A testing device and method for grouting reinforcement of layered rock tunnels

Abstract

A testing device and method for grouting reinforcement of layered rock tunnels are disclosed. The device comprises a layered rock mass composed of stacked rock slices, the layered rock mass being inserted into a mounting slot of a rock mass mounting frame, the rock mass mounting frame being placed within a grouting model device, and the grouting model device being equipped with a water injection device, a grouting device, a ground stress loading device, and a standard specimen processing device. The ground stress loading device comprises a press that applies pressure to the movable side of a box; the grouting model device comprises a box formed of sealed steel plates; and the water injection device comprises a height-adjustable water tank. The present invention utilizes the rock mass mounting frame to install the layered rock mass, and within the grouting model device, simulates and obtains the grouting reinforcement effects of the layered rock mass under the combined effects of different water pressures and different ground stress environments, with different grouting pressures, different joint cohesions and internal friction angles, and different joint intersection angles.

Description

Technical Field

[0001] The present invention relates to the field of underground engineering disaster prevention and control, and in particular to a grouting reinforcement testing device and a testing method suitable for layered rock tunnels. Background Art

[0002] my country's infrastructure development is booming, with a large number of infrastructure projects, including highways, railways, water conservancy and hydropower, and urban underground spaces, entering construction. Currently, my country has become the world's largest and most challenging country for tunnel and underground engineering construction. Tunnel and underground engineering construction often encounters unfavorable geological conditions, such as faults, broken rock masses, and weak strata. These conditions can easily trigger geological disasters such as rock collapses, water and mud bursts, and water and sand bursts. These sudden geological disasters cause significant losses to construction personnel and equipment, and pose a serious threat to the hydrological and ecological environment of the tunnel site.

[0003] Grouting is an effective means of treating adverse geological conditions and improving surrounding rock conditions. It has been widely used in many fields such as railways, highways, water conservancy, and mining. Grouting can structure the rock and soil around the tunnel, manage fault fracture zones, seal sudden water inrush in the tunnel, and manage adverse geological structures such as karst and underground rivers, ensuring the safety of tunnel construction and operation. However, due to the extremely complex slurry migration process, which involves slurry properties, formation properties, and the fluid-solid coupling effect between the two, its theoretical research progress has been relatively slow and cannot effectively guide grouting engineering practice. Model testing is an important method for studying the diffusion law of slurry in the formation and the reinforcement mechanism, and has been widely used at home and abroad.

[0004] However, most current model tests use homogeneous rock and soil, failing to consider the influence of the inclination angle of the surface in the layered rock mass on grout diffusion and grout reinforcement effectiveness. On the other hand, by reinforcing layered rock masses with different grouting materials, uniaxial and conventional triaxial tests are performed after curing to obtain the physical and mechanical parameters of the specimens and quantitatively evaluate the grouting reinforcement effect. This method focuses on analyzing the mechanical properties of the reinforced body and cannot intuitively demonstrate the diffusion and sealing process of the grout in the cracks. Furthermore, this method does not consider the effects of initial ground stress and water pressure, making it difficult to apply to the grouting reinforcement effect of layered rock masses under different ground stresses and water pressures.

[0005] Therefore, there is an urgent need for a testing device suitable for layered rock tunnel grouting reinforcement, which can visually simulate the layered rock grouting reinforcement effect under different ground stresses and different water pressures. Summary of the Invention

