A device for making test blocks for simulating broken surrounding rock grouting indoor test and a method of using the same

Abstract

The present application relates to broken surrounding rock grouting experimental technical field, disclose a kind of simulation broken surrounding rock grouting indoor test test block making device and use method, including parallelly arranged upper sealing disc and lower sealing disc, upper sealing disc and lower sealing disc are provided with the upper confining pressure tank and lower confining pressure tank stacked together between, the inside of upper confining pressure tank and lower confining pressure tank is provided with test block bin, the end of test block bin is provided with test block bin end, the bin wall of test block bin is provided with grout inlet, grout inlet is communicated with connecting pipe, the end of connecting pipe away from grout inlet is communicated with communicating pipe, the bottom of lower sealing disc is provided with grouting port communicated with communicating pipe, the upper sealing disc is provided with exhaust hole.The present application is designed by using multi-station parallel structure, eight test pieces can be simultaneously grouted in one time, greatly shorten batch sample preparation time, meet the efficient demand of multi-parameter comparison test.

Description

Technical Field

[0001] This invention relates to the field of experimental technology for grouting in fractured surrounding rock, specifically to a device for preparing and using indoor test blocks for grouting in fractured surrounding rock. Background Technology

[0002] In underground engineering fields such as coal mining and tunnel construction, grouting reinforcement of fractured surrounding rock is a key technology for improving rock mass stability and ensuring construction safety. Conducting indoor simulated grouting tests and producing standard test blocks for mechanical testing are core methods for studying the grouting reinforcement mechanism, optimizing engineering grouting parameters, and evaluating the grouting reinforcement effect. This provides theoretical basis and technical support for grouting projects in complex underground rock masses, avoiding cost waste and engineering risks caused by relying solely on experience.

[0003] Existing indoor grouting specimen fabrication devices generally have several limitations: most are single-channel grouting structures, capable of grouting only a single specimen at a time, resulting in low batch sample preparation efficiency; after grouting, specimens must remain in the device until the grout completely solidifies before demolding, leading to long-term device occupancy, a serial operation mode, long overall test cycles, and low equipment utilization; the grout preparation and grouting processes are separated, and sedimentation and segregation during grout transfer can easily occur, causing deviations in the mix proportions and affecting the accuracy and repeatability of test results; furthermore, the functional modules are dispersed and independent, the pipeline layout is complex, and post-test cleaning and maintenance are difficult, making it difficult to meet the needs of efficient and accurate multi-parameter comparative tests. To address these issues, it is necessary to develop a new type of testing device and method that enables multi-station parallel grouting, integrated operation, and continuous, streamlined operation. Summary of the Invention

[0004] This invention provides a device and method for preparing test blocks for grouting in simulated fractured surrounding rock in an indoor test, which solves the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A device for preparing test blocks for grouting in simulated fractured surrounding rock includes an upper sealing plate and a lower sealing plate arranged in parallel. An upper and lower pressure tank are stacked between the upper and lower sealing plates. Test block chambers are located inside the upper and lower pressure tanks, with test block end caps at each end. A grout inlet hole is provided in the wall of the test block chamber. A diaphragm-type one-way check valve structure is provided at the grout inlet hole, allowing grout to enter the test block chamber in only one direction. The grout inlet hole is connected to a connecting pipe, and the end of the connecting pipe away from the grout inlet hole is connected to a connecting pipe. A grouting port connected to the connecting pipe is provided at the bottom of the lower sealing plate. An vent hole is provided on the upper sealing plate. The device also includes a grouting mechanism and a venting mechanism. The grouting mechanism injects grout into the test block chamber through the grouting port, and the venting mechanism extracts gas from the test block chamber through the vent hole.

[0007] As a preferred embodiment of the present invention, the grouting mechanism includes a mixing chamber, and a grouting pump is provided between the mixing chamber and the test block chamber. The grouting pump injects the grout from the mixing chamber into the test block chamber.

