True triaxial rock-soil mass test device and test method therefor

Abstract

A true triaxial rock-soil mass test device and a test method therefor, the test device comprising a triaxial loading module, wherein the triaxial loading module comprises a triaxial servo loading system and a triaxial bearing system, the triaxial servo loading system being configured to apply an X-direction pressure, an Y-direction pressure and a Z-direction pressure to the triaxial bearing system; a grouting module, wherein the grouting module is connected to a grouting fracturing pipe (13) in the triaxial bearing system by means of a pipeline; a hydraulic cracking module, wherein the hydraulic cracking module is connected to the grouting fracturing pipe (13) in the triaxial bearing system by means of a pipeline; and a data acquisition and analysis module, wherein the data acquisition and analysis module is connected to an ultrasonic transmitting sensor and an ultrasonic receiving sensor in the triaxial bearing system by means of a line. With the test method using the test device, triaxial grouting tests and triaxial hydraulic cracking tests can be performed, a true triaxial hydraulic cracking and grouting test on a complete rock mass can be performed, and a true triaxial grouting test on a loose mass can also be performed.

Description

A true triaxial rock and soil test device and test method thereof Technical Field

[0001] The present invention relates to the technical field of mining engineering test devices, in particular to a true triaxial rock and soil test device and a test method thereof. Background Art

[0002] With the development of my country's economy, the demand for energy is increasing. Coal, the primary energy source, is being mined at deeper depths. Deep rock masses are subject to high stress, and this stress concentration leads to severe rock fragmentation. Grouting technology is a direct and effective means of engineering reinforcement and leak prevention. Hydraulic fracturing is a powerful measure for pressure-relief mining, gas extraction, and surrounding rock maintenance. Prior to specific construction, relevant experiments are required to ensure safety and accuracy. In-situ field testing is difficult due to equipment limitations. Therefore, laboratory testing of deep rock masses is the most economical and reasonable approach. The existing related patent (1) (patent number: CN115308043A) provides a temperature-variable experimental system for splitting grouting, which simulates the formation temperature by heating the slurry and rock blocks. The main research is the splitting grouting problem. However, the current grouting method is still mainly based on permeation grouting. The test system cannot provide grouting and pressurization for the fragmented body at the same time, making the experimental object relatively single and having certain limitations. Patent (2) (patent number: CN111638171B) provides a three-dimensional loaded rock splitting grouting system. , it is considered to splice regular small rock blocks into large regular rock masses with cracks, but the data show that most cracks are unevenly distributed and the rock masses are anisotropic, and the influence of larger-scale fragmented grouting and stress environment on the grouting effect should be considered; Patent (3) (patent number: CN109882183B) provides a grouting experimental device for water-rich loose broken coal rock mass, but the triaxial pressurization method used is a pseudo triaxial method, which cannot well simulate the actual conditions of the stratum and the influence of the confining pressure difference on the grouting diffusion range and reinforcement effect in the experiment.

[0003] However, in terms of functionality, most of the current rock mass experimental equipment is single triaxial grouting or triaxial hydraulic fracturing equipment, and the experimental equipment has single functionality; in terms of rock mass integrity, most of the current equipment is intact rock mass of standard specimens, and there are few equipment that can perform triaxial hydraulic fracturing and grouting tests on intact rock masses, as well as grouting tests for loose body triaxial tests. The adaptability of the experimental equipment to rock masses is poor; in terms of loose body grouting equipment, most experimental methods use open surfaces without pressurization, false triaxial, etc., which leads to large discrepancies between the experiment and the engineering site and reduced persuasiveness of the experimental results.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide a true triaxial rock and soil testing device and a testing method thereof to solve the problems existing in the above-mentioned prior art. It is capable of performing triaxial grouting and triaxial hydraulic fracturing tests, and can perform true triaxial hydraulic fracturing and grouting tests on intact rock masses, as well as grouting tests for true triaxial tests on loose bodies.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a true triaxial rock and soil test device, comprising a triaxial loading module, wherein the triaxial loading module comprises a triaxial servo loading system and a three-axis bearing system, wherein the three-axis servo loading system is used to apply pressure in the X, Y and Z directions to the three-axis bearing system; a grouting module, wherein the grouting module is connected to a grouting and fracturing pipe in the three-axis bearing system through a pipeline; a hydraulic fracturing module, wherein the hydraulic fracturing module is connected to the grouting and fracturing pipe in the three-axis bearing system through a pipeline; and a data acquisition and analysis module, wherein the data acquisition and analysis module is connected to an ultrasonic transmitting sensor and a receiving sensor in the three-axis bearing system through a line.

