Analog simulation apparatus and method

Abstract

The application discloses a similar simulation experiment device and method, and relates to the technical field of simulation experiment devices, and aims to provide a similar simulation experiment device and method, which can more accurately simulate a real stress environment on site and realize uniform and slow loading of a model.

Description

Technical Field

[0001] This invention belongs to the field of coal mine similarity simulation experiment technology, and particularly relates to a similarity simulation experiment device and method. Background Technology

[0002] Similarity simulation, as an important physical means of simulating overburden collapse and roadway deformation in mining engineering, can approximate phenomena and processes that are difficult to observe in mining engineering, possessing advantages that are difficult to replace with other experimental methods. However, many problems still exist in actual experimental processes:

[0003] 1. Compared to typical mining roadways, goaf roadways, due to their unique structure and spatial location, are closely linked to the evolution of mining stress throughout their entire stress and deformation process. Similarity tests must consider not only the roadway's dimensions in the model but also the synchronous simulation of the mining space at near-real-scale working faces. Given a certain roadway size, most existing similarity simulation devices are insufficient after converting the working face excavation space to the appropriate scale. Therefore, similarity simulation devices must have a larger size. Furthermore, typical planar similarity simulation devices can only achieve vertical stress loading by stacking top counterweights. This loading method has limited capacity and cannot simulate high-stress conditions in deep wells; moreover, due to the limitations of the loading method, it is difficult to accurately simulate the actual stress environment on-site, essentially only simulating the basic form of roof collapse, and failing to simulate floor heave.

[0004] 2. To reduce the complexity of hydraulic control system operation, hydraulic cylinders on the same side of similar simulation experimental devices are generally connected in series. However, due to factors such as the resistance of the hydraulic circuits between cylinders, asynchronous loading often occurs, leading to localized stress concentration and uneven loading during model loading, and even localized damage to the similar model during stress abrupt changes, severely affecting the accuracy of the experimental process and results. Conversely, designing more complex hydraulic circuits and precise control systems would significantly increase experimental costs and investment.

[0005] 3. Thick coal seam excavation, especially when the model similarity ratio is greater than 1:200, results in a large actual excavation area for the coal seam in the model. When the model thickness is large, manual excavation often faces the challenge of accurately controlling the excavation distance and range. Furthermore, the observation effect is poor in the frontal visualization window corresponding to the coal seam due to residual coal dust and incomplete extraction after excavation.

[0006] 4. The model is used to carry out working face excavation under high stress environment, especially for thick coal seam mining. If secondary sealing is not carried out in time after excavation on the back of the model, the large excavation range and collapse height will cause the collapsed roof to slide out of the model through the exposed space. It is difficult to completely preserve the broken roof after collapse, which will affect the overall structure of the roof collapse and may even cause the test to fail.

[0007] 5. Under high loading stress, similar models must be enclosed at the front and rear with high-strength protective plates to control the "expansion" of the unloaded surfaces caused by the Poisson effect, thus preventing overall shear failure and potential experimental failure. Therefore, the observable area on the model surface is severely limited, affecting large-area simultaneous visualization and observation throughout the experiment. Summary of the Invention

[0008] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a similar simulation experimental device and method. The similar simulation experimental device uses four independent pressurizing components to more accurately simulate the real stress environment on site. By setting up force transmission components, it effectively buffers the stress concentration caused by asynchronous loading and evenly transmits the buffered load to the top of the model through a rigid structure with hinged joints, thereby achieving uniform and slow loading of the model.

[0009] A second aspect of the present invention also proposes a similar simulation experiment method.

[0010] An embodiment of the present invention provides a similarity simulation experimental device comprising an experimental platform, a similar model, a pressurizing component, and a force transmission component. The similar model is disposed within the experimental platform and includes a first simulated rock mass, an excavated layer, and a second simulated rock mass, arranged sequentially from top to bottom. Four pressurizing components are connected to the experimental platform and are independent of each other. The first pressurizing component is located above the similar model, and the second pressurizing component is located below the similar model. Below, the third pressurizing component is located on the left side of the similar model, and the fourth pressurizing component is located on the right side of the similar model. The force transmission component includes a flexible component and a rigid component. The flexible component is located between the first pressurizing component and the rigid component. The upper end of the flexible component abuts against the first pressurizing component, and the lower end of the flexible component abuts against the upper end of the rigid component. The lower end of the rigid component abuts against the upper end of the similar model. There are multiple rigid components, which are arranged sequentially in the left-right direction. Adjacent rigid components are rotatably connected.

