Testing device and testing method for simulating grouting reinforcement surrounding rock penetration

Abstract

The invention relates to a test device and a test method for simulating grouting reinforcement surrounding rock penetration, and belongs to the technical field of mining. According to the technical scheme, the simulation grouting reinforcement surrounding rock penetration test device comprises a penetration test module, an inner cavity used for containing a sample body is formed in the penetration test module, and a gas filling and collecting module, a hydraulic loading module and a grouting filling module are arranged on the penetration test module; the gas filling and collecting module and the hydraulic loading module are connected to an inner cavity of the penetration testing module, and the grouting filling module is connected to the interior of the sample body. According to the scheme, the grouting form of the sample body is simulated, the grouting reinforcement process in the actual coal mine environment is simulated, the grouting pressure is monitored in real time, the permeability test of coal rock in the dynamic loading process and the permeability test of the coal rock after grouting are completed are completed through the gas filling and collecting module and the hydraulic loading module, the permeability test is closer to actual grouting filling, and the test efficiency is improved. And after testing, surrounding rock can be directly grouted, and the destructive effect of secondary sampling is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of mining, and particularly to a device for simulating the penetration test of surrounding rock grouting reinforcement, and a method for simulating the penetration test of surrounding rock grouting reinforcement. Background Art

[0002] During the process of coal mine exploitation, the stability of the surrounding rock is crucial for the safety of the mine. Due to the complexity and uncertainty of the underground environment, taking effective surrounding rock reinforcement measures is the key to ensuring the safe production of the mine. Grouting reinforcement is a very effective means of surrounding rock reinforcement.

[0003] The principle of grouting reinforcement technology is to inject a special slurry into the fissures, pores or cavities of the surrounding rock through pre-drilled holes. After injection, these slurries will undergo physical and chemical changes inside the surrounding rock and finally solidify into solids with a certain strength and stability, thereby playing the roles of bonding loose rock blocks, filling voids, compressing rock strata and providing additional support. There are various choices of grouting materials, including common cement slurries, chemical grouting materials and mixed grouting materials prepared according to needs, etc. Each material has its unique characteristics and applicable conditions. For example, cement slurries are suitable for filling larger fissures, while chemical grouting materials are more suitable for the penetration of fine fissures.

[0004] The process of the grouting technology includes steps such as drilling, slurry preparation, grouting and hole sealing. First of all, it is necessary to determine the position, depth and angle of the drilling according to the geological conditions and reinforcement requirements; secondly, in the slurry preparation link, the slurry should be prepared strictly in accordance with the formula ratio and stirring time; then, the slurry is injected into the drilling through a high-pressure pump; finally, after the grouting is completed, the drilling needs to be sealed to prevent slurry leakage and secondary damage to the surrounding rock.

[0005] In order to ensure the effect of grouting reinforcement, it is necessary to detect and evaluate the penetration effect after the surrounding rock is grouted. At present, most of the existing methods for testing the permeability of the surrounding rock after grouting need to be carried out underground, that is, after filling and reinforcement, samples are taken through drilling, and then the penetration performance of the samples is directly measured. However, this traditional testing method has certain limitations. For example, the sampling process may damage the original rock stress state, resulting in distorted test results; at the same time, this method cannot effectively simulate the actual grouting process, so it is difficult to accurately reflect the penetration characteristics of the surrounding rock after grouting. Summary of the Invention

[0006] In view of the problem that the current detection of the permeability of the surrounding rock after grouting requires drilling and sampling in the grouted surrounding rock, which is likely to damage the stress state of the surrounding rock and the test results are distorted, the present invention provides a device for simulating the penetration test of surrounding rock grouting reinforcement.

[0007] To solve the above problems, the technical solution adopted by the present invention is a simulated grouting reinforcement surrounding rock penetration test device, which includes a penetration test module. An inner cavity for accommodating a specimen body is provided in the penetration test module. A gas filling and collection module, a hydraulic loading module, and a grouting filling module are provided on the penetration test module. The gas filling and collection module and the hydraulic loading module are connected to the inner cavity of the penetration test module, and the grouting filling module is connected to the inside of the specimen body. This solution simulates the grouting form of the specimen body, simulates the grouting reinforcement process in the actual coal mine environment, and monitors the grouting pressure in real time. The permeability of coal and rock during the dynamic loading process and the permeability of coal and rock after grouting are tested through the gas filling and collection module and the hydraulic loading module, which is closer to the actual grouting filling. And after testing, the surrounding rock can be directly grouted without the destructive effect of secondary sampling, ensuring safety.

