Similar simulation frame and method for overlying strata separation layer grouting

Abstract

The invention discloses a similar simulation frame and method for overlying strata separation layer grouting, and belongs to the technical field of similar simulation experiments for overlying strata separation layer grouting. According to the analog simulation frame, a grouting orifice pressure monitor is arranged at a grouting orifice where an underground grouting channel pipe is located, a flow valve is arranged on a grouting hose, the grouting orifice pressure monitor and the flow valve are both connected with a controller, and the controller is used for receiving a pressure signal detected by the grouting orifice pressure monitor; when the pressure signal detected by the grouting orifice pressure monitor is smaller than a preset pressure value, the flow valve is turned up to increase the grouting amount; when a pressure signal detected by the grouting orifice pressure monitor is larger than a preset pressure value, the flow valve is turned down to increase the grouting amount, and when the pressure signal detected by the grouting orifice pressure monitor is equal to the preset pressure value, the current grouting amount is maintained; according to the similar simulation frame and method, the grouting amount can be dynamically regulated and controlled according to the size of the separation layer space, and a reliable basis is provided for exploring the dynamic rule of the grouting amount and the separation layer space change.

Description

Technical Field

[0001] This invention relates to the field of similar simulation experiments for overburden delamination grouting, and specifically to a similar simulation frame and method that can be used for overburden delamination grouting. Background Technology

[0002] Grouting for overburden delamination is an important method for reducing settlement and controlling losses, and its indoor physical experiments are also crucial. Obtaining the settlement reduction effect in the field through indoor physical experiments is essential for providing a reference for the field. Currently available simulation rigs for overburden delamination grouting can simulate the entire grouting and filling process. However, these existing simulation rigs only complete the grouting and filling process; they do not establish dynamic control over the relationship between grouting volume and delamination space development, and therefore cannot be used to explore the dynamic laws governing changes in grouting volume and delamination space. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems in the prior art and provide a similar simulation frame and method for grouting of overburden delamination. In this similar simulation frame and method, the grouting volume can be dynamically adjusted according to the size of the delamination space, providing a reliable basis for exploring the dynamic law of the change of grouting volume and delamination space.

[0004] This invention provides a similar simulation frame for grouting of overburden delamination, comprising an overburden delamination simulation chamber, a support frame, and a grouting filling system. The overburden delamination simulation chamber is mounted on the support frame. The grouting system includes a pressurizing device, a grouting mixing tank, and a grouting hose. The pressurizing device is connected to the grouting mixing tank to pressurize the tank. The outlet of the grouting mixing tank is connected to one end of the grouting hose, and a valve is installed at the connection point. The other end of the grouting hose is connected to one end of an underground grouting channel pipe pre-embedded in the overburden separation simulation chamber. The other end of the underground grouting channel pipe is used to inject grout into the separation location. A grouting borehole pressure monitoring instrument is installed at the grouting borehole where the underground grouting channel pipe is located. A flow valve is installed on the grouting hose. Both the grouting borehole pressure monitoring instrument and the flow valve are connected to a controller. The controller is used to receive the pressure signal detected by the grouting borehole pressure monitoring instrument. When the pressure signal detected by the grouting borehole pressure monitoring instrument is less than the preset pressure value, the flow valve is increased to increase the grouting volume. When the pressure signal detected by the grouting borehole pressure monitoring instrument is greater than the preset pressure value, the flow valve is decreased to increase the grouting volume. When the pressure signal detected by the grouting borehole pressure monitoring instrument is equal to the preset pressure value, the current grouting volume is maintained.

[0005] Preferably, the grouting hose is equipped with a flow monitoring device. The controller receives the grouting volume monitoring value from the flow monitoring device and compares it with a preset grouting volume value. When the pressure signal detected by the grouting orifice pressure monitoring instrument is less than the preset pressure value, and the grouting volume monitoring value is less than the preset grouting volume value, the grouting volume is increased, and the increased grouting volume is the difference between the grouting volume monitoring value and the preset grouting volume value. When the pressure signal detected by the grouting orifice pressure monitoring instrument is greater than the preset pressure value, and the grouting volume monitoring value is greater than the preset grouting volume value, the grouting volume is increased. When the grouting volume is below the preset value, the grouting volume is reduced by the difference between the monitored value and the preset value. The controller adjusts the opening of the flow valve based on the difference between the monitored value and the preset value. If the pressure signal detected by the grouting orifice pressure monitor is less than the preset pressure value, and the monitored grouting volume is greater than or equal to the preset value, it is considered abnormal. If the pressure signal detected by the grouting orifice pressure monitor is greater than the preset pressure value, and the monitored grouting volume is less than or equal to the preset value, it is considered abnormal.