[0011] The similar simulation experimental device of this invention uses four independent pressurization components to more accurately simulate the real stress environment on site. By setting up the force transmission components, it effectively buffers the stress concentration caused by asynchronous loading and evenly transmits the buffered load to the top of the model through the rigid structure of the hinged parts, so as to achieve uniform and slow loading of the model.

[0012] In some embodiments, the excavated layer includes a first wooden block, coal powder, and a second wooden block. The upper end of the first wooden block is in contact with the lower end of the first simulated rock mass. The coal powder is filled between the first wooden block and the second wooden block. The lower end of the second wooden block is in contact with the upper end of the second simulated rock mass. There are multiple first wooden blocks and multiple second wooden blocks. The multiple first wooden blocks are arranged sequentially along a first direction, and two adjacent first wooden blocks are in contact with each other. The multiple second wooden blocks correspond one-to-one with the multiple first wooden blocks, and the second wooden block is located below the corresponding first wooden block.

[0013] In some embodiments, the similar simulation experimental device of the present invention further includes a plurality of baffles. A first opening is provided on the experimental platform at the rear end face of the experimental platform. The projection of the excavation layer on the rear end face of the experimental platform is located within the projection of the first opening on the rear end face of the experimental platform. The plurality of baffles can be detachably connected to the experimental platform and block the first opening. The plurality of baffles are arranged sequentially along a first direction.

[0014] In some embodiments, the similar simulation experimental device of the present invention further includes a transparent plate, and a second opening is provided on the front surface of the experimental platform, and the transparent plate is connected to the experimental platform and seals the second opening.

[0015] In some embodiments, the similar simulation experimental apparatus of the present invention further includes multiple baffles and multiple sets of elastic pads. The multiple baffles are all connected to the experimental platform and located in front of the transparent plate, and the multiple baffles are spaced apart along the second direction. The multiple sets of elastic pads correspond one-to-one with the multiple baffles. Each set of elastic pads is connected to the corresponding baffle. Each set of elastic components includes multiple elastic pads, and the multiple elastic pads are spaced apart along the length direction of the corresponding baffle. The elastic pads abut against the transparent plate.

[0016] In some embodiments, the transparent plate is provided with a reference coordinate system, and the similar model is provided with image recognition feature points corresponding to the reference coordinate system.

[0017] In some embodiments, the experimental platform includes a top reaction frame, a bottom reaction frame, a left reaction frame, a right reaction frame, a front guard plate, and a rear guard plate. The top reaction frame, the left reaction frame, the bottom reaction frame, and the right reaction frame are connected end to end in sequence. The front guard plate is located in front of the left and right reaction frames, and its left and right ends are connected to the left and right reaction frames, respectively. There are multiple front guard plates, which are spaced apart in the vertical direction. The rear guard plate is located behind the left and right reaction frames, and its left and right ends are connected to the left and right reaction frames, respectively. There are multiple rear guard plates, which are spaced apart in the vertical direction.

[0018] In some embodiments, the pressurization assembly includes a plurality of loading cylinders and a plurality of rigid plates. The plurality of loading cylinders are distributed at circumferential intervals along the similar model. The plurality of rigid plates and the plurality of loading cylinders correspond one-to-one. The rigid plate is connected to the corresponding loading cylinder and is located between the similar model and the corresponding loading cylinder.

[0019] The similar simulation experiment method of this invention includes:

[0020] A similar simulation test apparatus as described in any of the above embodiments is provided. The similarity ratio of the similar model is determined according to the size of the test bench, and the corresponding coal and rock layer thickness and strength ratio are calculated. The similar model is laid according to the calculation results, and internal displacement monitoring optical fibers and stress sensors are buried at the set positions to complete the laying of the similar model.

