Experimental device and experimental method for simulating filling and sealing retaining wall of coal mine

Abstract

The application provides an experimental device and an experimental method for simulating a coal mine filling sealing retaining wall. The experimental device comprises a box, a cover plate assembly and a pressure detection assembly. One end of the box is provided in an open manner. The box has a containing cavity. The cover plate assembly is movably arranged at the opening of the box. The box and the cover plate assembly form a sealed space. A grouting hole is formed in the box. The grouting hole is used for filling a slurry into the sealed space. The pressure detection assembly is used for detecting the pressure received by the box. The experimental device of the application forms a sealed space by the box and the cover plate assembly. The shape of the cover plate assembly is adjusted to simulate the shape of a coal mine site roof. The slurry can simulate the working condition of the coal mine site to reach a top-contacting shape during the filling of the sealed space. The pressure detection assembly can detect the pressure received by the box in real time during the filling of the slurry. The detected pressure value can more accurately guide the construction of the coal mine site sealing retaining wall.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, and in particular to an experimental apparatus and method for simulating a coal mine filling and sealing retaining wall. Background Technology

[0002] With the development of the coal mining industry, my country produces hundreds of millions of tons of coal gangue annually, and this figure is increasing year by year, causing serious soil pollution. Underground backfilling for treating large volumes of coal-based solid waste is a relatively low-cost method, making it a major trend in coal-based solid waste treatment. This method can utilize 30-50% of the mining space, is 30% cheaper than other treatment methods, and is more than three times more efficient, providing an effective approach for the centralized and large-scale treatment of large quantities of coal-based solid waste. By implementing backfilling mining, solid waste generated by coal mines can be reduced at the source, effectively mitigating geological shifts and subsidence, and protecting water resources and the ecological environment.

[0003] Because paste backfilling is safe, efficient, stable, easy to transport, requires no dehydration, can process large quantities of solid waste, has low compression, and provides good surface subsidence reduction, it has become a major development direction for green backfilling. However, paste backfilling differs from dry backfilling. It requires the construction of a sealed backfilling space to ensure the backfill slurry doesn't leak everywhere, allowing it to quickly accumulate and contact the top of the backfill area. Once the slurry solidifies to a certain strength, it gradually supports the top slab of the backfill area, preventing collapse, bending, and subsidence, ultimately controlling surface subsidence. However, as the slurry gradually accumulates in the sealed space, the sealed retaining wall must withstand the lateral pressure of the flowing slurry. Therefore, the constructed sealed retaining wall must have sufficient lateral pressure resistance to ensure safe and efficient backfilling. The backfill slurry itself must also have a certain pressure to reach the top.

[0004] The connection between the filling space and the roof is a key factor affecting surface subsidence. Many coal mines have near-horizontal coal seams, and the roof is often uneven, or the roof may collapse locally due to mine pressure, making it difficult for the filling grout to connect with the roof. At the end of filling a space, the grout needs to be pressurized to push it towards the roof depression area, further improving the connection rate. However, the pressurization by the grouting pump further increases the lateral pressure of the filling grout on the sealed retaining wall. The safe, efficient, and economical construction of sealed retaining walls for filled spaces is a crucial step in improving filling efficiency. Simulating the lateral pressure on the sealed retaining wall during filling using experimental devices provides important guidance for its construction. Currently, there is no experimental device available to simulate the lateral pressure on the sealed retaining wall during filling. Summary of the Invention

[0005] This invention provides an experimental apparatus and method for simulating the filling of a sealed retaining wall in a coal mine, in order to solve the problem that in the prior art, the lateral pressure on the sealed retaining wall in the coal mine is calculated by theoretical formulas but cannot accurately obtain the pressure on the sealed retaining wall during the filling process.

[0006] In a first aspect, the present invention provides an experimental device for simulating a coal mine filling sealed retaining wall, comprising: a box, a cover plate assembly, and a pressure detection assembly;

[0007] One end of the box is open, the box has a receiving cavity, the cover plate assembly is movably covered by the open part of the box, and the box and the cover plate assembly enclose a sealed space; the box is provided with a grouting hole, which is used to fill the sealed space with grout;

[0008] The pressure detection component is used to detect the pressure applied to the housing.