[0008] As a preferred implementation of a simulated grouting reinforcement surrounding rock penetration test device, the penetration test module includes an axial pressure chamber cylinder and a confining pressure chamber cylinder. The axial pressure chamber cylinder is located above the confining pressure chamber cylinder. An axial pressure chamber is provided inside the axial pressure chamber cylinder, and a confining pressure chamber is provided inside the confining pressure chamber cylinder. The specimen body is located in the confining pressure chamber. A communication groove is provided between the axial pressure chamber cylinder and the confining pressure chamber cylinder. An axial piston is slidably provided in the axial pressure chamber. The piston rod of the axial piston passes through the communication groove and extends into the confining pressure chamber, and presses against the top of the specimen body. The gas filling and collection module includes an axial pressure gas assembly and a confining pressure gas assembly. The axial pressure gas assembly is connected to the axial pressure chamber cylinder, and the confining pressure gas assembly is connected to the confining pressure chamber cylinder. The hydraulic loading module includes an axial pressure hydraulic assembly and a confining pressure hydraulic assembly. The axial pressure hydraulic assembly is connected to the axial pressure chamber cylinder, and the confining pressure hydraulic assembly is connected to the confining pressure chamber cylinder. The grouting filling module passes through the confining pressure chamber cylinder and is connected to the specimen body. It realizes the multi-directional stress simulation of the specimen body, more truly reflects the stress state of the surrounding rock in the mine, improves the flexibility and adaptability of the test device, and is suitable for different types of surrounding rock specimens.

[0009] As a preferred implementation of a simulated grouting reinforcement surrounding rock penetration test device, the bottom of the confining pressure chamber cylinder is provided with a detachable mounting seat. A permeable sleeve is provided on the mounting seat for accommodating the specimen body. An upstream pore pressure pad is provided at the top of the permeable sleeve, and the top of the upstream pore pressure pad abuts against the piston rod of the axial piston.

[0010] As a preferred implementation of a simulation grouting reinforcement surrounding rock seepage test device, the confining pressure gas assembly includes a first through pipe. A first air port is provided on the barrel wall of the confining pressure chamber cylinder. One end of the first through pipe is connected to the first air port, and a pressure reducing valve seat is provided at the other end of the first air port. The pressure reducing valve seat is connected to a first gas source through a first gas transmission pipeline. A confining pressure sensor and a confining pressure closed-loop servo metering pump are provided on the first through pipe. The confining pressure sensor is arranged closer to the confining pressure chamber cylinder than the confining pressure closed-loop servo metering pump. It realizes the precise control and monitoring of the confining pressure, ensuring the accuracy of the test. Through the closed-loop servo metering pump, the automatic adjustment of the confining pressure can be realized, improving the automation level of the test.

[0011] As a preferred implementation of a simulation grouting reinforcement surrounding rock seepage test device, the axial pressure gas assembly includes a second through pipe. A second air port is provided on the barrel wall of the axial pressure chamber cylinder. One end of the second through pipe is connected to the second air port, and an axial pressure closed-loop servo metering pump is provided at the other end of the second through pipe. The axial pressure closed-loop servo metering pump is connected to a second gas source through a second gas transmission pipeline. An axial pressure sensor is provided on the second through pipe. Similarly, it realizes the precise control and monitoring of the axial pressure, ensuring the accuracy of the test. Through the axial pressure sensor, the change of the axial pressure can be monitored in real time, providing real-time data support for the test.

[0012] As a preferred implementation of a simulation grouting reinforcement surrounding rock seepage test device, the confining pressure hydraulic assembly includes a first oil transmission pipeline. One end of the first oil transmission pipeline is connected to the confining pressure closed-loop servo metering pump, and the other end of the first oil transmission pipeline is connected to a first hydraulic oil tank. A valve is provided on the first oil transmission pipeline.

[0013] As a preferred implementation of a simulation grouting reinforcement surrounding rock seepage test device, the axial pressure hydraulic assembly includes a second oil transmission pipeline. One end of the second oil transmission pipeline is connected to the axial pressure closed-loop servo metering pump, and the Lingui section of the second oil transmission pipeline is connected to a second hydraulic oil tank.

[0014] As a preferred implementation of a simulation grouting reinforcement surrounding rock seepage test device, the grouting filling module includes a grouting pipeline. One end of the grouting pipeline is communicated with the grouting chamber inside the specimen body, and a grouting pump is provided at the other end of the grouting pipeline. The grouting pump is connected to a slurry storage system through a slurry transmission pipe.

