A testing device and method for simulating the cohesion of a tunnel passing through layered rock mass

Abstract

A cohesion testing device and method for simulating tunnel tunneling through layered rock mass, including a layered rock mass composed of mutually stacked rock slices. The layered rock mass is inserted into the installation groove of a rock mass installation frame, and the rock mass installation frame is placed in a grouting model device. The grouting model device is equipped with a water injection device, a grouting device, and a grouting reinforcement effect device. The grouting model device includes a box body formed by hermetically connecting steel plates. The water injection device includes a water tank with adjustable height. The grouting device includes a grouting steel pipe drilled into the layered rock mass, and the grouting steel pipe is radially provided with grouting ports arranged along the axial direction. After grouting is completed, the layered rock mass is taken out for detection to obtain the cohesion between the rock slices. The present invention installs the layered rock mass through the rock mass installation frame, and simulates and obtains the cohesion and internal friction angle of the layered rock mass after grouting under the real water pressure environment in the grouting model device.

Description

Technical Field

[0001] The present invention relates to the field of prevention and control of underground engineering disasters, and particularly to a device and method for testing the cohesion of simulated tunnel passing through layered rock mass. Background Art

[0002] Passing through poor geological bodies and stratum structure interfaces usually becomes a controlling project for the construction of subsea tunnels, directly affecting construction safety. If not properly handled, it will induce disasters and lead to project failure. In order to achieve the stability control of layered rock mass in poor geological sections, grouting reinforcement technology has been widely applied worldwide, playing an important role in ensuring project safety and quality, and also strongly promoting the continuous progress and rapid development of underwater tunnel and water stratum tunnel construction technologies. During the tunnel construction process, the cohesion between rock layers of layered rock mass will change due to the influence of tunnel opening. In order to avoid collapse, it is extremely important to measure the cohesion between layered rock masses.

[0003] Layered rock mass is a very widely distributed rock mass type in the world. Due to various geological tectonic actions during the formation process, layered rock mass has significant differences compared with other rock masses, and there are bedding structures such as bedding planes and schistosity planes. In order to study the stability problems of surrounding rock of layered rock mass tunnels, scholars mostly use indoor model tests, theoretical modeling, numerical simulation, on-site monitoring and inversion analysis, etc. to comprehensively and systematically study the failure mechanism of layered rock mass, surrounding rock stability, etc. The strength of rock mass is affected by bedding planes. For different rock masses, the degree of influence of bedding planes on them varies greatly. Even for the same kind of rock, its mechanical properties will also vary due to various factors.

[0004] On the other hand, layered rock mass widely exists in tunnel engineering. The long-term geological history evolution process and tectonic movement make its physical and mechanical properties tend to be complicated. Many domestic and foreign scholars have deeply studied the constitutive model and mechanical parameters of layered rock mass through experimental or numerical simulation methods. Most of the research is physical simulation tests, and there is a lack of research on the cohesion and internal friction angle of rock mass structural planes with different bedding angles, different numbers and sizes of circular holes, etc.

[0005] Therefore, there is an urgent need for a device and method for testing the cohesion of simulated tunnel passing through layered rock mass to simulate the influence of tunnel hole size and quantity on the cohesion and internal friction angle of rock mass structural planes. Summary of the Invention

[0006] The purpose of the present invention is to provide, in view of the defects and deficiencies of the prior art, a cohesive force test device and method for simulating the grouting path planning and reinforcement of layered rock masses under the action of different water pressures, and accurately evaluating the grouting reinforcement effect during the tunneling through layered rock masses, so as to finally realize the acquisition of performance data on the influence of different tunnel hole sizes and quantities on the cohesive force and internal friction angle of the horizontal or inclined structural planes of layered rock masses.