[0006] The purpose of the present invention is to provide a grouting reinforcement testing device suitable for layered rock tunnels, which can visually simulate the grouting reinforcement effects of layered rock masses with different grouting pressures, different joint cohesion and internal friction angles, and different joint crossing angles under the combined action of ground stress and water pressure.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a grouting reinforcement test device suitable for layered rock tunnels, comprising a layered rock mass composed of stacked rock slices, the layered rock mass being inserted into the installation groove of a rock mass installation frame, the rock mass installation frame being placed in a grouting model device, the grouting model device being equipped with a water injection device, a grouting device, a ground stress loading device and a standard specimen processing device; the ground stress loading device comprising a press that applies pressure to a movable side of the box body; the grouting model device comprising a box body formed by a sealed connection of steel plates, the box body being provided with a water injection port, a grouting hole, a slurry outlet hole and a transparent grouting observation plate; the water injection device comprising a water tank with adjustable height, the water tank being connected to the box body through a water injection pipe to form different groundwater pressures on the rock mass; the grouting device comprising a grouting steel pipe drilled into the layered rock mass, the grouting steel pipe having grouting ports radially arranged along the axial direction, the grouting steel pipe being connected to an air pump and a first grouting pump in a first grouting barrel through a first grouting pipe, the first grouting barrel being provided with a first mixer. The present invention uses a ground stress loading device and a water injection device to simulate different water pressures and different ground stresses of underground rock masses, truly restores the construction site environment conditions, simulates the on-site grouting conditions through a grouting model device and a grouting device, and the data obtained by the monitoring device is used to guide on-site construction, greatly improving the seepage grouting reinforcement effect of underground complex environment rock masses during tunnel excavation.

[0008] The press is connected to a pressure plate via a hydraulic jack, and the pressure plate applies pressure to the movable steel plate to simulate the ground stress on the rock mass.

[0009] The movable steel plate on the top of the box is provided with a water inlet, the upper side of the box side is provided with a grouting hole, and the lower side is provided with a slurry outlet hole. Transparent grouting observation plates of different heights are respectively provided on the four sides of the box to facilitate observation of the grouting effect of the grouting slurry.

[0010] The water tank is connected to a chain hoist, and the chain hoist drives the water tank to move up and down, so as to simulate an underground water system environment with different water pressures.

[0011] The grouting model device is connected to a monitoring device, which includes sensors including a stress gauge, a strain gauge, a flow meter, and a pressure monitor. The stress gauge is placed in the grouting model device, the strain gauge is attached to the inner wall of the box, the flow meter is placed in the pipe connecting the water injection pipe, the grouting steel pipe, and the water outlet, and the pressure monitor is placed in the first grouting pipe. The monitoring device records the stress and stress changes of the rock mass in the grouting model device, and the changes in pressure, water injection, and grouting flow. It can restore the water vapor content and ground stress changes of the rock mass in the underground environment, providing accurate data support for actual grouting work on site.

[0012] The water injection port and the water injection pipe are sealed by epoxy resin AB glue, and the grouting hole and the grouting steel pipe are sealed by epoxy resin AB glue to prevent water and grouting slurry from leaking out.

[0013] The standard specimen processing device includes a cutting machine, a coring machine and a grinding machine.

[0014] A test method for grouting reinforcement testing of layered rock tunnels, comprising the following steps:

[0015] 1. Prepare the layered rock mass by stacking rock slices on each other, and form the layered rock mass with different parameters by setting the number and size of the stacked rock slices and the number of openings for grouting with grouting steel pipes;

[0016] Second, any layered rock mass is selected to be inserted horizontally or obliquely into the installation groove of the rock mass installation frame. Small parallel grooves are carved on the inner wall of the installation groove to simulate the rock mass joints.

[0017] 3. Prepare the grouting model device. The four side panels and the bottom plate of the grouting model device box are connected by high-strength bolts. The joints are sealed with rubber gaskets to ensure the impermeability of the box;

[0018] 4. Place the rock mass installation frame from step 2 into the open box, and then connect the movable steel plate to the box in a sealed manner;

[0019] 5. The water injection device injects water into the grouting model device through the water injection pipe, adjusts the height of the water tank, and forms different groundwater pressures on the layered rock mass to simulate the groundwater pressure environment at the construction site;

[0020] 6. The press in the ground stress loading device is connected to the pressure plate through a hydraulic jack. The pressure plate applies pressure to the moving steel plate to simulate the underground ground stress environment at the construction site.