[0015] As an optimal implementation solution of a simulation grouting reinforcement surrounding rock penetration test device, a pore pressure test module is further arranged outside the permeable sleeve. The pore pressure test module includes a first connecting pipe communicated with the top of the specimen body. One end of the first connecting pipe far away from the specimen body is provided with an osmotic pressure closed-loop servo metering pump, and an upstream pore pressure sensor is arranged on the first connecting pipe; a second connecting pipe is arranged at the bottom of the confining pressure chamber cylinder, and a downstream pore pressure sensor is arranged on the second connecting pipe; a deformation detection component is further arranged in the confining pressure chamber. The deformation detection component includes a positioning ring arranged on the outer periphery of the permeable sleeve. A plurality of pressure sensors are arranged inside the positioning ring. The piezoelectric induction end of each pressure sensor faces the permeable sleeve. The piezoelectric induction end of the pressure sensor is connected with a pressing ring through a spring ring, and the pressing ring is abutted against the outer peripheral surface of the permeable sleeve. A laser ranging sensor is further arranged on the top surface of the axial pressure chamber.

[0016] On the other hand, the present invention further provides a simulation grouting reinforcement surrounding rock penetration test method, which adopts the above simulation grouting reinforcement surrounding rock penetration test device. The method includes the following steps: S1. Place the specimen body into the penetration test module, and then respectively assemble and connect the gas filling and collecting module, the hydraulic loading module and the grouting filling module with the penetration test module. S2. First, uniformly pressurize the axial pressure chamber to 0.5 MPa through the second air port and the second connecting pipe, then uniformly pressurize the confining pressure chamber to 0.3 MPa through the first air port and the first connecting pipe, and then introduce 0.2 MPa of methane to stabilize the pressure. After stabilization, close the valve structures of each pipeline to check the airtightness. If the pressure value remains unchanged for a long time, it proves that the airtightness is good. S3. Remove the mounting seat at the bottom of the confining pressure chamber, and then install the specimen body and the permeable sleeve into the confining pressure chamber cylinder through the confining pressure chamber base. Connect the first connecting pipe and the second connecting pipe to a vacuum pump and evacuate for 24 h. S4. Sequentially pressurize the axial pressure chamber and the confining pressure chamber to the set pressure value through the hydraulic loading module, and ensure that the internal pressure of the axial pressure chamber is greater than the internal pressure of the confining pressure chamber. Then, grout the specimen body inside the permeable sleeve through the grouting filling module and maintain the current pressure for a period of time. After the grouting is completed, introduce high-pressure gas again from the first air port and the first connecting pipe, and ensure that the internal pressure of the confining pressure chamber is greater than the pressure of the introduced gas. Then, maintain the current pressure for 12 h. S5. Open the second air port and the second connecting pipe for exhaust. After the flow rate tends to be stable, collect the gas pressure, calculate the gas flow rate by the steady-state method, and then evaluate the grouting effect according to the osmotic pressure.

[0017] As can be seen from the above technical solutions, the advantages of the present invention are as follows: In this solution, the grouting pump is externally connected to a slurry storage system through a slurry delivery pipe, and grouting operation is carried out on the specimen body through the grouting pipeline, which can simulate the grouting reinforcement process in the actual coal mine environment, improve the accuracy of the test, and use the upstream pore pressure sensor and the downstream pore pressure sensor to monitor the grouting pressure in real time to ensure the safety of the grouting process; This solution completes the permeability test of coal and rock during dynamic loading and the permeability test of coal and rock after grouting through the gas filling and collection module and the hydraulic loading module, and determines the change in the permeability of the surrounding rock specimen after grouting to evaluate the grouting effect, providing a basis for the optimization of grouting parameters. At the same time, the axial height change of the axial piston is detected by a laser distance sensor, and the circumferential deformation data of the specimen body is detected by a pressure sensor, so as to realize the control of axial and circumferential stress loading on the specimen during the test process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 It is a schematic structural diagram of the specific embodiment of the present invention.

[0020] Figure 2 It is a cross-sectional view of the permeability test module in the specific embodiment of the present invention.

[0021] Figure 3 It is a schematic structural diagram of the hydraulic loading module in the specific embodiment of the present invention.

[0022] Figure 4 It is a schematic structural diagram of the grouting filling module and the pore pressure test module in the specific embodiment of the present invention.

[0023] Figure 5 It is a schematic structural diagram of the specimen body in the specific embodiment of the present invention.