[0006] Preferably, the lower end of the slurry outlet pipe is a conical structure, and the side wall of the conical structure is provided with multiple slurry outlets.

[0007] Preferably, the multiple pipe bodies and the connection between the pipe bodies and the slurry outlet pipe are all made by threaded connection.

[0008] Preferably, the pressurizing device is an air compressor.

[0009] Preferably, the system also includes the surface subsidence monitoring system, comprising a laser rangefinder and a close-range photogrammetry system, both of which are mounted on a support frame and located above the overburden separation simulation chamber.

[0010] Preferably, the similar simulation frame includes four height-adjustable support legs.

[0011] The simulation method for a similar simulation frame that can be used for grouting of overburden delamination disclosed in this invention includes the following steps: Based on the geological data of the required simulated mining face, calculate and determine the location of the delamination and the number of grouting boreholes to be set; Based on the simulated mining face, a similar simulation model was built in the overburden separation simulation room using similar materials. During the construction process, the underground grouting channel pipe was pre-buried according to the judgment results. Prepare the grouting material in advance and use a grouting mixing tank to stir it to maintain its fluidity; The grouting pressure is calculated based on the self-weight of the grouting material and the load of the overlying strata at the grouting layer, and this pressure is used as the preset pressure value. At the same time, the grouting volume is calculated based on the mining distance, and this grouting volume is used as the preset grouting volume value. After delamination occurs, the grouting system is activated, and the grouting pressure and volume are monitored in real time. Grouting is carried out as mining progresses. A grouting pressure monitoring instrument is installed at the grouting orifice. When the pressure value detected by the grouting orifice pressure monitoring instrument reaches the preset pressure value, it indicates that the grouting volume is reasonable. If the grouting pressure is too low, it indicates that the grouting volume is too low, and the grouting volume needs to be increased. If the grouting pressure is too high, it indicates that the grouting volume is too high, and the grouting volume needs to be reduced. Once the excavation is complete, the grouting flow rate is gradually reduced, and grouting is stopped after a period of time.

[0012] Compared with the prior art, the beneficial effects of the present invention are: The present invention can be used as a similar simulation frame for grouting of overburden delamination, including a grouting orifice pressure monitoring instrument installed at the grouting orifice, and a flow valve installed on the grouting hose. Changes in the delamination space are fed back through the pressure at the grouting orifice. At the same time, the present invention also dynamically controls the grouting volume by monitoring the grouting orifice pressure in real time, in order to explore the law between the grouting volume and the development and changes of the delamination space.

[0013] This invention also monitors the grout output flow rate of the grouting hose. Combined with the pressure monitoring results, the opening of the flow valve is adjusted by the difference between the grouting volume monitoring value and the preset grouting volume value, achieving more precise control. Furthermore, the linkage analysis of pressure and flow data in this invention can identify abnormal situations such as a sudden drop in pressure but an abnormal increase in flow rate due to grout leakage, or a sudden rise in pressure but a decrease in flow rate due to blockage, avoiding experimental failure due to equipment problems and improving reliability.

[0014] This invention sets up a surface subsidence monitoring system on the top of a similar simulation frame to accurately measure the amount of surface subsidence during mining. It can study the inhibition effect of different grouting pressures or grouting flows on surface subsidence, and can better study the surface subsidence law under the influence of coal seam mining in indoor simulated field based on overburden separation grouting technology. Attached Figure Description

[0015] Figure 1 This is a front view of a similar simulation frame that can be used for overburden separation grouting according to an embodiment of the present invention.

[0016] Figure 2 This is a top view of a similar simulation frame that can be used for overburden separation grouting in an embodiment of the present invention.