[0009] According to the present invention, an experimental device for simulating a coal mine filling sealed retaining wall is provided, wherein the cover plate assembly includes a sliding cover plate and a rotating cover plate;

[0010] The rotating cover plate includes a connecting part and two movable cover plates rotatably connected to the connecting part, and at least one of the two movable cover plates is connected to the sliding cover plate.

[0011] The sliding cover is slidably connected to the box body, and the sliding cover can drive the movable cover to rotate relative to the connecting part, so that the angle between the two movable covers is adjustable.

[0012] According to the experimental device for simulating a coal mine filling sealed retaining wall provided by the present invention, the number of sliding cover plates is multiple, the number of rotating cover plates is multiple, and the sliding cover plates are sandwiched between two adjacent rotating cover plates.

[0013] According to the present invention, an experimental device for simulating the filling of a sealed retaining wall in a coal mine is provided. The rotating cover plate is provided with an exhaust hole, through which the moisture in the slurry in the sealed space can be obtained to detect the parameters of the slurry.

[0014] According to the present invention, an experimental device for simulating the filling of a sealed retaining wall in a coal mine is provided. The pressure detection component includes a first pressure detection unit, which is disposed on the outer wall surface of the box and is used to detect the pressure on the box.

[0015] According to the experimental apparatus for simulating a coal mine filling sealed retaining wall provided by the present invention, the pressure detection component further includes a second pressure detection unit, which is disposed on the cover plate assembly and is used to detect the pressure on the cover plate assembly.

[0016] According to the present invention, an experimental device for simulating the filling of a sealed retaining wall in a coal mine is provided, wherein the box body and the cover plate assembly are both made of transparent material.

[0017] Secondly, the present invention provides an experimental method for simulating a coal mine filling sealed retaining wall, and the experimental apparatus based on the aforementioned simulated coal mine filling sealed retaining wall includes:

[0018] Based on the filling space and filling flow rate at the coal mine site, the simulated filling flow rate of the experimental device was calculated;

[0019] The cover plate assembly is placed over the open part of the box body to form a closed space by the box body and the cover plate assembly. Grout is filled into the closed space through the grouting holes on the box body to simulate the filling flow rate.

[0020] The pressure on the housing is detected by a pressure detection component.

[0021] According to the experimental method for simulating a coal mine filling sealed retaining wall provided by the present invention, the step of covering the box body with the cover plate assembly so that the box body and the cover plate assembly enclose the sealed space further includes: adjusting the opening angle of the rotating cover plate by sliding the cover plate.

[0022] The process of filling the sealed space with grout through the grouting holes on the box body to simulate the filling flow rate also includes: observing the diffusion pattern and the top contact pattern of the grout in the sealed space.

[0023] An experimental method for simulating a coal mine filling sealed retaining wall according to the present invention further includes:

[0024] The moisture content of the slurry in the sealed space is obtained through the vent on the box body in order to detect the slurry's water bleeding rate and solidification shrinkage rate.

[0025] The present invention provides an experimental device and method for simulating the filling of a sealed retaining wall in a coal mine. The cover plate assembly is movably installed at the opening of the box, and the box and the cover plate assembly enclose a sealed space. The shape of the cover plate assembly is adjusted to simulate the shape of the roof of the coal mine. During the filling of the sealed space, the slurry can simulate the working conditions of the coal mine and reach the roof. The pressure detection component detects the pressure on the box during the filling process in real time. The detected pressure value can more accurately guide the construction of the sealed retaining wall in the coal mine. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a front view of the experimental apparatus provided by the present invention;

[0028] Figure 2 This is a top view of the experimental apparatus provided by the present invention;

[0029] Figure 3 This is a side view of the experimental apparatus provided by the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of the sliding cover plate provided by the present invention;

[0031] Figure 5 This is one of the structural schematic diagrams of the rotating cover plate provided by the present invention;

[0032] Figure 6 This is the second schematic diagram of the rotating cover plate provided by the present invention;

[0033] Reference numerals in the attached drawings: 1: Box body; 101: First side plate; 2: Sliding cover plate; 3: Rotating cover plate; 301: Movable cover plate; 302: Recessed area; 303: Vent hole; 304: Movable top plate; 4: First pressure sensor; 5: Second pressure sensor; 6: Third pressure sensor; 7: Grouting pipe; 8: Grout. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] The following is combined with Figures 1 to 6 An experimental apparatus for simulating a coal mine filling sealed retaining wall, according to an embodiment of the present invention, is described.

