Rock mass fracture grouting test method for researching different grouting materials and grouting pressures

Abstract

A rock mass fracture grouting test method for researching different grouting materials and grouting pressures, specifically comprising the following steps: (I) designing and assembling a multifunction

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of engineering fluid mechanics tests, in particular to a rock mass fracture grouting test method for researching different grouting materials and grouting pressures. BACKGROUND

[0002] Nowadays, construction engineering is facing many problems caused by large or small fissures and weak joint zones in the strata. Ground engineering often encounters problems of unstable foundations and even sinking, and underground engineering (tunnel projects, coal mine projects, etc.) often encounters problems such as rock stratum seepage, excessive pressure of underground standing supports and even collapse of tunnels. The above problems can be effectively solved by using a suitable grouting technique, as a whole, grouting has two major roles:

[0003] (1) The grouting can fill pores and fractures of the rock mass microscopically so as to improve the intactness of the rock mass and enhance the strength and the stability of the rock mass. For ground engineering, the foundation can be effectively reinforced to reduce the subsidence distance of the foundation is reduced. For underground engineering, the pressure of the support can be reduced by reinforcing the rock stratum.

[0004] (2) The grouting can fill the joints and fractures of the rock strata to reduce the permeability of the surrounding rock, thus effectively reducing the discharge amount of harmful gas or water flow above the roadway.

[0005] During practical construction, due to different terrain environments, different rock stratum structures, different rock stratum depths and different rock types of the rock strata at different places, different grouting materials and different grouting processes are needed for different rock strata. While grouting parameters in the current construction are usually set according to experience without the scientific theoretical guidance, and there is a lack of more professional grouting equipment on the market, such that a comprehensive study of grouting materials and grouting process cannot be conducted, and the test data of its simulation test also lacks scientificity and accuracy.

[0006] Moreover, the grouting pressure acquisition element of the grouting instrument currently on the market is mostly arranged in the grout tank and takes the pressure in the grout tank as the grouting pressure, and the grouting flow acquisition element is also mostly arranged at the front end of the grouting pipeline, which ignores the flow and pressure loss caused by the flowing of the grout in the grouting pipeline, leading to inaccurate test data. SUMMARY

[0007] An objective of the present disclosure is to provide a rock mass fracture grouting test method for researching different grouting materials and grouting pressures. In accordance with the present disclosure, it can be ensured that correct grouting data may be acquired, the workload is small, a large amount of manpower can be saved, the test can be carried out by changing the grouting pressure, raw materials for the grout or a ratio of the materials for the grout, a constant-pressure grouting is achieved, and thus a test basis is provided for researching the flow law of the grout under constant pressure.

[0008] To achieve the objective above, the present disclosure employs the following technical solution:

[0009] The rock mass fracture grouting test method for researching different grouting materials and grouting pressures specifically comprises the following steps:

[0010] (1) designing and assembling a multi-functional rock mass fracture grouting test device, wherein the multi-functional rock mass fracture grouting test device comprises a water injection device, a constant-pressure gas injection device, a grout storage tank, a data acquisition control system, and a computer; a water injection port, a gas injection port and a pressure relief port are formed in the top of the grout storage tank; a grouting filling port with a sealing cover is formed in the upper side part of the outer side wall of the grout storage tank, and a grouting outlet and a grout drainage outlet are formed in the bottom of the grout storage tank; a water outlet of the water injection device is connected to the water injection port of the grout storage tank through a water injection pipe, and a gas outlet of the constant-pressure gas injection device is connected to the gas injection port of the grout storage tank through a gas injection pipe; a pressure relief pipe is connected to the pressure relief port of the grout storage tank, and a pressure relief valve is arranged on the pressure relief pipe; a mixing device is arranged in the grout storage tank; a grouting pipe is connected to the grouting outlet of the grout storage tank, the other end of the grouting pipe is connected to external required grouting equipment, a grout drainage pipe is connected to the grout drainage outlet of the grout storage tank, and a grout drainage valve is arranged on the grout drainage pipe; a grouting valve, a grout flowmeter and a grouting pressure gauge are sequentially arranged on the grouting pipe in a liquid flowing direction; the grouting valve is arranged at the front end of the grouting pipe, the grout flowmeter and the grouting pressure gauge are arranged at the tail end of the grouting pipe; the data acquisition control system is in signal connection with the grout flowmeter and the grouting pressure gauge, respectively; and the computer is in signal connection with the data acquisition control system;