[0021] 7. Prepare the grouting device, drill the grouting steel pipe into the opening at the layered rock mass, connect the grouting steel pipe to the first grouting pipe, and deliver the grouting slurry to the grouting model device through the grouting hole of the grouting steel pipe; when slurry flows out of the grouting effect observation pipe and the flow meters installed in the grouting effect observation pipe and the grouting steel pipe show that the flow rates of the grouting effect observation pipe and the grouting steel pipe are similar, stop grouting to obtain the target grouting layered rock mass;

[0022] 8. The monitoring device monitors the grouting parameters in real time and records the final grouting parameters for guiding the formation of a reinforced body by tunnel seepage grouting under different water pressures and ground stresses at the construction site;

[0023] 9. After grouting is completed, the reinforcement body is cured for 3 days, 7 days, or 28 days. By observing the stone efficiency of the grouting reinforcement body under different grouting pressures and water pressure environments, a preliminary analysis of the reinforcement effect under various factors is conducted to preliminarily analyze the grouting reinforcement effect under various conditions. The reinforcement body is then cut by the cutting machine of the standard specimen processing device, and the core is drilled and cored by the coring machine to form a core sample. The core sample is then cut and smoothed. The core sample is then subjected to uniaxial compression and shear tests to test the compressive strength and shear strength of the core sample. Through a comprehensive analysis of the mechanical properties of the core sample, the effect of reinforcement on the layered rock mass under various conditions is obtained. The comprehensive analysis of the mechanical properties of the core sample can be carried out using existing analytical methods.

[0024] By adopting the above-mentioned technical scheme, a test device for grouting reinforcement of layered rock tunnels is used. The layered rock mass is composed of stacked rock slices, and the layered rock mass is inserted into the installation groove of the rock mass installation frame. The grouting model device and the ground stress loading device are used to simulate the grouting conditions of the layered rock tunnel under different water pressures and different ground stresses at the construction site, and the grouting effect is evaluated by the grouting reinforcement effect device. At the same time, the optimal grouting parameters are obtained by the monitoring device. After the grouting is completed, the reinforced body is cured by a standard specimen processing device to obtain a core sample. With reference to the core sample data, the cohesion and internal friction angle between the stacked rock slices of the target grouting rock mass with different parameters are finally measured to provide accurate data support for the actual tunnel passing through the layered rock mass. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of 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.

[0026] FIG1 is a schematic structural diagram of a tunnel seepage grouting reinforcement testing device for simulating different water pressures and ground stresses according to the present invention;

[0027] FIG2 is a schematic diagram of the grouting steel pipe installation structure of the present invention;

[0028] FIG3 is a schematic structural diagram of the grouting model device in the invention;

[0029] FIG4 is a schematic diagram of the rock mass installation frame structure in the present invention;

[0030] FIG5 is a schematic diagram of the layered rock mass structure of the horizontally inserted rock mass installation frame in the present invention;

[0031] FIG6 is a schematic diagram of the layered rock mass structure of the inclined plug-in rock mass installation frame in the present invention. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of 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. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] like Figure 1-6 A grouting reinforcement test device suitable for layered rock tunnels includes a layered rock mass composed of stacked rock slices. The layered rock mass is inserted into the installation groove 73 of the rock mass installation frame 70. The rock mass installation frame is placed in the grouting model device. The grouting model device is equipped with a water injection device, a grouting device, a ground stress loading device and a standard specimen processing device; the grouting model device includes a box body 10 formed by a closed connection of steel plates. The box body 10 is provided with a water injection port, a grouting hole, a slurry outlet hole and a transparent grouting observation plate.

[0034] As a preferred structural stress loading device, the stress loading device includes a press 11 that can apply pressure to the movable side of the box 10. The press 11 is connected to the pressure plate 12 through a hydraulic jack. The pressure plate 12 applies pressure to the movable steel plate 30 to simulate the actual ground stress of the rock mass underground.

