An experimental device and experimental method for failure mode of layered rock tunnel

Abstract

The present invention relates to an experimental device and method for layered rock tunnel failure modes, belonging to the field of tunnel engineering experiments, comprising a reaction frame, jacks fixedly provided on all four sides of the inner side of the reaction frame, the telescopic ends of the jacks pointing to the geometric center of the reaction frame and fixed with reaction steel plates, a layered rock specimen placed between the reaction steel plates, a distributed optical fiber sensor provided in the layered rock specimen; a jacking device provided on one side of the reaction frame, and a high-speed camera provided on the other side of the reaction frame relative to the jacking device. The beneficial effects of the present invention are as follows: a layered rock specimen is placed between the reaction steel plates, an extrusion failure experiment is performed on the layered rock specimen using the jacking device and the jacks, and a high-speed camera is used for recording, making it convenient for experimenters to study the failure laws of layered rock masses, the operation is simple, the data obtained are more diverse and intuitive, and the mechanical behavior and failure mode of the entire process of tunnel excavation and failure in layered rock masses can be comprehensively judged.

Description

Technical Field

[0001] The present invention relates to the field of tunnel engineering tests, in particular to a layered rock tunnel failure mode test device and test method. Background Art

[0002] After a long period of diagenesis and tectonic movement, the rock mass will produce a large number of discontinuous structural planes, such as bedding planes. The presence of bedding planes can have a significant impact on the failure mode after tunnel excavation. Therefore, it is necessary to study the failure behavior of tunnels under bedding planes.

[0003] Current research on tunnel failure modes often uses strain gauges to monitor the deformation characteristics of tunnel linings. However, the adhesive used in these strain gauges can affect the deformation of the lining, and the strain gauges are typically distributed, which in turn prevents them from fully reflecting the deformation characteristics of the lining under load. For surrounding rock deformation, a growing number of researchers are using distributed fiber optic sensors, embedded within the surrounding rock mass during pouring. However, excessive fiber optics within the surrounding rock mass increase the tensile strength of the rock material, leading to significant distortion of the deformation and failure morphology of the surrounding rock. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a layered rock tunnel failure mode experimental device and experimental method with more diverse test data and more accurate test results.

[0005] The present invention solves the above-mentioned technical problem with the following technical solution: a layered rock mass tunnel failure mode experimental device, comprising a frame-shaped reaction frame, jacks fixedly provided on all four sides of the inner side of the reaction frame, the telescopic ends of the jacks pointing to the geometric center of the reaction frame and fixed with reaction steel plates, a layered rock mass specimen placed between the reaction steel plates, and a distributed optical fiber sensor provided in the layered rock mass specimen;

[0006] A jacking device is provided on one side of the reaction frame, a telescopic end of the jacking device extends into the reaction frame and contacts the layered rock specimen, and a high-speed camera is provided on the other side of the reaction frame relative to the jacking device.

[0007] The beneficial effects of the present invention are as follows: a layered rock specimen is placed between reaction steel plates, an extrusion failure test is performed on the layered rock specimen by means of jacking equipment and a jack, and a high-speed camera is used to record the test, so that the experimenters can study the failure laws of the layered rock mass easily, the operation is simple, the data obtained are more diverse and intuitive, and the mechanical behavior and failure mode of the entire process of tunnel excavation and failure in the layered rock mass can be judged in all directions.

[0008] On the basis of the above technical solution, the present invention can also be improved as follows.

[0009] Furthermore, a lifting bracket is provided below the jacking equipment.

[0010] The beneficial effect of adopting the above further solution is that the height of the jacking equipment can be adjusted to accommodate layered rock specimens of different sizes.