[0011] (2) adding the grout prepared as required into the grout storage tank, and uniformly mixing the grout by the mixing device;

[0012] (3) injecting gas into the grout storage tank by the constant-pressure gas injection device to increase the pressure in the grout storage tank;

[0013] (4) when the pressure in the grout storage tank reaches the set grouting pressure, opening the grouting valve, and starting injecting the grout into the required grouting equipment;

[0014] (5) monitoring test data by the data acquisition control system at any time, and extracting the test data by the computer for research or storage;

[0015] (6) changing grouting pressure, raw materials for the grout, or a ratio of materials for the grout, repeating the step (2) to the step (5), and continuing to perform test; and

[0016] (7) after the test is completed, discharging remaining grout from the grout storage tank, and cleaning the whole system by the water injection device and the constant-pressure gas injection device, thus facilitating the next test.

[0017] The water injection device comprises a water tank, a water injection pump, and a liquid pressure regulating valve; a water outlet of the water tank is connected to a water inlet of the water injection pump by a water pumping pipe, a water outlet of the water injection pump is connected to the water injection port of the grout storage tank by the water injection pipe, the liquid pressure regulating valve is arranged on the water injection pipe, and the data acquisition control system is in signal connection with the water injection pump and the liquid pressure regulating valve, respectively.

[0018] The constant-pressure gas injection device comprises a gas pump, a gas injection valve, a pressure stabilizer, an overflow pressure regulating valve, and a gas injection pressure gauge; a gas outlet of the gas pump is connected to the gas injection port of the grout storage tank by the gas injection pipe; the gas injection valve, the pressure stabilizer, the overflow pressure regulating valve and the gas injection pressure gauge are sequentially arranged on the gas injection pipe in a gas flowing direction; and the data acquisition control system is in signal connection with the gas pump, the overflow pressure regulating valve and the gas injection pressure gauge, respectively.

[0019] The mixing device comprises a mixing motor, a mixing shaft, and mixing blades; the mixing motor is fixedly installed at the top of the grout storage tank, the mixing shaft is concentrically and vertically arranged in the grout storage tank, the upper end of the mixing shaft is rotatably installed at the center of the top of the grout storage tank, the lower end of a power shaft of the mixing motor is in coaxially transmission connection with the upper end of the mixing shaft, and the lower end of the mixing shaft is located at the lower part in the grout storage tank; a plurality of mixing blades are provided, and the mixing blades are fixedly installed on the outer circumference of the lower end part of the mixing shaft in a circumferential array manner; and the data acquisition control system is in signal connection with the mixing motor.

[0020] The data acquisition control system comprises a case and an integrated computer; the bottom of the case is fixedly supported on the ground by a rack; the integrated computer is arranged in the case , a control panel is arranged at the left side part of the front side face of the case, and a liquid crystal display screen is arranged at the upper side part of the control panel; a gas injection control switch, a water injection control switch, a mixing control switch and a main power supply control switch are arranged at the lower side part of the control panel; the integrated computer is in signal connection with the grout flowmeter, the grouting pressure gauge, the liquid pressure regulating valve, the overflow pressure regulating valve, the gas injection pressure gauge and the liquid crystal display screen, respectively; and the computer is in signal connection with the integrated computer.

[0021] The step (2) specifically comprises the following steps: opening the sealing cover, adding the grout prepared as required into the grout storage tank through the grout filling port; turning on the main power supply control switch, starting the mixing motor by the mixing control switch, driving, by the mixing motor, the mixing shaft to rotate, and driving, by the mixing shaft, the mixing blades to rotate to mix the grout, thus preventing the grout from depositing.

