A method for grouting and gap detection in the collapsed area behind a fully mechanized mining frame in a coal mine

Abstract

The present invention discloses a method for grouting and gap detection of a collapsed area behind a coal mine fully-mechanized mining frame, including the steps of trenching construction, trench body frame shifting and protection, arranging a grouting and gap detection device for a collapsed area behind a coal mine fully-mechanized mining frame, gap detection of collapsed space behind the frame, and gangue grouting and filling. In the present invention, when the coal seam roof behind the hydraulic support collapses, the protection frame can provide support and protection for the detection pipe and the grouting pipe, and can avoid detection obstruction and grouting obstruction caused by damage to the detection pipe and the grouting pipe to the maximum extent; as the hydraulic support moves forward in a step-by-step manner, the grouting pipe can follow the hydraulic support in a step-by-step manner, which not only does not affect the gangue grouting and filling, but also does not require additional drilling operations for the gangue grouting and filling operation. At the same time, the gangue slurry migration can be observed in real time through the detection pipe during the gangue grouting and filling process, and the slurry diffusion radius can be detected in real time, which can accurately guide the gangue grouting and filling operation, thereby ensuring the safety of the gangue grouting and filling construction behind the frame.

Description

Technical Field

[0001] The present invention relates to a method for grouting filling and gap detection in underground coal mine goaf, specifically a method for grouting filling and gap detection in the collapsed area behind the fully mechanized mining frame of a coal mine based on the mining and grouting technology behind the frame, belonging to the technical field of coal mine goaf management. Background Art

[0002] The gangue in-situ filling technology is a technology that grinds and crushes the by-product of coal mining, the gangue, underground, and adds water to make a slurry (or directly uses the original gangue through mechanical transportation), and fills it into the gap of the caving zone behind the coal mining face by pumping (or mechanical power such as throwing). It can not only reduce the ineffective transportation of gangue, improve the quality of raw coal, and save processing and gangue disposal costs, but also realize the simultaneous mining and filling to reduce the space of the goaf and improve the resource recovery rate. At the same time, it can effectively solve the problem of gangue emission, reduce pollution to the environment, and improve the safety and economic benefits of mines.

[0003] There are four types of underground gangue grouting filling technology, depending on the filling position: low-position grouting, adjacent-position grouting, high-position grouting, and grouting after mining. Low-position grouting and adjacent-position grouting are limited by the diffusion radius of gangue slurry, and cannot fully utilize the middle area of ​​the collapsed space after the frame. The drilling cost of high-position grouting and adjacent-position grouting is high and the grouting time is delayed. At this time, the collapse of the goaf is relatively dense, which will affect the amount of gangue filling. The technology of grouting after mining after the frame can not only make full use of the collapsed space after the frame in a timely manner, but also save drilling costs, thereby efficiently and low-costly increasing the amount of gangue consumption and reducing rock and surface deformation. However, due to the different coal mining conditions, surrounding rock characteristics and layout of hydraulic supports in the coal mining working face, the existing technology cannot form a unified standard and specification for the pipeline layout, protection method, construction process, and control of the diffusion radius of the gangue slurry and the safe distance of grouting for the post-frame mining and injection technology, which is the main factor restricting the development of the post-frame mining and injection technology. In addition, the void ratio of the collapsed space after the coal mining frame is the main condition for evaluating whether the underground gangue grouting filling technology is applicable, and it is also the premise for three-dimensional modeling and theoretical calculation. However, due to the relatively broken rocks in the collapsed area after the coal mining frame and the relatively harsh working environment on the underground comprehensive mining hydraulic support, the underground drilling construction conditions are limited and the drilling construction is difficult. The existing technology lacks an effective detection method for the void ratio of the collapsed space after the frame. The traditional point drilling method combined with the drilling television is difficult to implement in the collapsed space after the frame, and the cost is high. It is impossible to accurately guide the on-site construction through numerical simulation and theoretical calculation results. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for grouting and filling and void detection in the collapsed area behind a coal mine comprehensive mining frame. The method can accurately detect the void distribution and void ratio of the collapsed space behind the frame under the premise of realizing simultaneous grouting behind the frame, and can also monitor the diffusion and migration of slurry, thereby facilitating the determination of the spacing between grouting pipes and the safe distance for gangue grouting. The method is particularly suitable for underground gangue grouting filling in the goaf behind the frame of inclined coal seam mining.