[0035] The movable steel plate 30 on the top of the box body 10 is provided with a water injection port 24, the upper side of the box body is provided with a grouting hole 26, and the lower side is provided with a slurry outlet hole 25. Transparent grouting observation panels of different heights are respectively provided on the four sides of the box body.

[0036] As a preferred structure, the water injection device 14 includes a water tank 16 with adjustable height. The water tank 16 is connected to the box body 10 through the water injection pipe 13 to form different underground water pressures on the rock mass; the water tank 16 is connected to the chain hoist 15, and the chain hoist 15 drives the water tank 16 to move up and down to achieve changes in water pressure.

[0037] As a structurally preferred grouting device, it includes a grouting steel pipe 22 drilled into the layered rock mass, the grouting steel pipe 22 has radially opened grouting ports 52 arranged axially, the grouting steel pipe 22 is connected to the air pump 1 and the first grouting pump 2 in the first grouting barrel 3 through the first grouting pipe 21; the first grouting barrel 3 is provided with a first mixer 4, which increases the uniformity of the grouting slurry.

[0038] As a structurally preferred monitoring device 7, the monitoring device 7 includes sensors, including a stress gauge, a strain gauge, a flow meter and a pressure monitor; the stress gauge is placed in the grouting model device, the strain gauge is pasted on the inner wall of the box 10, the flow meter is placed on the water injection pipe, the grouting steel pipe 22 and the pipeline connected to the water outlet, and the pressure monitor is placed in the first grouting pipe 21.

[0039] In order to improve the sealing performance, the water injection port 24 and the water injection pipe 13 are sealed by epoxy resin AB glue, and the grouting hole 26 and the grouting steel pipe 22 are sealed by epoxy resin AB glue.

[0040] As a preferred structure, the standard specimen processing device includes a cutting machine, a coring machine and a grinding machine.

[0041] A test method for grouting reinforcement testing of layered rock tunnels, comprising the following steps:

[0042] 1. Prepare the layered rock mass by stacking rock slices on each other, and form the layered rock mass with different parameters by setting the number and size of the stacked rock slices and the number of openings for grouting with grouting steel pipes;

[0043] Second, any layered rock mass is selected to be inserted horizontally or obliquely into the installation groove of the rock mass installation frame. Small parallel grooves are carved on the inner wall of the installation groove to simulate the rock mass joints.

[0044] 3. Prepare the grouting model device. The four side panels and the bottom panel of the grouting model device box 10 are connected by high-strength bolts, and the joints are sealed with rubber gaskets to ensure the impermeability of the box;

[0045] 4. Place the rock mass installation frame from step 2 into the open box 10, and then tightly connect the movable steel plate 30 to the box;

[0046] 5. The water injection device 14 injects water into the grouting model device through the water injection pipe 13, adjusts the height of the water tank 16, and generates different groundwater pressures on the layered rock mass to simulate the groundwater pressure environment at the construction site;

[0047] 6. The press 11 in the ground stress loading device is connected to the pressure plate 12 via a hydraulic jack. The pressure plate 12 applies pressure to the movable steel plate 30 to simulate the underground ground stress environment at the construction site.

[0048] 7. Prepare the grouting device. Drill the grouting steel pipe 22 into the opening that matches the layered rock mass. Connect the grouting steel pipe 22 to the first grouting pipe 21. Transport the grouting slurry into the grouting model device through the grouting port 52 of the grouting steel pipe 22. When slurry flows out of the grouting effect observation pipe and the flow meters installed in the grouting effect observation pipe and the grouting steel pipe 22 show that the flow rates of the grouting effect observation pipe and the grouting steel pipe 22 are similar, stop grouting to obtain the target grouting layered rock mass.