[0022] The step (3) specifically comprises the following steps: starting the gas pump by the gas injection control switch, opening the gas injection valve to inject gas into the grout storage tank; monitoring the internal pressure of the grout storage tank in real time by the gas injection pressure gauge, and transmitting the internal pressure to the integrated computer, then displaying, by the liquid crystal display screen, the pressure data of the gas injection pressure gauge in real time, wherein the internal pressure of the grout storage tank starts to increase.

[0023] The step (4) specifically comprises the following steps: setting, by the overflow pressure regulating valve, the gas injection pressure to be higher than the required grouting pressure, after the liquid crystal display screen displays that the internal pressure of the grout storage tank is increased to a set value, opening the grouting valve to inject the grout from the grout storage tank into the external required grouting equipment by the grouting pipe under the action of the gas injection pressure.

[0024] The step (5) specifically comprises the following steps: monitoring, by the grout flowmeter and the grouting pressure gauge, the grout flow rate and the grouting pressure in the grouting process in real time; acquiring, by the integrated computer, the test data of the grout flowmeter and the grouting pressure gauge, and extracting, by the computer the test data acquired by the integrated computer for analysis and processing, thus obtaining the change law of the pressure of the grout during injection; and storing the test data.

[0025] The step (7) specifically comprises the following steps: after the test is completed, closing the grouting valve and turning off the gas pump, and opening the pressure relief valve and the grout drainage valve to release the air pressure in the grout storage tank by the pressure relief pipe and to drain the remaining grout in the grout storage tank by the grout drainage pipe; then closing the pressure relief valve and the grout drainage valve, starting the water injection pump by the water injection control switch; injecting, by the water injection pump, a certain amount of clear water from the water tank into the grout storage tank through the water injection pipe, and then turning off the water injection pump; mixing, by the mixing blades, the clear water to clean the interior of the grout storage tank, and then opening the grouting valve and turning on the gas pump to inject the clear water from the grout storage tank into the external required grouting equipment through the grouting pipe to be completely discharged and to blow out all the remaining clear water in the grouting pipe by the gas pump, thus avoiding affecting the grout composition in the next grouting test, wherein the clear water may clean the interiors of the grouting pipe and the external required grouting equipment in the process of flowing in the grouting pipe and the external required grouting equipment; afterwards, closing the grouting valve and turning off the gas pump, starting the water injection pump; injecting, by the water injection pump, a certain amount of clear water from the water tank into the grout storage tank through the water injection pipe, then turning off the water injection pump; mixing, by the mixing device, the clear water to clean the interior of the grout storage tank, and then opening the grouting valve and turning on the gas pump to inject the clear water from the grout storage tank into the external required grouting equipment through the grouting pipe to be completely discharged and to blow out all the remaining clear water in the grouting pipe by the gas pump, thus avoiding affecting the grout composition in the next grouting test, wherein the clear water may clean the interiors of the grouting pipe and the external required grouting equipment in the process of flowing in the grouting pipe and the external required grouting equipment; and repeating the above steps for multiple times to clean the whole system, thus facilitating the next test.

[0026] Compared with the prior art, the present disclosure, the present disclosure has outstanding substantive features and significant progress. Specifically, the present disclosure has the following beneficial effects:

[0027] (1) The grout flowmeter and the grouting pressure gauge are arranged at the tail end of the grouting pipe as acquisition elements for the grouting flow rate and grouting pressure, ensuring that the correct grouting data may be acquired.

[0028] (2) As equipment control and data acquisition are integrated together by the data acquisition control system with a high integration level, automatic data acquisition can be achieved in real time with a small workload, the equipment can be controlled by only one to two persons, and a large amount of manpower can be saved.