[0005] To achieve the above purpose, the grouting filling and gap detection device for the collapsed area behind the fully mechanized mining frame of a coal mine comprises a protection frame and a grouting pipe, a detection pipe and a grouting stopper arranged in the protection frame;

[0006] The protection frame fixedly arranged as an integrated frame structure comprises a detection pipe protection frame part located at the upper part and a grouting pipe protection frame part located at the lower part, the longitudinal section of the detection pipe protection frame part is an isosceles triangle structure, the longitudinal section of the grouting pipe protection frame part is a door-shaped structure with an open bottom, the width and height dimensions of the grouting pipe protection frame part match the outer diameter dimension of the grouting pipe, the detection pipe and the grouting pipe are respectively arranged in the detection pipe protection frame part and the grouting pipe protection frame part, and the protection frame as a whole is in a state of straddling the grouting pipe, the grouting pipe that can be butt-jointed and installed front and back is made of a rigid material, the detection pipe that can be butt-jointed and installed front and back is made of a transparent material, the height and width dimensions of the grouting plug made of an elastic material match the width and height dimensions of the grouting pipe protection frame part, the grouting plug is provided with a through hole corresponding to the grouting pipe and matching the outer diameter dimension of the grouting pipe, and the grouting plug is positioned and installed in the grouting pipe protection frame part;

[0007] The grouting filling and gap detection method of the collapsed area behind the fully mechanized mining frame in a coal mine specifically includes the following steps:

[0008] Step 1, slotting construction: after comprehensively determining the total length of the grouting pipe according to the coal seam inclination and the fluidity of the gangue slurry, a slot is constructed on the coal seam floor in the gap between two adjacent hydraulic supports of the coal mining working face to form a slot body. The width and depth of the slot body match the width and height of the protective frame part of the protective frame grouting pipe;

[0009] Step 2, trough body moving frame protection: before the hydraulic support step-by-step moving frame, a rigid pad matching the inner space size of the trough body is temporarily placed in the trough body. After the moving frame operation is completed and the hydraulic support firmly supports the coal seam roof, the rigid pad is first taken out of the trough body, and then the trough construction is continued in the gap between two adjacent hydraulic supports on the basis of the trough body, so that the trough body extends forward as the hydraulic support moves forward;

[0010] Step 3, arrange the grouting filling and gap detection device of the collapsed area behind the coal mine comprehensive mining frame: as the hydraulic support moves forward, after the length of the trough is greater than the length of the protection frame, install the protection frame in the trough behind the hydraulic support, as the hydraulic support continues to move forward, continue to install the protection frame in the trough in turn, and make the two adjacent protection frames fit tightly, when the number of installed protection frames reaches the set number, send the detection pipe and grouting pipe into the protection frame, and so on, as the hydraulic support moves forward, install the protection frame, detection pipe and grouting pipe in turn, and the corresponding The two adjacent detection pipes are fixedly installed and butted against each other, and the two adjacent grouting pipes are fixedly installed and butted against each other; after the total length of the grouting pipes reaches the set total length, the grouting pipes are fixedly installed and connected to the hydraulic support; after the grouting pipes are fixedly installed and connected to the hydraulic support, as the hydraulic support moves forward step by step, the grouting pipes follow the hydraulic support to move forward step by step, and the trenching construction, installation of the protection frame and installation of the detection pipes are continuously carried out; when installing the protection frame, a grouting plug is fixedly installed at every set length, and the grouting pipe is connected to the through hole of the grouting plug, and mortar is filled above the grouting plug to form a local plugging section;

[0011] Step 4, post-collapse space gap detection: After the coal seam roof behind the hydraulic support collapses, the detection equipment is sent into the detection pipe to take photos or scan the distribution of the space gaps after the collapse. The void ratio, gap spacing, and block volume distribution data of the collapsed space are determined by analyzing the on-site detection results;

[0012] Step 5, gangue grouting filling: after completing the detection of the gap in the collapsed space behind the frame, connect the front end of the grouting pipe to the grouting output end of the grouting system, start the grouting system to carry out the pipe dragging grouting operation, and the gangue grouting filling and the fully mechanized hydraulic support support coal mining are carried out simultaneously; during the gangue grouting filling process, the filling situation is photographed or scanned through the detection equipment in the detection pipe, and the movement of the gangue slurry is observed in real time, and the slurry diffusion radius is detected in real time, which is used to accurately guide the grouting safety distance and grouting pipe spacing of the gangue grouting filling.