[0017] Figure 3 This is a side view of a similar simulation frame that can be used for overburden separation grouting in an embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the underground grouting channel according to an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. Overburden separation simulation chamber; 2. Support frame; 3. Pressurization equipment; 4. Grouting mixing tank; 5. Grouting hose; 6. Valves; 7. Underground grouting channel pipe; 71. Pipe body; 72. Grout outlet pipe; 73. Grout outlet; 8. Surface subsidence monitoring system. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present 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 the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” indicate that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0022] This embodiment presents a similar simulation frame for overburden delamination grouting, used to simulate the delamination phenomenon of underground rock strata, i.e., overburden, under mining or engineering disturbance. It can also obtain the surface subsidence pattern under the influence of coal seam mining based on overburden delamination grouting technology. Furthermore, through similar simulation experiments, grouting parameters, such as grouting pressure and dynamic grouting volume under different delamination spaces, can be optimized to guide on-site grouting construction and reduce engineering risks. This embodiment of the similar simulation frame for overburden delamination grouting includes an overburden delamination simulation chamber and a support frame. The support frame supports the overburden delamination simulation chamber, provides stable support, and facilitates experimental observation. The overburden delamination simulation chamber is mounted on the support frame and includes steel plates surrounding the chamber and a bottom steel plate, all fixed to the support frame. In a preferred embodiment, observation windows can be provided on the sides for monitoring delamination development and grouting effects. This embodiment of the similar simulation frame for overburden delamination grouting also includes a grouting filling system, which simulates the grouting process in actual engineering projects. The grouting system of this embodiment includes a pressurizing device, a grouting mixing tank, and a grouting hose. The pressurizing device is connected to the grouting mixing tank to provide pressure, ensuring that the grout can be smoothly pumped to the separation location. The pressurizing device can use pneumatic, hydraulic, or mechanical pressurization methods, and the pressure is adjustable to adapt to different grouting needs. The grouting mixing tank of this embodiment is used to store and mix grouting materials (such as cement grout, chemical grout, etc.), and is equipped with a liquid inlet for easy replenishment of grout, ensuring continuous grouting. It is equipped with a stirring device to prevent the grout from solidifying or separating. A valve is installed at the discharge port to control the start and stop of grouting and to regulate the flow rate. The discharge port of the grouting mixing tank is connected to one end of the grouting hose, and a valve is also installed at the connection end between the discharge port and the grouting hose. The other end of the grouting hose is connected to one end of an underground grouting channel pipe pre-embedded in the overburden separation simulation chamber. The grouting hose is used to connect the grouting mixing tank and the underground grouting channel pipe, transporting grout. Its flexible design allows for easy adjustment of the grouting hole position according to experimental needs. Furthermore, the grouting hose can be made of pressure-resistant and corrosion-resistant materials, adaptable to different grout types. The other end of the underground grouting channel pipe is used for grouting at the delamination location; as a preferred embodiment, the underground grouting channel pipe is designed as an adjustable-length underground grouting channel pipe, which can adapt to different delamination depths and grouting layer requirements, and can simulate the grouting pipe arrangement in actual engineering, such as single-hole or multi-hole grouting. As a preferred embodiment, a diffusion structure can be designed at the pipe end to improve the diffusion effect of grout in the delamination.

[0023] This embodiment can be used as a similar simulation frame for overburden delamination grouting. Through adjustable grouting channel pipes and flexible hoses, the grouting position can be precisely controlled to simulate delamination grouting conditions under different geological conditions. Parameters such as delamination position, grouting pressure, and grout ratio can be adjusted, making it suitable for simulation experiments of various rock strata conditions, such as coal seams and metal ore layers.