[0011] An experimental method, using a layered rock tunnel failure mode experimental device, includes the following steps:

[0012] S1. Make two or more partitions and carve out the bedding surface characteristics on both sides of the partition according to the JRC coefficient of the bedding surface of the on-site rock mass;

[0013] S2. Prepare a layered rock specimen model box with an open top, vertically place a tunnel model column and two or more parallel partitions in the layered rock specimen model box, assuming that the number of partitions is N, and the partitions divide the layered rock specimen model box into N+1 chambers;

[0014] S3, first pouring: select a number of cavities at intervals, use gypsum slurry to pour the cavities in this batch, and after the gypsum is initially set, remove all partitions in the layered rock specimen model box;

[0015] S4. Embed a number of distributed optical fiber sensors on both sides of the gypsum board formed by the first pouring;

[0016] S5. Second pouring: Use gypsum slurry to pour all the remaining cavities. After the gypsum is initially set, remove the tunnel model columns;

[0017] S6. Third pouring: Use gypsum slurry to pour the cavity after removing the tunnel model column, and obtain a layered rock specimen after solidification;

[0018] S7. Remove the layered rock specimen and place it in a reaction frame, ensuring that the axis of the third pouring portion is parallel to the ground. Set the preload pressure of the jacks around it according to the stress conditions of the on-site rock mass, restore the on-site stress conditions, and fix the layered rock specimen with reaction steel plates.

[0019] S8. Arrange the jacking equipment on one side of the layered rock specimen, adjust the jacking position to the third pouring position, set the drilling speed and other parameters, and ensure that the drilling distance is greater than the thickness of the layered rock specimen;

[0020] S9. Place the high-speed camera on the other side of the layered rock specimen, and adjust the angle and position of the high-speed camera so that its photographic range completely covers the layered rock specimen;

[0021] S10, connect several distributed optical fiber sensors to the data acquisition terminal, prepare for debugging, and set parameters such as acquisition frequency;

[0022] S11. Arrange several acoustic emission instruments in one corner of the layered rock specimen;

[0023] S12. Start the high-speed camera, distributed fiber optic sensor, and acoustic emission instrument. Load the jacks on all sides to the target load. The jacking equipment starts to push the third pouring part until the third pouring part is completely separated from the layered rock specimen. During the jacking process, check the collection status of each monitoring instrument at all times. If any abnormal situation occurs, stop drilling and adjust the parameters in time.

[0024] S13. After the jacking is completed, the jacks on all sides are used to apply pressure in multiple stages. After the target load is reached, the load is held for a period of time. After all information is recorded and there are no abnormalities, the next stage of loading is continued. Each holding time is at least 5 minutes, and the loading is stopped until the layered rock specimen shows obvious damage.

[0025] S14. The images from the high-speed camera are transmitted to the DIC device for the experimenters to view the change pattern of the tunnel surrounding rock stress field during the tunnel drilling, loading, and destruction processes. The displacement of the deep rock mass along the bedding structure surface is viewed through the data transmitted by the distributed fiber optic sensor. The number of surrounding rock cracks generated at different stages is analyzed through the acoustic emission instrument data, and the final experimental data is summarized.

[0026] The beneficial effects of adopting the above technical solution are: it is possible to manufacture layered rock specimens with multi-layer bedding surface characteristics, and to conduct destruction experiments on the layered rock specimens. By coordinating high-speed cameras, distributed fiber optic sensors and acoustic emission instruments to collect data in all directions, verify each other, improve data accuracy, and comprehensively judge the mechanical behavior and failure mode of the entire process of tunnel excavation and failure in layered rock.

[0027] Furthermore, before executing step S7, white paint is sprayed on the surface of the layered rock specimen, and black scattered spots are evenly arranged on the surface of the layered rock specimen.

[0028] The beneficial effect of adopting the above further solution is that when conducting a destruction test on a layered rock specimen, the degree of deformation of the specimen surface can be judged by the displacement of the black scattered spots.

[0029] Furthermore, before executing step S6, lubricant is applied to the cavity formed by removing the tunnel model column.

[0030] The beneficial effect of adopting the above further solution is to prevent the jamming during the pushing of the third pouring part, which would affect the experimental progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the layered rock tunnel failure mode experimental device of the present invention.

[0032] Figure 2This is a schematic diagram of the first pouring of the layered rock specimen model box of the present invention.

[0033] Figure 3 This is a schematic diagram of the second pouring of the layered rock specimen model box of the present invention.

[0034] Figure 4 This is a schematic diagram of the third pouring of the layered rock specimen model box of the present invention.