[0007] To achieve the above purpose, the present invention provides a cohesive force test device for simulating tunneling through layered rock masses, which includes a layered rock mass composed of mutually stacked rock slices. The layered rock mass is inserted into the installation groove of a rock mass installation frame, and the rock mass installation frame is placed in a grouting model device. The grouting model device is equipped with a water injection device, a grouting device, and a grouting reinforcement effect device. The grouting model device includes a box body formed by hermetically connecting steel plates. The box body is provided with a transparent grouting observation board, a grouting hole, and a water outlet hole. The water injection device includes 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 layered rock mass. The grouting device includes 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. After the grouting is completed, the layered rock mass is taken out for testing to obtain the cohesive force between the rock slices. The cohesive force test device for simulating tunneling through layered rock masses of the present invention uses the water injection device to simulate the stress environment of underground layered rock masses, truly restoring the construction site environment. The on-site grouting situation is simulated through the grouting model device and the grouting device. According to the grouting reinforcement effect device, a nearly real grouting effect is obtained. After the grouting is completed, the layered rock mass is taken out for testing to obtain the cohesive force between the rock slices, so as to judge the influence of the tunnel hole size and quantity on the cohesive force and internal friction angle of the structural plane of the layered rock mass. The present invention installs the layered rock mass through the rock mass installation frame, and simulates and obtains the cohesive force and internal friction angle of the layered rock mass after grouting under the real water pressure environment in the grouting model device.

[0008] The box body is formed by hermetically connecting steel plates to each other. The top of the box body is provided with a top plate, and the top plate is provided with a water injection port. The steel plates on the side of the box body are provided with a grouting hole and a water outlet hole arranged vertically. A transparent grouting observation board is arranged between the grouting hole and the water outlet hole, which is convenient for observing the grouting effect of the grouting slurry.

[0009] The water tank is connected to a chain hoist, and the chain hoist drives the water tank to move up and down to simulate the formation of a groundwater system environment with different water pressures.

[0010] 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. The first grouting pipe is connected to a second grouting pipe, and the second grouting pipe is connected to an air pump and a second grouting pump in a second grouting barrel.

[0011] A first stirrer is arranged in the first grouting barrel, and a second stirrer is arranged in the second grouting barrel, which are used to uniformly mix the grouting slurry.

[0012] The grouting model device is connected with a monitoring device, and the monitoring device includes sensors, and the sensors include a stress gauge, a strain gauge, a flow velocity 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 body, the flow velocity meter is placed on the pipeline connected with the water injection pipe, the grouting steel pipe and the water outlet hole, and the pressure monitor is placed in the first grouting pipe. The monitoring device realizes the stress and stress change conditions of the layered rock mass in the grouting model device, has the flow change conditions of pressure, water injection and grouting, and realizes the restoration of the water vapor content change conditions of the layered rock mass in the underground environment where it occurs, providing accurate data support for the grouting work at the actual site.

[0013] The water injection port and the water injection pipe are sealed with epoxy resin AB glue, and the grouting hole and the grouting steel pipe are sealed with epoxy resin AB glue to prevent water and grouting slurry from leaking out.

[0014] The grouting reinforcement effect device includes a grouting effect observation pipe with zero grouting pressure. The internal layer of the grouting effect observation pipe is embedded with a layered rock mass, and the porosity of the embedded layered rock mass is limited to the entry of the grouting slurry. The grouting slurry concentration flowing out of the grouting effect observation pipe is used to judge the grouting effect in real time.

[0015] A method for testing the cohesion of a simulated tunnel passing through a layered rock mass includes the following steps:

[0016] I. Prepare layered rock masses composed of stacked rock slices, and form layered rock masses with different parameters by setting the number, size of the stacked rock slices and the number of holes for grouting through the grouting steel pipe.

[0017] II. Optionally insert a layered rock mass horizontally or obliquely into the installation groove of the rock mass installation frame.

[0018] III. Prepare a grouting model device. The four side plates and the bottom plate of the box body of the grouting model device are connected by high-strength bolts, and the joints are sealed with rubber gaskets to ensure the water impermeability of the box body.

[0019] IV. Put the rock mass installation frame in step II into the open box body, and then hermetically connect the top plate with the box body.