[0008] As a preferred embodiment of the present invention, the mixing chamber is equipped with a stirrer, the mixing chamber is connected to the grouting pump's grouting port via a grouting pipe, the grouting pump is equipped with a third pressure gauge in the middle, and the grouting pump's outlet is connected to the grouting port via a hose.

[0009] As a preferred embodiment of the present invention, the exhaust mechanism includes an air pump and an air extraction chamber. The air extraction chamber is provided with a second connection port and a first connection port on both sides. The second connection port is connected to the air extraction connection port of the air pump. The air pump is provided with a second pressure gauge, which is in communication with the exhaust port. An exhaust switch is provided inside the exhaust port.

[0010] As a preferred embodiment of the present invention, the upper sealing plate is provided with a slurry outlet hole on its side, the slurry outlet hole is connected to a third connection port through a pipe, the third connection port is provided at the end of the liquid storage tank, and a connection hole is provided in the middle of the upper sealing plate, and a first pressure gauge is provided on the connection hole.

[0011] As a preferred embodiment of the present invention, a fixing post is provided between the upper sealing plate and the lower sealing plate, and the fixing post is connected to the upper sealing plate and the lower sealing plate by fixing screws. A support leg is provided at the bottom of the lower sealing plate.

[0012] The method of using a device for preparing test blocks for grouting in simulated fractured surrounding rock includes the following steps:

[0013] 1) Material preparation: Open the end of the test block silo, load in the pre-crushed and proportioned simulated rock mass material, compact it, and then reseal the end of the test block silo. Check the sealing performance of the upper and lower pressure tanks and the test block silo, and close all valves.

[0014] 2) Vacuum treatment: Connect the external air pump to the air extraction port, open the corresponding exhaust switch of the air extraction chamber, and evacuate the test block chamber and connected pipelines. Monitor the vacuum level through the first pressure gauge. After reaching the standard, close the exhaust switch to maintain negative pressure in the chamber, so as to facilitate the filling of rock fissures with grout.

[0015] 3) Grout preparation and storage: Add cement, water, additives and other raw materials to the mixing chamber according to the proportion, start the mixer to mix evenly, and after mixing is completed, turn on the grouting pump to pump the grout into each test block chamber through the grouting port, connecting pipe and connecting pipe.

[0016] 4) Grouting and confining pressure loading: Start the grouting pump, and the grout is transported to each test block chamber through the grouting pipe, grouting port and branch pipeline. The grouting pressure opens the grout inlet hole, and the grout enters the chamber to fill the gaps in the broken rock mass. At the same time, liquid is injected into the upper confining pressure tank and the lower confining pressure tank through the external confining pressure pump to apply confining pressure, simulating the on-site in-situ stress environment. Grouting is stopped after the grouting pressure reaches the set value, and the diaphragm closes automatically to prevent grout backflow.

[0017] 5) Pressure holding demolding and continuous operation: After maintaining the confining pressure until the grout has initially solidified, disassemble the end of the corresponding test block compartment, remove the entire specimen, and move it to the curing environment to continue solidification. Empty workstations can be immediately refilled with material to start the next round of grouting.

[0018] 6) Cleaning and maintenance: After all tests are completed, open the vent, slurry outlet and corresponding switch, introduce cleaning fluid, start the mixing chamber and grouting pump, and circulate and clean all pipelines and mixing chamber to avoid slurry residue blockage.