[0024] MAIN REFERENCE NUMERAL DESCRIPTION 1. Test support, 2. Penetration test module, 201. Axial pressure chamber cylinder, 2011. Axial pressure chamber, 2012. Top cover plate, 202. Confining pressure chamber cylinder, 2021. Confining pressure chamber, 2022. Mounting seat, 203. Axial piston, 204. Permeable sleeve, 205. Upstream pore pressure pad, 206. Specimen body, 3. Gas filling and collection module, 301. First air port, 302. First connecting pipe, 303. Confining pressure sensor, 304. Pressure reducing valve seat, 305. Confining pressure closed-loop servo metering pump, 306. First gas pipeline, 307. First gas source, 308. Second air port, 309. Second connecting pipe, 310. Axial pressure sensor, 311. Axial pressure closed-loop servo metering pump, 312. Second gas pipeline, 313. Second gas source, 4. Hydraulic loading module, 401. First oil pipeline, 402. First hydraulic oil tank, 403. Second oil pipeline, 404. Second hydraulic oil tank, 5. Grouting filling module, 501. Grouting pipeline, 502. Grouting pump, 6. Grouting chamber, 7. Pore pressure test module, 701. First connecting pipe, 702. Upstream pore pressure sensor, 703. Osmotic pressure closed-loop servo metering pump, 704. Second connecting pipe, 705. Downstream pore pressure sensor, 8. Deformation detection component, 801. Positioning ring, 802. Pressure sensor, 803. Spring ring, 804. Extrusion ring piece, 805. Laser distance measuring sensor. Detailed implementation manners

[0025] In order to make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the present invention will be clearly and completely described below in conjunction with the drawings in the specific embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in this patent, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this patent.

[0026] Embodiment 1 As Figure 1 shown, this embodiment provides a simulated grouting reinforcement surrounding rock penetration test device, including a test support 1. A penetration test module 2 is installed in the test support 1. An inner cavity for accommodating a specimen body 206 is provided in the penetration test module 2. The specimen body 206 is an ungrouted rock layer sample obtained from the surrounding rock of a roadway, and a grouting chamber 6 is opened inside the specimen body 206. As Figure 2As shown, the penetration test module includes an axial pressure chamber cylinder 201 and a confining pressure chamber cylinder 202. The axial pressure chamber cylinder 201 is located above the confining pressure chamber cylinder 202. An axial pressure chamber 2011 is provided inside the axial pressure chamber cylinder 201, and a confining pressure chamber 2021 is provided inside the confining pressure chamber cylinder 202. The specimen body 206 is located in the confining pressure chamber 2021. Specifically, a water-permeable sleeve 204 is provided on the mounting seat 2022. The water-permeable sleeve 204 is used to accommodate the specimen body 206. A clamp 207 is fixedly connected to the top of the specimen body 206, and a rubber sleeve 208 is wrapped around the outside of the specimen body 206. The top of the water-permeable sleeve 204 is provided with a communication groove between the axial pressure chamber cylinder 201 and the confining pressure chamber cylinder 202. An axial piston 203 is slidably provided in the axial pressure chamber 2011. The piston rod of the axial piston 203 passes through the communication groove and extends into the confining pressure chamber 201, and presses against the top of the upstream pore pressure pad 205.

[0027] A gas filling and collecting module 3, a hydraulic loading module 4 and a grouting filling module 5 are provided on the penetration test module 2. The gas filling and collecting module 3 and the hydraulic loading module 4 are connected to the inner cavity of the penetration test module 2, and the grouting filling module 5 is connected to the grouting chamber 6 inside the specimen body 206.

[0028] Specifically, as Figure 2 shown, the gas filling and collecting module 3 includes an axial pressure gas assembly and a confining pressure gas assembly. The axial pressure gas assembly is connected to the axial pressure chamber cylinder 201, and the confining pressure gas assembly is connected to the confining pressure chamber cylinder 202: The confining pressure gas assembly includes a first through pipe 302. A first air port 301 is provided on the barrel wall of the confining pressure chamber cylinder 202. One end of the first through pipe 302 is connected to the first air port 301. A pressure reducing valve seat 304 is provided at the other end of the first air port 301. The pressure reducing valve seat 304 is connected to a first gas source 307 through a first gas transmission pipeline 306. A confining pressure sensor 303 and a confining pressure closed-loop servo metering pump 305 are provided on the first through pipe 302. The confining pressure sensor 303 is arranged closer to the confining pressure chamber cylinder 202 than the confining pressure closed-loop servo metering pump 305; The axial pressure gas assembly includes a second through pipe 309. A second air port 308 is provided on the barrel wall of the axial pressure chamber cylinder 201. One end of the second through pipe 309 is connected to the second air port 308. The other end of the second through pipe 309 is provided with an axial pressure closed-loop servo metering pump 311. The axial pressure closed-loop servo metering pump 311 is connected to a second gas source 313 through a second gas transmission pipeline 312. An axial pressure sensor 310 is provided on the second through pipe 309.