[0029] (3) The test can be carried out by changing the grouting pressure, raw materials for the grout or a ratio of various materials for the grout, constant-pressure grouting is achieved, and thus a test basis is provided for researching the flow law of the grout under constant pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 is a schematic diagram of a visualized test system for simulating multi-type single-fracture grouting seepage in accordance with the present disclosure.

[0031] FIG. 2 is an axonometric schematic view of a visualized single fracture seepage device in accordance with the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The embodiments of the present disclosure are further described below with reference to the accompanying drawings.

[0033] As shown in FIG. 1 and FIG. 2, a rock mass fracture grouting test method for researching different grouting materials and grouting pressures specifically comprises the following steps:

[0034] (1) A multi-functional rock mass fracture grouting test device is designed and assembled. The multi-functional rock mass fracture grouting test device comprises a water injection device, a constant-pressure air injection device, a grout storage tank 1, a data acquisition control system 2, and a computer. A water injection port 3, a gas injection port 4 and a pressure relief port 5 are formed in the top of the grout storage tank 1; a grouting filling port 6 with a sealing cover is formed in the upper side part of the outer side wall of the grout storage tank 1, and a grouting outlet 7 and a grout drainage outlet 8 are formed in the bottom of the grout storage tank 1. A water outlet of the water injection device is connected to the water injection port 3 of the grout storage tank 1 through a water injection pipe 9. A gas outlet of the constant-pressure gas injection device is connected to the gas injection port 4 of the grout storage tank 1 through a gas injection pipe 10. A pressure relief pipe 11 is connected to the pressure relief port 5 of the grout storage tank 1, and a pressure relief valve 12 is arranged on the pressure relief pipe 11. A mixing device 13 is arranged in the grout storage tank 1. A grouting pipe 14 is connected to the grouting outlet 7 of the grout storage tank 1, and the other end of the grouting pipe 14 is connected to external required grouting equipment 40. A grout drainage pipe 15 is connected to the grout drainage outlet 8 of the grout storage tank 1, and a grout drainage valve 16 is arranged on the grout drainage pipe 15. A grouting valve 17, a grout flowmeter 18 and a grouting pressure gauge 19 are sequentially arranged on the grouting pipe 14 in a liquid flowing direction. The grouting valve 17 is arranged at the front end of the grouting pipe 14, the grout flowmeter 18 and the grouting pressure gauge 19 are arranged at the tail end of the grouting pipe 14. The data acquisition control system 2 is in signal connection with the grout flowmeter 18 and the grouting pressure gauge 19, respectively; and the computer is in signal connection with the data acquisition control system 2.

[0035] (2) The grout prepared as required is added into the grout storage tank 1, and is uniformly mixed by the mixing device 13.

[0036] (3) The gas is injected into the grout storage tank 1 by the constant-pressure gas injection device to increase the pressure in the grout storage tank 1.

[0037] (4) When the pressure in the grout storage tank 1 reaches the set grouting pressure, the grouting valve 17 is opened to start injecting the grout into the required grouting equipment.

[0038] (5) Test data is monitored by the data acquisition control system 2 at any time, and the test data is extracted by the computer for research or storage;

[0039] (6) The grouting pressure, raw materials for the grout, or a ratio of materials for the grout are changed, and then the step (2) to the step (5) are repeated to continue to perform test.

[0040] (7) After the test is completed, remaining grout in the grout storage tank 1 is drained, and the whole system is cleaned by the water injection device and the constant-pressure gas injection device, thus facilitating the next test.

[0041] The water injection device comprises a water tank 20, a water injection pump 21, and a liquid pressure regulating valve 22. A water outlet of the water tank 20 is connected to a water inlet of the water injection pump 21 by a water pumping pipe 23, and a water outlet of the water injection pump 21 is connected to the water injection port 3 of the grout storage tank 1 by the water injection pipe 9. The liquid pressure regulating valve 22 is arranged on the water injection pipe 9, and the data acquisition control system 2 is in signal connection with the water injection pump 21 and the liquid pressure regulating valve 22, respectively.