[0035] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0036] 1. Reaction frame; 2. Jack; 3. Reaction steel plate; 4. Jacking equipment; 5. High-speed camera; 6. Lifting bracket; 7. Partition; 8. Layered rock specimen model box; 9. Tunnel model column; 10. Chamber; 11. Layered rock specimen. DETAILED DESCRIPTION

[0037] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0038] Example 1

[0039] like Figure 1 As shown, a layered rock mass tunnel failure mode experimental device includes a frame-shaped reaction frame 1, jacks 2 are fixedly provided on all four sides of the reaction frame 1, the telescopic ends of the jacks 2 point to the geometric center of the reaction frame 1 and are fixed with reaction steel plates 3, a layered rock mass specimen 11 is placed between the reaction steel plates 3, and a distributed optical fiber sensor is provided in the layered rock mass specimen 11;

[0040] A jacking device 4 is provided on one side of the reaction frame 1 , and the telescopic end of the jacking device 4 extends into the reaction frame 1 and contacts the layered rock specimen 11 . A high-speed camera 5 is provided on the other side of the reaction frame 1 relative to the jacking device 4 .

[0041] The beneficial effects of the present invention are as follows: a layered rock specimen 11 is placed between reaction steel plates 3, an extrusion failure test is performed on the layered rock specimen 11 by means of a jacking device 4 and a jack 2, and a high-speed camera 5 is used to record the test, so that the experimenter can study the failure law of the layered rock mass easily, the operation is simple, the data obtained are more diverse and intuitive, and the mechanical behavior and failure mode of the entire process of tunnel excavation and failure in the layered rock mass can be judged in all directions.

[0042] In this embodiment, layered rock mass refers to sedimentary, parametamorphic, and volcanic rock masses with a layered structure. Layers and schistosity are the primary structural planes of layered rock mass. The primary forms of deformation and failure in layered rock mass include bending, shear, and slip. In underground projects such as tunnels and underground power plants, the failure of layered rock mass can cause significant economic losses.

[0043] In this solution, the layered rock specimen 11 needs to be manufactured according to the bedding plane at the tunnel construction site to ensure the accuracy of the experimental data. The frame-shaped reaction frame 1 is placed vertically on the ground. Three jacks 2 are installed on each side of the reaction frame 1. The telescopic ends of the jacks 2 are fixed with reaction steel plates 3. The reaction steel plates 3 in four directions are assembled to form a frame to fix the layered rock specimen 11 on the inside.

[0044] The jacks 2 on all sides can be controlled to expand and contract separately. The reaction steel plates 3 are used to transmit pressure, reduce the pressure, and prevent the expansion and contraction ends of the jacks 2 from directly crushing the layered rock specimen 11. The reaction steel plates 3 have a certain elasticity. When the jacks 2 are pushed out, the reaction steel plates 3 deform and squeeze the layered rock specimen 11 to perform a destructive experiment. The high-speed camera 5 collects data, and the distributed optical fiber sensor collects data on the displacement of the rock layer.

[0045] Specifically, the high-speed camera 5 is a type of industrial camera with high image stability, high transmission capacity, and strong anti-interference capabilities. The distributed fiber optic sensor uses unique distributed fiber optic detection technology to measure or monitor the spatial distribution and temporal variation of information along the fiber optic transmission path. By arranging the sensing fibers along the field, it can simultaneously obtain spatial distribution and temporal variation information of the measured field.

[0046] As a parallel technical solution of this embodiment, the jack 2 can be replaced by a telescopic cylinder or other telescopic equipment.

[0047] Example 2

[0048] like Figure 1 As shown, preferably, on the basis of Example 1, a lifting bracket 6 is provided below the jacking device 4 .

[0049] The beneficial effect of adopting the preferred solution in the above embodiment is that the height of the jacking device 4 can be adjusted to accommodate layered rock specimens 11 of different sizes.

[0050] Specifically, the lifting bracket 6 includes a base and a column. The base is placed on the ground, and the column is vertically arranged above the base. The column can be a threaded column, which is threadedly connected to the base and is raised and lowered by twisting the thread. The column can also be a pneumatic telescopic column, which is raised and lowered by pneumatic control.