[0029] The confining pressure closed-loop servo metering pump 305 extracts the high-pressure gas inside the first gas source 307 through the first gas pipeline 306. After adjusting the gas pressure using the pressure reducing valve seat 304, it enters the confining pressure chamber 2021 through the first through pipe 302. The confining pressure sensor 303 is used to detect the pressure data inside the confining pressure chamber 2021. Similarly, the axial pressure closed-loop servo metering pump 311 and the axial pressure sensor 310 are used to fill the axial pressure chamber 2011 with gas to adjust the pressure difference between the axial pressure chamber 2011 and the confining pressure chamber 2021, thereby completing the simulation of providing a stable gas seepage pressure for the triaxial pressure system, realizing the intelligent control and high-precision high-frequency acquisition of air pressure, providing a sealed space for pressure loading and gas seepage of coal and rock specimens, and measuring the permeability of coal and rock specimens under triaxial stress loading conditions.

[0030] The confining pressure closed-loop servo metering pump 305 and the axial pressure closed-loop servo metering pump 311 are respectively used to transport hydraulic oil to the confining pressure chamber 2021 and the axial pressure chamber 2011 to complete the axial loading control and circumferential stress loading control of the coal and rock specimens.

[0031] As Figure 4 shown, the hydraulic loading module 4 includes an axial pressure hydraulic component and a confining pressure hydraulic component. The axial pressure hydraulic component is connected to the axial pressure chamber cylinder 201, and the confining pressure hydraulic component is connected to the confining pressure chamber cylinder 202; the grouting filling module 5 passes through the confining pressure chamber cylinder 202 and is connected to the specimen body 206: the confining pressure hydraulic component includes a first oil pipeline 401. One end of the first oil pipeline 401 is connected to the confining pressure closed-loop servo metering pump 305, and the other end of the first oil pipeline 401 is connected to a first hydraulic oil tank 402. A valve is provided on the first oil pipeline 401; the axial pressure hydraulic component includes a second oil pipeline 403. One end of the second oil pipeline 403 is connected to the axial pressure closed-loop servo metering pump 311, and the Lingui section of the second oil pipeline 403 is connected to a second hydraulic oil tank.

[0032] The grouting filling module 5 includes a grouting pipeline 501. One end of the grouting pipeline 501 is communicated with the grouting chamber 6 inside the specimen body 206, and the other end of the grouting pipeline 501 is provided with a grouting pump 502. The grouting pump 502 is connected to a slurry storage system through a slurry delivery pipe.

[0033] Furthermore, a pore pressure testing module 7 is also provided outside the permeable sleeve 204. As Figure 4 shown, the pore pressure testing module 7 includes a first connecting pipe 701 communicated with the top of the specimen body 206. One end of the first connecting pipe 701 far from the specimen body 206 is provided with an osmotic pressure closed-loop servo metering pump 703, and an upstream pore pressure sensor 702 is provided on the first connecting pipe 701; a second connecting pipe 704 is provided at the bottom of the confining pressure chamber cylinder 202, and a downstream pore pressure sensor 705 is provided on the second connecting pipe 704. A deformation detection component 8 is also provided in the confining pressure chamber 2021. AsFigure 5 As shown, the deformation detection component 8 includes a positioning ring 801 arranged on the outer periphery of the permeable sleeve 204. A plurality of pressure sensors 802 are arranged inside the positioning ring 801. The piezoelectric induction end of each pressure sensor 802 faces the permeable sleeve 204. The piezoelectric induction end of the pressure sensor 802 is connected with a pressing ring piece 804 through a spring ring 803. The pressing ring piece 804 is in contact with the outer peripheral surface of the permeable sleeve 204. A laser ranging sensor 805 is further arranged on the top surface of the axial pressure chamber 2011.