[0008] Optionally, the three-axis load-bearing system includes a cubic structure surrounded by a plurality of pressure plates, the three-axis load-bearing system is provided with a three-bearing pressure chamber, the pressure plates are fixed on the positioning grooves in the fixed square frame; a grouting fracturing hole is provided at the center of the pressure plate in the X-axis direction, and a grouting fracturing pipe is passed through the grouting fracturing hole; a feed port is provided on the pressure plate in the Z-axis direction, and a sealing plug is fixedly sealed at the feed port; the three-axis servo loading system includes an X-axis cylinder, a Y-axis cylinder and a Z-axis cylinder, the X-axis cylinder, the Y-axis cylinder and the Z-axis cylinder are respectively connected to an X-axis servo loading pump, a Y-axis servo loading pump and a Z-axis servo loading pump through pipelines, the X-axis servo loading pump, The Y-axis servo loading pump and the Z-axis servo loading pump are externally connected to the main oil pump through pipelines; a base is provided at the bottom of the three-axis bearing system, and a longitudinal limit frame is provided outside the three-axis bearing system. The longitudinal limit frame includes a top plate horizontally arranged on the top of the three-axis bearing system, and vertical plates are fixed at both ends of the top plate. The bottom of the vertical plate is fixed on the base. The outer ring of the three-axis bearing system is provided with a transverse limit frame with a square cross-section, and the bottom of the transverse limit frame is connected to the base through a lifting bracket; the X-axis cylinder is fixed on the transverse limit frame, and the Y-axis cylinder and the Z-axis cylinder are respectively fixed on the longitudinal limit frame, and a groove is provided on the upper surface of the base.

[0009] Optionally, the grouting module includes a slurry mixing and stirring tank; a pre-buried grouting and fracturing pipe is provided in the three-bearing pressure chamber, the pre-buried grouting and fracturing pipe is connected to one end of the grouting and fracturing pipe through a first switch, and the end of the grouting and fracturing pipe away from the first switch is connected to the slurry mixing and stirring tank through a pipeline and a second switch; the slurry mixing and stirring tank is connected to a high-pressure air storage pump through a pipeline and a third switch.

[0010] Optionally, the hydraulic fracturing module includes a pressurized water storage tank; the end of the grouting fracturing pipe away from the first switch is connected to the pressurized water storage tank through a pipeline and the second switch; the pressurized water storage tank is connected to the high-pressure air storage pump through a pipeline and a third switch; the second switch and the third switch are both three-way switches, and the second switch and the third switch both have three-speed knobs, the middle speed is the closed speed, and turning it left can open the fracturing line connected to the pressurized water storage tank, and turning it right can open the grouting line connected to the slurry mixing tank; an electronic flow meter is installed at the outlet of the second switch, and a pressure regulating valve is installed at the outlet of the third switch.

[0011] Optionally, the data acquisition module includes an ultrasonic probe, an ultrasonic transmitter and receiver, a flow meter, an operating system, and a data storage center; the ultrasonic probe array is embedded in the pressure plate opposite to the Y-axis in the three-bearing pressure chamber, and the ultrasonic transmitting sensor and the receiving sensor are transmitted to the data processing center via the line, and the processed data is transmitted to the data storage center via the line; the operating system can control the pressure of the X-axis servo loading pump, the Y-axis servo loading pump and the Z-axis servo loading pump, can collect ultrasonic data and form images, set the injection pressure, and collect cumulative injection flow data.

[0012] Optionally, the sealing plug includes a thread, a hexagonal groove, a sealing ring, and a rigid sealing plug; the rigid sealing plug has the hexagonal groove on the top, the thread is engraved on the upper part of the outer wall of the rigid sealing plug, two circles of grooves are engraved on the lower part of the outer wall of the rigid sealing plug, the grooves are filled with sealing rings, the rigid sealing plug has a hexagonal groove on the top, and a hexagonal tensioning wrench can be clamped in the hexagonal groove.

[0013] Optionally, the hexagonal tensioning wrench includes a rigid body, a rotating handle is fixedly connected to the top of the rigid body, and a hexagonal protrusion is fixedly provided at the bottom of the rigid body, and the hexagonal protrusion can be snapped into the hexagonal groove.

[0014] The present invention also provides a test method for a true triaxial rock and soil test device, including a bulk grouting test method, wherein the bulk grouting test method comprises the following steps:

[0015] S1, configure the broken pieces that meet the actual site conditions, test the operation of the test device, and ensure that the test device can operate stably and safely;

[0016] S2. Use a hexagonal tension wrench to unscrew and remove the sealing plug of the top feed port. At the same time, fix the pre-buried grouting and fracturing pipe to the grouting and fracturing hole with screws, and connect the first switch to the grouting and fracturing pipe externally. Load the six pressure plates on the three-axis bearing cavity to the initial position to keep the bearing cavity sealed and ensure that the crushed material will not be squeezed out during the pressurization process.