[0013] As a further improvement of the present invention, the grouting filling and gap detection device for the collapse area behind the coal mine fully mechanized mining frame also includes a tube-mounted sliding roller arranged in the left and right directions in the axial direction, the tube-mounted sliding roller is rollingly arranged at the inner bottom of the protective frame part of the grouting pipe of the protective frame, and the plurality of tube-mounted sliding rollers are arranged at intervals at set intervals along the front-back direction;

[0014] In Step 3, before installing the protection frame in the tank body, a plurality of tube-mounted sliding rollers are positioned and arranged in the tank body at set intervals along the front-to-back direction; when the grouting pipe is fed into the protection frame, the grouting pipe is mounted on the tube-mounted sliding rollers.

[0015] As a further improvement of the present invention, a cement mortar protective layer is provided on the inner surface of the tank body;

[0016] In step 1, after the tank body is formed, a cement mortar protective layer is constructed on the inner surface of the tank body.

[0017] As a further improvement of the present invention, a gangue graded cushion layer is provided on the cement mortar protective layer on the bottom plane of the tank body;

[0018] In Step 1, after the cement mortar protective layer of the trough body is constructed and finally set, a graded gangue cushion layer is laid on the cement mortar protective layer on the bottom plane of the trough body, and then leveled and compacted.

[0019] As an implementation mode of the present invention, the grouting pipe is a seamless steel pipe, the detection pipe is an acrylic pipe, and the grouting stopper is an inflatable rubber airbag.

[0020] As a further improvement of the present invention, a plurality of troughs are constructed and arranged along the width direction of the coal mining face according to the fluidity of the gangue slurry, the slurry diffusion radius and the spacing between the grouting pipes.

[0021] Compared with the prior art, the grouting filling and gap detection method for the collapsed area behind the fully mechanized mining frame of a coal mine has a detection pipe arranged in parallel above the grouting pipe, and the detection pipe and the grouting pipe are arranged in the detection pipe protection frame part and the grouting pipe protection frame part of the protection frame respectively. Therefore, when the coal seam roof behind the hydraulic support collapses in the later stage, the protection frame can provide support and protection for the detection pipe and the grouting pipe, and can avoid detection obstruction and grouting obstruction caused by damage to the detection pipe and the grouting pipe to the greatest extent; since the trough is opened between two adjacent hydraulic supports on the coal mining working face The trough is on the coal seam bottom plate of the gap, and the width and depth of the trough body match the width and height of the protective frame grouting pipe protection frame. Therefore, on the one hand, the trough body can be opened under the support and protection of the hydraulic support, with high operation safety and no impact on normal coal mining operations. On the other hand, the grouting pipe is grouted in the trough body, which can not only further avoid the grouting pipe from being damaged when the coal seam roof behind the hydraulic support collapses, but also does not affect the spatial distribution of the collapse on the left and right sides observed through the detection pipe, and the results of on-site detection are analyzed through the detection pipe. The analysis can determine the void ratio, void spacing, block volume distribution and other data of the collapsed space, which can provide data support for subsequent numerical simulation tests, model tests and other theoretical research calculations and the calculation of the filling capacity of the collapsed space; because a grouting plug is fixedly installed at every set length when installing the protection frame and the detection pipe, a local blocking section can be formed during the gangue grouting filling, which can prevent the gangue slurry from flowing along the trough to the working face; because the grouting pipe is fixedly connected to the hydraulic support after the total length of the grouting pipe reaches the set total length , and continue to carry out trenching construction, install protection frames and install detection pipes. Therefore, as the hydraulic support moves forward step by step, the grouting pipe can move forward with the hydraulic support. It not only does not affect the gangue grouting filling, but also the gangue grouting filling operation does not require additional drilling operations. At the same time, the gangue grouting filling operation can be carried out through the detection pipe to observe the movement of gangue slurry in real time and detect the slurry diffusion radius in real time, which can be used to accurately guide the grouting safety distance and grouting pipe spacing of gangue grouting filling, thereby ensuring the safety of gangue grouting filling construction after the frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the pipe-drag grouting method for the collapsed space behind the frame of the present invention;

[0023] Figure 2 It is a plan view of the pipe-drag grouting method for the collapsed space behind the frame of the present invention;

[0024] Figure 3 It is a schematic diagram of the slotting position of the present invention;

[0025] Figure 4 It is a longitudinal cross-sectional view of the grouting filling and gap detection device for the collapsed area behind the fully mechanized mining frame of a coal mine according to the present invention;

[0026] Figure 5 It is a three-dimensional structural schematic diagram of the grouting filling and gap detection device of the collapse area behind the fully mechanized mining frame of a coal mine according to the present invention.