[0037] like Figure 1 , Figure 2 and Figure 3 As shown, the experimental device for simulating a coal mine filling sealed retaining wall provided in this embodiment of the invention includes: a box body 1, a cover plate assembly, and a pressure detection assembly; one end of the box body 1 is open, the box body 1 has a receiving cavity, the cover plate assembly is movably covered at the open end of the box body 1, and the box body 1 and the cover plate assembly enclose a sealed space; a grouting hole is provided on the box body 1, which is used to fill the sealed space with grout 8; the pressure detection assembly is used to detect the pressure on the box body 1.

[0038] Specifically, the experimental apparatus includes a box body 1 and a cover plate assembly. The box body 1 simulates the shape of a sealed retaining wall in a coal mine. The box body 1 is a hollow square and includes two first side plates 101 spaced apart, two second side plates spaced apart, and a bottom plate. The box body 1 is made of transparent material, such as transparent, high-strength tempered glass. The connection between the first side plates 101 and the second side plates can be fixed with angle steel, and the gaps at the connection can be firmly bonded with adhesive. Fasteners pass through the mounting holes on the angle steel and the first side plates 101 to connect the angle steel and the first side plates 101, and fasteners pass through the mounting holes on the angle steel and the second side plates to connect the angle steel and the second side plates. Bolts and nuts can be used for the fasteners. Similarly, the connection between the first side plates 101 and the bottom plate, as well as the connection between the second side plates and the bottom plate, can be fixed with angle steel and firmly bonded with adhesive to ensure the overall strength of the box body 1. The dimensions of box 1 are set according to actual needs. For example, the length, width and height of box 1 are 5m, 1m and 3m respectively.

[0039] The top of the box 1 is open, and the cover plate assembly is movably connected to the box 1. The cover plate assembly and the box 1 are separable. The cover plate assembly is placed over the open end, and the cover plate assembly and the box 1 enclose a sealed space. The shape of the cover plate assembly is adjustable. By adjusting the shape of the cover plate assembly, the irregular shape of the roof in a coal mine can be simulated, allowing the grout 8 to simulate the roof contact shape in a coal mine and fill the sealed space formed by the box 1 and the cover plate assembly. The first side plate 101 is defined as the side plate in the width direction of the box 1, and the second side plate is defined as the side plate in the length direction of the box 1. The first side plate 101 of the box 1 is equivalent to the sealed retaining wall at the entrance of a coal mine roadway. A grouting hole is provided on the top of the first side plate 101, and a grouting pipe 7 is installed at the grouting hole. One end of the grouting pipe 7 is connected to the grouting pump, and the other end of the grouting pipe 7 is located in the sealed space. Grout 8 is filled into the box 1 through the grouting pipe 7. It can be understood that the grout 8 can be prepared from coal-based solid waste. The other end of the grouting pipe 7 is located in the center of the closed space to facilitate the smooth flow of the grout 8 in the box 1.

[0040] The pressure detection component can be installed on the first side plate 101 or the second side plate. For example, the grouting pipe 7 is installed on one first side plate 101, and the pressure detection component is installed on the other first side plate 101. Grout 8 is injected into the box 1 at a suitable simulated filling flow rate. During the filling process of grout 8, the pressure on the first side plate 101 can be detected in real time by the pressure detection component.