[0017] S3, conveying the prepared loose material into the three-axis bearing cavity through the feed port until the loose material fills the entire cavity, and then tightening the sealing plug with a hexagonal tensioning wrench to block the feed port and seal the cavity;

[0018] S4, preparing the required slurry in the slurry mixing and stirring tank according to the preset slurry ratio, and sealing the slurry mixing and stirring tank after the preparation is completed, and the slurry mixing and stirring tank is not shut down during the process;

[0019] S5, load the three-axis bearing cavity to the preset pressure, turn on the high-pressure air storage pump, make the gas storage pressure of the high-pressure air storage pump greater than the preset grouting pressure, turn the third switch clockwise to allow the high-pressure gas to pass through the slurry mixing tank, turn the second switch clockwise to start grouting, and turn on the ultrasonic wave to collect data during the grouting process;

[0020] S6, after the slurry flow rate drops to the set range, the grouting experiment is completed, the first switch is turned off, the ultrasonic acquisition system is turned off, the high-pressure air storage pump is turned off in sequence, the third switch, the slurry mixing tank, and the second switch are turned off, the grouting fracturing pipe is removed, and the pipe and grouting mixing tank are cleaned;

[0021] S7, after the grouting of the broken and bulked body, the pressure is maintained in the three-axis bearing cavity for a required time, and then the three-axis bearing cavity is depressurized, the pressure plates in the X-axis and Y-axis directions are retracted, and the horizontal limiting frame is moved into the groove of the base using the lifting bracket to remove the broken and bulked body;

[0022] S8, after taking out the broken reinforcement, clean the three-axis bearing cavity and reset the device to its original state for the next experiment.

[0023] The test method of the present invention also includes a complete rock mass hydraulic fracturing test method, which includes the following steps:

[0024] S1: Prepare a complete rock mass or rock mass similar to the actual site, test the operation of the test device, ensure that the test device can operate stably and safely, and lower the lateral restraining frame to facilitate the loading of the specimen;

[0025] S2: Pre-buried grouting pipe. Drill a hole in the center of the intact rock mass and fix the pre-buried grouting fracturing pipe in the hole with epoxy resin glue. When prefabricating similar rock mass, directly bury the pre-buried grouting pipe. Load the specimen, raise the transverse restraining frame to the initial height, extend the X-axis bearing plate to the initial position, ensure that the pre-buried grouting fracturing pipe passes through the grouting fracturing hole, connect it to the first switch, and keep the first switch in the open state. Load the six-sided pressure bearing plates of the three-axis bearing cavity to the initial position.

[0026] S3: After filling the pressure water storage tank with water for fracturing, keep it sealed, apply triaxial pressure to the preset pressure, turn on the high-pressure gas storage pump, make the gas pressure in the high-pressure gas storage pump greater than the preset fracturing pressure, set the flow rate of fracturing water, turn the third switch counterclockwise to allow high-pressure gas to pass through the pressure water storage tank, turn the second switch counterclockwise to start fracturing, and simultaneously turn on the ultrasonic wave to collect data during the grouting process;

[0027] S4, when the fracturing pressure drops suddenly, the fracturing is completed, and the test ends, the first switch is closed, the ultrasonic acquisition system is closed, and the high-pressure air storage pump, the third switch, and the second switch are closed in sequence;

[0028] S5, saving the data collected during the test, unloading the triaxial pressure, retracting the bearing plate in the X-axis direction, removing the pre-buried grouting fracturing tube from the grouting fracturing hole, moving the transverse restraining frame into the groove of the base using the lifting bracket, and removing the fractured rock mass;

[0029] S6, remove the fractured rock mass, clean the three-axis bearing cavity, and reset the test device to its original state for the next experiment.

[0030] Compared with the prior art, the present invention has achieved the following technical effects:

[0031] The present invention provides a true triaxial rock test device with grouting and hydraulic fracturing functions, which provides a test method that is more in line with engineering practice for fracturing and grouting of intact and fragmented rock masses. On the basis of a true triaxial testing machine, a grouting module and a hydraulic fracturing module are integrated to form a multifunctional rock true triaxial testing machine, which has the advantages of complete functions, wide application, and strong operability. A feed port is set at the top, and fragmented rock can be poured into the sealed triaxial cavity, and triaxial tests and grouting tests of the fragmented rock can be carried out, making the equipment more applicable and fully functional. A detachable grouting and fracturing pipe is set, which can maintain pressure after grouting is completed, avoiding changes in the rock stress environment and causing a decrease in the credibility of the test and the site. It has the advantages of stability, reliability, and strong practicality. In terms of monitoring means, ultrasonic monitoring equipment is used, which has the advantages of being non-destructive, accurate, and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] FIG1 is a diagram showing the overall structural arrangement of the present invention;

[0034] Figure 2 is a top view of the three-axis bearing cavity;

[0035] Figure 3 is a left view of the three-axis bearing cavity;

[0036] Figure 4 is a front view of the three-axis bearing cavity;

[0037] Figure 5 is an enlarged view of the hexagonal tensioning wrench and the sealing plug;

[0038] Figure 6 is an enlarged view of the vicinity of the grouting fracturing hole;

[0039] FIG7 is an enlarged view of the second switch;

[0040] FIG8 is an enlarged view of the third switch;