[0034] The deformation detection component 8 is used to detect the axial and circumferential deformation data during the test of the coal and rock specimen, including: first, the pressing ring piece 804 is annularly attached to the outside of the permeable sleeve 204. When the specimen body 206 undergoes circumferential deformation, it will exert pressure on the pressing ring piece 804. The pressing ring piece 804 moves towards the spring ring 803 to drive the spring structure to undergo elastic deformation. At this time, the other side of the spring ring 803 is connected to the piezoelectric induction end of the pressure sensor 802. By applying pressure to the piezoelectric induction end, a piezoelectric signal will be generated inside the sensor, and then it is transmitted to an external control system through the signal processing circuit inside the sensor, so as to calculate the change in the pressure data of the permeable sleeve 204 on the pressing ring piece 804, calculate the change in the spring structure through the elastic coefficient, and thus obtain the deformation data of the specimen body 206 in the circumferential direction; Connect the top of the permeable sleeve 204 to the upstream pore pressure cushion block 205. The upstream pore pressure cushion block 205 is in contact with the bottom end of the axial piston 203. At this time, when the specimen body 206 undergoes axial deformation, it will exert pressure on the axial piston 203 through the upstream pore pressure cushion block 205. At this time, the height of the axial piston 203 changes, and then the laser ranging sensor 805 is used to detect the change data of the height of the axial piston 203, so as to obtain the deformation data of the specimen body 206 in the axial direction.

[0035] In summary, through this device, the grouting pump 502 is externally connected with a slurry storage system through a slurry delivery pipe, and the slurry injection operation is carried out on the specimen body 206 by using the grouting pipeline 501, which can simulate the grouting reinforcement process in the actual coal mine environment, improve the accuracy of the test, and use the upstream pore pressure sensor 702 and the downstream pore pressure sensor 705 to monitor the grouting pressure in real time to ensure the safety of the grouting process. And through the gas filling and collection module 3 and the hydraulic loading module 4, the permeability test of the coal and rock during the dynamic loading process and the permeability test of the coal and rock after the grouting are completed, and the change in the permeability of the surrounding rock specimen after the grouting is measured to evaluate the grouting effect, providing a basis for the optimization of the grouting parameters. At the same time, the change in the axial height of the axial piston 203 is detected by the laser ranging sensor 805, and the circumferential deformation data of the specimen body 206 is detected by the pressure sensor 802, so as to realize the control of the axial and circumferential stress loading of the specimen during the test process.

[0036] Embodiment 2 This embodiment further provides a method for simulating the penetration test of surrounding rock grouting reinforcement, using the device for simulating the penetration test of surrounding rock grouting reinforcement provided in Embodiment 1. The method includes the following steps: S1. Place the specimen body 6 into the penetration test module 2, and then assemble and connect the gas filling and collection module 3, the hydraulic loading module 4, and the grouting filling module 5 with the penetration test module 2 respectively; S2. First, uniformly pressurize the axial pressure chamber 2011 to 0.5 MPa through the second air port 308 and the second connecting pipe 309, then uniformly pressurize the confining pressure chamber 2021 to 0.3 MPa through the first air port 301 and the first connecting pipe 302, and then introduce methane at 0.2 MPa to stabilize the pressure. After stabilization, close the valve structures of each pipeline to check the airtightness. If the pressure value remains unchanged for a long time, it proves good airtightness; S3. Remove the mounting seat 2022 at the bottom of the confining pressure chamber 2021, and then install the specimen body 206 and the permeable sleeve 204 into the confining pressure chamber cylinder 202 through the confining pressure chamber base. Connect the first connecting pipe 302 and the second connecting pipe 309 to a vacuum pump to extract vacuum for 24 hours; S4. Use the hydraulic loading module 4 to pressurize the axial pressure chamber 2011 and the confining pressure chamber 2021 to the set pressure values in sequence, and ensure that the internal pressure of the axial pressure chamber 2011 is greater than the internal pressure of the confining pressure chamber 2021. Then, use the grouting filling module 5 to grout the specimen body 206 inside the permeable sleeve 204 and maintain the current pressure for a period of time. After grouting is completed, introduce high-pressure gas again from the first air port 301 and the first connecting pipe 302, and ensure that the internal pressure of the confining pressure chamber 2021 is greater than the pressure of the introduced gas, and then maintain the current pressure for 12 hours; S5. Open the second air port 308 and the second connecting pipe 309 to exhaust gas. After the flow rate tends to be stable, collect the gas pressure, calculate the gas flow rate using the steady-state method, and then evaluate the grouting effect according to the osmotic pressure.