[0041] The shape of the cover plate assembly can be adjusted to closely resemble the shape of the roof of the coal mine. During the filling process, after the grout 8 overflows the grouting pipe 7, the grouting pump increases its pumping force to fill the box 1 with grout 8, and then diffuses into the recessed area formed by the cover plate assembly, eventually filling the recessed area. During the diffusion of grout 8 into the recessed area of ​​the cover plate assembly, the pressure on the first side plate 101 can be detected in real time by a pressure detection component. The detected pressure value can guide the construction of the sealed retaining wall at the coal mine site. For example, if the pressure value detected at a local location on the first side plate 101 is high, the local location can be reinforced by adding diagonal supports or other methods when constructing the sealed retaining wall at the coal mine site.

[0042] Adjust the shape of the cover plate assembly, and conduct a filling experiment for each adjusted cover plate assembly shape. Record the pressure on the first side plate 101 during each filling experiment to obtain multiple sets of experimental data. Through multiple sets of experimental data, the pressure on the box 1 under different top connection modes of the slurry 8 can be more accurately reflected, so as to more accurately guide the construction of the sealed retaining wall on the coal mine site.

[0043] In this embodiment of the invention, the cover plate assembly is movably installed over the opening of the box 1, and the box 1 and the cover plate assembly enclose a sealed space. The shape of the cover plate assembly is adjusted to simulate the shape of the roof of the coal mine. During the filling of the sealed space, the slurry 8 can simulate the working conditions of the coal mine and reach the roof. The pressure detection component detects the pressure on the box 1 during the filling process of the slurry 8 in real time. The detected pressure value can more accurately guide the construction of the sealed retaining wall at the coal mine.

[0044] like Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, in an optional embodiment, the cover assembly includes a sliding cover 2 and a rotating cover 3; the rotating cover 3 includes a connecting part and two movable cover plates 301 rotatably connected to the connecting part, at least one of the two movable cover plates 301 being connected to the sliding cover 2; the sliding cover 2 is slidably connected to the housing 1, and the sliding cover 2 can drive the movable cover plates 301 to rotate relative to the connecting part, so that the angle between the two movable cover plates 301 is adjustable.

[0045] Specifically, the cover assembly includes a sliding cover 2 and a rotating cover 3, the number of which is determined according to actual needs. The sliding cover 2 can slide horizontally. For example, the inner wall of the housing 1 is provided with two opposing sliding grooves, which are horizontally oriented. The two opposite end faces of the sliding cover 2 are located in the sliding grooves, allowing the sliding cover 2 to slide along them. The other two opposite ends of the sliding cover 2 are connected to the rotating cover 3.

[0046] The rotating cover 3 includes a connecting part and two movable cover plates 301 rotatably connected to the connecting part. For example, the connecting part can be made of a flexible material with certain flexibility and strength, such as rubber. One end of the movable cover plate 301 is rotatably connected to the connecting part, and the other end of the movable cover plate 301 can also be connected to the end of the sliding cover plate 2 through a flexible material. The two movable cover plates 301 of the rotating cover 3 can have different dimensions. It can be understood that the end face of the movable cover plate 301 abuts against the inner wall surface of the second side plate of the housing 1. The two movable cover plates 301 and the two second side plates enclose a recessed area 302. The shape of the recessed area 302 can be adjusted by adjusting the angle between the two movable cover plates 301. During the sliding of the sliding cover plate 2 along the groove, the movable cover plate 301 can rotate relative to the end of the sliding cover plate 2, thereby adjusting the angle between the two movable cover plates 301.

[0047] In this embodiment of the invention, the rotating cover plate 3 includes a connecting part and two movable cover plates 301 rotatably connected to the connecting part. One end of the movable cover plate 301 is rotatably connected to the connecting part, and the other end of the movable cover plate 301 is rotatably connected to the end of the sliding cover plate 2. The sliding cover plate 2 is slidably connected to the box body 1. The opening angle of the rotating cover plate 3 can be conveniently adjusted by sliding the sliding cover plate 2 to simulate the irregular shape of the roof of the coal mine to the greatest extent, while also being easy to operate.

[0048] like Figure 1 As shown, in an optional embodiment, there are multiple sliding cover plates 2 and multiple rotating cover plates 3, with the sliding cover plate 2 sandwiched between two adjacent rotating cover plates 3.