[0042] The constant-pressure gas injection device comprises a gas pump 24, a gas injection valve 25, a pressure stabilizer 26, an overflow pressure regulating valve 27, and a gas injection pressure gauge 28. A gas outlet of the gas pump 24 is connected to the gas injection port 4 of the grout storage tank 1 by the gas injection pipe 10. The gas injection valve 25, the pressure stabilizer 26, the overflow pressure regulating valve 27 and the gas injection pressure gauge 28 are sequentially arranged on the gas injection pipe 10 in a gas flowing direction. The data acquisition control system 2 is in signal connection with the gas pump 24, the overflow pressure regulating valve 27 and the gas injection pressure gauge 28, respectively.

[0043] The mixing device 13 comprises a mixing motor 29, a mixing shaft 30, and mixing blades 31. The mixing motor 29 is fixedly installed at the top of the grout storage tank 1, the mixing shaft 30 is concentrically and vertically arranged in the grout storage tank 1, the upper end of the mixing shaft 30 is rotatably installed at the center of the top of the grout storage tank 1, the lower end of a power shaft of the mixing motor 29 is in coaxially transmission connection with the upper end of the mixing shaft 30, and the lower end of the mixing shaft 30 is located at the lower part in the grout storage tank 1. A plurality of mixing blades 31 are provided, the mixing blades 31 are fixedly installed on the outer circumference of the lower end part of the mixing shaft 30 in a circumferential array manner. The data acquisition control system 2 is in signal connection with the mixing motor 29.

[0044] The data acquisition control system 2 comprises a case 32 and an integrated computer. The bottom of the case 32 is fixedly supported on the ground by a rack 33. The integrated computer is arranged in the case 32, a control panel 35 is arranged at the left side part of the front side face of the case 32, and a liquid crystal display screen 34 is arranged at the upper side part of the control panel 35. A gas injection control switch 36, a water injection control switch 37, a mixing control switch 38 and a main power supply control switch 39 are arranged at the lower side part of the control panel 35. The integrated computer is in signal connection with the grout flowmeter 18, the grouting pressure gauge 19, the liquid pressure regulating valve 22, the overflow pressure regulating valve 27, the gas injection pressure gauge 28 and the liquid crystal display screen 34, respectively, and the computer is in signal connection with the integrated computer.

[0045] The step (2) specifically comprises the following steps: the sealing cover is opened, the grout prepared as required is added into the grout storage tank 1 through the grout filling port 6. The main power supply control switch 39 is turned on, the mixing motor 29 is started by the mixing control switch 38, the mixing shaft 30 is driven by the mixing motor 29 to rotate, and the mixing blades 31 are driven by the mixing shaft 30 to rotate to stir the grout, thus preventing the grout from depositing.

[0046] The step (3) specifically comprises the following steps: the gas pump 24 is started by the gas injection control switch 36, the gas injection valve 25 is opened to inject gas into the grout storage tank 1; the internal pressure of the grout storage tank 1 is monitored in real time by the gas injection pressure gauge 28 and then is transmitted to the integrated computer, the pressure data of the gas injection pressure gauge 28 is displayed by the liquid crystal display screen 34 in real time, and the internal pressure of the grout storage tank 1 starts to increase.

[0047] The step (4) specifically comprises the following steps: the gas injection pressure is set, by the overflow pressure regulating valve 27, to be higher than the required grouting pressure, after the liquid crystal display screen 34 displays that the internal pressure of the grout storage tank 1 is increased to a set value, the grouting valve 17 is opened to inject the grout from the grout storage tank 1 into the external required grouting equipment 40 via the grouting pipe 14 under the action of the gas injection pressure.

[0048] The step (5) specifically comprises the following steps: the grout flow rate and the grouting pressure in the grouting process are monitored in real time by the grout flowmeter 18 and the grouting pressure gauge 19. The integrated computer is configured to acquire test data of the grout flowmeter 18 and the grouting pressure gauge 19, and the computer is configured to extract the test data collected by the integrated computer for analysis and processing, thus obtaining the change law of pressure of the grout during injection, and to store the test data.