[0037] As can be seen from the above embodiments, the beneficial effects of the present invention are as follows: in this solution, the grouting pump is externally connected to a slurry storage system through a slurry delivery pipe, and grouting operation is carried out on the specimen body through the grouting pipeline, which can simulate the grouting reinforcement process in the actual coal mine environment, improve the accuracy of the test, and use the upstream pore pressure sensor and the downstream pore pressure sensor to monitor the grouting pressure in real time to ensure the safety of the grouting process; this solution completes the permeability test of coal and rock during dynamic loading and the permeability test of coal and rock after grouting through the gas filling and collection module and the hydraulic loading module, and determines the change in the permeability of the surrounding rock specimen after grouting to evaluate the grouting effect, providing a basis for the optimization of grouting parameters. At the same time, the axial height change of the axial piston is detected by a laser distance sensor, and the circumferential deformation data of the specimen body is detected by a pressure sensor, so as to realize the axial and circumferential stress loading control of the specimen during the test process.

[0038] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A test device for simulating grouting reinforcement of surrounding rock permeability, characterized in that: The invention comprises a penetration test module (2), wherein an inner cavity for accommodating a sample body (206) is provided in the penetration test module (2), and a gas filling and collection module (3), a hydraulic loading module (4) and a grouting filling module (5) are provided on the penetration test module (2), wherein the gas filling and collection module (3) and the hydraulic loading module (4) are connected to the inner cavity of the penetration test module (2), and the grouting filling module (5) is connected to the inside of the sample body (206).

2. The simulated grouting reinforcement surrounding rock permeability test device according to claim 1 is characterized in that: The penetration test module comprises an axial pressure chamber cylinder (201) and a confining pressure chamber cylinder (202), wherein the axial pressure chamber cylinder (201) is located above the confining pressure chamber cylinder (202), an axial pressure chamber (2011) is provided inside the axial pressure chamber cylinder (201), a confining pressure chamber (2021) is provided inside the confining pressure chamber cylinder (202), a sample body (206) is located in the confining pressure chamber (2021), a connecting groove is provided between the axial pressure chamber cylinder (201) and the confining pressure chamber cylinder (202), an axial piston (203) is slidably provided in the axial pressure chamber (2011), a piston rod of the axial piston (203) passes through the connecting groove and extends into the confining pressure chamber (201), and presses against the top of the sample body (206); The gas filling and collection module (3) comprises an axial pressure gas component and a confining pressure gas component, the axial pressure gas component is connected to the axial pressure chamber cylinder (201), and the confining pressure gas component is connected to the confining pressure chamber cylinder (202); the hydraulic loading module (4) comprises an axial pressure hydraulic component and a confining pressure hydraulic component, the axial pressure hydraulic component is connected to the axial pressure chamber cylinder (201), and the confining pressure hydraulic component is connected to the confining pressure chamber cylinder (202); the grouting filling module (5) passes through the confining pressure chamber cylinder (202) and is connected to the sample body (206).

3. The simulated grouting reinforcement surrounding rock permeability test device according to claim 2 is characterized in that: The bottom of the confining pressure chamber cylinder (202) is provided with a detachable mounting seat (2022), the mounting seat (2022) is provided with a water-permeable sleeve (204), the water-permeable sleeve (204) is used to accommodate a sample body (206), and the top of the water-permeable sleeve (204) is provided with an upstream pore pressure pad (205), and the top of the upstream pore pressure pad (205) is in conflict with the piston rod of the axial piston (203).

4. The simulated grouting reinforcement surrounding rock permeability test device according to claim 3 is characterized in that: The confining pressure gas component comprises a first through pipe (302), a first gas port (301) is provided on the wall of the confining pressure chamber cylinder (202), one end of the first through pipe (302) is connected to the first gas port (301), the other end of the first gas port (301) is provided with a pressure reducing valve seat (304), the pressure reducing valve seat (304) is connected to a first gas source (307) via a first gas transmission pipeline (306), a confining pressure sensor (303) and a confining pressure closed-loop servo metering pump (305) are provided on the first through pipe (302), and the confining pressure sensor (303) is arranged close to the confining pressure chamber cylinder (202) relative to the confining pressure closed-loop servo metering pump (305).

5. The simulated grouting reinforcement surrounding rock permeability test device according to claim 4 is characterized in that: The axial pressure gas component comprises a second through pipe (309), a second gas port (308) is provided on the wall of the axial pressure chamber cylinder (201), one end of the second through pipe (309) is connected to the second gas port (308), the other end of the second through pipe (309) is provided with an axial pressure closed-loop servo metering pump (311), the axial pressure closed-loop servo metering pump (311) is connected to a second gas source (313) via a second gas pipeline (312), and an axial pressure sensor (310) is provided on the second through pipe (309).