[0021] After the similar model has dried completely, the front protective plate of the experimental platform within the observation range is removed to form a second opening, and white paint is sprayed on the surface of the similar model within the observation range at uniform horizontal and vertical intervals to generate an image recognition feature dot matrix on the surface of the similar model.

[0022] A transparent plate is laid on the experimental platform to seal the second opening, and a reference coordinate system is pre-formed on the surface of the transparent plate.

[0023] The stress loading levels at the top and bottom and on both sides are calculated based on the burial depth of the similar model and the measured in-situ stress data, and the pressure is slowly and gradually applied to the calculated value using the pressurization component until the pressure stabilizes at the calculated value.

[0024] A surface displacement monitoring system is installed on the front side of the experimental platform, and the surface displacement monitoring system, the monitoring system of the internal displacement monitoring fiber and the monitoring system of the stress sensor are debugged respectively to complete the equipment initialization;

[0025] According to the established mining process, the excavation layer is excavated cyclically and progressively according to the excavation progress.

[0026] After excavation, the model was left to stand for at least 48 hours to observe the final morphology of the complete overburden collapse and to collect stress, strain, and image data.

[0027] The similarity simulation experiment method of this invention, by adopting the similarity simulation experiment device of the above embodiment, more accurately simulates the real stress environment on site, effectively buffers the stress concentration caused by asynchronous loading, and makes the buffered load uniformly transferred to the top of the model through the rigid structure of the hinged parts, so as to realize uniform and slow loading of the model; by setting image recognition feature point array on the surface of the similar model and laying a transparent plate with a reference coordinate system, large-area dynamic visualization synchronous observation of the entire process of local roof and floor deformation in the mining area and along the goaf is realized.

[0028] In some embodiments, the step of progressively excavating the excavation layer according to the excavation progress includes:

[0029] Excavate tunnels;

[0030] After the goaf is excavated for a certain distance, a filling body is constructed next to the roadway according to the design parameters;

[0031] Repeat the excavation and construction of the backfill until the entire excavation layer has been excavated. Attached Figure Description

[0032] Figure 1 This is a front view of a similar simulation experimental apparatus according to an embodiment of the present invention.

[0033] Figure 2 This is the present invention. Figure 1 A cross-sectional view along the AA direction.

[0034] Figure 3 This is a rear view of a similar simulation experimental device according to an embodiment of the present invention.

[0035] Figure 4 This is a schematic diagram of a similar model and a transparent plate according to an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of the excavation layer according to an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram of a similar simulation experiment method according to an embodiment of the present invention.

[0038] Figure 7 This is a schematic diagram illustrating the progressive excavation of the excavation layer according to the excavation progress in an embodiment of the present invention.

[0039] Figure label:

[0040] Experimental platform 1; Top reaction frame 11; Bottom reaction frame 12; Left reaction frame 13; Right reaction frame 14; Front guard plate 15; Rear guard plate 16;

[0041] Similar model 2; First simulated rock mass 21; Excavated layer 22; First wooden block 221; Coal powder 222; Second wooden block 223; Second simulated rock mass 23; Image recognition feature point 24;

[0042] Pressurization component 3; loading cylinder 31; rigid plate 32;

[0043] Force transmission component 4; flexible component 41; rigid component 42;

[0044] baffle 5;

[0045] Transparent plate 6; Reference coordinate system 61;

[0046] Stop lever 7;

[0047] 8. Elastic gasket. Detailed Implementation

[0048] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0049] The following describes a similar simulation experimental apparatus according to an embodiment of the present invention with reference to the accompanying drawings.

[0050] like Figures 1 to 3 As shown, a similar simulation experimental device according to an embodiment of the present invention includes an experimental platform 1, a similar model 2, a pressurization component 3, and a force transmission component 4.