[0020] V. 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.

[0021] VI. Prepare the grouting device, drill the grouting steel pipe into the opening corresponding to the layered rock mass, connect the grouting steel pipe to the first grouting pipe, and transport the grouting slurry into the grouting model device through the grouting holes 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 grouted layered rock mass;

[0022] VII. The monitoring device monitors the grouting parameters in real time and records the grouting parameters after the grouting reinforcement is finally completed for guiding the tunnel seepage grouting reinforcement under different water pressures at the construction site;

[0023] VIII. After taking out the target grouted rock mass completed in Step VII, sequentially select the other layered rock masses with different parameters formed in Step I for Steps I to VII. Finally, detect the cohesion and internal friction angle between the laminated rock flakes of the obtained target grouted rock masses with different parameters to provide accurate data support for the actual tunnel crossing of the layered rock mass.

[0024] In Step V, different groundwater pressures are formed on the layered rock mass by adjusting the height of the water tank, an artificial water head is set manually, and the grouting slurry is guided to flow directionally as required through the artificial water head. By observing the concentration of the slurry flowing out of the grouting effect observation pipe, the grouting reinforcement effect is judged in real time. The artificial water head is the groundwater pressure set manually, and the grouting slurry is guided to flow directionally as required through different water pressures to improve the grouting effect.

[0025] In the above steps, there are two or more grouting steel pipes, which are evenly distributed up and down, and the grouting pressure is greater than the water pressure of the occurrence environment to avoid the collapse of the rock stratum.

[0026] Adopting the above technical solution, the device and method for testing the cohesion of a simulated tunnel crossing a layered rock mass form a layered rock mass composed of mutually laminated rock flakes, insert the layered rock mass into the installation groove of the rock mass installation frame, simulate the water content and water head of the layered rock mass occurrence under different water pressures at the construction site through the grouting model device by the water injection device, restore the construction layered rock mass environment, grout the layered rock mass through the grouting steel pipe by the grouting device, evaluate the grouting effect through the grouting reinforcement effect device, and at the same time obtain the best grouting parameters by the monitoring device. Finally, detect the cohesion and internal friction angle between the laminated rock flakes of the obtained target grouted rock masses with different parameters to provide accurate data support for the actual tunnel crossing of the layered rock mass. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 is a schematic structural diagram of a cohesion test device for simulating tunnel tunneling through layered rock masses according to the present invention;

[0029] Figure 2 is a schematic structural diagram of the installation of grouting steel pipes in the present invention;

[0030] Figure 3 is a schematic structural diagram of a grouting model device in the invention;

[0031] Figure 4 is a schematic structural diagram of a rock mass installation frame in the invention;

[0032] Figure 5 is a schematic structural diagram of a layered rock mass of a horizontally inserted rock mass installation frame in the invention;

[0033] Figure 6 is a schematic structural diagram of a layered rock mass of an inclined inserted rock mass installation frame in the invention. Detailed implementation manners

[0034] Next, in combination with the drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] Such as Figures 1-6 A cohesion test device and method for simulating tunnel tunneling through layered rock masses, including a layered rock mass composed of mutually stacked rock flakes. The layered rock mass is inserted into the installation groove 73 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, and a grouting reinforcement effect device.

[0036] The grouting model device includes a box body 10 formed by airtight connection of steel plates. The box body 10 is provided with a transparent grouting observation board 5, a grouting hole 26, and a water outlet hole 25. The box body is provided with a top plate 30 at the top, and the top plate is provided with a water injection port 24. The steel plate on the side of the box body is provided with a grouting hole 26 and a water outlet hole 25 arranged up and down, and a transparent grouting observation board 5 is arranged between the grouting hole and the water outlet hole.

[0037] 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 a water injection pipe 13 to form different groundwater pressures on the layered rock mass. The water tank 16 is connected to a chain hoist 15, and the chain hoist 15 drives the water tank 16 to move up and down to realize the change of water pressure.