[0019] The present invention has the following advantages:

[0020] By adopting a multi-station parallel structure design, grouting can be performed on eight specimens simultaneously, significantly shortening the batch sample preparation time and meeting the high-efficiency requirements of multi-parameter comparative tests. The mixing chamber, storage chamber, and grouting pipeline are organically integrated to achieve integrated operation of grout preparation and grouting, avoiding errors and cumbersome processes caused by external transfer, and ensuring the uniformity of grout and the repeatability of the test. Each specimen can be removed immediately after grouting without waiting for solidification in situ, thus breaking the serial limitation of "grouting-waiting" and realizing continuous flow operation, greatly improving the utilization rate of the equipment. Each grouting channel is equipped with an independent pressure regulation and control system, which can simultaneously simulate the impact of different grouting pressures on the grouting effect of fractured surrounding rock, providing a reliable parallel comparison platform for grouting parameter optimization. At the same time, the functional modules such as the pressure tank, air extraction chamber, storage chamber, and mixing chamber are highly integrated, simplifying the pipeline layout, centralizing operation and control, and facilitating cleaning and maintenance after the test. This invention provides an efficient, scientific, and integrated indoor simulation grouting test block fabrication device and method, offering a more advanced and practical experimental platform for the study of grouting mechanism and optimization of engineering parameters in fractured surrounding rock. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1This is a schematic diagram of a device for fabricating test blocks for indoor grouting simulation of fractured surrounding rock.

[0023] Figure 2 This is a schematic diagram of the structure of the upper and lower sealing discs in a device for fabricating test blocks for grouting in simulated fractured surrounding rock.

[0024] Figure 3 This is a schematic diagram of the structure of the upper and lower pressure tanks in a device for fabricating test blocks for grouting in simulated fractured surrounding rock.

[0025] Figure 4 This is a schematic diagram of the lower pressure tank in a device for fabricating test blocks for indoor grouting in simulated fractured surrounding rock.

[0026] Figure 5 This is a schematic diagram of the upper pressure tank in a device for fabricating test blocks for indoor grouting of simulated fractured surrounding rock.

[0027] Figure 6 This is a schematic diagram of the connection between the connecting pipe and the connecting tube in a device for fabricating test blocks for grouting in simulated fractured surrounding rock.

[0028] Figure 7 This is a schematic diagram of the second connecting pipe interface in a device for fabricating test blocks for indoor grouting of simulated fractured surrounding rock.

[0029] Figure 8 This is a schematic diagram of the second connecting pipe interface and the connecting pipe connection in a device for fabricating test blocks for indoor grouting of simulated fractured surrounding rock.

[0030] Figure 9 This is a schematic diagram of the air extraction chamber in a device for fabricating test blocks for indoor grouting in simulated fractured surrounding rock.

[0031] Figure 10 This is a schematic diagram of the liquid storage tank in a device for fabricating test blocks for indoor grouting in simulated fractured surrounding rock.

[0032] Figure 11 This is a schematic diagram of the air pump in a device for fabricating test blocks for indoor grouting in simulated fractured surrounding rock.

[0033] Figure 12 This is a schematic diagram of the grouting pump in a device for fabricating test blocks for grouting in simulated fractured surrounding rock.

[0034] Figure 13 This is a schematic diagram of the mixing chamber in a device for making test blocks for indoor grouting of simulated fractured surrounding rock.

[0035] Figure 14 This is a schematic diagram of the test block chamber in a device for fabricating test blocks for indoor grouting tests in simulated fractured surrounding rock.

[0036] In the diagram: 1. First pressure gauge; 2. Connecting hole; 3. Vent hole; 4. Vent switch; 5. Fixing screw; 6. Support leg; 7. Fixing column; 8. Lower pressure tank; 9. Upper sealing plate; 10. Lower sealing plate; 11. Upper pressure tank; 12. Grouting port; 13. End of test block compartment; 14. Test block compartment; 15. Connecting pipe; 16. First connecting pipe interface; 17. Second connecting pipe interface; 18. Connecting pipe; 19. Grout outlet hole; 20. Grout outlet switch; 21. Second pressure gauge; 22. Air extraction connection port; 23. Third pressure gauge; 24. Grout extraction connection port; 25. Grout outlet connection port; 26. First connection port; 27. Second connection port; 28. Air extraction chamber; 29. ​​Third connection port; 30. Liquid storage tank; 31. Agitator; 32. Grout extraction pipe; 33. Grout mixing chamber; 34. Hose; 35. Grout inlet hole. Detailed Implementation