[0041] In the figure: 1-base; 2-lateral limiting frame; 3-pressure plate; 4-shaped square frame; 5-longitudinal limiting frame; 6-hexagonal tensioning wrench; 7-sealing plug; 8-feeding port; 9-loading oil cylinder; 10-lifting bracket; 11-embedded grouting and fracturing pipe; 12-first switch; 13-grouting and fracturing pipe; 14-base groove; 15-second switch; 16-slurry mixing tank; 17-pressure water storage tank; 18-third switch; 19-high-pressure air storage pump; 20-main oil pump; 21-X-axis servo loading pump; 22-Y-axis servo loading pump; 23-Z-axis servo loading pump; 2 4-Data storage center; 25-Operation integrated control center; 26-Turn handle; 27-Rigid body; 28-Hexagonal protrusion; 29-Hexagonal groove; 30-Rigid sealing plug; 31-Thread; 32-Sealing ring; 33-X-axis pressure plate with grouting and fracturing hole; 34-Sealing connector; 35-Second switch outlet; 36-Electronic flowmeter; 37-Second switch knob; 38-Slurry inlet; 39-High-pressure water inlet; 40-Slurry mixing tank interface; 41-Pressure water storage tank interface; 42-Third switch knob; 43-High-pressure gas inlet; 44-Pressure regulating valve. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] The purpose of the present invention is to provide a true triaxial rock and soil testing device and a testing method thereof to solve the problems existing in the above-mentioned prior art. It is capable of performing triaxial grouting and triaxial hydraulic fracturing tests, and can perform true triaxial hydraulic fracturing and grouting tests on intact rock masses, as well as grouting tests for true triaxial tests on loose bodies.

[0044] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Currently, most rock mass testing equipment consists of single triaxial grouting or triaxial hydraulic fracturing equipment, with limited functionality. These equipment typically tests intact rock masses with standard specimens. Few can perform both triaxial hydraulic fracturing and grouting tests on intact rock masses and triaxial tests on loose bodies. Consequently, these equipment exhibits poor adaptability to rock masses. For loose body grouting equipment, most often employ methods such as open-face, unpressurized, and pseudo-triaxial testing, leading to significant discrepancies between the experimental results and the actual project, reducing the persuasiveness of the experimental results. Regarding triaxial grouting equipment, the sealing properties of triaxial testing currently prevent the grouting and fracturing pipes from being disassembled, making pressure-maintained grouting impossible. The rock mass must be removed, and after the grouting and fracturing pipes are removed, the rock mass placed in a triaxial stress environment to maintain pressure. However, in relatively fragmented rock masses, the grouting slurry has not yet solidified and cannot be removed. Once it solidifies and is removed, the grouting pipes become clogged, making cleaning difficult and unsustainable.

[0046] Based on the defects of the above-mentioned prior art, the present invention provides a true triaxial rock and soil testing device, as shown in Figures 1, 2, 3, 4, 5, 6, 7 and 8, which includes a triaxial loading module, a grouting module, a hydraulic fracturing module, and a data acquisition and analysis module. The triaxial loading module includes a triaxial servo loading system and a three-axis load-bearing system. The three-axis servo loading system is used to apply pressure in the X, Y and Z directions to the pressure plate of the three-axis load-bearing system; the grouting module and the hydraulic fracturing module are respectively connected to the grouting and fracturing pipe 13 in the three-axis load-bearing system through pipelines; the data analysis and acquisition module is connected to the ultrasonic transmitting sensor and receiving sensor in the three-axis load-bearing system through lines.