[0049] Specifically, there are multiple rotating cover plates 3, which can fully simulate the multiple recessed areas formed by the roof of a coal mine. The depths of the multiple recessed areas formed by the roof are also different, and at least two rotating cover plates 3 are different in size, that is, when the rotating cover plate 3 is at its maximum opening angle, the relative height between the top and bottom of the rotating cover plate 3 is different.

[0050] The number of sliding cover plates 2 and rotating cover plates 3 is set according to actual needs; for example, there may be three sliding cover plates 2 and four rotating cover plates 3. The two ends of the sliding cover plates 2 are connected to the movable cover plates 301 of two adjacent rotating cover plates 3. By sliding the three sliding cover plates 2, the opening angles of the four rotating cover plates 3 can be adjusted to simulate the irregular shape of the roof at a coal mine site, i.e., the shape of the recessed areas at the roof. After reaching their maximum opening angles, the relative heights of the four rotating cover plates 3 can be different. The roof at a coal mine site typically has multiple recessed areas; the multiple recessed areas 302 formed by the multiple rotating cover plates 3 can simulate the shape of the coal mine roof to the greatest extent possible.

[0051] Grout 8 is filled into the box 1 through the grouting pipe 7. During the filling process, the diffusion pattern of grout 8 within the box 1 can be observed. After the grout 8 overflows the grouting pipe 7, the pumping force of the grouting pump is increased. After the grout 8 fills the box 1, it continues to flow and diffuse into the four recessed areas 302 formed by the four rotating cover plates 3. The diffusion pattern of grout 8 within the recessed areas 302 can be observed through the transparent movable cover plate 301. The pressure on the box 1 during the filling of the recessed areas 302 by the pressure detection component can be detected.

[0052] In this embodiment of the invention, there are multiple rotating cover plates 3, and a sliding cover plate 2 is located between two adjacent rotating cover plates 3. Multiple rotating cover plates 3 can form multiple different recessed areas 302, so that the top contact shape of the slurry 8 in the sealed space is diverse, maximally simulating the top contact shape of the slurry in the sealed retaining wall at the coal mine site.

[0053] like Figure 1 As shown, in an optional embodiment, the rotating cover plate 3 is provided with an exhaust hole 303, through which the moisture in the slurry 8 in the sealed space can be obtained to detect the parameters of the slurry 8.

[0054] Specifically, the rotating cover plate 3 is provided with an exhaust hole 303. The exhaust hole 303 can be provided on the top of a movable cover plate 301 of the rotating cover plate 3. The diameter of the exhaust hole 303 is set according to actual needs, for example, the diameter of the exhaust hole 303 is 50mm.

[0055] After the slurry 8 fills the sealed space, the slurry 8 in the sealed space begins to solidify. During different time periods of solidification of the slurry 8, the water in the slurry 8 in the sealed space can be extracted through the vent 303. The water bleeding rate of the slurry 8 and the shrinkage rate of the slurry 8 after solidification are calculated from the extracted water. The water bleeding rate and solidification shrinkage rate are used to analyze whether the proportion of the slurry 8 used for filling is appropriate.

[0056] In this embodiment of the invention, the movable cover plate 301 of the rotating cover plate 3 is provided with an exhaust hole 303. The exhaust hole 303 has an exhaust function. At the same time, the water in the slurry 8 during different solidification time periods can be extracted through the exhaust hole 303 to calculate the water bleeding rate of the slurry 8 and the shrinkage rate of the slurry 8 after solidification, so as to guide the preparation of filling slurry in the construction of sealed retaining walls in coal mines.

[0057] like Figure 1 , Figure 2 and Figure 3 As shown, in an optional embodiment, the pressure detection component includes a first pressure detection unit, which is disposed on the outer wall surface of the housing 1 and is used to detect the pressure on the housing 1.

[0058] Specifically, the first pressure detection unit is installed on a first side plate 101 of the housing 1, and the first pressure detection unit includes a first pressure sensor 4. There can be one first pressure sensor 4. During the process of filling the sealed space with slurry 8, the first pressure sensor 4 can be moved along the height direction of the first side plate 101 to detect the pressure at different height positions of the first side plate 101.