[0051] Example 3

[0052] like Figures 2 to 4 As shown, preferably, based on Examples 1-2, an experimental method is used to conduct an experiment using a layered rock tunnel failure mode experimental device, comprising the following steps:

[0053] S1. Make two or more partitions 7 and depict bedding surface features on both sides of the partitions 7 according to the JRC coefficient of the bedding surface of the on-site rock mass;

[0054] S2. Prepare a layered rock specimen model box 8 with an open top, vertically place a tunnel model column 9 and two or more mutually parallel partitions 7 in the layered rock specimen model box 8, assuming that the number of partitions 7 is N, and the partitions 7 divide the layered rock specimen model box 8 into N+1 chambers 10;

[0055] S3, first pouring: select a number of cavities 10 at intervals, use gypsum slurry to pour the batch of cavities 10, after the gypsum is initially set, remove all partitions 7 in the layered rock specimen model box 8;

[0056] S4. Embed a number of distributed optical fiber sensors on both sides of the gypsum board formed by the first pouring;

[0057] S5, second pouring: use gypsum slurry to pour all the remaining cavities 10, and after the gypsum is initially set, remove the tunnel model columns 9;

[0058] S6, third pouring: using gypsum slurry to pour the cavity after removing the tunnel model column 9, and after solidification, a layered rock specimen 11 is obtained;

[0059] S7. Remove the layered rock specimen 11 and place it in the reaction frame 1, ensuring that the axis of the third pouring part is parallel to the ground. Set the preload pressure of the jacks 2 around it according to the stress conditions of the rock mass on site, restore the stress conditions on site, and fix the layered rock specimen with the reaction steel plate 3.

[0060] S8, placing the jacking device 4 on one side of the layered rock specimen 11, adjusting the jacking position to the third pouring position, setting parameters such as the drilling speed, and ensuring that the drilling distance is greater than the thickness of the layered rock specimen 11;

[0061] S9, placing the high-speed camera 5 on the other side of the layered rock specimen 11, and adjusting the angle and position of the high-speed camera 5 so that its photographic range completely covers the layered rock specimen 11;

[0062] S10, connect several distributed optical fiber sensors to the data acquisition terminal, prepare for debugging, and set parameters such as acquisition frequency;

[0063] S11. Arrange several acoustic emission instruments in one corner of the layered rock specimen 11;

[0064] S12, start the high-speed camera 5, distributed fiber optic sensor and acoustic emission instrument, load the surrounding jacks 2 to the target load, and start the jacking device 4 to push the third pouring part until the third pouring part is completely separated from the layered rock specimen 11. During the jacking process, check the collection status of each monitoring instrument at all times. If any abnormal situation occurs, stop drilling and adjust the parameters in time;

[0065] S13. After the jacking is completed, the jacks 2 on all sides are used to apply pressure in multiple stages. After the target load is reached, the load is held for a period of time. After all information is recorded and no abnormalities are found, the next stage of loading is continued. Each holding time is at least 5 minutes, and the loading is stopped until the layered rock specimen 11 shows obvious damage.

[0066] S14. The images from the high-speed camera 5 are transmitted to the DIC device so that the experimenters can view the change pattern of the tunnel surrounding rock stress field during the tunnel drilling, loading, and destruction processes. The displacement of the deep rock mass along the bedding structure surface is viewed through the data transmitted by the distributed optical fiber sensor. The number of surrounding rock cracks generated at different stages is analyzed through the acoustic emission instrument data, and the final experimental data is summarized.

[0067] The beneficial effects of adopting the above technical solution are: it is possible to manufacture a layered rock specimen 11 with multi-layer bedding surface characteristics, and to conduct a destruction experiment on the layered rock specimen 11. In combination with a high-speed camera 5, a distributed optical fiber sensor and an acoustic emission instrument, data can be collected in all directions, verified with each other, and the accuracy of the data can be improved. It is possible to comprehensively judge the mechanical behavior and destruction mode of the entire process of tunnel excavation and failure in the layered rock mass.

