Testing device and testing method suitable for layered rock mass tunnel grouting reinforcement

Abstract

The invention relates to a tunnel grouting reinforcement test device and test method suitable for stratified rock mass, the device comprises the stratified rock mass formed by mutually laminated rock slices, the stratified rock mass is inserted into a mounting groove of a rock mass mounting frame, the rock mass mounting frame is placed in a grouting model device, and the grouting model device is connected with the stratified rock mass. The grouting model device is matched with a water injection device, a grouting device, a ground stress loading device and a standard test piece processing device; the ground stress loading device comprises a press for applying pressure to the movable side surface of the box body; the grouting model device comprises a box body formed by hermetically connecting steel plates; the water injection device comprises a height-adjustable water tank. The layered rock mass is mounted through the rock mass mounting frame, and the grouting reinforcement effects of the layered rock mass with different grouting pressures, different joint cohesion and internal friction angles and different joint crossing angles under the combined action of different water pressures and different ground stress environments are simulated and obtained in the grouting model device.

Description

Technical Field

[0001] The 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 construction is booming, and a large number of infrastructure projects such as highways, railways, water conservancy and hydropower, and urban underground space have been put into construction. At present, my country has become the country with the largest scale and difficulty in tunnel and underground engineering construction in the world. During the construction of tunnels and underground projects, unfavorable geological conditions such as faults, broken rock masses, and soft strata are often encountered, which can easily induce geological disasters such as surrounding rock collapse, sudden water and mud, and water and sand bursts. Sudden geological disasters cause huge losses to construction personnel and machinery, and also seriously threaten the hydrological and ecological environment of the tunnel site area.

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

[0004] However, most of the current model tests are conducted on homogeneous rock and soil, which cannot take into account the influence of the inclination angle of the layer in the layered rock mass on the slurry diffusion and slurry reinforcement effect. On the other hand, the layered rock mass is reinforced with different grouting materials, and the uniaxial and conventional triaxial tests are carried out after the specimens are cured to obtain the physical and mechanical parameters of the specimens and quantitatively evaluate the grouting reinforcement effect. This method focuses on the mechanical property analysis of the reinforced body and cannot intuitively show the diffusion and plugging process of the slurry in the cracks. In addition, this method does not take into account the influence of initial ground stress and water pressure, and is difficult to apply to the grouting reinforcement effect of layered rock mass under different ground stresses and different water pressures.

[0005] Therefore, there is an urgent need for a test 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 mutually stacked rock slices, the layered rock mass is inserted into the installation groove of the rock mass installation frame, the rock mass 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 comprises a press machine that applies pressure to the movable side of the box body; the grouting model device comprises a box body composed of steel plates sealed together, the box body is provided with a water injection port, a grouting hole, a grouting hole and a transparent grouting observation plate; the water injection device comprises a water tank with adjustable height, the water tank is connected to the box body through a water injection pipe to form different groundwater pressures on the rock mass; the grouting device comprises a grouting steel pipe drilled into the layered rock mass, the grouting steel pipe is radially provided with grouting ports arranged along the axial direction, the grouting steel pipe is connected to an air pump and a first grouting pump in a first grouting barrel through a first grouting pipe, and the first grouting barrel is provided with a first mixer. The present invention adopts a geostress loading device and a water injection device to simulate different water pressures and different geostresses 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, which greatly improves 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 body is provided with a water injection port, and the side of the box body is provided with grouting holes and slurry outlet holes arranged up and down. Transparent grouting observation plates of different heights are respectively arranged on the four sides of the box body to facilitate observation of the grouting effect of the grouting slurry. 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.

[0010] The grouting model device is connected to a monitoring device, which includes sensors, including stress gauges, strain gauges, flow meters and pressure monitoring meters; 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 on the pipe connected to the water injection pipe, the grouting steel pipe and the water outlet, and the pressure monitoring meter is placed in the first grouting pipe. The monitoring device realizes the stress and stress change of the rock mass in the grouting model device, and has the pressure, water injection, and grouting flow change conditions, and realizes the restoration of the water vapor content and ground stress changes of the rock mass in the underground environment, providing accurate data support for the actual on-site grouting work.