[0051] The similar model 2 is set up in the test bench. The similar model 2 includes a first simulated rock mass 21, an excavated layer 22, and a second simulated rock mass 23. The first simulated rock mass 21, the excavated layer 22, and the second simulated rock mass 23 are arranged sequentially from top to bottom. The first simulated rock mass 21 and the second simulated rock mass 23 are used to simulate the rock mass near the coal seam, and the excavated layer 22 is used to simulate the excavated coal seam.

[0052] There are four pressurizing components 3 connected to the experimental platform 1. The four pressurizing components 3 are independent of each other. The first pressurizing component 3 is located above the similar model 2, the second pressurizing component 3 is located below the similar model 2, the third pressurizing component 3 is located on the left side of the similar model 2, and the fourth pressurizing component 3 is located on the right side of the similar model 2. The four independent pressurizing components 3 can independently pressurize one side of the similar model 2, more accurately simulating the real stress environment on site. The non-uniform pressure loading of the four independent pressurizing components 3 not only realizes the loading of lateral horizontal stress, but also can more realistically simulate the stress in the mining area, structural evolution, and deformation process of the roof and floor plates of the goaf roadway after the stress is applied at the bottom. This overcomes the problems that the original device size is difficult to meet and the initial stress conditions are significantly different from the actual situation.

[0053] The force transmission component 4 includes a flexible component 41 and a rigid component 42. The flexible component 41 is located between the first pressurizing component 3 and the rigid component 42. The upper end of the flexible component 41 abuts against the first pressurizing component 3, and the lower end of the flexible component 41 abuts against the upper end of the rigid component 42. The lower end of the rigid component 42 abuts against the upper end of the similar model 2. There are multiple rigid components 42, which are arranged sequentially in the left-right direction. Adjacent rigid components 42 can be rotatably connected. When the pressurizing component 3 pressurizes the similar model 2, the flexible component 41 buffers the load applied by the pressurizing component, avoiding stress concentration caused by asynchronous loading. The mutually hinged rigid components 42 uniformly transfer the buffered load to the top of the model, realizing uniform and slow loading of the model.

[0054] The similar simulation experimental device of this invention uses four independent pressurization components 3 to more accurately simulate the real stress environment on site, and through the setting of the force transmission component 4, it effectively buffers the stress concentration caused by asynchronous loading and makes the buffered load uniformly transmitted to the top of the model through the rigid component 42 structure that is hinged to each other, so as to achieve uniform and slow loading of the model.

[0055] Optionally, there are multiple force transmission components 4, and each force transmission component 4 corresponds to a multiple pressurization component 3. The force transmission components 4 are located between the similar model 2 and the corresponding force transmission components 4.

[0056] like Figure 5 As shown, in some embodiments, the excavated layer 22 includes a first wooden block 221, coal powder 222, and a second wooden block 223. The upper end of the first wooden block 221 contacts the lower end of the first simulated rock mass 21. The coal powder 222 fills the space between the first wooden block 221 and the second wooden block 223. The lower end of the second wooden block 223 contacts the upper end of the second simulated rock mass 23. There are multiple first wooden blocks 221 and multiple second wooden blocks 223. The multiple first wooden blocks 221 are arranged along a first direction (e.g., ...). Figure 5The first wooden blocks 221 are arranged in sequence in the left and right directions as shown, and two adjacent first wooden blocks 221 are in contact with each other. Multiple second wooden blocks 223 correspond one-to-one with multiple first wooden blocks 221, and the second wooden blocks 223 are located below the corresponding first wooden blocks 221.

[0057] Therefore, in this embodiment of the invention, the excavation layer 22 is constructed by setting up the first wooden block 221, coal powder 222, and the second wooden block 223. By removing the wooden block and coal powder 222, the excavation of the excavation layer 22 can be simulated. On the one hand, the distance of one excavation can be simulated by controlling the width of the wooden block, making the excavation process faster, more accurate, and easier to control. On the other hand, the coal powder 222 reduces the friction between the wooden blocks, thereby reducing the damage to the similar model 2 when the wooden block is removed.