[0068] In this embodiment, the JRC coefficient (Joint Roughness Coefficient) refers to the surface roughness of rock joints. After the construction personnel detect the rock bedding surface structure at the tunnel construction site, they make the corresponding partitions 7;

[0069] The layered rock specimen model box 8 has symmetrical slots on its two opposite inner walls. The slots are perpendicular to the top surface of the layered rock specimen model box 8. The partitions 7 are inserted into the slots from the top of the layered rock specimen model box 8 to divide the layered rock specimen model box 8 into a plurality of chambers 10. Each chamber 10 is equivalent to a rock layer.

[0070] The cross-section of the tunnel model column 9 is horseshoe-shaped, which simulates the real situation to the greatest extent. The tunnel model column 9 has two placement methods. Method 1: Place it in any cavity 10. After pouring, the tunnel is located in that rock layer; Method 2: Break a partition 7 and place the tunnel model column 9 at the broken position of the partition 7. The tunnel model column 9 is located between two cavities 10. After pouring, the tunnel is located between two rock layers at the same time, which can be used to experiment with different stress conditions.

[0071] like Figure 2 As shown, a batch of chambers 10 are first cast at intervals. After the gypsum solidifies, all partitions 7 are removed. After the partitions 7 are removed, the solidified gypsum board can still divide the layered rock specimen model box 8 into a number of chambers 10. Both sides of the solidified gypsum board have undulating bedding plane characteristics. At this time, a distributed optical fiber sensor is buried in certain bedding planes to be tested to minimize the influence of the distributed optical fiber sensor on the tensile strength of the layered rock specimen 11.

[0072] Then as Figure 3 As shown, a second pouring is performed, and new gypsum slurry is poured between two solidified gypsum boards. The gypsum slurry is closely combined with the bedding surface characteristics of the side of the gypsum board after the first pouring, simulating the actual rock layer. After solidification, the tunnel model column 9 is removed;

[0073] Then as Figure 4 As shown, the third pouring is carried out, and the gypsum slurry fills the holes exposed after the tunnel model column 9 is removed, and the layered rock specimen 11 is completed after solidification.

[0074] After that, the layered rock specimen 11 is taken out of the layered rock specimen model box 8 and placed in the reaction steel plate 3. Then, the jack 2 clamps the layered rock specimen 11, and the jacking device 4 is started to align with the third pouring position. The jacking device 4 gradually pushes the gypsum columns of the third pouring part out of the layered rock specimen 11. Then, according to the on-site rock stress distribution, the jacks 2 on all sides are controlled to partially or fully extend to squeeze the layered rock specimen 11.

[0075] During this process, when the material to be tested deforms or moves, acoustic vibrations are generated. The acoustic emission instrument is used to detect, record, analyze the acoustic emission signals, and use the acoustic emission signals to infer the source of the acoustic emission. The high-speed camera 5 captures the surface deformation, and the distributed fiber optic sensor senses the displacement of the rock layer simulated by the gypsum board. The above equipment is used to detect from multiple fields and compile experimental data.

[0076] Among them, DIC equipment (Digital Image Correlation) is mainly used to measure the deformation and strain of the object surface. It is an algorithm that compares related points in the image. Through this method, the displacement and strain distribution of the object surface can be calculated.

[0077] The distributed optical fiber sensor and the data acquisition terminal can be connected by wire or by wireless transmission to reduce the impact on the layered rock specimen 11.

[0078] Example 4

[0079] like Figures 2 to 4As shown, preferably, based on Examples 1-3, before executing step S7, the surface of the layered rock specimen 11 is sprayed with white paint, and black scattered spots are evenly arranged on the surface of the layered rock specimen 11.

[0080] The beneficial effect of adopting the preferred solution in the above embodiment is that when conducting a destruction test on a layered rock specimen 11, the degree of deformation of the specimen surface can be determined by the displacement of the black scattered spots.

[0081] Specifically, by pre-spraying white paint to form a base color, and then spraying black spots, it will be more conspicuous. Multiple black spots form a grid. Once the layered rock specimen 11 is squeezed and deformed, the observation is more intuitive, and it is easier to judge the deformation amount, reducing the difficulty of the experiment.