[0011] 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.

[0012] The standard specimen processing device comprises a cutting machine, a coring machine and a grinding machine.

[0013] A test method for grouting reinforcement test of layered rock tunnels, comprising the following steps: 1. Prepare mutually stacked rock pieces to form a layered rock mass, and form a layered rock mass with different parameters by setting the number and size of the stacked rock pieces and the number of holes for grouting with a grouting steel pipe; Second, any layered rock mass is selected to be inserted horizontally or obliquely into the installation groove of the rock mass installation frame, and small parallel grooves are carved on the inner wall of the installation groove to simulate the rock mass joints; 3. Prepare the grouting model device. The four side plates and the bottom plate of the grouting model device box are connected by high-strength bolts, and the joints are sealed with rubber gaskets to ensure the impermeability of the box; 4. Place the rock mass installation frame in step 2 into the open box, and then connect the movable steel plate to the box in a sealed manner; 5. The water injection device injects water into the grouting model device through the water injection pipe, adjusts the height of the water tank, forms different groundwater pressures on the layered rock mass, and simulates the groundwater pressure environment at the construction site; 6. The press in the ground stress loading device is connected to the pressure plate through a hydraulic jack, and the pressure plate applies pressure to the moving steel plate to simulate the underground ground stress environment at the construction site; 7. Prepare the grouting device, drill the grouting steel pipe into the opening of the layered rock mass, connect the grouting steel pipe to the first grouting pipe, and transport the grouting slurry to the grouting model device through the grouting hole of the grouting steel pipe; when the grouting effect observation pipe has slurry flowing out, 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; 8. The monitoring device monitors the grouting parameters in real time, and records the grouting parameters that are finally completed for 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, and 28 days. By observing the stone efficiency of the grouting reinforcement body under different grouting pressures and water pressure environments, the reinforcement effect under various factors is preliminarily analyzed. Then the reinforcement body is cut by the cutting machine of the standard specimen processing device, and the core sample is formed by drilling and coring by the coring machine. 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 the comprehensive analysis of the mechanical properties of the core sample, the effect of reinforcing 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 analysis methods.

[0014] By adopting the above-mentioned technical scheme, a test device suitable for grouting reinforcement of layered rock tunnels is used to insert the layered rock mass composed of stacked rock slices 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 reinforcement effect device is used to evaluate the grouting effect. At the same time, the monitoring device obtains the best grouting parameters. After the grouting is completed, the reinforced body is cured by a standard specimen processing device to obtain a core sample. Referring 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 detected to provide accurate data support for the actual tunnel passing through the layered rock mass. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0016] 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; FIG2 is a schematic diagram of the grouting steel pipe installation structure in the present invention; FIG3 is a schematic diagram of the structure of the grouting model device in the invention; FIG4 is a schematic diagram of the rock mass installation frame structure in the invention; FIG5 is a schematic diagram of a layered rock mass structure of a horizontally inserted rock mass installation frame in the present invention; FIG. 6 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

[0017] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. 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 creative work are within the protection scope of the present invention.

[0018] like Figure 1-6 A grouting reinforcement test device suitable for layered rock tunnels includes a layered rock mass composed of mutually 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, and the box body 10 is provided with a water injection port, a grouting hole, a grouting hole and a transparent grouting observation plate.

[0019] As a preferred structure, 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 a pressure plate 12 through a hydraulic jack. The pressure plate 12 applies pressure to the movable steel plate 30 to simulate the real ground stress of the rock mass underground.

[0020] The movable steel plate 30 on the top of the box body 10 is provided with a water injection port 24, and the side of the box body is provided with grouting holes 26 and grouting holes 25 arranged up and down, and transparent grouting observation panels of different heights are respectively arranged on the four sides of the box body.

[0021] 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.