[0024] A grouting borehole pressure monitoring instrument is installed at the grouting borehole where the underground grouting channel pipe is located. As an example, the grouting borehole pressure monitoring instrument can be a MEMS piezoresistive sensor with a range of 0-2.5 MPa and an accuracy of ±0.05% FS, installed 5 cm from the grouting borehole, with a sampling frequency of 500 Hz. A flow valve, which is an electric ball valve, is installed on the grouting hose. Both the grouting borehole pressure monitoring instrument and the flow valve are connected to a controller. The controller receives the pressure signal detected by the grouting borehole pressure monitoring instrument. When the pressure signal detected by the grouting borehole pressure monitoring instrument is less than the preset pressure value, the flow valve is increased to increase the grouting volume; when the pressure signal detected by the grouting borehole pressure monitoring instrument is greater than the preset pressure value, the flow valve is decreased to increase the grouting volume; when the pressure signal detected by the grouting borehole pressure monitoring instrument is equal to the preset pressure value, the current grouting volume is maintained. This embodiment can realistically simulate the grouting process by monitoring the grouting borehole pressure and adjusting the flow rate of the grouting volume. In this embodiment, the change in the delamination space is fed back by the pressure at the grouting orifice. At the same time, this embodiment also dynamically adjusts the grouting volume by monitoring the grouting orifice pressure in real time, in order to explore the relationship between the grouting volume and the development and change of the delamination space.

[0025] In a preferred embodiment, the grouting hose is equipped with a flow monitoring device. The controller receives the grouting volume monitoring value from the flow monitoring device and compares it with a preset grouting volume value. When the pressure signal detected by the grouting orifice pressure monitoring instrument is less than the preset pressure value, and the grouting volume monitoring value is less than the preset grouting volume value, the grouting volume is increased, and the increased grouting volume is the difference between the grouting volume monitoring value and the preset grouting volume value. When the pressure signal detected by the grouting orifice pressure monitoring instrument is greater than the preset pressure value, and the grouting volume monitoring value is less than the preset grouting volume value, the grouting volume is increased. When the measured value exceeds the preset grouting volume, the grouting volume is reduced by the difference between the monitored value and the preset grouting volume. The controller adjusts the opening of the flow valve based on this difference. An anomaly is identified when the pressure signal detected by the grouting orifice pressure monitor is less than the preset pressure value, but the measured grouting volume is greater than or equal to the preset grouting volume. Similarly, an anomaly is identified when the pressure signal detected by the grouting orifice pressure monitor is greater than the preset pressure value, but the measured grouting volume is less than or equal to the preset grouting volume. This embodiment also monitors the grout output flow rate of the grouting hose. Combined with the pressure monitoring results, the flow valve opening is adjusted based on the difference between the measured grouting volume and the preset grouting volume, achieving more precise control. Furthermore, the linkage analysis of pressure and flow data in this embodiment can identify abnormal situations such as a sudden drop in pressure due to grout leakage but an abnormal increase in flow rate, or a sudden rise in pressure due to blockage but a decrease in flow rate, preventing experimental failure due to equipment problems and improving reliability.

[0026] In a preferred embodiment, the underground grouting channel includes multiple detachably connected pipes and a grout outlet pipe. The lower end of the grout outlet pipe has a pointed conical structure, and multiple grout outlets are provided on the sidewall of the pointed conical structure. In this embodiment, the grouting channel is formed by connecting multiple short pipes through threads, snaps, or flanges. The number of pipes can be freely increased or decreased according to experimental needs, and the length of the grouting channel can be adjusted. For shallow or deep delamination, only pipes need to be added or removed, without replacing the entire pipe. After disassembly, locally blocked pipe sections can be cleaned or replaced, reducing the risk of experimental interruption. The lower end of the grout outlet pipe is designed as a pointed conical shape (similar to a drill bit). The pointed conical structure reduces insertion resistance, making it easier to insert into simulated rock strata and simulate the real drilling and grouting process. Multiple grout outlets are provided on the sidewall of the pointed conical structure (not a single end outlet), forming multi-directional grouting. The multi-outlet design allows the grout to diffuse radially and evenly, avoiding local accumulation caused by single-point grouting. As a preferred method, the pipe diameter includes multiple specifications to simulate the influence of different borehole diameters on the grouting effect.

[0027] In a preferred embodiment, multiple pipe sections and the connection between the pipe sections and the grout outlet pipe are all threaded to facilitate obtaining underground grouting channels of different lengths. In this embodiment, each pipe section has standard threads machined at both ends, such as a male thread on one end and a female thread on the other, which are tightened by rotation. The upper end of the grout outlet pipe also uses a threaded interface, securely connected to the lowermost pipe section. Preferably, PTFE tape or rubber gaskets can be wrapped around the threads to prevent grout leakage. The threaded connection of multiple pipe sections allows for independent replacement.