[0037] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In one embodiment, see Figures 1-14 A device for fabricating test blocks for grouting in simulated fractured surrounding rock is disclosed. It includes an upper sealing plate 9 and a lower sealing plate 10 arranged in parallel. An upper pressure tank 11 and a lower pressure tank 8 are stacked between the upper sealing plate 9 and the lower sealing plate 10. Test block chambers 14 are located inside the upper pressure tank 11 and the lower pressure tank 8. Test block chamber end caps 13 are provided at the ends of the test block chambers 14. In the test block forming unit, multiple independent test block chambers 14 are used to accommodate fractured rock mass and form standard test specimens (50mm × 100mm). Each test block chamber 14 has a detachable test block chamber end cap 13 at one end for specimen removal. The chamber wall of the test block chamber 14 has a grout inlet hole 35. A diaphragm-type one-way check valve structure is provided at the grout inlet hole 35 to allow grout to enter the test block chamber in only one direction, preventing grout backflow. The diaphragm-type one-way check valve structure includes an annular base and an ultra-thin elastic sealing diaphragm attached to the end face of the annular base. The annular base is fixedly connected to the pipe joint outside the grout inlet 35. The sealing diaphragm opens under grouting pressure and resets to seal by its own elasticity and back pressure after grouting stops. Neither the sealing diaphragm nor the annular base protrudes from the inner wall of the test block chamber. The upper confining pressure tank 11 and the lower confining pressure tank 8 are respectively fitted onto the upper and lower ends of the test block chamber 14, and are sealed by the upper sealing plate 9 and the lower sealing plate 10, for applying confining pressure simulating in-situ stress to the specimen.

[0039] The test block chamber 14 has a grout inlet hole 35 on its wall, which is connected to a connecting pipe 15. The end of the connecting pipe 15 away from the grout inlet hole 35 is connected to a connecting pipe 18. The bottom of the lower sealing plate 10 is provided with a grouting port 12 connected to the connecting pipe 18. Each test block chamber 14 is connected to the corresponding grout inlet hole 35 through the connecting pipe 15. The two ends of the connecting pipe 18 are respectively provided with a first connecting pipe interface 16 and a second connecting pipe interface 17 for connecting the upper and lower pipelines. The grouting port 12 is provided on the lower pressure tank 8 as the inlet for the grout to enter the test block chamber 14.

[0040] The upper sealing plate 9 is provided with an exhaust hole 3, and also includes a grouting mechanism and an exhaust mechanism. The grouting mechanism injects grout into the test block chamber 14 through the grouting port 12, and the exhaust mechanism extracts the gas inside the test block chamber 14 through the exhaust hole 3.

[0041] The test block chamber 14 has a flush-mounted grout inlet hole 35 on its wall. The grout inlet hole 35 penetrates the chamber wall and one side inside the chamber remains flat without protrusions or grooves, so as not to damage the shape of the test piece. The outer wall of the test block chamber 14 is provided with a diaphragm-type one-way check structure at the grout inlet hole 35, including an ultra-thin elastic sealing diaphragm and an outer grouting joint. Under the action of grouting pressure, the sealing diaphragm is pushed open, and the grout enters the test block chamber 14 through the grout inlet hole 35. After grouting stops, the sealing diaphragm adheres tightly to the outside of the grout inlet hole 35 under the action of its own elasticity and the pressure of the grout inside the chamber, so as to achieve a seal and prevent backflow, so that the grout can only enter and cannot flow back, and does not invade the internal space of the test block chamber 14.