[0022] As a structurally preferred grouting device, it includes a grouting steel pipe 22 drilled into the layered rock mass, the grouting steel pipe 22 radially opens grouting ports 52 arranged along the axial direction, 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.

[0023] As a preferred structural monitoring device 7, the monitoring device 7 includes a sensor, which includes 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 pipeline connecting the water injection pipe, the grouting steel pipe 22 and the water outlet 25, and the pressure monitor is placed in the first grouting pipe 21.

[0024] 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.

[0025] As a structural preference, the standard specimen processing device includes a cutting machine, a coring machine, and a grinding machine.

[0026] A test method for grouting reinforcement test of layered rock tunnels, comprising the following steps: 1. Prepare mutually stacked rock pieces to form a layered rock mass, and form a layered rock mass with different parameters by setting the number and size of the stacked rock pieces and the number of holes for grouting with a grouting steel pipe; Second, any layered rock mass is selected to be inserted horizontally or obliquely into the installation groove of the rock mass installation frame, and small parallel grooves are carved on the inner wall of the installation groove to simulate the rock mass joints; 3. Prepare a 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, forms different groundwater pressures on the layered rock mass, and simulates the groundwater pressure environment at the construction site; 6. The press machine 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 the grouting effect observation pipe has slurry flowing out, 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 tunnel seepage grouting reinforcement to form a reinforcement body 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 and 28 days. The stone efficiency of the grouting reinforcement body under different grouting pressures and water pressure environments is observed to preliminarily analyze the reinforcement effect under various factors. 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 a 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. The mechanical properties of the core sample are comprehensively analyzed to obtain the reinforcement effect of the layered rock mass under various conditions.

[0027] 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, which can meet the requirement of maximum grouting pressure of 10Mpa. The side, bottom and top surfaces are connected by 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, using high-strength organic glass, the organic glass is 225mm*100mm, and the bottom of the organic glass is 225mm, 450mm, 675mm, and 900mm away from the bottom of the model box. 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 mass sample is placed in the box, the movable steel plate 30 is embedded in the open part of the box for sealing, and the joints are sealed with thick rubber pads and sealants.

[0028] The specific installation process of the layered rock mass composed of mutually stacked rock slices is as follows: Step 1: Sampling, the size of this rock mass installation frame 70 is 150mm*150mm*150mm, the left and right sides of the rock mass installation frame 70 are solid wood boards, the front and rear sides are surrounded by equidistant installation grooves 73, the upper side is surrounded by wooden strips, the center position is empty, which is convenient for different numbers of grouting holes, and the lower side is solid wood boards. The eight corners of the rock mass installation frame 70 are fixed with gaskets and bolts 72 to facilitate the disassembly and maintenance of the layered rock mass after grouting.

[0029] 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°.

[0030] Step 3: Insert the layered rock mass with circular holes into the installation groove 73 layer by layer, and fix the connecting bolts. Inject cement slurry into each circle, requiring high water pressure and low flow rate to inject into the hole to ensure that each layer is filled with cement slurry. Use a glass rod to stir to prevent bubbles. After the slurry solidifies, remove the rock mass mounting frame 70, take out the test piece, and cure for 28 days to make the cement completely solidify. Place the prepared sample in the rock chamber direct shear instrument for direct shear tests 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 size and different number of circular holes 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 cross angles under different grouting pressures.

[0031] The present invention simulates the different cohesion and internal friction angles of the layered rock structure surface through tunnels by adjusting the size and number of holes, thereby solving the problem of complex processing and difficult production of standard rock specimens in the existing layered rock cohesion and internal friction angle test. The present invention drills a plurality of circular holes of different sizes and numbers at a certain distance on each rock slice, and inserts the rock slices with grouting holes into the installation groove 73 layer by layer. Cement slurry is injected into each grouting hole, requiring high water pressure and low flow rate to inject into the hole to ensure that each layer is filled with cement slurry. A glass rod is used for stirring to prevent the generation of bubbles. After the slurry solidifies, the rock slice is disassembled to form a reinforcement body for curing for 28 days to completely solidify the cement. The prepared sample is placed in an indoor direct shear instrument for direct shear tests under different normal stresses, and the cohesion and internal friction angle of the sample can be obtained. The same number of grouting holes but different sizes are made on the rock slices and the above steps are repeated to obtain the cohesion and internal friction angle 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.