[0027] In the figure: 1. trough body, 2. cement mortar protective layer, 3. gangue graded cushion layer, 4. tube slide roller, 5. grouting pipe, 6. protection frame, 7. detection pipe, 8. grouting plug. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings (hereinafter, the description is made with the moving direction of the hydraulic support as the front-to-back direction, the front-to-back direction as the length direction of the protection frame 6, and the left-to-right direction as the width direction of the protection frame 6).

[0029] like Figure 4 , Figure 5 As shown, the grouting filling and gap detection device for the collapse area behind the fully mechanized mining frame of a coal mine includes a protection frame 6 and a grouting pipe 5, a detection pipe 7 and a grouting plug 8 arranged in the protection frame 6.

[0030] The protective frame 6 fixedly arranged as an integrated frame structure includes a detection pipe protection frame part located at the upper part and a grouting pipe protection frame part located at the lower part. The longitudinal section of the detection pipe protection frame part is an isosceles triangle structure, and the longitudinal section of the grouting pipe protection frame part is a door-shaped structure with an open bottom. The width and height dimensions of the grouting pipe protection frame part match the outer diameter dimension of the grouting pipe 5. The detection pipe 7 and the grouting pipe 5 are respectively arranged in the detection pipe protection frame part and the grouting pipe protection frame part, and the protective frame 6 as a whole straddles the grouting pipe 5. The grouting pipe 5 that can be installed and connected by butt joint front and back is made of rigid material, preferably a seamless steel pipe with a larger wall thickness; the detection tube 7 that can be installed and connected by butt joint front and back is made of transparent material, preferably an acrylic tube with better transparency; the height and width of the slurry stop plug 8 are matched with the width and height of the grouting pipe protection frame; the slurry stop plug 8 is provided with a through hole corresponding to the grouting pipe 5 and matched with the outer diameter of the grouting pipe 5; the slurry stop plug 8 can be positioned and installed in the grouting pipe protection frame; the slurry stop plug 8 is made of elastic material, preferably an inflatable rubber airbag.

[0031] The method for grouting and filling and gap detection in the collapsed area behind the fully mechanized mining frame of a coal mine specifically includes the following steps:

[0032] Step 1, trenching construction: after comprehensively determining the total length of the grouting pipe 5 according to the coal seam inclination and the fluidity of the gangue slurry, Figures 1 to 4As shown, a slot is constructed on the coal seam floor in the gap between two adjacent hydraulic supports of the coal mining face to form a slot body 1. The width and depth of the slot body 1 match the width and height of the grouting pipe protection frame part of the protection frame 6. According to the fluidity of the gangue slurry, the slurry diffusion radius and the spacing of the grouting pipes, multiple slot bodies 1 can be constructed and arranged along the width direction of the coal mining face. The purpose of the slot is mainly to avoid the grouting pipe 5 being directly exposed on the coal seam floor after the hydraulic support is moved and pushed forward, thereby avoiding the grouting pipe 5 being directly subjected to the impact of the roof collapse, which may cause the grouting pipe 5 to be damaged and the difficulty of dragging the pipe.

[0033] Step 2, protection of trough body moving frame: When the hydraulic support is moving frame step by step, the hydraulic support exerts a large force on the coal seam bottom plate. If no protective measures are taken for the trough body 1, there is a risk of damage by the hydraulic support. Therefore, before the hydraulic support is moving frame step by step, a rigid pad matching the inner space size of the trough body 1 is temporarily placed in the trough body 1. The rigid pad can be a square steel or a square welded structural member. During the frame moving process, the rigid pad can play a temporary support role to protect the trough body 1. After the frame moving operation is completed and the hydraulic support firmly supports the coal seam top plate, the rigid pad is first removed from the trough body 1, and then the trough construction is continued in the gap between the two adjacent hydraulic supports on the basis of the trough body 1, so that the trough body 1 extends forward as the hydraulic support moves forward.