[0028] In a preferred embodiment, the pressurizing device is an air compressor, which provides stable and adjustable air pressure to the grouting mixing tank, thereby propelling the grout through the grouting hose and underground grouting channel pipe, and finally injecting it into the simulated overburden separation layer. Preferably, a quiet, oil-free air compressor suitable for laboratory use or an industrial-grade high-pressure air compressor suitable for engineering simulation can be selected. The pressure range is typically 0.5~1.5MPa (adjustable), and the flow rate must match the grouting volume requirements. The air compressor in this embodiment is equipped with a pressure regulating valve and a pressure gauge to monitor and precisely control the output pressure in real time.

[0029] In a preferred embodiment, the system further includes a surface subsidence monitoring system, comprising a laser rangefinder and a close-range photogrammetry system. Both the laser rangefinder and the close-range photogrammetry system are mounted on a support frame and positioned above the overburden separation simulation chamber. The laser rangefinder periodically monitors the surface at designed and predetermined points as the coal seam is excavated to obtain information on surface movement and deformation during the excavation process. The close-range photogrammetry system periodically photographs the surface above the coal seam as it is excavated, extracting the migration values ​​of non-coded points to monitor surface movement and deformation. This embodiment sets up a surface subsidence monitoring system on top of the simulation frame to accurately measure surface subsidence during mining operations. This allows for the study of the suppression effect of different grouting pressures or flow rates on surface subsidence, and provides a better understanding of the surface subsidence patterns under coal seam mining influence based on overburden separation grouting technology in the simulated indoor environment.

[0030] In a preferred embodiment, the similar simulation frame includes four height-adjustable support legs, each equipped with an adjustment screw to adjust the height of the support legs in different directions, thereby adjusting the coal seam dip angle and simulating the excavation of working faces with different coal seam dip angles.

[0031] As a preferred embodiment, a simulation method for a similar simulation frame that can be used for grouting of overburden delamination includes: calculating and determining the delamination location and setting the number of grouting boreholes based on the geological data of the working face of the required simulated mining area; Based on the simulated mining face, a similar simulation model was built in the overburden separation simulation room using similar materials. During the construction process, the underground grouting channel pipe was pre-buried according to the judgment results. Prepare the grouting material in advance and use a grouting mixing tank to stir it to maintain its fluidity; The grouting pressure is calculated based on the self-weight of the grouting material and the load of the overlying strata at the grouting layer, and this pressure is used as the preset pressure value. At the same time, the grouting volume is calculated based on the mining distance, and this grouting volume is used as the preset grouting volume value. After delamination occurs, the grouting system is activated, and the grouting pressure and volume are monitored in real time. Grouting is carried out as mining progresses. A grouting pressure monitoring instrument is installed at the grouting orifice. When the pressure value detected by the grouting orifice pressure monitoring instrument reaches the preset pressure value, it indicates that the grouting volume is reasonable. If the grouting pressure is too low, it indicates that the grouting volume is too low, and the grouting volume needs to be increased. If the grouting pressure is too high, it indicates that the grouting volume is too high, and the grouting volume needs to be reduced. Once the excavation is complete, the grouting flow rate is gradually reduced, and grouting is stopped after a period of time.

[0032] Grouting volume is a dynamic process that is related to the coal seam mining and the rate at which overburden separation space is generated. When an increase in separation volume is found during excavation, the grouting flow rate should be increased in time to prevent insufficient grout. If a decrease in the amount of delamination is found during the excavation process, the grouting flow rate should be reduced in time to prevent grout collapse and leakage.