[0038] The grouting device includes 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. After the grouting is completed, the layered rock mass is taken out for detection to obtain the cohesion between the rock flakes. The grouting steel pipe 22 is connected to an air pump 1 and a first grouting pump 2 in a first grouting barrel 3 through a first grouting pipe 21. The first grouting pipe 21 is connected with a second grouting pipe 20. The second grouting pipe 20 is connected to the air pump 1 and a second grouting pump 17 in a second grouting barrel 18 to increase the grouting flow rate, and can also be connected to different grouting steel pipes to achieve the grouting performance at multiple points. In order to increase the uniformity of the grouting slurry, a first stirrer 4 is provided in the first grouting barrel 3, and a second stirrer 19 is provided in the second grouting barrel 18.

[0039] As a structural optimization, the monitoring device 7 includes sensors. The sensors include a stress gauge, a strain gauge, a flow velocity 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 body 10. The flow velocity meter is placed on the pipeline connected to the water injection pipe, the grouting steel pipe 22, and the water outlet hole 25. The pressure monitor is placed in the first grouting pipe 21. The monitoring device 7 monitors the grouting parameters in real time through the induction wire 6 connected to the sensors. The grouting parameters at least include the grouting pressure and the flow rate.

[0040] The grouting reinforcement effect device includes a grouting effect observation pipe with zero grouting pressure. The grouting effect observation pipe is internally embedded in the rock mass. The porosity of the embedded rock mass is limited to allow the grouting slurry to enter. The grouting effect is judged in real time according to the concentration of the grouting slurry flowing out of the grouting effect observation pipe.

[0041] To improve the airtight performance of the box body 10, the water injection port 24 and the water injection pipe 13 are sealed with epoxy resin AB glue, and the grouting hole 26 and the grouting steel pipe 22 are sealed with epoxy resin AB glue.

[0042] A method for testing the cohesion of a simulated tunnel passing through a layered rock mass includes the following steps:

[0043] I. Prepare layered rock flakes stacked on each other to form a layered rock mass. Different parameters of the layered rock mass are formed by setting the number, size of the stacked rock flakes, and the number of holes for grouting in cooperation with the grouting steel pipe.

[0044] II. Optionally, insert a layered rock mass horizontally or obliquely into the installation groove of the rock mass installation frame.

[0045] III. Prepare a grouting model device. The four side plates and the bottom plate of the box body 10 of the grouting model device are connected by high-strength bolts, and the joints are sealed with rubber gaskets to ensure the water impermeability of the box body.

[0046] IV. Put the rock mass installation frame in step II into the open box body 10, and then connect the top plate 30 to the box body in a sealed manner.

[0047] V. 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.

[0048] VI. Prepare the grouting device. The grouting steel pipe 22 is drilled into the opening that matches the layered rock mass. The grouting steel pipe 22 is connected to the first grouting pipe 21, and the grouting slurry is conveyed 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 grouted layered rock mass.

[0049] VII. The monitoring device 7 monitors the grouting parameters in real time and records the grouting parameters after the final completion of grouting reinforcement for guiding the tunnel seepage grouting reinforcement under different water pressures at the construction site.

[0050] VIII. After taking out the target grouted rock mass completed in step VII, sequentially select the other layered rock masses with different parameters formed in step I for steps I to VII. Finally, detect the cohesion and internal friction angle between the laminated rock slices of the obtained target grouted rock masses with different parameters to provide accurate data support for the actual tunnel passing through the layered rock mass.

[0051] In step V, different groundwater pressures are formed on the layered rock mass by adjusting the height of the water tank, an artificial water head is set manually, and the grouting slurry is guided to flow directionally as needed through the artificial water head.