[0047] Specifically, the three-axis bearing system of the present invention includes a cubic structure surrounded by multiple pressure plates 3, in which a three-bearing pressure cavity is formed. The pressure plates 3 are fixed on the positioning grooves in the fixed square frame 4, and the sides of the pressure plates 3 are provided with rubber sealing strips; a grouting fracturing hole is opened in the center of the pressure plate 3 in the X-axis direction, forming an X-axis pressure plate 33 with a grouting fracturing hole, and a sealing connector 34 is provided at the opening of the X-axis pressure plate 33 with a grouting fracturing hole to ensure the sealing performance of the opening, and a grouting fracturing pipe 13 is passed through the grouting fracturing hole; A feed port 8 is provided on the pressure plate in the axial direction, and a sealing plug 7 is fixedly sealed at the feed port 8. The sealing plug 7 includes a thread 31, a hexagonal groove 29, a sealing ring 32, and a rigid sealing plug 30; a hexagonal groove 29 is provided on the top of the rigid sealing plug 30, a thread 31 is engraved on the upper part of the outer wall of the rigid sealing plug 30, and two circles of grooves are engraved on the lower part of the outer wall of the rigid sealing plug 30. The groove is sleeved and filled with a sealing ring 32, and a hexagonal groove 29 is provided on the top of the rigid sealing plug 30, and the hexagonal groove 29 can be clamped in the hexagonal tensioning wrench 6. The hexagonal tensioning wrench 6 includes a rigid body 27, a rotating handle 26 is fixedly connected to the top of the rigid body 27, and a hexagonal protrusion 28 is fixedly provided at the bottom of the rigid body 27, and the hexagonal protrusion 28 can be snapped into the hexagonal groove 29; the three-axis servo loading system includes a loading cylinder 9, and the loading cylinder 9 includes an X-axis cylinder, a Y-axis cylinder and a Z-axis cylinder. The X-axis cylinder, the Y-axis cylinder and the Z-axis cylinder are respectively connected to the X-axis servo loading pump 21, the Y-axis servo loading pump 22 and the Z-axis servo loading pump 23 through pipelines, and the X-axis servo loading pump 21, the Y-axis servo loading pump 22 and the Z-axis servo loading pump 23 are connected to the main oil pump 20 through pipelines; a base 1 is provided at the bottom of the three-axis loading system, and a longitudinal limit is provided on the outer cover of the three-axis loading system Frame 5, the longitudinal limiting frame 5 includes a top plate horizontally arranged on the top of the three-axis load-bearing system, vertical plates are fixed at both ends of the top plate, and the bottom of the vertical plate is fixed on the base 1. The outer ring of the three-axis load-bearing system is provided with a transverse limiting frame 2 with a mouth-shaped cross-section. The bottom of the transverse limiting frame 2 is connected to the base 1 through a lifting bracket 10, the lower part of the lifting bracket 10 is connected to the base 1, and the top is connected to the transverse limiting frame 2. A lifting bracket 10 is distributed at each of the four corners, and the lifting bracket 10 can be lifted and lowered simultaneously, and the lifting amplitude is consistent; the X-axis cylinder is fixed on the transverse limiting frame 2, and the Y-axis cylinder and the Z-axis cylinder are respectively fixed on the longitudinal limiting frame 5. The upper surface of the base 1 is provided with a base groove 14, which can be clamped with the bottom of the transverse limiting frame 2.

[0048] The grouting module includes a slurry mixing and stirring tank 16; a pre-buried grouting and fracturing pipe 11 is provided in the three-bearing pressure chamber, and the pre-buried grouting and fracturing pipe 11 is connected to the first switch 12 interface through a pipe thread, and the other end interface of the first switch 12 is connected to the grouting and fracturing pipe 13 through a threaded interface, and the end of the grouting and fracturing pipe 13 away from the first switch 12 is connected to the slurry mixing and stirring tank 16 through a pipeline and a second switch 15; the slurry mixing and stirring tank 16 is connected to a high-pressure air storage pump 19 through a pipeline and a third switch 18; the hydraulic fracturing module includes a pressure water storage tank 17; the end of the grouting and fracturing pipe away from the first switch is connected to the pressure water storage tank 17 through a pipeline and a second switch; the pressure water storage tank 17 is connected to the high-pressure air storage pump 19 through a pipeline and the third switch; the second switch 15 and the third switch 18 are both three-way The switch is connected to the slurry mixing tank 16 and the pressure water storage tank 17 through the slurry inlet 38 and the high-pressure water inlet 39 respectively. The third switch 18 is connected to the slurry mixing tank 16 and the pressure water storage tank 17 through the slurry mixing tank interface 40 and the pressure water storage tank interface 41 respectively. The second switch knob 37 of the second switch 15 and the third switch knob 42 of the third switch 18 are both three-speed knobs, the middle gear is the closed gear, and the left rotation can open the fracturing line connected to the pressure water storage tank, and the right rotation can open the grouting line connected to the slurry mixing tank; an electronic flow meter 36 is installed at the second switch outlet 35 for measuring the flow of slurry or water, and a pressure regulating valve 44 is installed at the high-pressure gas inlet 43 of the third switch 18 for stabilizing the pressure of the outflowing gas.

[0049] The data acquisition module includes an ultrasonic probe, an ultrasonic transmitter and receiver, a flow meter, an operating system, and a data storage center 24 respectively connected to the three-axis loading module. The operating system includes an operation integrated control center 25; the ultrasonic probe array is embedded in the pressure plate opposite to the Y axis in the three-bearing pressure chamber, and the ultrasonic transmitting sensor and the receiving sensor are transmitted to the data processing center via the line, and the processed data are transmitted to the data storage center 24 via the line; the operating system can control the pressure of the X-axis servo loading pump, the Y-axis servo loading pump and the Z-axis servo loading pump, can collect ultrasonic data and form images, set the injection pressure, and collect cumulative injection flow data.