[0042] In one embodiment, the grouting mechanism includes a mixing chamber 33, and a grouting pump is installed between the mixing chamber 33 and the test block chamber 14. The grouting pump injects the grout from the mixing chamber 33 into the test block chamber 14. An agitator 31 is installed inside the mixing chamber 33. The mixing chamber 33 is connected to the grouting pump's pumping port 24 via a pumping pipe 32. A third pressure gauge 23 is installed in the middle of the grouting pump, and the grout outlet port 25 of the grouting pump is connected to the grouting port 12 via a hose 34. A grout outlet hole 19 is provided on the side of the upper sealing plate 9. The grout outlet hole 19 is connected to the third connection port 29 via a pipe. The third connection port 29 is located at the end of the liquid storage chamber 30. A connection hole 2 is provided in the middle of the upper sealing plate 9, and a first pressure gauge 1 is installed on the connection hole 2. In the grouting mechanism, a mixer 31 is installed inside the mixing chamber 33 for preparing grouting slurry on site; the storage chamber 30 is connected to the slurry outlet 19 and the third connection port 29 on the storage chamber 30 through a hose 34; one end of the slurry pumping pipe 32 is inserted into the mixing chamber 33, and the other end is connected to the slurry pumping connection port 24, and then connected to the external grouting pump; the outlet of the grouting pump is connected to the grouting port 12 through a pipeline, and then distributed to each test block chamber 14 through the grouting port 12; the pipeline is equipped with a slurry outlet 19 and a slurry outlet switch 20 for venting or cleaning.

[0043] In one embodiment, the venting mechanism includes an air pump and an air extraction chamber 28. The air extraction chamber 28 has a second connection port 27 and a first connection port 26 on both sides. The second connection port 27 connects to the air extraction connection port 22 of the air pump. The air pump is equipped with a second pressure gauge 21, which is connected to an exhaust port 3. An exhaust switch 4 is installed inside the exhaust port 3. The venting mechanism includes an air extraction chamber 28, which is connected to an external air pump via the air extraction connection port 22 and connected to the venting circuit of the pressure tank via interfaces such as the first connection port 26, the second connection port 27, and the exhaust port 3. An exhaust port 3 and an exhaust switch 4 are provided on the pipeline. A third pressure gauge 23 monitors the pressure of the grouting pipeline, a first pressure gauge 1 monitors the pressure of the pressure tank, and a second pressure gauge 21 monitors the air extraction chamber 28. A connection hole 2 is used to connect the first pressure gauge 2 and the pressure tank.

[0044] In one embodiment, a fixing column 7 is provided between the upper sealing plate 9 and the lower sealing plate 10. The fixing column 7 is connected to the upper sealing plate 9 and the lower sealing plate 10 by fixing screws 5. A support leg 6 is provided at the bottom of the lower sealing plate 10. In terms of structural connection, the four support legs 6 support the entire device, and the fixing column 7 and fixing screws 5 are used to connect and fix the upper and lower pressure tanks 8 and the test block chamber 14 components.

[0045] A method for using a device for preparing test blocks for grouting in simulated fractured surrounding rock includes the following steps:

[0046] 1. Material preparation: Open end 13 of the test block silo, load the pre-crushed and proportioned simulated rock mass material into the test block silo 14, compact it, and then reseal the end. Check the sealing performance of the upper pressure tank 11, lower pressure tank 8 and test block silo 14, and close all valves.

[0047] 2. Vacuum treatment: Connect the external air pump to the air extraction port 22, open the exhaust switch 4 corresponding to the air extraction chamber 28, and evacuate the test block chamber 14 and the connected pipeline. Monitor the vacuum degree through the first pressure gauge 1. After completion, close the exhaust switch 4 to keep the chamber under negative pressure to facilitate the filling of cracks by the slurry.

[0048] 3. Grout preparation and storage: Cement, water, additives, etc. are added to the mixing bin 33 according to the proportion. The mixer 31 is started to mix evenly. After the mixing is completed, the grouting pump is turned on to pump the grout into each test block bin 14 through the grouting port 12, the connecting pipe and the connecting pipe 18.

