine begins to transfer large pieces of gangue from the transition bin, proceeding to step 414; Step 414: Starting from the side of the alley, each support moves sequentially to throw the gangue to the rear end, cyclically throwing from left to right, and gradually reducing the belt speed until it is filled to the front end, then proceed to step 415; Step 415: Determine if the laying height of this layer is ≥50%*H 模 If yes, proceed to step 416; otherwise, proceed to step 414. Step 416: The working face filling and transfer machine starts to transfer small pieces of gangue from the transition bin and throws gangue to the rear end until the middle and rear end laying height reaches 90% of the laying height of the layer and gangue is leaking out at the front end. Then, stop the transportation and throwing of gangue, raise the movable end of the telescopic baffle to the top, start the grouting device to grout, and proceed to step 417. Step 417: The process ends when the adhesive liquid level reaches the top and overflows from the gap in the tail beam of the support.

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