[0034] Step 3, arrange the grouting filling and gap detection device in the collapsed area behind the coal mine comprehensive mining frame: as the hydraulic support moves forward, after the length of the trough body 1 is greater than the length of the protection frame 6, install the protection frame 6 in the trough body 1 within 1m behind the hydraulic support, as the hydraulic support continues to move forward, continue to install the protection frame 6 in the trough body 1 in turn, and make the two adjacent protection frames 6 fit tightly, and when the number of installed protection frames 6 reaches the set number (the total length of multiple protection frames 6 meets the length specification size of the detection pipe 7 and the grouting pipe 5 for installation), send the detection pipe 7 and the grouting pipe 5 into the protection frame 6, and so on, as the hydraulic support moves forward, install the protection frame 6, the detection pipe 7 and the grouting pipe 5 in turn, and the two adjacent detection pipes 7 are butt-jointed and fixedly installed, and the two adjacent grouting pipes 5 are butt-jointed and fixedly installed. Since the trough body 1 is located between two adjacent hydraulic supports After the grouting pipe 5 is installed and connected with the hydraulic support, the grouting pipe 5 and the detection pipe 7 can be connected and connected to each other under the top beam of the hydraulic support. The top beam of the hydraulic support can provide stable support and protection, and the butt connection and installation are fast, simple and safe. After the total length of the grouting pipe 5 reaches the set total length, the grouting pipe 5 is fixedly installed and connected with the hydraulic support. After the grouting pipe 5 and the hydraulic support are fixedly installed and connected, as the hydraulic support moves forward step by step, the grouting pipe 5 follows the hydraulic support to move forward step by step, and the trenching construction, the installation of the protection frame 6 and the installation of the detection pipe 7 are continuously carried out. When the coal seam roof behind the hydraulic support collapses in the later stage, the gangue slurry is diffused to the surrounding at the rear end of the grouting pipe 5, and the slurry usually diffuses along the channel with less resistance. At this time, the gap between the trough body 1 and the protection frame 6 is easy to become a channel for the slurry diffusion, which will cause the gangue slurry to surge toward the working face along the trough body 1. Therefore, in order to avoid the gangue slurry surging toward the working face, such as Figure 5 As shown, when installing the protection frame 6, a grouting plug 8 is fixedly installed at a set length, and the grouting pipe 5 is passed through the through hole of the grouting plug 8, and mortar is filled above the grouting plug 8 to form a local blocking section.

[0035] Step 4, post-collapse space void detection: after the coal seam roof behind the hydraulic support collapses, insert detection equipment such as a borehole television or a three-dimensional scanning probe into the detection tube 7, take photos or scan the distribution of voids in the space after the collapse, and determine the void ratio, void spacing, block volume distribution and other data of the collapsed space through analysis of the on-site detection results, which can provide data support for subsequent numerical simulation, theoretical research and evaluation of the collapsed space filling capacity.

[0036] Step 5, gangue grouting filling: The principle of gangue grouting filling is that it should not affect the normal production of the working face. Therefore, it is particularly important to determine the grouting end standard of the pipe dragging grouting method in the collapsed space behind the frame. In addition, determining the diffusion radius of the gangue slurry in the collapsed space behind the frame is a prerequisite for designing the spacing between grouting pipes and determining the safe distance for grouting. However, the existing technology lacks real-time detection of the diffusion radius of the gangue slurry in the collapsed space behind the frame. Therefore, after completing the detection of the gap in the collapsed space behind the frame, the front end of the grouting pipe 5 is connected to the grouting output end of the grouting system, and the grouting system is started to carry out the pipe dragging grouting operation. The gangue grouting filling and the comprehensive hydraulic support support coal mining are carried out simultaneously. When the hydraulic support moves forward, the grouting pipe 5 can be driven to move synchronously without affecting the gangue grouting filling. During the gangue grouting filling process, the filling situation is photographed or scanned by the detection equipment such as the drilling TV or three-dimensional scanning probe in the detection tube 7, and the movement of the gangue slurry is observed in real time, and the slurry diffusion radius is detected in real time, which can be used to accurately guide the grouting safety distance and the spacing between the grouting pipes of the gangue grouting filling, thereby ensuring the safety of the gangue grouting filling construction behind the frame.