[0058] like Figure 3 As shown, in some embodiments, the similar simulation experimental device of the present invention further includes multiple baffles 5. A first opening (not shown) is provided on the experimental platform 1 located on the rear end face of the experimental platform 1. The projection of the excavation layer 22 on the rear end face of the experimental platform 1 is located within the projection of the first opening on the rear end face of the experimental platform 1. Multiple baffles 5 can be detachably connected to the experimental platform 1 and sealed in the first opening, and multiple baffles 5 are arranged sequentially along the first direction.

[0059] It should be noted that when excavating the excavation layer 22, the baffle 5 at the corresponding position is removed from the test bench 1. Then, the wooden block is pulled out from the first opening to simulate the excavation of the excavation layer 22. This simplifies the excavation operation and simulates the excavation process of the coal seam full-height mining and fully mechanized caving roadway more quickly and accurately. After the excavation is completed, the baffle 5 is reinstalled on the test bench 1 to seal the first opening and prevent the collapsed rock layers from falling from behind the model, which would not be able to completely fill the goaf and affect the test results.

[0060] like Figure 1 , Figure 2 and Figure 4 As shown, in some embodiments, the similar simulation experimental device of the present invention further includes a transparent plate 6. A second opening (not shown) is provided on the front surface of the experimental platform 1. The transparent plate 6 is connected to the experimental platform 1 and sealed in the second opening. The transparent plate 6 facilitates the observation of the similar model 2, realizing large-area visualization of the entire process of deformation and structural evolution of the mining area's top and bottom plates, and providing conditions for systematic observation by means of digital speckle, image analysis and other methods.

[0061] Optionally, the left and right ends of the transparent plate 6 are connected to the experimental table 1 by high-strength screws, which facilitates the assembly and disassembly of the transparent plate 6.

[0062] Optionally, the transparent panel 6 is made of high-strength acrylic sheet.

[0063] like Figure 1 , Figure 2and Figure 4 As shown, in some embodiments, the similar simulation experimental device of the present invention further includes multiple stop bars 7 and multiple sets of elastic pads 8. The multiple stop bars 7 are all connected to the experimental platform 1 and located in front of the transparent plate 6, and the multiple stop bars 7 are along a second direction (e.g., Figure 1 As shown in the left and right directions, multiple sets of elastic pads 8 are spaced apart, and multiple stops 7 are corresponding one-to-one. Each set of elastic pads 8 is connected to the corresponding stop 7. Each set of elastic components includes multiple elastic pads 8. The multiple elastic pads 8 are spaced apart along the length direction of the corresponding stop 7. The elastic pads 8 abut against the transparent plate 6.

[0064] Optionally, the stop bar 7 can be made of steel reinforcement.

[0065] Optionally, the elastic gasket 8 is a silicone gasket.

[0066] Therefore, in these embodiments, the similar simulation experimental device of the present invention further limits the transparent plate 6 by setting the stop bar 7 and the elastic pad 8, so that the transparent plate 6 is in full contact with the surface of the similar model 2 to prevent the surface of the similar model 2 from falling off. At the same time, the overall strength coupling between the transparent plate 6 and the experimental platform 1 is realized.

[0067] like Figure 4 As shown, in some embodiments, a reference coordinate system 61 is provided on the transparent plate 6, and image recognition feature points 24 corresponding to the reference coordinate system 61 are provided on the similar model 2. The transparent plate 6 provides an accurate reference coordinate system 61 for the graphic processing of feature points, which facilitates observation and monitoring.

[0068] like Figures 1 to 3 As shown, in some embodiments, the experimental platform 1 includes a top reaction frame 11, a bottom reaction frame 12, a left reaction frame 13, a right reaction frame 14, a front guard plate 15, and a rear guard plate 16. The top reaction frame 11, left reaction frame 13, bottom reaction frame 12, and right reaction frame 14 are connected end to end in sequence. The first pressurizing component 3 is connected to the top reaction frame 11, the second pressurizing component 3 is connected to the bottom reaction frame 12, the third pressurizing component 3 is connected to the left reaction frame 13, and the fourth pressurizing component 3 is connected to the right reaction frame 14. Force frame 14, front guard plate 15 is located in front of left reaction frame 13 and right reaction frame 14, and the left and right ends of front guard plate 15 are connected to left reaction frame 13 and right reaction frame 14 respectively. There are multiple front guard plates 15, which are distributed at intervals in the vertical direction. Rear guard plate 16 is located behind left reaction frame 13 and right reaction frame 14, and the left and right ends of rear guard plate 16 are connected to left reaction frame 13 and right reaction frame 14 respectively. There are multiple rear guard plates 16, which are distributed at intervals in the vertical direction.