[0049] 8. The monitoring device 7 monitors the grouting parameters in real time and records the grouting parameters of the final grouting reinforcement to guide the tunnel seepage grouting reinforcement to form a reinforcement body under different water pressures and different ground stresses at the construction site;

[0050] 9. After the grouting is completed, the reinforcement body is cured for 3 days, 7 days or 28 days. By observing the stone efficiency of the grouting reinforcement body under different grouting pressure and water pressure environments, the reinforcement effect under various factors is preliminarily analyzed. The grouting reinforcement effect under various conditions is then preliminarily analyzed. The reinforcement body is then cut by the cutting machine of the standard specimen processing device, and the core is drilled and cored by the coring machine to form a core sample. The core sample is then cut and smoothed, and then the core sample is subjected to uniaxial compression test and shear test to test the compressive strength and shear strength of the core sample. Through comprehensive analysis of the mechanical properties of the core sample, the effect of reinforcement on the layered rock mass under various conditions is obtained.

[0051] As a specific implementation scheme, the platform size of the box 10 is 1000mm*1000mm*1000mm. The model box is made of 10mm thick steel plate and can meet the maximum grouting pressure requirement of 10Mpa. The sides, bottom and top surfaces are all connected with high-strength bolts. To ensure the airtightness of the model box, the joints are sealed with 2mm thick rubber gaskets and sealants. Transparent grouting observation panels of different heights are set on the sides. They are made of high-strength organic glass. The organic glass is 225mm*100mm. The bottom of the organic glass is 225mm, 450mm, 675mm, and 900mm away from the bottom of the model box, respectively. A grouting hole with a radius of 25mm is reserved at the top of the box, and a grouting hole with a radius of 5mm is reserved at the bottom of the side. After the above-mentioned layered rock sample is placed in the box, the movable steel plate 30 is embedded in the open part of the box to seal it, and the joints are sealed with thick rubber pads and sealants.

[0052] The specific installation process of the layered rock mass composed of stacked rock slices is as follows:

[0053] Step 1: Sampling. This rock mass mounting frame 70 measures 150mm*150mm*150mm. The left and right sides of the rock mass mounting frame 70 are made of solid wood. The front and rear sides are surrounded by equally spaced mounting slots 73. The top side is surrounded by wooden strips, with the center left empty to facilitate the placement of different numbers of grouting holes. The bottom side is made of solid wood. All eight corners of the rock mass mounting frame 70 are secured with washers and bolts 72 to facilitate disassembly and maintenance of the layered rock mass after grouting.

[0054] Step 2: Drill multiple circular holes of different sizes and numbers at regular intervals on each layered rock mass, with inclination angles of 0° and 45°.

[0055] Step 3: Insert the layered rock mass with circular holes into the mounting groove 73 layer by layer and secure the connecting bolts. Inject cement slurry into each circle, requiring high water pressure and low flow rate to ensure that each layer is filled with cement slurry. Use a glass rod to stir to prevent the formation of bubbles. After the slurry solidifies, remove it from the rock mass mounting frame 70, remove the test piece, and cure it for 28 days to allow the cement to completely solidify. Place the prepared sample in the rock chamber direct shear instrument for direct shear testing under different ground stresses. According to the formula, the cohesion and internal friction angle of this sample can be obtained. Make the same number of circular holes of different sizes on the layered rock mass and repeat the above steps to obtain the cohesion and internal friction angle of the layered rock mass. Make the same number of circular holes of the same size and different numbers on the layered rock mass and repeat the above steps to obtain the cohesion and internal friction angle of the layered rock mass, so as to achieve the effect of grouting reinforcement of layered rock mass with different joint cohesion and internal friction angles and different joint intersection angles under different grouting pressures.