[0037] Since the grouting pipe 5 is filled with gangue slurry during the mining and injection process and has a heavy overall weight, in order to reduce the drag load of the hydraulic support on the grouting pipe 5 and ensure that the grouting pipe 5 can smoothly follow the hydraulic support to move forward, as a further improvement scheme of the present invention, Figure 4 , Figure 5 As shown, the grouting filling and gap detection device for the collapse area behind the coal mine comprehensive mining frame also includes a trustee sliding roller 4 arranged in the left and right direction in the axial direction, the trustee sliding roller 4 is rollingly arranged at the inner bottom of the grouting pipe protection frame part of the protection frame 6, and the trustee sliding roller 4 is correspondingly arranged below the grouting pipe 5, and multiple trustee sliding rollers 4 are arranged at set intervals along the front and rear directions; in Step 3, multiple trustee sliding rollers 4 are first positioned and arranged at set intervals along the front and rear directions in the trough body 1, and then the protection frame 6 is installed in the trough body 1; when the grouting pipe 5 is fed into the protection frame 6, the grouting pipe 5 is mounted on the trustee sliding roller 4.

[0038] In order to prevent the tank body 1 from collapsing during the production and injection process and to avoid the difficulty of subsequent pipe dragging caused by the unevenness of the tank body 1 itself, as a further improvement scheme of the present invention, Figure 4As shown, a cement mortar protective layer 2 is provided on the inner surface of the trough body 1; in Step 1, after the trough body 1 is formed, a cement mortar protective layer 2 is constructed on the inner surface of the trough body 1, and the cement mortar protective layer 2 can make the trough body 1 flat and reinforce the relatively broken rock mass of the coal seam bottom plate, so as to facilitate the subsequent pipe dragging operation and the protection of the trough body 1 during the frame shifting process. Since the amount of cement mortar protective layer material for the trough body is small, it can be directly stirred manually underground and a certain amount of accelerator can be added. The final setting time of the cement mortar is controlled and the reinforcement material is mixed based on the frame shifting interval time. Square steel or square welded structural parts of appropriate specifications can be used as forming molds to achieve rapid construction. In order to effectively protect the trough body 1, the thickness of the cement mortar protective layer 2 can be 15 to 30 cm.

[0039] When the coal seam roof behind the hydraulic support collapses, in order to achieve buffering and prevent the protection frame 6 from being damaged to the greatest extent, as a further improvement of the present invention, Figure 4 As shown, a gangue graded cushion layer 3 is provided on the cement mortar protective layer 2 on the bottom plane of the trough body 1; in Step 1, after the cement mortar protective layer 2 of the trough body 1 is constructed and finally set, a gangue graded cushion layer 3 is laid on the cement mortar protective layer 2 on the bottom plane of the trough body 1, and is leveled and compacted. The gangue grade ingredients are produced after the gangue is crushed by underground high-fine crushing equipment. The gangue particle size of the material is less than 3 mm, and the particle size distribution of 0.25-3 mm is relatively uniform. The gangue graded cushion layer 3 can provide a certain buffering effect when the coal seam roof behind the hydraulic support collapses and hits the protection frame 6. In order to effectively achieve the buffering effect, the laying thickness of the gangue graded cushion layer 3 can be 15-30 cm.