[0033] In this embodiment, the grouting pressure is determined by the weight of the grouting material and the load of the overlying rock strata at the grouting layer. The specific method is as follows: Let the grouting pressure be P. 注 Let P1 be the pressure generated by the weight of the grouting material, and P0 be the load on the overlying rock layer at the grouting location. Then, according to the following formula: P 注 = P0-P1(1) (2); (3); (4); In the formula, The density of the grouting material is expressed in kg·m³. -3 g is the acceleration due to gravity, in m·s². -2 ; h Let be the vertical length of the grouting channel, in meters (m). The load on the rock strata is expressed in MPa. The elastic modulus of similar materials is expressed in MPa. The thickness of the corresponding rock layer in the similar simulation model is in meters (m). For the corresponding volume forces of similar materials in rock strata, MN·m -3 ; For the density of similar materials, kg·m -3 Where i = 1, 2, 3, ..., n.

[0034] Simultaneously, the pressure change at the grouting orifice is monitored at all times: The grouting orifice pressure monitor reached the predetermined pressure (P). 注 If the grouting pressure is too low, it indicates that the grouting volume is too low, and the grouting volume needs to be increased; if the grouting pressure is too high, it indicates that the grouting volume is too high, and the grouting volume needs to be reduced.

[0035] In this embodiment, the specific method for calculating the preset value of grouting volume is as follows: 1. Basic Assumptions and Model Geometric conditions: The grouting space is a rectangular area with a fixed width A, a mining distance x (variable), and a grouting layer thickness h.

[0036] Boundary conditions: The overburden separation simulation chamber is supported by a four-sided fixed plate (a steel plate fixed on all four sides), and the bottom is a Winkler elastic foundation (foundation coefficient k).

[0037] Load: Uniformly distributed overlying load (in, (where H is the unit weight of the rock stratum and H is the burial depth).

[0038] 2. Deflection governing equations (1) Equation of thin plate on elastic foundation Deflection of a four-sided fixed plate satisfy: (5) The bending stiffness of the plate; k This refers to the subgrade coefficient; q The load is a uniformly distributed load covering the surface.

[0039] E The elastic modulus of the grout. v Poisson's ratio; It is a bitone operator.

[0040] (2) Analytical solution (approximate) For a rectangular plate with four fixed sides, the deflection can be expressed as a double series (Navier solution): (6) 3. Calculation of grouting space volume volume V The deflection function in the region [0, A ]×[0, x Integrals on: A For a constant value (7) Using the series solution, the volume is approximately: (8) Simplified formula (taking the first term m=n=1): (9) 4. Calculation of unit grouting volume The mining distance is x The grouting volume is calculated using formula (9). V x Excavation x The distance required to travel is t x The volume of ash (dry powder) injected per unit time is V f = V x / t x .

[0041] The grouting volume is calculated by back-calculating the grouting volume concentration; Let the volume concentration of the grout be... φ Then, the grouting volumeV z = V f / φ .

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A similar simulation frame that can be used for grouting of overburden separation, characterized in that, It includes an overburden separation simulation chamber, a support frame, and a grouting and filling system. The overburden separation simulation chamber is mounted on the support frame. The grouting and filling system includes a pressurizing device, a grouting mixing tank, and a grouting hose. The pressurizing device is connected to the grouting mixing tank. The outlet of the grouting mixing tank is connected to one end of the grouting hose, and a valve is also provided at the connection end between the outlet and the grouting hose. The other end of the grouting hose is connected to one end of an underground grouting channel pipe pre-embedded in the overburden separation simulation chamber. The other end of the underground grouting channel pipe is used to grout the separation location. A grouting borehole pressure monitoring instrument is installed at the grouting borehole where the underground grouting channel pipe is located. A flow valve is installed on the grouting hose. Both the grouting borehole pressure monitoring instrument and the flow valve are connected to a controller. The controller is used to receive the pressure signal detected by the grouting borehole pressure monitoring instrument. When the pressure signal detected by the grouting borehole pressure monitoring instrument is less than the preset pressure value, the flow valve is increased to increase the grouting volume. When the pressure signal detected by the grouting borehole pressure monitoring instrument is greater than the preset pressure value, the flow valve is decreased to increase the grouting volume. When the pressure signal detected by the grouting borehole pressure monitoring instrument is equal to the preset pressure value, the current grouting volume is maintained.