[0059] Alternatively, multiple first pressure sensors 4 can be spaced apart along the height direction of the first side plate 101. For example, one first pressure sensor 4 can be installed every 300mm along the height direction of the first side plate 101. As the slurry 8 accumulates in the sealed space, the pressure detected by the first pressure sensor 4 has a certain trend of change. By using multiple first pressure sensors 4, the pressure change trend at different height positions of the box 1 during the process of the slurry 8 filling the sealed space can be detected in real time.

[0060] In this embodiment of the invention, a plurality of first pressure sensors 4 are spaced apart on the first side plate 101 of the box 1 along the height direction of the box 1. During the process of filling the sealed space with slurry 8, the pressure change trend at different height positions of the box 1 can be detected in real time by the plurality of first pressure sensors 4.

[0061] like Figure 1 , Figure 2 and Figure 3 As shown, in an optional embodiment, the pressure detection assembly further includes a second pressure detection unit, which is disposed on the cover plate assembly and is used to detect the pressure on the cover plate assembly.

[0062] Specifically, the second pressure detection unit can be disposed on the sliding cover plate 2 or the rotating cover plate 3. The second pressure detection unit includes a second pressure sensor 5 and a third pressure sensor 6. The second pressure sensor 5 is disposed on the sliding cover plate 2, and the third pressure sensor 6 is disposed on the rotating cover plate 3. One second pressure sensor 5 can be installed on each sliding cover plate 2, or one first pressure sensor 4 can be installed on one of multiple sliding cover plates 2. Similarly, one third pressure sensor 6 can be installed on each rotating cover plate 3, or one third pressure sensor 6 can be installed on one of multiple rotating cover plates 3.

[0063] The second pressure sensor 5 is used to detect the pressure on the sliding cover plate 2. During the filling process of the grout 8, the second pressure sensor 5 detects the pressure value, indicating that the grout 8 has filled the box 1. At this time, the pumping force of the grouting pump can be increased so that the grout 8 can flow and diffuse fully into the recessed area 302 formed by the rotating cover plate 3. It is also possible to observe whether the grout 8 has filled the box 1 through the transparent box 1 and the sliding cover plate 2.

[0064] like Figure 1 and Figure 6 As shown, the third pressure sensor 6 is used to detect the pressure on the rotating cover plate 3. A movable top plate 304 can be set between the two movable cover plates 301. The two ends of the movable top plate 304 are connected to the ends of the two movable cover plates 301 respectively by flexible material. The third pressure sensor 6 is installed on the movable top plate 304. After the slurry 8 fills the tank 1, it diffuses into the recessed area 302 formed by the rotating cover plate 3. The third pressure sensor 6 detects the pressure value, indicating that the slurry 8 has reached the top. At this time, the top-reaching shape of the slurry 8 in other recessed areas can be observed through the transparent movable cover plate 301 until the slurry 8 fills all the recessed areas. During the process of the slurry 8 filling the recessed area 302, the pressure on the tank 1 at different heights is detected in real time by multiple first pressure sensors 4.

[0065] In this embodiment of the invention, the second pressure sensor 5 can detect whether the slurry 8 fills the box 1, and the third pressure sensor 6 can detect whether the slurry 8 fills the recessed area 302 formed by the rotating cover plate 3. This allows for real-time understanding of the filling status of the slurry 8 in the sealed space, so that the slurry 8 can fill the sealed space.

[0066] In an optional embodiment, both the housing 1 and the cover assembly are made of transparent material.

[0067] Specifically, both the box 1 and the cover plate assembly can be made of transparent tempered glass. During the process of filling the sealed space with slurry 8, the diffusion pattern of slurry 8 in the box 1 can be observed through the transparent box 1, and the diffusion pattern of slurry 8 in the recessed area 302 can be observed through the transparent movable cover plate 301. This facilitates understanding the slump and fluidity of slurry 8, so as to guide the preparation of filling slurry on the coal mine site.