[0052] As a specific implementation plan, the platform size of the box body 10 is 1000mm * 1000mm * 1000mm. The box body 10 is made of 10mm thick steel plate, which can meet the requirement of the maximum grouting pressure of 10Mpa. The side and bottom are both connected by high-strength bolts. To ensure the airtightness of the model box, the joints are sealed with 2mm thick rubber gaskets and sealant. Transparent grouting observation plates with different heights are arranged on the sides, made of 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 box body 10 in turn. A water injection port with a radius of 20mm is reserved at the top of the box body 10, and a water outlet hole with a radius of 5mm is reserved at the bottom. When a rock mass sample is placed in the box body, the top plate 30 is embedded at the open mouth of the box body for sealing, and the joints are sealed with thick rubber gaskets and sealant.

[0053] The specific installation process of the layered rock mass composed of mutually laminated rock slices is as follows:

[0054] Step 1: Sampling. The size of the rock mass installation frame 70 is 150mm * 150mm * 150mm. The left and right sides of the rock mass installation frame 70 device are steel bars. The front and rear sides of the steel bars 71 are surrounded by equally spaced installation grooves 73. The upper side is surrounded by steel bars, the center position is empty, and the lower side is steel bars. All eight corners of the rock mass installation frame 70 are fixed with gaskets and bolts 72 for convenient disassembly of the layered rock mass.

[0055] Step 2: Drill a plurality of round holes with different sizes and quantities at regular intervals on each piece of layered rock mass, with inclination angles of 0° and 45°.

[0056] Step 3: Insert the layered rock mass with drilled round holes into the installation groove 73 layer by layer. Set the horizontally inserted layered rock mass 81, set the first round hole 82, or set the inclined inserted layered rock mass 83, set the second round hole 84 to complete the specific installation of the mutually stacked rock flakes to form a layered rock mass.

[0057] The present invention simulates different cohesion and internal friction angles of the structural planes of the tunnel passing through the layered rock mass by adjusting the size and quantity of the holes, and solves the problems of complex processing and difficult production of standard rock specimens in the existing tests for measuring the cohesion and internal friction angle of layered rocks.

[0058] The specific grouting steps in the grouting device are as follows:

[0059] ① First, drill two vertically parallel grouting steel pipes and a grouting effect observation pipe with zero grouting pressure in the layered rock mass. The two vertically parallel grouting steel pipes are the grouting steel pipe 22 and the first grouting steel pipe 23 respectively. The first grouting steel pipe 23 is provided with equally spaced first grouting holes 44, and the grouting steel pipe 22 is provided with equally spaced grouting ports 52. The grouting steel pipe 22 and the first grouting steel pipe 23 cooperate with the first round hole 82 or cooperate with the second round hole 84.

[0060] ② Each grouting steel pipe is symmetrically distributed up and down, and the spacing between adjacent holes is adjusted in a timely manner according to the situation;

[0061] ③ The grouting pressure of the grouting steel pipe is greater than the water pressure of the occurrence environment; for the grouting effect observation pipe with zero grouting pressure, the grouting effect observation pipe is internally embedded in the layered rock mass, and the porosity of the embedded layered rock mass only allows the grouting slurry to enter. The concentration of the grouting slurry flowing out of the grouting effect observation pipe is used to evaluate the grouting effect in real time.

[0062] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cohesion test device for simulating tunnel crossing stratified rock mass, characterized in that: It includes a layered rock mass composed of mutually overlapping rock flakes. 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 a grouting model device, and the grouting model device is equipped with a water injection device, a grouting device, and a grouting reinforcement effect device; the grouting model device includes a box body (10) formed by airtight connection of steel plates. The box body (10) is provided with a transparent grouting observation board (5), a grouting hole (26), and a water outlet hole (25); 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 a water injection pipe (13) to form different groundwater pressures on the layered rock mass; the grouting device includes 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. After grouting is completed, the layered rock mass is taken out for detection to obtain the cohesion between the rock flakes. The grouting model device is connected with a monitoring device (7). The monitoring device (7) includes sensors, and the sensors include a stress gauge, a strain gauge, a flow velocity 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 body (10), the flow velocity meter is placed on the pipeline connected to the water injection pipe, the grouting steel pipe (22), and the water outlet hole (25), and the pressure monitor is placed in the first grouting pipe (21).