[0049] 4. Grouting and confining pressure loading: Start the grouting pump. Grout enters the grouting pump from the mixing chamber 33 through the grouting pipe 32 and the grouting connection port 24, and then reaches each test block chamber 14 through the hose 34, grouting port 12, connecting pipe 15, and connecting pipe 18. Under the action of grouting pressure, the diaphragm-type one-way check structure at the grout inlet 35 of the test block chamber 14 is opened, and the grout enters the chamber to fill the gaps in the fractured rock mass. At the same time, liquid is injected into the upper confining pressure tank 11 and the lower confining pressure tank 8 through the external confining pressure pump to apply confining pressure simulating the in-situ stress environment, which is monitored by the first pressure gauge 1. When the grouting pressure of the test block chamber 14 reaches the required level, grouting is stopped. At this time, the diaphragm at the grout inlet 35 automatically closes to prevent grout backflow.

[0050] 5. Pressure holding and demolding and continuous operation: After maintaining the confining pressure for a period of time to allow the grout to initially solidify, remove the end 13 of the test block chamber 14, take out the grouted specimen as a whole, and move it to the curing environment to continue solidification. After the test block chamber 14 is emptied, immediately reinstall a new test block chamber 14 and then load the material for the next round of grouting, realizing a streamlined continuous operation of "loading material → vacuuming → grouting → taking out the specimen → loading material again", with eight workstations operating in parallel.

[0051] 6. Cleaning and maintenance: Start the mixing chamber 33 and the grouting pump to circulate and clean all pipelines and the mixing chamber 33 to prevent grout residue from clogging.

[0052] This invention provides a device and method for fabricating test blocks for grouting in simulated fractured surrounding rock. By employing a multi-station parallel structure design, grouting can be performed on eight specimens simultaneously, significantly shortening batch sample preparation time and meeting the high-efficiency requirements of multi-parameter comparative experiments. The mixing chamber 33, storage chamber 30, and grouting pipeline are organically integrated, achieving integrated operation of grout preparation and grouting, avoiding errors and cumbersome processes caused by external transfer, and ensuring grout uniformity and test repeatability. Each specimen can be removed immediately after grouting, eliminating the need to wait for solidification in situ, thus breaking the serial limitation of "grouting-waiting" and achieving continuous, streamlined operation, greatly improving device utilization. Each grouting channel is equipped with an independent pressure regulation and control system, enabling simultaneous simulation of the impact of different grouting pressures on the grouting effect of fractured surrounding rock, providing a reliable parallel comparison platform for grouting parameter optimization. Simultaneously, the functional modules such as the pressure tank, extraction chamber 28, storage chamber 30, and mixing chamber 33 are highly integrated, simplifying pipeline layout, centralizing operation and control, and facilitating post-test cleaning and maintenance. This invention provides an efficient, scientific, and integrated indoor simulation grouting test block fabrication device and method, offering a more advanced and practical experimental platform for the study of grouting mechanism and optimization of engineering parameters in fractured surrounding rock.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A device for fabricating test blocks for grouting in simulated fractured surrounding rock in an indoor test, characterized in that, The system includes an upper sealing plate and a lower sealing plate arranged in parallel. An upper pressure tank and a lower pressure tank are stacked between the upper and lower sealing plates. A test block chamber is located inside each of the upper and lower pressure tanks. A test block chamber end is located at the end of each test block chamber. The chamber wall of each test block chamber has a grout inlet hole. The grout inlet hole is equipped with a diaphragm-type one-way check valve structure that allows grout to enter the test block chamber in only one direction. The grout inlet hole is connected to a connecting pipe. The end of the connecting pipe away from the grout inlet hole is connected to a connecting pipe. A grout injection port connected to the connecting pipe is located at the bottom of the lower sealing plate. An vent hole is located on the upper sealing plate. The system also includes a grout injection mechanism and a venting mechanism. The grout injection mechanism injects grout into the test block chamber through the grout injection port, and the venting mechanism extracts gas from the test block chamber through the vent hole.