[0068] This invention also provides an experimental method for simulating a coal mine filling sealed retaining wall, comprising:

[0069] Based on the filling space and filling flow rate at the coal mine site, the simulated filling flow rate of the experimental device was calculated;

[0070] The cover plate assembly is placed over the opening of the box 1 so that the box 1 and the cover plate assembly enclose a sealed space. Grout is then filled into the sealed space through the grouting holes on the box 1 to simulate the filling flow rate.

[0071] The pressure on housing 1 is detected by a pressure detection component.

[0072] Specifically, the experimental setup can be described above, using transparent tempered glass to make the box 1 and cover assembly. The length, width, and height of the box 1 are 5m, 1m, and 3m, respectively, and the height of the box 1 can be adjusted according to the height of the goaf being filled. Multiple first pressure sensors 4 are spaced apart along the height direction of the first side plate 101 of the box 1, and a grouting pipe 7 is installed on the top of another first side plate 101. The cover assembly includes a sliding cover 2 and a rotating cover 3 spaced apart. A second pressure sensor 5 is installed on the sliding cover 2, and a third pressure sensor 6 is installed on the rotating cover 3. A vent hole 303 with a diameter of 50mm is provided on the top of one of the rotating cover 3. The opening angle of the rotating cover 3 is adjusted by sliding the cover 2 to simulate the irregular shape of the roof in a coal mine.

[0073] Based on the filling space and filling flow rate at the coal mine site, the filling time required for filling the sealed retaining wall under actual working conditions is calculated. This filling time is the same as the time required for slurry 8 to fill box 1. Based on the filling volume and filling time of box 1, the simulated filling flow rate of slurry 8 in box 1 is calculated.

[0074] Grout 8 is injected into the box 1 through the grouting pipe 7 at a simulated filling flow rate. Multiple first pressure sensors 4 can detect in real time the pressure change trend of the grout 8 at different height positions of the box 1 during the filling process.

[0075] After the grout 8 overflows the grouting pipe 7, the pumping force of the grouting pump is increased. After the grout 8 fills the box 1, it diffuses into the recessed area 302 formed by the rotating cover plate 3. The second pressure sensor 5 detects the pressure value, indicating that the grout 8 has filled the box 1. The third pressure sensor 6 detects the pressure value, indicating that the grout 8 at the current position has reached the top, until the grout 8 fills all the recessed areas 302.

[0076] During the filling process of the grout 8 into the box 1 and the recessed area 302, multiple first pressure sensors 4 can detect in real time the pressure change trend of the grout 8 at different height positions of the box 1 during the filling process. The experimental data obtained can accurately guide the construction of the sealed retaining wall on the coal mine site.

[0077] In an optional embodiment, placing the cover assembly over the opening of the housing 1 so that the housing 1 and the cover assembly enclose a sealed space further includes: adjusting the opening angle of the rotating cover 3 by sliding the cover 2.

[0078] The process of filling the sealed space with grout 8 through the grouting holes on the box 1 to simulate the filling flow also includes: observing the diffusion pattern and the top contact pattern of the grout 8 in the sealed space.

[0079] Specifically, the opening angle of the rotating cover plate 3 can be easily adjusted by sliding cover plate 2. For example, there can be three sliding cover plates 2 and four rotating cover plates 3. By sliding the three sliding cover plates 2, the opening angle of the four rotating cover plates 3 can be adjusted respectively to simulate the irregular shape of the roof at a coal mine site. The roof at a coal mine site usually has multiple recessed areas. The multiple recessed areas 302 formed by the multiple rotating cover plates 3 can simulate the shape of the roof at a coal mine site to the greatest extent.

[0080] Multiple rotating cover plates 3 can form multiple different recessed areas 302, making the top contact shape of the slurry 8 in the sealed space diverse, maximally simulating the process of slurry filling the roof plate in the sealed retaining wall at the coal mine site, and providing more practical guidance for the construction of sealed retaining walls at the coal mine site.