2. The cohesion test device for simulating tunnel crossing stratified rock mass according to claim 1, wherein: The top of the box body (10) is provided with a top plate (30). The top plate is provided with a water injection port (24). The steel plates on the side of the box body are provided with grouting holes (26) and water outlet holes (25) arranged up and down. A transparent grouting observation board (5) is arranged between the grouting hole and the water outlet hole.

3. The cohesion test device for simulating tunnel crossing stratified rock mass according to claim 1, wherein: The water tank (16) is connected with a chain hoist (15), and the chain hoist (15) drives the water tank (16) to move up and down.

4. A cohesion test device for simulating tunnel crossing layered rock mass according to claim 1, characterized in that: The grouting steel pipe (22) is connected to an air pump (1) and a first grouting pump (2) in a first grouting barrel (3) through a first grouting pipe (21). The first grouting pipe (21) is connected with a second grouting pipe (20), and the second grouting pipe (20) is connected to the air pump (1) and a second grouting pump (17) in a second grouting barrel (18).

5. The cohesion testing device for simulating tunnel crossing stratified rock mass according to claim 4, wherein: A first stirrer (4) is arranged in the first grouting barrel (3), and a second stirrer (19) is arranged in the second grouting barrel (18).

6. The cohesion testing device for simulating tunnel crossing stratified rock mass according to claim 2, characterized in that: The water injection port (24) and the water injection pipe (13) are sealed with epoxy resin AB glue, and the grouting hole (26) and the grouting steel pipe (22) are sealed with epoxy resin AB glue.

7. The cohesion test device for simulating tunnel crossing layered rock mass according to claim 1, characterized in that: The grouting reinforcement effect device includes a grouting effect observation pipe with zero grouting pressure. The grouting effect observation pipe is internally embedded in the layered rock mass. The porosity of the embedded layered rock mass is limited to allow the grouting slurry to enter. The grouting effect is judged in real time according to the concentration of the grouting slurry flowing out of the grouting effect observation pipe.

8. A method for testing the cohesion of a layered rock mass during simulated tunnel tunneling according to claim 1, characterized in that: It includes the following steps:

1. Prepare a layered rock mass composed of mutually overlapping rock flakes. Different parameters of the layered rock mass are formed by setting the number, size of the overlapping rock flakes, and the number of openings for grouting in cooperation with the openings of the grouting steel pipe.

2. Arbitrarily select a layered rock mass and insert it horizontally or obliquely into the installation groove of the rock mass installation frame. III. Prepare the grouting model device. The four side plates and the bottom plate of the grouting model device box body (10) are connected by high-strength bolts, and rubber gaskets are used for sealing at the joints to ensure the water impermeability of the box body; IV. Place the rock mass installation frame in step II into the open box body (10), and then hermetically connect the top plate (30) to the box body; V. 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; VI. Prepare the grouting device. The grouting steel pipe (22) drills into the opening matching the layered rock mass. The grouting steel pipe (22) is connected to the first grouting pipe (21), and the grouting slurry is transported 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 grouted layered rock mass; VII. The monitoring device (7) monitors the grouting parameters in real time, and records the grouting parameters finally completed for guiding the tunnel seepage grouting reinforcement under different water pressures at the construction site; VIII. After taking out the target grouted rock mass completed in step VII, successively select the other layered rock masses with different parameters formed in step I for steps I to VII. Finally, detect the cohesion and internal friction angle between the laminated rock slices of the target grouted rock masses with different parameters to provide accurate data support for the actual tunnel passing through the layered rock mass.

9. A method for testing the cohesion of a simulated tunnel passing through layered rock mass according to claim 8, characterized in that: In step V, different groundwater pressures are formed on the layered rock mass by adjusting the height of the water tank, an artificial water head is set manually, and the grouting slurry is guided to flow directionally as required through the artificial water head.

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