[0040] In the present method for grouting filling and gap detection in the collapsed area behind the fully mechanized mining frame of a coal mine, since the detection pipe 7 is arranged in parallel above the grouting pipe 5, and the detection pipe 7 and the grouting pipe 5 are arranged in the detection pipe protection frame part and the grouting pipe protection frame part of the protection frame 6 respectively, when the coal seam roof behind the hydraulic support collapses in the later stage, the protection frame 6 can provide support and protection for the detection pipe 7 and the grouting pipe 5, and can avoid the detection obstruction and grouting obstruction caused by the damage of the detection pipe 7 and the grouting pipe 5 to the greatest extent; since the trough body 1 is opened in the gap between two adjacent hydraulic supports on the coal mining working face The width and depth of the trough 1 match the width and height of the grouting pipe protection frame 6. Therefore, on the one hand, the trough 1 can be opened under the support and protection of the hydraulic support, with high operational safety and without affecting normal coal mining operations. On the other hand, the grouting pipe 5 is grouted in the trough 1, which can not only further avoid damaging the grouting pipe 5 when the coal seam roof behind the hydraulic support collapses, but also does not affect the observation of the collapse space distribution on the left and right sides through the detection pipe 7. The results of the on-site detection through the detection pipe 7 The analysis can determine the void ratio, void spacing, and block volume distribution of the collapsed space, and can provide data support for subsequent numerical simulation tests, model tests, and other theoretical research calculations and for evaluating the calculation of the collapsed space filling capacity; since a grouting stopper 8 is fixedly installed at intervals of a set length when installing the protection frame 6 and the detection pipe 7, a local blocking section can be formed during the gangue grouting filling, which can prevent the gangue slurry from flowing toward the working face along the trough body 1; since the grouting pipe 5 is fixedly connected to the hydraulic support after the total length of the grouting pipe 5 reaches the set total length, The grouting pipe 5 can be followed by the hydraulic support to move forward step by step, which not only does not affect the gangue grouting filling, but also does not require additional drilling operations for the gangue grouting filling operation. At the same time, the detection pipe 7 can be used to observe the movement of gangue slurry in real time and detect the slurry diffusion radius in real time during the gangue grouting filling process, which can be used to accurately guide the grouting safety distance and the spacing between grouting pipes for the gangue grouting filling, thereby ensuring the safety of the gangue grouting filling construction after the frame is installed.

Claims

1. A method for grouting and gap detection in the collapsed area behind a fully mechanized mining frame in a coal mine, characterized in that: The device for grouting and filling and detecting gaps in the collapsed area behind a fully mechanized mining frame in a coal mine comprises a protection frame (6) and a grouting pipe (5), a detection pipe (7) and a grouting stopper (8) arranged in the protection frame (6); The protective frame (6) is fixedly arranged as an integral frame structure and comprises a detection pipe protection frame portion located at the upper part and a grouting pipe protection frame portion located at the lower part. The longitudinal section of the detection pipe protection frame portion is an isosceles triangle structure, and the longitudinal section of the grouting pipe protection frame portion is a door-shaped structure with an open bottom. The width and height of the grouting pipe protection frame portion match the outer diameter of the grouting pipe (5). The detection pipe (7) and the grouting pipe (5) are respectively arranged in the detection pipe protection frame portion and the grouting pipe protection frame portion, and the protective frame (6) as a whole is in a state of straddling the grouting pipe (5). The grouting pipe (5) that can be butt-jointed and installed front and back is made of a rigid material, and the detection pipe (7) that can be butt-jointed and installed front and back is made of a transparent material. The height and width of the grouting plug (8) made of an elastic material match the width and height of the grouting pipe protection frame portion. The grouting plug (8) is provided with a through hole corresponding to the grouting pipe (5) and matching the outer diameter of the grouting pipe (5). The grouting plug (8) is positioned and installed in the grouting pipe protection frame portion. The grouting filling and gap detection method of the collapsed area behind the fully mechanized mining frame in a coal mine specifically includes the following steps: Step 1, trenching construction: after comprehensively determining the total length of the grouting pipe (5) according to the coal seam inclination and the fluidity of the gangue slurry, a trench is constructed on the coal seam floor in the gap between two adjacent hydraulic supports of the coal mining working face to form a trench body (1), and the width and depth of the trench body (1) match the width and height of the grouting pipe protection frame part of the protection frame (6); Step 2, trough body moving frame protection: before the hydraulic support is moved step by step, a rigid pad that matches the inner cavity space size of the trough body (1) is temporarily placed in the trough body (1). After the frame moving operation is completed and the hydraulic support firmly supports the coal seam roof, the rigid pad is first taken out of the trough body (1), and then the trough construction is continued in the gap between two adjacent hydraulic supports on the basis of the trough body (1), so that the trough body (1) extends forward as the hydraulic support moves forward; Step 3, arranging the grouting filling and gap detection device of the collapsed area behind the coal mine comprehensive mining frame: as the hydraulic support step-by-step moving frame moves forward, after the length of the trough body (1) is greater than the length of the protection frame (6), the protection frame (6) is installed in the trough body (1) behind the hydraulic support; as the hydraulic support continues to step-by-step moving frame moves forward, the protection frames (6) are successively installed in the trough body (1), and two adjacent protection frames (6) are closely fitted; when the number of installed protection frames (6) reaches a set number, the detection pipe (7) and the grouting pipe (5) are inserted into the protection frame (6); and so on; as the hydraulic support step-by-step moving frame moves forward, the protection frame (6), the detection pipe (7) and the grouting pipe (5) are successively installed. The two adjacent detection pipes (7) are butt-jointed and fixedly installed, and the two adjacent grouting pipes (5) are butt-jointed and fixedly installed; after the total length of the grouting pipes (5) reaches a set total length, the grouting pipes (5) are fixedly connected to the hydraulic support; after the grouting pipes (5) are fixedly connected to the hydraulic support, as the hydraulic support moves forward step by step, the grouting pipes (5) follow the hydraulic support to move forward step by step, and the trenching construction, installation of the protection frame (6) and installation of the detection pipes (7) are continuously performed; when installing the protection frame (6), a grouting stopper (8) is fixedly installed at intervals of a set length, and the grouting pipes (5) are connected to the through holes of the grouting stopper (8), and mortar is filled above the grouting stopper (8) to form a local plugging section; Step 4, post-collapse space gap detection: After the coal seam roof behind the hydraulic support collapses, a detection device is sent into the detection pipe (7), and the distribution of the gaps in the space after the collapse is photographed or scanned. The void ratio, gap spacing, and block volume distribution data of the collapsed space are determined by analyzing the on-site detection results; Step 5, gangue grouting filling: after completing the detection of the gap in the collapsed space behind the frame, the front end of the grouting pipe (5) is connected to the grouting output end of the grouting system, and the grouting system is started to carry out the pipe dragging grouting operation. The gangue grouting filling and the fully mechanized hydraulic support support coal mining are carried out simultaneously; during the gangue grouting filling process, the filling situation is photographed or scanned by the detection equipment in the detection pipe (7), the movement of the gangue slurry is observed in real time, and the slurry diffusion radius is detected in real time, which is used to accurately guide the grouting safety distance and grouting pipe spacing of the gangue grouting filling.