[0032] The specific grouting steps in the grouting device are as follows: 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.

[0033] 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; 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.

[0034] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose 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 of layered rock tunnels, characterized in that: The following steps are involved:

1. Prepare mutually stacked rock pieces to form a layered rock mass, and form a layered rock mass with different parameters by setting the number and size of the stacked rock pieces and the number of holes for grouting with a grouting steel pipe; 2. Select any layered rock mass and insert it horizontally or obliquely into the installation groove of the rock mass installation frame (70), and carve small grooves parallel to each other on the inner wall of the installation groove to simulate rock mass joints; 3. Prepare a 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 seal the movable steel plate (30) with the box; 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), forms different groundwater pressures on the layered rock mass, and simulates the groundwater pressure environment at the construction site; 6. The press machine (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 a grouting device, drill a grouting steel pipe (22) into an opening at a 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 a 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 and 28 days. The stone efficiency of the grouting reinforcement body under different grouting pressures and water pressure environments is observed to preliminarily analyze the reinforcement effect under various factors. 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 a 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. The mechanical properties of the core sample are comprehensively analyzed to obtain the reinforcement effect of the layered rock mass under various conditions.

2. A grouting reinforcement test device suitable for layered rock tunnels, characterized in that: The invention comprises a layered rock mass composed of mutually stacked rock slices, the layered rock mass is inserted into an installation groove (73) of a rock mass installation frame (70), the rock mass installation frame is placed in a 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 comprises a press (11) capable of applying pressure to a movable side of a box body (10); the grouting model device comprises a box body (10) composed of steel plates sealed together, the box body (10) being provided with a water injection port, a grouting hole, and a pressure relief valve. , a grouting hole and a transparent grouting observation plate; the water injection device (14) comprises a water tank (16) with adjustable height, the water tank (16) being connected to the box body (10) via a 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) being radially provided with grouting ports (52) arranged along the axial direction, the grouting steel pipe (22) being connected to the air pump (1) and the first grouting pump (2) in the first grouting barrel (3) via a first grouting pipe (21).

3. A grouting reinforcement testing device for layered rock tunnels according to claim 2, 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).

4. A grouting reinforcement testing device for layered rock tunnels according to claim 2, characterized in that: The movable steel plate (30) on the top of the box body (10) is provided with a water injection port (24), and the side of the box body is provided with grouting holes (26) and grouting outlet holes (25) arranged up and down, and transparent grouting observation panels of different heights are respectively provided on the four sides of the box body.

5. The grouting reinforcement testing device for layered rock tunnel according to claim 2, 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.

6. The grouting reinforcement testing device for layered rock tunnel according to claim 2, characterized in that: A first mixer (4) is provided in the first grouting barrel (3).

7. The cohesion testing device for simulating tunneling through layered rock mass according to claim 2, characterized in that: The grouting model device is connected to a monitoring device (7), the monitoring device (7) comprising a sensor, the sensor comprising a stress gauge, a strain gauge, a flow meter and a pressure monitoring gauge; the stress gauge is placed in the grouting model device, the strain gauge is adhered to the inner wall of the box (10), the flow meter is placed in the pipeline connecting the water injection pipe, the grouting steel pipe (22) and the water outlet (25), and the pressure monitoring gauge is placed in the first grouting pipe (21).

8. The grouting reinforcement testing device for layered rock tunnels according to claim 2 is 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.

9. The grouting reinforcement testing device for layered rock tunnel according to claim 2, characterized in that: The standard specimen processing device comprises a cutting machine, a coring machine and a grinding machine.

Images