2. The similar simulation frame for overburden separation grouting as described in claim 1, characterized in that, The grouting hose is equipped with a flow monitoring device. The controller receives the grouting volume monitoring value from the flow monitoring device and compares it with a preset grouting volume value. When the pressure signal detected by the grouting orifice pressure monitoring instrument is less than the preset pressure value, and the grouting volume monitoring value is also less than the preset grouting volume value, the grouting volume is increased by the difference between the monitored and preset grouting volumes. When the pressure signal detected by the grouting orifice pressure monitoring instrument is greater than the preset pressure value, and the grouting volume monitoring value is also greater than the preset grouting volume value, the grouting volume is decreased by the difference between the monitored and preset grouting volumes. The controller adjusts the opening of the flow valve based on the difference between the monitored and preset grouting volumes. When the pressure signal detected by the grouting orifice pressure monitoring instrument is less than the preset pressure value, and the grouting volume monitoring value is greater than or equal to the preset grouting volume value, an abnormality is detected. When the pressure signal detected by the grouting orifice pressure monitoring instrument is greater than the preset pressure value, and the grouting volume monitoring value is less than or equal to the preset grouting volume value, it is judged as abnormal.

3. The similar simulation frame for overburden separation grouting as described in claim 1, characterized in that, The underground grouting channel includes multiple detachably connected pipes and grout outlet pipes. The lower end of the grout outlet pipe is a pointed cone structure, and multiple grout outlets are provided on the side wall of the pointed cone structure.

4. The similar simulation frame for overburden delamination grouting as described in claim 3, characterized in that, Multiple pipes and the connection between the pipes and the slurry outlet pipe are all made by threaded connection.

5. The similar simulation frame for overburden separation grouting as described in claim 1, characterized in that, The pressurizing device is an air compressor.

6. The similar simulation frame for overburden separation grouting as described in claim 1, characterized in that, It also includes a surface subsidence monitoring system, comprising a laser rangefinder and a close-range photogrammetry system, both of which are mounted on a support frame and located above the overburden separation simulation chamber.

7. The similar simulation frame for overburden separation grouting as described in claim 1, characterized in that, The similar simulation frame includes four height-adjustable support legs.

8. The simulation method for a similar simulation frame applicable to overburden delamination grouting as described in claim 1, characterized in that, Includes the following steps: Based on the geological data of the required simulated mining face, calculate and determine the location of the delamination and the number of grouting boreholes to be set; Based on the simulated mining face, a similar simulation model was built in the overburden separation simulation room using similar materials. During the construction process, the underground grouting channel pipe was pre-buried according to the judgment results. Prepare the grouting material in advance and use a grouting mixing tank to stir it to maintain its fluidity; The grouting pressure is calculated based on the self-weight of the grouting material and the load of the overlying strata at the grouting layer, and this pressure is used as the preset pressure value. At the same time, the grouting volume is calculated based on the mining distance, and this grouting volume is used as the preset grouting volume value. After delamination occurs, the grouting system is activated, and the grouting orifice pressure and grouting volume are monitored in real time. Grouting is carried out as mining progresses. A grouting pressure monitoring instrument is installed at the grouting orifice. When the pressure value detected by the grouting orifice pressure monitoring instrument reaches the preset pressure value, it indicates that the grouting volume is reasonable. If the grouting pressure is too low, it indicates that the grouting volume is too low, and the grouting volume needs to be increased. If the grouting pressure is too high, it indicates that the grouting volume is too high, and the grouting volume needs to be reduced. Once the excavation is complete, the grouting flow rate is gradually reduced, and grouting is stopped after a period of time.

9. The simulation method for a similar simulation frame applicable to overburden delamination grouting as described in claim 8, characterized in that, The grouting pressure is composed of the self-weight of the grouting material and the load of the overlying rock strata at the grouting layer. The grouting pressure is calculated based on the pressure generated by the self-weight of the grouting material, the load of the overlying rock strata at the grouting layer, the density of the grouting material, the vertical length of the grouting channel, the elastic modulus of similar materials, the density of similar materials, and the volume force of similar materials in the corresponding rock strata.

10. The simulation method for a similar simulation frame applicable to overburden delamination grouting as described in claim 8, characterized in that, The preset grouting volume is calculated based on the mining distance, the width of the overburden separation simulation chamber, the bending stiffness of the fixed plates around the overburden separation simulation chamber, and the foundation coefficient.

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