[0069] like Figures 1 to 3As shown, specifically, the length directions of the top reaction frame 11 and the bottom reaction frame 12 are both set along the left-right direction, while the length directions of the left reaction frame 13 and the right reaction frame 14 are both set along the up-down direction. The left end of the top reaction frame 11 is connected to the upper end of the left reaction frame 13, and the right end of the top reaction frame 11 is connected to the upper end of the right reaction frame 14. The left end of the bottom reaction frame 12 is connected to the lower end of the left reaction frame 13, and the right end of the bottom reaction frame 12 is connected to the lower end of the right reaction frame 14.

[0070] Therefore, in these embodiments, the experimental platform 1 of the present invention fixes the pressurizing component 3 by setting up the top reaction frame 11, the bottom reaction frame 12, the left reaction frame 13 and the right reaction frame 14, so as to avoid the pressurizing component 3 from being misaligned or moved and affecting the experimental results. The similar model 2 is held in place by setting up the front guard plate 15 and the rear guard plate 16, so as to avoid the surface of the similar model 2 from falling off.

[0071] like Figures 1 to 3 As shown, in some embodiments, the pressurizing component 3 includes multiple loading cylinders 31 and multiple rigid plates 32. The multiple loading cylinders 31 are distributed at intervals along the circumference of the similar model 2. The multiple rigid plates 32 correspond one-to-one with the multiple loading cylinders 31. The rigid plates 32 are connected to the corresponding loading cylinders 31 and are located between the similar model 2 and the corresponding loading cylinders 31.

[0072] The following describes a similar simulation experiment method according to a second aspect of the present invention with reference to the accompanying drawings.

[0073] like Figure 6 and Figure 7 As shown, the similar simulation experiment method of this invention includes:

[0074] S1. Provide a similar simulation test device as described in any of the above embodiments, determine the similarity ratio of the similar model according to the size of the test bench, calculate and determine the corresponding coal and rock layer thickness and strength ratio, lay the similar model according to the calculation results, and embed internal displacement monitoring optical fibers and stress sensors at set positions to complete the laying of the similar model.

[0075] S2. After the similar model has dried completely, remove the front guard plate of the experimental platform within the observation range to form a second opening, and spray white paint on the surface of the similar model within the observation range at uniform horizontal and vertical intervals to generate an image recognition feature dot matrix on the surface of the similar model.

[0076] S3. A transparent plate is laid on the experimental platform to seal the second opening. The surface of the transparent plate has a pre-made reference coordinate system.

[0077] S4. Calculate the stress loading levels at the top and bottom and on both sides according to the burial depth of the similar model and the measured ground stress data on site, and slowly load the pressure to the calculated value using the pressurization component until the pressure stabilizes at the calculated value.

[0078] To ensure that the boundary conditions of the simulation model do not change, the pressurization component is always kept under pressure.

[0079] S5. Set up a surface displacement monitoring system on the front side of the experimental platform, and debug the surface displacement monitoring system, the monitoring system of the internal displacement monitoring fiber optic cable, and the monitoring system of the stress sensor respectively to complete the equipment initialization.

[0080] S6. According to the set mining process, the excavation layer is excavated cyclically and gradually according to the excavation progress.

[0081] S7. After excavation, the model should be left to stand for at least 48 hours to observe the final shape of the complete overburden collapse and to collect stress, strain, and image data.