6. The simulated grouting reinforcement surrounding rock permeability test device according to claim 5 is characterized in that: The confining pressure hydraulic assembly comprises a first oil pipeline (401), one end of the first oil pipeline (401) is connected to the confining pressure closed-loop servo metering pump (305), the other end of the first oil pipeline (401) is connected to a first hydraulic oil tank (402), and a valve is provided on the first oil pipeline (401).

7. The simulated grouting reinforcement surrounding rock permeability test device according to claim 6 is characterized in that: The axial pressure hydraulic assembly comprises a second oil pipeline (403), one end of the second oil pipeline (403) is connected to the axial pressure closed-loop servo metering pump (311), and the Lingui section of the second oil pipeline (403) is connected to a second hydraulic oil tank.

8. The simulated grouting reinforcement surrounding rock permeability test device according to claim 7 is characterized in that: The grouting filling module (5) comprises a grouting pipeline (501), one end of which is in communication with a grouting chamber (6) inside the sample body (206), and the other end of which is provided with a grouting pump (502), which is connected to a grouting storage system via a grouting pipe.

9. The simulated grouting reinforcement surrounding rock permeability test device according to claim 8 is characterized in that: A pore pressure test module (7) is also provided outside the permeable sleeve (204), and the pore pressure test module (7) comprises a first connecting pipe (701) connected to the top of the sample body (206), an osmotic pressure closed-loop servo metering pump (703) is provided at one end of the first connecting pipe (701) away from the sample body (206), and an upstream pore pressure sensor (702) is provided on the first connecting pipe (701); a second connecting pipe (704) is provided at the bottom of the confining pressure chamber cylinder (202), and a downstream pore pressure sensor (705) is provided on the second connecting pipe (704); A deformation detection component (8) is also provided in the confining pressure chamber (2021), and the deformation detection component (8) comprises a positioning ring (801) arranged on the outer periphery of the water-permeable sleeve (204), and a plurality of pressure sensors (802) are provided inside the positioning ring (801), and the piezoelectric sensing end of each of the pressure sensors (802) faces the water-permeable sleeve (204), and the piezoelectric sensing end of the pressure sensor (802) is connected to an extrusion ring sheet (804) via a spring coil (803), and the extrusion ring sheet (804) is in contact with the outer peripheral surface of the water-permeable sleeve (204), and a laser distance measuring sensor (805) is also provided on the top surface of the axial pressure chamber (2011).

10. A method for simulating grouting to reinforce surrounding rock permeability test, characterized in that: Using a simulated grouting reinforcement surrounding rock permeability test device as claimed in claim 9, the method comprises the following steps: S1. Place the sample body (6) into the permeability test module (2), and then assemble and connect the gas filling and collection module (3), the hydraulic loading module (4) and the grouting filling module (5) to the permeability test module (2); S2. First, the axial pressure chamber (2011) is pressurized to 0.5 MPa at a uniform speed through the second air port (308) and the second through pipe (309), and then the confining pressure chamber (2021) is pressurized to 0.3 MPa at a uniform speed through the first air port (301) and the first through pipe (302), and then 0.2 MPa of methane is introduced to stabilize the pressure. After stabilization, the valve structures of each pipeline are closed to check the air tightness. If the pressure value remains unchanged for a long time, it proves that the air tightness is good; S3. Remove the mounting seat (2022) at the bottom of the confining pressure chamber (2021), and then install the sample body (206) and the water-permeable sleeve (204) into the confining pressure chamber cylinder (202) through the confining pressure chamber base, and draw a vacuum for 24 hours by connecting the first through pipe (302) and the second through pipe (309) to a vacuum pump; S4. The axial pressure chamber (2011) and the confining pressure chamber (221) are pressurized to a set pressure value in sequence through the hydraulic loading module (4), and the internal pressure of the axial pressure chamber (2011) is ensured to be greater than the internal pressure of the confining pressure chamber (221). The sample body (206) inside the water-permeable sleeve (204) is then grout-treated through the grouting filling module (5) and the current pressure is maintained for a period of time. After the grouting is completed, high-pressure gas is introduced again from the first gas port (301) and the first through pipe (302), and the internal pressure of the confining pressure chamber (2021) is ensured to be greater than the pressure of the introduced gas. The current pressure is then maintained for 12 hours. S5. Open the second gas port (308) and the second through pipe (309) to exhaust gas, collect the gas pressure after the flow rate becomes stable, calculate the gas flow rate using the steady-state method, and then evaluate the grouting effect based on the osmotic pressure.

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