[0081] During the process of filling the sealed space with slurry 8, the diffusion pattern of slurry 8 in the box 1 is observed through the transparent box 1, and the diffusion pattern and top contact pattern of slurry 8 in the recessed area 302 are observed through the transparent movable cover plate 301. This is to facilitate understanding of the slump and fluidity of slurry 8, so as to guide the preparation of filling slurry in the coal mine.

[0082] In an optional embodiment, the experimental method for simulating a coal mine filling sealed retaining wall further includes:

[0083] The moisture content of the slurry 8 in the sealed space is obtained through the vent 303 on the box 1 to detect the bleeding rate and solidification shrinkage rate of the slurry 8.

[0084] Specifically, after the grout 8 fills the sealed space, grouting is stopped, and the grout 8 in the sealed space begins to solidify. A vent 303 is provided on the top of a movable cover plate 301 of the rotating cover plate 3. During different time periods of grout 8 solidification, water can be extracted from the grout 8 in the sealed space through the vent 303. The water bleeding rate and solidification shrinkage rate of the grout 8 after solidification are calculated from the extracted water. The water bleeding rate and solidification shrinkage rate guide the preparation of the filling grout during the filling of sealed retaining walls in coal mines.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An experimental device simulating a coal mine filling bulkhead, characterized in that, The utility model relates to a kind of experimental device for simulating the filling process of coal mine, including: Box, cover plate assembly and pressure detection component; One end of the box is provided with an open, the box has accommodating cavity, the cover plate assembly movable cover is set at the open of the box, and the box and the cover plate assembly form a closed space;Slip casting hole is opened on the box, and the slip casting hole is used to fill slurry into the closed space; The pressure detection component is used to detect the pressure received by the box; The cover plate assembly includes sliding cover plate and rotating cover plate; The rotating cover plate includes a connecting portion and two movable covers rotatably connected to the connecting portion, at least one of the two movable covers is connected to the sliding cover plate; The sliding cover plate is slidably connected to the box, and the sliding cover plate can drive the movable cover to rotate relative to the connecting portion to adjust the angle between the two movable covers; The pressure detection component includes a first pressure detection unit, which is provided on the outer wall of the box for detecting the pressure received by the box; The pressure detection component further includes a second pressure detection unit, which is provided on the cover plate assembly for detecting the pressure received by the cover plate assembly.

2. The experimental device for simulating the sealing barrier of coal mine filling according to claim 1, characterized in that, The number of sliding cover plates is multiple, and the number of rotating cover plates is multiple, and the sliding cover plates are clamped between adjacent two rotating cover plates.

3. The experimental device for simulating the sealing barrier of coal mine filling according to claim 1, characterized in that, The rotating cover plate is provided with an exhaust hole, through which the moisture in the slurry in the closed space can be obtained to detect the parameters of the slurry.

4. The experimental device for simulating the sealing barrier of coal mine filling according to any one of claims 1 to 3, characterized in that, The materials of the box and the cover plate assembly are transparent.

5. An experimental method for simulating a coal mine filling bulkhead, based on the experimental device for simulating a coal mine filling bulkhead according to any one of claims 1 to 4, characterized in that, Including: According to the filling space and filling flow of the coal mine site, the simulated filling flow of the experimental device is calculated; The cover plate assembly is covered on the open of the box to form a closed space between the box and the cover plate assembly, and slurry is filled into the closed space through the slip casting hole on the box at the simulated filling flow; The pressure received by the box is detected by the pressure detection component.

6. The experimental method of simulating a coal mine backfilling sealing retaining wall according to claim 5, characterized in that, The cover plate assembly is covered on the open of the box to form a closed space between the box and the cover plate assembly, and the opening angle of the rotating cover plate is adjusted by the sliding cover plate; During the process of filling slurry into the closed space through the slip casting hole on the box at the simulated filling flow, the diffusion form and the top contact form of the slurry in the closed space are observed.

7. The experimental method of simulating a coal mine backfilling sealing retaining wall according to claim 5, characterized in that, Further including: The moisture in the slurry in the closed space is obtained through the exhaust hole on the box to detect the bleeding rate and the solidification shrinkage rate of the slurry.

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