[0049] The step (7) specifically comprises the following steps: after the test is completed, the grouting valve 17 is closed and the gas pump 24 is turned off, and the pressure relief valve 12 and the grout drainage valve 16 are opened to release the air pressure in the grout storage tank 1 by the pressure relief pipe 11 and to drain the remaining grout in the grout storage tank 1 by the grout drainage pipe 15. Afterwards, the pressure relief valve 12 and the grout drainage valve 16 are closed, the water injection pump 21 is started by the water injection control switch 37 to inject a certain amount of clear water from the water tank 20 into the grout storage tank 1 through the water injection pipe 9, and then the water injection pump 21 is turned off. The clear water is mixed by the mixing blades 31 to clean the interior of the grout storage tank 1, and then the grouting valve 17 is opened and the gas pump 24 is turned on to inject the clear water from the grout storage tank 1 into the external required grouting equipment 40 through the grouting pipe 14 to be completely discharged and to blow out all the remaining clear water in the grouting pipe 14 by the gas pump 24, thus avoiding affecting the grout composition in the next grouting test, wherein the clear water may clean the interiors of the grouting pipe 14 and the external required grouting equipment 40 in the process of flowing in the grouting pipe 14 and the external required grouting equipment 40. Subsequently, the grouting valve 17 is closed and the gas pump 24 are turned off, the water injection pump 21 is started to inject a certain amount of clear water from the water tank 20 into the grout storage tank 1 through the water injection pipe 9, and then the water injection pump 21 is turned off. The clear water is mixed by the mixing device 13 to clean the interior of the grout storage tank 1, and then the grouting valve 17 is opened and the gas pump 24 is turned on to inject the clear water from the grout storage tank 1 into the external required grouting equipment 40 through the grouting pipe 14 to be completely discharged and to blow out all the remaining clear water in the grouting pipe 14 by the gas pump 24, thus avoiding affecting the grout composition in the next grouting test, wherein the clear water may clean the interiors of the grouting pipe 14 and the external required grouting equipment 40 in the process of flowing in the grouting pipe 14 and the external required grouting equipment 40. The above operations are repeated for multiple times to clean the whole system, thus facilitating the next test.

[0050] The computer and the integrated computer both are not shown in the figures.

[0051] The present disclosure has the following beneficial effects:

[0052] (1) The grout flowmeter 18 and the grouting pressure gauge 19 are arranged at the tail end of the grouting pipe 14 as acquisition elements for the grouting flow rate and grouting pressure, ensuring that the correct grouting data may be acquired.

[0053] (2) As equipment control and data acquisition are integrated together by the data acquisition control system 2 with a high integration level, automatic data acquisition can be achieved in real time with a small workload, the equipment can be controlled by only one to two persons, and a large amount of manpower can be saved.

[0054] (3) The test can be carried out by changing the grouting pressure, raw materials for the grout or a ratio of various materials for the grout, constant-pressure grouting is achieved, and thus a test basis is provided for researching the flow law of the grout under constant pressure.

[0055] The above embodiments are only used to illustrate rather than limiting the technical solution of the present disclosure. Although the present disclosure is described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that modifications or equivalent substitutions may still be made to the present disclosure, and any modifications or partial substitutions without departing from disclosure.