[0056] The present invention simulates the varying cohesion and internal friction angles of a tunnel traversing a layered rock mass by adjusting the size and number of holes, thereby resolving the complex and difficult production of standard rock specimens used in existing tests for testing the cohesion and internal friction angles of layered rock. The present invention drills multiple circular holes of varying sizes and numbers at regular intervals on each rock slice. The rock slices, with grouting holes drilled in layers, are then inserted into mounting slots 73 one layer at a time. Cement slurry is injected into each grouting hole, requiring high water pressure and low flow rate to ensure that each layer is filled with slurry. A glass rod is used for stirring to prevent bubbles. After the slurry solidifies, the rock slices are disassembled to form a reinforcement body and cured for 28 days to allow the cement to fully solidify. The prepared specimens are then placed in an indoor direct shear apparatus and subjected to direct shear tests under varying normal stresses to determine their cohesion and internal friction angles. The above steps are repeated by making the same number of grouting holes of varying sizes on the rock slice to determine the cohesion and internal friction angles of the layered rock mass. The above steps are repeated by making grouting holes of the same size and different numbers on the rock slices to obtain the cohesion and internal friction angle of the layered rock mass, so as to achieve the effect of grouting reinforcement of layered rock mass with different joint cohesion and internal friction angles and different joint crossing angles under different grouting pressures.

[0057] The specific grouting steps in the grouting device are as follows:

[0058] ① First, two upper and lower parallel grouting steel pipes and a grouting effect observation pipe with zero grouting pressure are drilled into the rock mass. The two upper and lower parallel grouting steel pipes are the grouting steel pipe 22 and the first grouting steel pipe 23. The first grouting steel pipe 23 is provided with first grouting holes 44 at equal intervals, and the grouting steel pipe 22 is provided with grouting ports 52 at equal intervals.

[0059] ② Each grouting steel pipe is symmetrically distributed up and down, and the spacing between adjacent holes is adjusted in time according to the situation;

[0060] ③ The grouting pressure of the grouting steel pipe is greater than the existing environmental water pressure; the grouting effect observation tube with zero grouting pressure is embedded in the rock mass, and the porosity of the embedded rock mass is only limited to the entry of grouting slurry. The concentration of the grouting slurry flowing out of the grouting effect observation tube is used to judge the grouting effect in real time.

[0061] Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are illustrative and are not to be construed as limiting the present invention. Those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments without departing from the principles and intent of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A test method for grouting reinforcement testing of layered rock tunnels, characterized by: The following steps are involved:

1. Prepare the layered rock mass by stacking rock slices on each other, and form the layered rock mass with different parameters by setting the number and size of the stacked rock slices and the number of openings for grouting with grouting steel pipes; 2. Select any layered rock mass and insert it horizontally or obliquely into the installation groove of the rock mass installation frame (70). Carve small parallel grooves on the inner wall of the installation groove to simulate rock mass joints; 3. Prepare the grouting model device. The four side plates and the bottom plate of the grouting model device box (10) are connected by high-strength bolts, and the joints are sealed with rubber gaskets to ensure the watertightness of the box; 4. Place the rock mass installation frame of step 2 into the open box (10), and then connect the movable steel plate (30) to the box in a sealed manner; 5. The water injection device (14) injects water into the grouting model device through the water injection pipe (13), adjusts the height of the water tank (16), and forms different groundwater pressures on the layered rock mass to simulate the groundwater pressure environment at the construction site; 6. The press (11) in the ground stress loading device is connected to the pressure plate (12) through a hydraulic jack, and the pressure plate (12) applies pressure to the movable steel plate (30) to simulate the underground ground stress environment at the construction site; 7. Prepare the grouting device, drill the grouting steel pipe (22) into the opening of the layered rock mass, connect the grouting steel pipe (22) to the first grouting pipe (21), and deliver the grouting slurry to the grouting model device through the grouting port (52) of the grouting steel pipe (22); when slurry flows out of the grouting effect observation pipe and the flow meters installed in the grouting effect observation pipe and the grouting steel pipe (22) show that the flow rates of the grouting effect observation pipe and the grouting steel pipe (22) are similar, stop grouting to obtain the target grouting layered rock mass; 8. The monitoring device (7) monitors the grouting parameters in real time and records the grouting parameters of the final grouting reinforcement to guide the formation of a reinforcement body by tunnel seepage grouting reinforcement under different water pressures and different ground stresses at the construction site; 9. After the grouting is completed, the reinforcement body is cured for 3 days, 7 days or 28 days. By observing the stone efficiency of the grouting reinforcement body under different grouting pressure and water pressure environments, the reinforcement effect under various factors is preliminarily analyzed. The grouting reinforcement effect under various conditions is then preliminarily analyzed. The reinforcement body is then cut by the cutting machine of the standard specimen processing device, and the core is drilled and cored by the coring machine to form a core sample. The core sample is then cut and smoothed, and then the core sample is subjected to uniaxial compression test and shear test to test the compressive strength and shear strength of the core sample. Through comprehensive analysis of the mechanical properties of the core sample, the reinforcement effect of the layered rock mass under various conditions is obtained. The above-mentioned test method for grouting reinforcement test of layered rock tunnel is implemented by a grouting reinforcement test device for layered rock tunnel, which includes a layered rock composed of stacked rock slices, the layered rock is inserted into the installation groove (73) of the rock installation frame (70), and the rock installation frame is placed in the grouting model device, and the grouting model device is equipped with a water injection device, a grouting device, a ground stress loading device and a standard specimen processing device; the ground stress loading device includes a press (11) that can apply pressure to the movable side of the box (10); the grouting model device includes a box (10) formed by a sealed connection of steel plates, and the box (10) is provided with a water injection port, a grouting hole, a grouting hole and a transparent grouting observation plate; the water injection device (14) includes a water tank (16) with adjustable height, The water tank (16) is connected to the box body (10) via the water injection pipe (13) to form different underground water pressures on the rock mass; the grouting device comprises a grouting steel pipe (22) drilled into the layered rock mass, the grouting steel pipe (22) is radially provided with grouting ports (52) arranged along the axial direction, and the grouting steel pipe (22) is connected to the air pump (1) and the first grouting pump (2) in the first grouting barrel (3) via the first grouting pipe (21); the grouting model device is connected to a monitoring device (7), the monitoring device (7) comprises a sensor, and the sensor comprises a stress gauge, a strain gauge, a flow meter and a pressure monitoring meter; the stress gauge is placed in the grouting model device, the strain gauge is attached to the inner wall of the box body (10), the flow meter is placed on the pipeline connecting the water injection pipe, the grouting steel pipe (22) and the water outlet, and the pressure monitoring meter is placed in the first grouting pipe (21).

2. A test method for grouting reinforcement testing of layered rock tunnels according to claim 1, characterized in that: The press (11) is connected to a pressure plate (12) via a hydraulic push rod, and the pressure plate (12) applies pressure to the movable steel plate (30).

3. The method for testing grouting reinforcement of layered rock tunnels according to claim 1, characterized in that: The movable steel plate (30) on the top of the box (10) is provided with a water injection port (24), the upper side of the box side is provided with a grouting hole (26), and the lower side is provided with a grouting hole (25), and transparent grouting observation panels of different heights are respectively provided on the four sides of the box.

4. The method for testing grouting reinforcement of layered rock tunnels according to claim 1, characterized in that: The water tank (16) is connected to the chain hoist (15), and the chain hoist (15) drives the water tank (16) to move up and down.

5. The method for testing grouting reinforcement of layered rock tunnels according to claim 1, characterized in that: A first mixer (4) is provided in the first grouting barrel (3).

6. The method for testing grouting reinforcement of layered rock tunnels according to claim 1, characterized in that: The water injection port (24) and the water injection pipe (13) are sealed by epoxy resin AB glue, and the grouting hole (26) and the grouting steel pipe (22) are sealed by epoxy resin AB glue.

7. The method for testing grouting reinforcement of layered rock tunnels according to claim 1, characterized in that: The standard specimen processing device includes a cutting machine, a coring machine and a grinding machine.

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