[0082] The similarity simulation experiment method of this invention, by adopting the similarity simulation experiment device of the above embodiment, more accurately simulates the real stress environment on site, effectively buffers the stress concentration caused by asynchronous loading, and makes the buffered load uniformly transferred to the top of the model through the rigid structure of the hinged parts, so as to realize uniform and slow loading of the model; by setting image recognition feature point array on the surface of the similar model and laying a transparent plate with a reference coordinate system, large-area dynamic visualization synchronous observation of the entire process of local roof and floor deformation in the mining area and along the goaf is realized.

[0083] like Figure 7 As shown, in some embodiments, the step of progressively excavating the excavation layer according to the excavation progress includes:

[0084] Excavate tunnels;

[0085] After the goaf is excavated for a certain distance, a filling body is constructed next to the roadway according to the design parameters;

[0086] Repeat the excavation and construction of the backfill until all excavated layers have been excavated.

[0087] like Figure 7 As shown, in a specific embodiment, the mining process is set as fully mechanized longwall mining. The excavated layer includes a first wooden block, coal powder, and a second wooden block arranged sequentially from top to bottom. The thickness of the first wooden block and the coal powder is the coal release thickness, and the thickness of the second wooden block is the coal seam extraction thickness. When simulating the entire process of the roof collapse in the goaf of the fully mechanized longwall roadway, after the roadway is excavated, the second wooden block is first removed. After the first wooden block and the coal powder collapse during the excavation process, they are then extracted to simulate one excavation. After the goaf is excavated for a certain distance, a backfill body is constructed next to the roadway according to the design parameters. Then, the excavation and backfill body construction are repeated until the entire excavated layer is completed.

[0088] In another specific embodiment, when the mining process is set to full-height mining in one go, the excavated layer includes a first wooden block, coal powder and a second wooden block arranged sequentially from top to bottom. The total thickness of the first wooden block, coal powder and the second wooden block is the thickness of the coal seam. When simulating the entire process of roof collapse in the goaf area of ​​a goaf roadway in one goaf mining, after excavating the roadway, the second wooden block is first removed, and then the first wooden block and coal powder corresponding to the second wooden block are taken out to simulate one excavation. After the goaf area is excavated for a certain distance, a backfill body is constructed next to the roadway according to the design parameters. Then the excavation and construction of the backfill body are repeated until the entire excavated layer is completed.

[0089] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0090] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0091] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0092] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0093] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0094] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A similar simulation experimental device, characterized in that, include: experimental platform A similar model is set inside the experimental platform. The similar model includes a first simulated rock mass, an excavated layer, and a second simulated rock mass, which are arranged sequentially from top to bottom. A pressurization assembly is connected to the experimental platform. There are four pressurization assemblies, which are independent of each other. The first pressurization assembly is located above the similar model, the second pressurization assembly is located below the similar model, the third pressurization assembly is located to the left of the similar model, and the fourth pressurization assembly is located to the right of the similar model. A force transmission component includes a flexible component and a rigid component. The flexible component is located between the first pressurizing component and the rigid component. The upper end of the flexible component abuts against the first pressurizing component, and the lower end of the flexible component abuts against the upper end of the rigid component. The lower end of the rigid component abuts against the upper end of the similar model. There are multiple rigid components, which are arranged sequentially in the left-right direction. Adjacent rigid components are rotatably connected. The similarity simulation experiment method using the aforementioned similarity simulation experimental apparatus includes: S1. Determine the similarity ratio of the similar model according to the size of the experimental platform and calculate the corresponding coal and rock layer thickness and strength ratio. Lay the model according to the calculation results and embed internal displacement monitoring optical fibers and stress sensors at the set positions to complete the laying of the similar model. S2. After the similar model is fully dried, the front protective plate of the experimental platform within the observation range is removed to form a second opening, and white paint is sprayed on the surface of the similar model within the observation range at uniform horizontal and vertical intervals so that the surface of the similar model produces an image recognition feature dot matrix. S3. A transparent plate is laid on the experimental platform to block the second opening. A reference coordinate system is pre-made on the surface of the transparent plate. S4. Calculate the stress loading levels at the top and bottom and on both sides according to the burial depth of the similar model and the measured ground stress data on site, and slowly load the pressure to the calculated value using the pressurizing component until the pressure stabilizes at the calculated value. S5. Set up a surface displacement monitoring system on the front side of the experimental platform, and debug the surface displacement monitoring system, the monitoring system of the internal displacement monitoring fiber and the monitoring system of the stress sensor respectively to complete the equipment initialization; S6. According to the set mining process, the excavation layer is excavated cyclically and progressively according to the excavation progress; The steps for progressively excavating the excavation layer according to the excavation progress include: Excavate tunnels; After the goaf is excavated for a certain distance, a filling body is constructed next to the roadway according to the design parameters; Repeat the excavation and construction of the backfill body until all the excavated layers have been excavated; S7. After excavation, the model should be left to stand for at least 48 hours to observe the final shape of the complete overburden collapse and to collect stress, strain, and image data.