[0050] The present invention also provides a test method for a true triaxial rock and soil test device, including a bulk grouting test method, the bulk grouting test method comprising the following steps:

[0051] S1, according to the broken bulk material obtained from the site or configured according to a certain particle size distribution that meets the actual site requirements, test the equipment operation status to ensure that the equipment can operate stably and safely;

[0052] S2. Use the hexagonal tensioning wrench 6 to unscrew and remove the sealing plug 7 of the top feed port to keep the top feed port 8 unobstructed; at the same time, first fix the pre-buried grouting and fracturing pipe 11 to the grouting and fracturing hole with screws, connect the first switch 12 to the grouting and fracturing pipe 13 externally, and keep the first switch 12 in the open state; load the six-sided pressure-bearing plates of the three-axis bearing cavity to the initial position, so that the bearing cavity remains relatively sealed to ensure that the crushed material will not be squeezed out during the pressurization process;

[0053] S3, conveying the prepared loose material into the three-axis bearing cavity through the feed port. If a pile of loose material blocks the feed port 8 during the process, use a stick to smooth the pile and then convey the loose material until the loose material fills the entire cavity. Then use the hexagonal tensioning wrench 6 to tighten the sealing plug 7 to block the feed port 8 and seal the cavity.

[0054] S4, preparing the required slurry in the slurry mixing and stirring tank 16 according to the preset slurry ratio, and sealing the slurry mixing and stirring tank 16 after the preparation is completed. The slurry mixing and stirring tank 16 is not stopped during the process to prevent the slurry from solidifying and clogging the grouting stirring tank;

[0055] S5, load the three-axis bearing cavity to the preset pressure, turn on the high-pressure air storage pump 19, make the gas storage pressure of the high-pressure air storage pump 19 greater than the preset grouting pressure, turn the third switch 18 clockwise to allow the high-pressure gas to pass through the slurry mixing tank, turn the second switch 15 clockwise to start grouting, and turn on the ultrasonic wave to collect data during the grouting process;

[0056] S6, after the slurry flow rate drops to the set range, the grouting experiment is completed, the first switch 12 is closed, the ultrasonic acquisition system is turned off, the high-pressure air storage pump 19 is turned off in sequence, the third switch 18, the slurry mixing tank 16, and the second switch 15 are turned off, the grouting and fracturing pipe 13 is removed, and the pipeline slurry mixing tank 16 is cleaned;

[0057] S7, after the grouting of the broken and bulked body, the pressure is maintained in the three-axis bearing cavity for a required time, and then the three-axis bearing cavity is depressurized, the pressure plates in the X-axis and Y-axis directions are retracted, and the horizontal limiting frame is moved into the groove of the base using the lifting bracket to remove the broken and bulked body;

[0058] S8, after taking out the broken reinforcement, clean the three-axis bearing cavity and reset the device to its original state for the next experiment.

[0059] The test method of the present invention also includes a complete rock mass hydraulic fracturing test method, which includes the following steps:

[0060] S1: Obtain a complete rock mass or rock mass similar to the actual site from the site or make it according to a certain ratio, test the operation of the equipment to ensure that the equipment can operate stably and safely, and lower the horizontal restraining frame to facilitate the loading of the test piece;

[0061] S2: Pre-buried grouting and fracturing pipe. A hole needs to be drilled in the center of the rock mass on site. The pre-buried grouting and fracturing pipe 11 is fixed in the hole with epoxy resin glue. When prefabricating similar rock mass, the pre-buried grouting and fracturing pipe 11 is directly buried. After loading the specimen, raise the horizontal restraining frame to the initial height, extend the X-axis bearing plate to the initial position, ensure that the pre-buried grouting and fracturing pipe 11 passes through the grouting and fracturing hole, connect it to the first switch 12, and keep the first switch 12 in the open state; load the six-sided pressure plates of the three-axis bearing cavity to the initial position;

[0062] S3, after filling the pressure water storage tank with water for fracturing, keep it sealed, load the triaxial pressure to the preset pressure, turn on the high-pressure air storage pump 19, make the air pressure of the pump greater than the preset fracturing pressure, set the flow rate of fracturing water, turn the third switch 18 to the left to allow the high-pressure gas to pass through the pressure water storage tank 17, turn the second switch 15 to the left to start fracturing, and turn on the ultrasonic wave to collect data during the grouting process for analysis;

[0063] S4, when the fracturing pressure drops suddenly, the fracturing is completed, and the test ends, the first switch 12 is closed, the ultrasonic acquisition system is closed, and the high-pressure air storage pump 19, the third switch 18, and the second switch 15 are closed in sequence;

[0064] S5, saving the data collected during the test, unloading the triaxial pressure, retracting the bearing plate in the X-axis direction, removing the pre-buried grouting fracturing tube from the grouting fracturing hole, moving the transverse restraining frame into the groove of the base using the lifting bracket, and removing the fractured rock mass;

[0065] S6, remove the fractured rock mass, clean the three-axis bearing cavity, and reset the test device to its original state for the next experiment.

[0066] The present invention integrates a grouting module with a hydraulic fracturing module to form a multifunctional experimental device and test method that simultaneously performs grouting and hydraulic fracturing functions. Furthermore, a feed port for feeding fragmented rock is provided above the device, enabling testing on both intact rock specimens and fragmented rock masses. The present invention improves the grouting and fracturing tube, converting it into a detachable grouting and fracturing tube. This simultaneously maintains the pressure of the rock stress environment and the slurry after grouting, facilitating cleaning of the grouting and fracturing tube, making the experiment more suitable for engineering sites and the data more convincing.