Claims

1. A rock mass fracture grouting test method for researching different grouting materials and grouting pressures, comprising the following steps:(1) designing and assembling a multi-functional rock mass fracture grouting test device, wherein the multi-functional rock mass fracture grouting test device comprises a water injection device, a constant-pressure gas injection device, a grout storage tank, a data acquisition control system, and a computer; a water injection port, a gas injection port and a pressure relief port are formed in the top of the grout storage tank; a grouting filling port with a sealing cover is formed in the upper side part of the outer side wall of the grout storage tank, and a grouting outlet and a grout drainage outlet are formed in the bottom of the grout storage tank; a water outlet of the water injection device is connected to the water injection port of the grout storage tank through a water injection pipe; a gas outlet of the constant-pressure gas injection device is connected to the gas injection port of the grout storage tank through a gas injection pipe; a pressure relief pipe is connected to the pressure relief port of the grout storage tank, and a pressure relief valve is arranged on the pressure relief pipe; a mixing device is arranged in the grout storage tank; a grouting pipe is connected to the grouting outlet of the grout storage tank, the other end of the grouting pipe is connected to external required grouting equipment, a grout drainage pipe is connected to the grout drainage outlet of the grout storage tank, and a grout drainage valve is arranged on the grout drainage pipe; a grouting valve, a grout flowmeter and a grouting pressure gauge are sequentially arranged on the grouting pipe in a liquid flowing direction; the grouting valve is arranged at the front end of the grouting pipe, the grout flowmeter and the grouting pressure gauge are arranged at the tail end of the grouting pipe; the data acquisition control system is in signal connection with the grout flowmeter and the grouting pressure gauge, respectively; and the computer is in signal connection with the data acquisition control system;(2) adding the grout prepared as required into the grout storage tank, and uniformly mixing the grout by the mixing device;(3) injecting gas into the grout storage tank by the constant-pressure gas injection device to increase the pressure in the grout storage tank;(4) when the pressure in the grout storage tank reaches the set grouting pressure, opening the grouting valve, and starting injecting the grout into the required grouting equipment;(5) monitoring test data by the data acquisition control system at any time, and extracting the test data by the computer for research or storage;(6) changing grouting pressure, raw materials for the grout, or a ratio of materials for the grout, repeating the step (2) to the step (5), and continuing to perform test; and(7) after the test is completed, discharging remaining grout from the grout storage tank, and cleaning the whole system by the water injection device and the constant-pressure gas injection device, thus facilitating the next test.

2. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 1, wherein the water injection device comprises a water tank, a water injection pump, and a liquid pressure regulating valve; a water outlet of the water tank is connected to a water inlet of the water injection pump by a water pumping pipe, a water outlet of the water injection pump is connected to the water injection port of the grout storage tank by the water injection pipe, the liquid pressure regulating valve is arranged on the water injection pipe, and the data acquisition control system is in signal connection with thewater injection pump and the liquid pressure regulating valve, respectively.

3. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 2, wherein the constant-pressure gas injection device comprises a gas pump, a gas injection valve, a pressure stabilizer, an overflow pressure regulating valve, and a gas injection pressure gauge; a gas outlet of the gas pump is connected to the gas injection port of the grout storage tank by the gas injection pipe; the gas injection valve, the pressure stabilizer, the overflow pressure regulating valve and the gas injection pressure gauge are sequentially arranged on the gas injection pipe in a gas flowing direction; and the data acquisition control system is in signal connection with the gas pump, the overflow pressure regulating valve and the gas injection pressure gauge, respectively.

4. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 3, wherein the mixing device comprises a mixing motor, a mixing shaft, and mixing blades; the mixing motor is fixedly installed at the top of the grout storage tank, the mixing shaft is concentrically and vertically arranged in the grout storage tank, the upper end of the mixing shaft is rotatably installed at the center of the top of the grout storage tank, the lower end of a power shaft of the mixing motor is in coaxially transmission connection with the upper end of the mixing shaft, and the lower end of the mixing shaft is located at the lower part in the grout storage tank; a plurality of mixing blades are provided, and the mixing blades are fixedly installed on the outer circumference of the lower end part of the mixing shaft in a circumferential array manner; and the data acquisition control system is in signal connection with the mixing motor.

5. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 4, wherein the data acquisition control system comprises a case and an integrated computer; the bottom of the case is fixedly supported on the ground by a rack; the integrated computer is arranged in the case , a control panel is arranged at the left side part of the front side face of the case, and a liquid crystal display screen is arranged at the upper side part of the control panel; a gas injection control switch, a water injection control switch, a mixing control switch and a main power supply control switch are arranged at the lower side part of the control panel; the integrated computer is in signal connection with the grout flowmeter, the grouting pressure gauge, the liquid pressure regulating valve, the overflow pressure regulating valve, the gas injection pressure gauge and the liquid crystal display screen, respectively; and the computer is in signal connection with the integrated computer.

6. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 5, wherein the step (2) specifically comprises the following steps: opening the sealing cover, adding the grout prepared as required into the grout storage tank through the grout filling port; turning on the main power supply control switch, starting the mixing motor by the mixing control switch, driving, by the mixing motor, the mixing shaft to rotate, and driving, by the mixing shaft, the mixing blades to rotate to mix the grout, thus preventing the grout from depositing.

7. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 5, wherein the step (3) specifically comprises the following steps: starting the gas pump by the gas injection control switch, opening the gas injection valve to inject gas into the grout storage tank; monitoring the internal pressure of the grout storage tank in real time by the gas injection pressure gauge, and transmitting the internal pressure to the integrated computer, then displaying, by the liquid crystal display screen, thepressure data of the gas injection pressure gauge in real time, wherein the internal pressure of the grout storage tank starts to increase.

8. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 5, wherein the step (4) specifically comprises the following steps: setting, by the overflow pressure regulating valve, the gas injection pressure to be higher than the required grouting pressure, after the liquid crystal display screen displays that the internal pressure of the grout storage tank is increased to a set value, opening the grouting valve to inject the grout from the grout storage tank into the external required grouting equipment by the grouting pipe under the action of the gas injection pressure.

9. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 5, wherein the step (5) specifically comprises the following steps: monitoring, by the grout flowmeter and the grouting pressure gauge, the grout flow rate and the grouting pressure in the grouting process in real time; acquiring, by the integrated computer, the test data of the grout flowmeter and the grouting pressure gauge, and extracting, by the computer the test data acquired by the integrated computer for analysis and processing, thus obtaining the change law of the pressure of the grout during injection; and storing the test data.

10. The rock mass fracture grouting test method for researching different grouting materials and grouting pressures according to claim 5, wherein the step (7) specifically comprises the following steps: after the test is completed, closing the grouting valve and turning off the gas pump, and opening the pressure relief valve and the grout drainage valve to release the air pressure in the grout storage tank by the pressure relief pipe and to drain the remaining grout in the grout storage tank by the grout drainage pipe; then closing the pressure relief valve and the grout drainage valve, starting the water injection pump by the water injection control switch; injecting, by the water injection pump, a certain amount of clear water from the water tank into the grout storage tank through the water injection pipe, and then turning off the water injection pump; mixing, by the mixing blades, the clear water to clean the interior of the grout storage tank, and then opening the grouting valve and turning on the gas pump to inject the clear water from the grout storage tank into the external required grouting equipment through the grouting pipe to be completely discharged and to blow out all the remaining clear water in the grouting pipe by the gas pump, thus avoiding affecting the grout composition in the next grouting test, wherein the clear water is able to clean the interiors of the grouting pipe and the external required grouting equipment in the process of flowing in the grouting pipe and the external required grouting equipment; afterwards, closing the grouting valve and turning off the gas pump, starting the water injection pump; injecting, by the water injection pump, a certain amount of clear water from the water tank into the grout storage tank through the water injection pipe, then turning off the water injection pump; mixing, by the mixing device, the clear water to clean the interior of the grout storage tank, and then opening the grouting valve and turning on the gas pump to inject the clear water from the grout storage tank into the external required grouting equipment through the grouting pipe to be completely discharged and to blow out all the remaining clear water in the grouting pipe by the gas pump, thus avoiding affecting the grout composition in the next grouting test, wherein the clear water is able to clean the interiors of the grouting pipe and the external required grouting equipment in the process of flowing in the grouting pipe and the external required grouting equipment; and repeating the above steps for multiple times to clean the whole system, thus facilitating the next test.

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