2. The similar simulation experimental apparatus according to claim 1, characterized in that, The excavated layer includes a first wooden block, coal powder, and a second wooden block. The upper end of the first wooden block is in contact with the lower end of the first simulated rock mass. The coal powder is filled between the first wooden block and the second wooden block. The lower end of the second wooden block is in contact with the upper end of the second simulated rock mass. There are multiple first wooden blocks and multiple second wooden blocks. The multiple first wooden blocks are arranged sequentially along a first direction, and two adjacent first wooden blocks are in contact with each other. The multiple second wooden blocks correspond one-to-one with the multiple first wooden blocks, and the second wooden block is located below the corresponding first wooden block.

3. The similar simulation experimental apparatus according to claim 2, characterized in that, It also includes multiple baffles. The experimental platform has a first opening located on the rear end face of the experimental platform. The projection of the excavation layer on the rear end face of the experimental platform is located within the projection of the first opening on the rear end face of the experimental platform. The multiple baffles can be detachably connected to the experimental platform and sealed in the first opening. The multiple baffles are arranged sequentially along the first direction.

4. The similar simulation experimental apparatus according to claim 1, characterized in that, It also includes a transparent plate, and the experimental platform has a second opening located on the front surface of the experimental platform. The transparent plate is connected to the experimental platform and seals the second opening.

5. The similar simulation experimental apparatus according to claim 4, characterized in that, It also includes multiple stop bars and multiple sets of elastic pads. The multiple stop bars are all connected to the experimental platform and located in front of the transparent plate. The multiple stop bars are spaced apart along the second direction. The multiple sets of elastic pads correspond one-to-one with the multiple stop bars. Each set of elastic pads is connected to the corresponding stop bar. Each set of elastic pads includes multiple elastic pads. The multiple elastic pads are spaced apart along the length direction of the corresponding stop bar. The elastic pads abut against the transparent plate.

6. The similar simulation experimental apparatus according to claim 4, characterized in that, The transparent plate is provided with a reference coordinate system, and the similar model is provided with image recognition feature points corresponding to the reference coordinate system.

7. The similar simulation experimental apparatus according to claim 1, characterized in that, The experimental platform includes a top reaction frame, a bottom reaction frame, a left reaction frame, a right reaction frame, a front guard plate, and a rear guard plate. The top reaction frame, the left reaction frame, the bottom reaction frame, and the right reaction frame are connected end to end in sequence. The front guard plate is located in front of the left and right reaction frames, and its left and right ends are connected to the left and right reaction frames, respectively. There are multiple front guard plates, which are spaced apart in the vertical direction. The rear guard plate is located behind the left and right reaction frames, and its left and right ends are connected to the left and right reaction frames, respectively. There are multiple rear guard plates, which are spaced apart in the vertical direction.

8. The similar simulation experimental apparatus according to claim 1, characterized in that, The pressurization assembly includes multiple loading cylinders and multiple rigid plates. The multiple loading cylinders are distributed circumferentially along the similar model. The multiple rigid plates and the multiple loading cylinders correspond one-to-one. The rigid plate is connected to the corresponding loading cylinder and is located between the similar model and the corresponding loading cylinder.

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