[0067] In the description of the present invention, it should be noted that the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0068] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A true triaxial rock and soil test device, characterized in that: It includes a three-axis loading module, which includes a three-axis servo loading system and a three-axis bearing system, and the three-axis servo loading system is used to apply pressure in the X direction, the Y direction and the Z direction to the three-axis bearing system; a grouting module, which is connected to the grouting and fracturing pipe in the three-axis bearing system through a pipeline; and a hydraulic fracturing module, which is connected to the grouting and fracturing pipe in the three-axis bearing system through a pipeline; The data acquisition and analysis module is connected to the ultrasonic transmitting sensor and the receiving sensor in the three-axis bearing system through a line.

2. The true triaxial rock and soil test device according to claim 1, characterized in that: The three-axis load-bearing system comprises a cubic structure formed by a plurality of pressure plates, wherein a three-bearing pressure chamber is arranged in the three-axis load-bearing system, and the pressure plates are fixed on the positioning grooves in the stereotyped square frame; a grouting fracturing hole is provided at the center of the pressure plate in the X-axis direction, and a grouting fracturing pipe is passed through the grouting fracturing hole; a feed port is provided on the pressure plate in the Z-axis direction, and a sealing plug is fixedly sealed at the feed port; the three-axis servo loading system comprises an X-axis oil cylinder, a Y-axis oil cylinder and a Z-axis oil cylinder, and the X-axis oil cylinder, the Y-axis oil cylinder and the Z-axis oil cylinder are respectively connected to an X-axis servo loading pump, a Y-axis servo loading pump and a Z-axis servo loading pump through pipelines, and the X-axis servo loading pump, the Y-axis servo loading pump and the Z-axis servo loading pump are respectively connected to the X-axis servo loading pump, the Y-axis servo loading pump and the Z-axis servo loading pump through pipelines. The servo loading pump and the Z-axis servo loading pump are externally connected to the main oil pump through pipelines; a base is provided at the bottom of the three-axis bearing system, and a longitudinal limiting frame is provided outside the three-axis bearing system, and the longitudinal limiting frame includes a top plate horizontally arranged on the top of the three-axis bearing system, and vertical plates are fixed at both ends of the top plate, and the bottom of the vertical plate is fixed on the base; a transverse limiting frame with a square cross-section is provided on the outer ring of the three-axis bearing system, and the bottom of the transverse limiting frame is connected to the base through a lifting bracket; the X-axis cylinder is fixed on the transverse limiting frame, and the Y-axis cylinder and the Z-axis cylinder are respectively fixed on the longitudinal limiting frame, and a groove is provided on the upper surface of the base.

3. The true triaxial rock and soil test device according to claim 2, characterized in that: The grouting module includes a slurry mixing and stirring tank; a pre-buried grouting and fracturing pipe is provided in the three-bearing pressure chamber, the pre-buried grouting and fracturing pipe is connected to one end of the grouting and fracturing pipe through a first switch, and the end of the grouting and fracturing pipe away from the first switch is connected to the slurry mixing and stirring tank through a pipeline and a second switch; the slurry mixing and stirring tank is connected to a high-pressure air storage pump through a pipeline and a third switch.

4. The true triaxial rock and soil test device according to claim 3, characterized in that: The hydraulic fracturing module includes a pressure water storage tank; the end of the grouting fracturing pipe away from the first switch is connected to the pressure water storage tank through a pipeline and the second switch; the pressure water storage tank is connected to the high-pressure air storage pump through a pipeline and a third switch; the second switch and the third switch are both three-way switches, and the second switch and the third switch both have three-speed knobs, the middle speed is the closed speed, and the left rotation can open the fracturing line connected to the pressure water storage tank, and the right rotation can open the grouting line connected to the slurry mixing tank; the second switch outlet is equipped with an electronic flow meter, and the third switch outlet is equipped with a pressure regulating valve.

5. The true triaxial rock and soil testing device according to claim 2, characterized in that: The data acquisition module includes an ultrasonic probe, an ultrasonic transmitter and receiver, a flow meter, an operating system, and a data storage center; the ultrasonic probe array is embedded in the pressure plate opposite to the Y-axis in the three-bearing pressure chamber, and the ultrasonic transmitting sensor and the receiving sensor are transmitted to the data processing center via the line, and the processed data are transmitted to the data storage center via the line; the operating system can control the pressure of the X-axis servo loading pump, the Y-axis servo loading pump and the Z-axis servo loading pump, can collect ultrasonic data and form images, set the injection pressure, and collect the cumulative injection flow data.

6. The true triaxial rock and soil test device according to claim 2, characterized in that: The sealing plug includes a thread, a hexagonal groove, a sealing ring, and a rigid sealing plug; the rigid sealing plug is provided with the hexagonal groove on the top, the thread is engraved on the upper part of the outer wall of the rigid sealing plug, two circles of grooves are engraved on the lower part of the outer wall of the rigid sealing plug, the groove is sleeved and filled with a sealing ring, the rigid sealing plug is provided with a hexagonal groove on the top, and a hexagonal tensioning wrench can be clamped in the hexagonal groove.