2. The method for grouting and gap detection in the collapse area behind the fully mechanized mining frame of a coal mine according to claim 1 is characterized in that: The device for grouting and filling and detecting gaps in the collapsed area behind a fully mechanized mining frame in a coal mine further comprises a tube-mounted sliding roller (4) arranged in the left-right direction in the axial direction, the tube-mounted sliding roller (4) being arranged in a rolling manner on the inner bottom of the grouting pipe protection frame portion of the protection frame (6), and a plurality of tube-mounted sliding rollers (4) being arranged at intervals at set intervals in the front-back direction; In step 3, before installing the protection frame (6) in the trough body (1), a plurality of tube-mounted sliding rollers (4) are positioned and arranged at set intervals along the front-to-back direction in the trough body (1); when the grouting pipe (5) is introduced into the protection frame (6), the grouting pipe (5) is mounted on the tube-mounted sliding rollers (4).

3. The method for grouting and gap detection in the collapsed area behind the fully mechanized mining frame of a coal mine according to claim 1 is characterized in that: A cement mortar protective layer (2) is provided on the inner surface of the tank body (1); In step 1, after the tank body (1) is formed, a cement mortar protective layer (2) is constructed on the inner surface of the tank body (1).

4. The method for grouting and gap detection in the collapsed area behind the fully mechanized mining frame of a coal mine according to claim 3 is characterized in that: A gangue graded cushion layer (3) is provided on the cement mortar protective layer (2) on the bottom plane of the tank body (1); In step 1, after the cement mortar protective layer (2) of the trough body (1) is constructed and finally set, a gangue graded cushion layer (3) is laid on the cement mortar protective layer (2) on the bottom plane of the trough body (1), and is leveled and compacted.

5. The method for grouting and gap detection in the collapsed area behind a fully mechanized mining frame in a coal mine according to any one of claims 1 to 4, characterized in that: The grouting pipe (5) is a seamless steel pipe, the detection pipe (7) is an acrylic pipe, and the grouting stopper (8) is an inflatable rubber airbag.

6. The method for grouting and gap detection in the collapsed area behind a fully mechanized mining frame in a coal mine according to any one of claims 1 to 4, characterized in that: According to the fluidity of the gangue slurry, the slurry diffusion radius and the spacing between grouting pipes, a plurality of troughs (1) are constructed and arranged along the width direction of the coal mining working face.

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