2. The apparatus for fabricating indoor test blocks for grouting in simulated fractured surrounding rock according to claim 1, characterized in that, The grouting mechanism includes a mixing chamber, and a grouting pump is installed between the mixing chamber and the test block chamber. The grouting pump injects the grout from the mixing chamber into the test block chamber.

3. The apparatus for fabricating indoor test blocks for grouting in simulated fractured surrounding rock according to claim 2, characterized in that, The mixing chamber is equipped with a stirrer. The mixing chamber is connected to the grouting pump's pumping port via a pumping pipe. A third pressure gauge is installed in the middle of the grouting pump. The grouting pump's outlet is connected to the grouting port via a hose.

4. The apparatus for fabricating indoor test blocks for grouting in simulated fractured surrounding rock according to claim 1, characterized in that, The exhaust mechanism includes an air pump and an air extraction chamber. The air extraction chamber has a second connection port and a first connection port on its two sides, respectively. The second connection port is connected to the air extraction connection port of the air pump. The air pump is equipped with a second pressure gauge, which is connected to the exhaust port. An exhaust switch is installed inside the exhaust port.

5. The apparatus for fabricating indoor test blocks for grouting in simulated fractured surrounding rock according to claim 1, characterized in that, The upper sealing plate has a slurry outlet on its side, which is connected to a third connection port via a pipe. The third connection port is located at the end of the liquid storage tank. The upper sealing plate has a connection hole in its middle, and a first pressure gauge is installed on the connection hole.

6. The apparatus for fabricating indoor test blocks for grouting in simulated fractured surrounding rock according to claim 1, characterized in that, A fixing post is provided between the upper sealing plate and the lower sealing plate. The fixing post is connected to the upper sealing plate and the lower sealing plate by fixing screws. A support leg is provided at the bottom of the lower sealing plate.

7. A method for using the apparatus for preparing grouting test blocks for simulating fractured surrounding rock as described in any one of claims 1-6, characterized in that, Includes the following steps: 1) Material preparation: Open the end of the test block silo, load in the pre-crushed and proportioned simulated rock mass material, compact it, and then reseal the end of the test block silo. Check the sealing performance of the upper and lower pressure tanks and the test block silo, and close all valves. 2) Vacuum treatment: Connect the external air pump to the air extraction port, open the corresponding exhaust switch of the air extraction chamber, and evacuate the test block chamber and connected pipelines. Monitor the vacuum level through the first pressure gauge. After reaching the standard, close the exhaust switch to maintain negative pressure in the chamber, so as to facilitate the filling of rock fissures with grout. 3) Grout preparation and storage: Add cement, water, additives and other raw materials to the mixing chamber according to the proportion, start the mixer to mix evenly, and after mixing is completed, turn on the grouting pump to pump the grout into each test block chamber through the grouting port, connecting pipe and connecting pipe. 4) Grouting and confining pressure loading: Start the grouting pump, and the grout is transported to each test block chamber through the grouting pipe, grouting port and branch pipeline. The grouting pressure opens the grout inlet hole, and the grout enters the chamber to fill the gaps in the broken rock mass. At the same time, liquid is injected into the upper confining pressure tank and the lower confining pressure tank through the external confining pressure pump to apply confining pressure, simulating the on-site in-situ stress environment. Grouting is stopped after the grouting pressure reaches the set value, and the diaphragm closes automatically to prevent grout backflow. 5) Pressure holding demolding and continuous operation: After maintaining the confining pressure until the grout has initially solidified, disassemble the end of the corresponding test block compartment, remove the entire specimen, and move it to the curing environment to continue solidification. Empty workstations can be immediately refilled with material to start the next round of grouting. 6) Cleaning and maintenance: After all tests are completed, open the vent, slurry outlet and corresponding switch, introduce cleaning fluid, start the mixing chamber and grouting pump, and circulate and clean all pipelines and mixing chamber to avoid slurry residue blockage.

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