7. The true triaxial rock and soil testing device according to claim 6, characterized in that: The hexagonal tensioning wrench comprises a rigid body, a rotating handle is fixedly connected to the top of the rigid body, a hexagonal protrusion is fixedly provided at the bottom of the rigid body, and the hexagonal protrusion can be snapped into the hexagonal groove.

8. A test method for a true triaxial rock and soil test device, characterized in that: The invention comprises a grouting test method for a dispersed body, wherein the grouting test method for a dispersed body comprises the following steps: S1, configure the broken pieces that meet the practical site, detect the operation of the test device, and ensure that the test device can operate stably and safely; S2, unscrew and remove the sealing plug of the top feed port with a hexagonal tension wrench; at the same time, fix the pre-buried grouting and fracturing pipe on the grouting and fracturing hole with screws, and connect the first switch and the grouting and fracturing pipe externally; load the six-sided pressure plates of the three-axis bearing cavity to the initial position, so that the bearing cavity remains sealed to ensure the crushed body pressurization process The middle part will not be squeezed out by pressure; S3, conveying the prepared loose material into the three-axis bearing cavity through the feed port until the loose material fills the entire cavity, and then tightening the sealing plug with a hexagonal tensioning wrench to block the feed port and seal the interior of the cavity; S4, preparing the required slurry in a slurry mixing and stirring tank according to a preset slurry ratio, and sealing the slurry mixing and stirring tank after the preparation is completed, and the slurry mixing and stirring tank is not stopped during the process; S5, load the three-axis bearing cavity to a preset pressure, turn on the high-pressure air storage pump, make the air storage pressure of the high-pressure air storage pump greater than the preset grouting pressure, turn the third switch right to make the high-pressure gas pass through the slurry mixing tank, turn the second switch right to start grouting, and turn on the ultrasonic wave to collect data during the grouting process; S6, after the slurry flow rate drops to the set range, the grouting experiment is finished, the first switch is turned off, the ultrasonic acquisition system is turned off, the high-pressure air storage pump, the third switch, the slurry mixing tank, and the second switch are turned off in sequence, the grouting fracturing pipe is removed, and the pipe and the grouting mixing tank are cleaned; S7, after the crushed and grouted body is pressurized in the three-axis bearing cavity for a required time, the three-axis bearing cavity is depressurized, the pressure-bearing plates in the X-axis and Y-axis directions are retracted, the transverse limiting frame is moved into the groove of the base by using the lifting bracket, and the crushed and reinforced body is taken out; S8, after taking out the broken and scattered reinforcement, clean the three-axis load chamber and reset the device to its original state for the next experiment.

9. The test method of the true triaxial rock and soil test device according to claim 8, characterized in that: Also included is a complete rock mass hydraulic fracturing test method, the complete rock mass hydraulic fracturing test method comprising the following steps: S1, make a complete rock mass or rock mass similar to the actual site, test the operation of the test device, ensure that the test device can operate stably and safely, and make the lateral restraining frame fall down to facilitate the loading of the test piece; S2, pre-buried grouting pipe, drill a hole in the center of the complete rock mass, fix the pre-buried grouting fracturing pipe in the hole with epoxy resin glue, and directly bury the pre-buried grouting pipe when prefabricating similar rock mass; load the test piece, raise the lateral limit frame to the initial height, extend the X-axis direction bearing plate to the initial position, ensure that the pre-buried grouting fracturing pipe passes through the grouting fracturing hole, connect it to the first switch, and keep the first switch in the open state; load the six-sided pressure plates of the three-axis bearing cavity to the initial position; S3, after filling the pressure water storage tank with water for fracturing, keep it sealed and increase the triaxial pressure When the pressure reaches the preset pressure, the high-pressure gas storage pump is turned on, so that the pressure of the gas stored in the high-pressure gas storage pump is greater than the preset fracturing pressure, the flow rate of fracturing water is set, the third switch is turned left to allow the high-pressure gas to pass through the pressure water storage tank, the second switch is turned left to start fracturing, and at the same time, the ultrasonic wave is turned on to collect data during the grouting process; S4, when the fracturing pressure drops suddenly, the fracturing is completed, and the test is over, the first switch is turned off, the ultrasonic acquisition system is turned off, and the high-pressure gas storage pump, the third switch, and the second switch are turned off in sequence; S5, save the data collected during the test, unload the three axes, retract the pressure plate in the X-axis direction, remove the pre-buried grouting fracturing pipe from the grouting fracturing hole, move the lateral restraining frame into the groove of the base using the lifting bracket, and take out the fracturing rock mass; S6, take out the rock mass after fracturing, clean the three-axis bearing cavity, and reset the test device to its original state for the next experiment.

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