[0082] Example 5

[0083] like Figures 2 to 4 As shown, preferably, based on Examples 1-4, before executing step S6, lubricant is applied to the cavity formed by removing the tunnel model column 9.

[0084] The beneficial effect of adopting the preferred solution in the above embodiment is to prevent the jamming during the pushing of the third pouring part, thereby preventing the experimental process from being affected.

[0085] In this embodiment, the lubricant may be vaseline, talcum powder or any other type of lubricant.

[0086] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0087] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0088] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0089] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0090] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0091] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An experimental method, characterized in that The following steps are involved: S1. Make two or more partitions (7), and depict the bedding surface characteristics on both sides of the partition (7) according to the JRC coefficient of the bedding surface of the on-site rock mass; S2. A layered rock specimen model box (8) with an open top is prepared. A tunnel model column (9) and two or more mutually parallel partitions (7) are vertically placed in the layered rock specimen model box (8). The number of partitions (7) is N. The partitions (7) divide the layered rock specimen model box (8) into N+1 chambers (10). S3, first pouring: all N+1 chambers (10) are selected at intervals, and the selected chambers (10) are poured with gypsum slurry. After the gypsum is initially set, all partitions (7) in the layered rock specimen model box (8) are removed; S4. Embed a number of distributed optical fiber sensors on both sides of the gypsum board formed by the first pouring; S5, second pouring: use gypsum slurry to pour all the remaining cavities (10), and after the gypsum is initially set, remove the tunnel model column (9); S6, the third pouring: using gypsum slurry to pour the cavity after removing the tunnel model column (9), and obtaining a layered rock specimen (11) after solidification; S7, take out the layered rock mass specimen (11) and place it in the reaction frame (1), ensure that the axis of the third pouring part is parallel to the ground, set the preload pressure of the jacks (2) around it according to the stress conditions of the on-site rock mass, restore the on-site stress conditions and fix the layered rock mass specimen through the reaction steel plate (3); S8, placing the jacking device (4) on one side of the layered rock specimen (11), adjusting the jacking position to the third pouring position, setting the drilling speed parameters, and ensuring that the jacking distance is greater than the thickness of the layered rock specimen (11); S9, placing the high-speed camera (5) on the other side of the layered rock specimen (11), and adjusting the angle and position of the high-speed camera (5) so that its photographic range completely covers the layered rock specimen (11); S10, connecting several distributed optical fiber sensors to the data acquisition terminal, making preparations for debugging, and setting acquisition frequency parameters; S11. Arrange several acoustic emission instruments in one corner of the layered rock specimen (11); S12, start the high-speed camera (5), the distributed optical fiber sensor and the acoustic emission instrument, load the jacks (2) around the periphery to the target load, and start the jacking device (4) to push the third pouring part until the third pouring part is completely separated from the layered rock specimen (11). During the jacking process, check the collection status of each monitoring instrument at all times. If any abnormal situation occurs, stop drilling and adjust the parameters in time; S13. After the jacking is completed, the jacks (2) on all sides are pressurized in multiple stages. After the target load is reached, the load is held for a period of time. After all aspects of the information are recorded and there are no abnormalities, the next stage of loading is continued. Each holding time is at least 5 minutes, and the loading is stopped until the layered rock specimen (11) shows obvious damage. S14. The images from the high-speed camera (5) are transmitted to the DIC device so that the experimenters can check the stress field change of the tunnel surrounding rock during the tunnel drilling, loading and destruction process. The displacement of the deep rock mass along the bedding structure surface is checked by transmitting data through the distributed optical fiber sensor. The number of surrounding rock cracks generated at different stages is analyzed by the acoustic emission instrument data, and the data are summarized as the final experimental data.

2. An experimental method according to claim 1, characterized in that: Before executing step S7, the surface of the layered rock mass specimen (11) is sprayed with white paint, and black scattered spots are evenly arranged on the surface of the layered rock mass specimen (11).

3. An experimental method according to claim 1, characterized in that: Before executing step S6, lubricant is applied to the cavity formed by removing the tunnel model column (9).

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