Rectangular tunnel three-dimensional excavation model test device and method

Abstract

The present application relates to a kind of rectangular tunnel three-dimensional excavation model test device and method, including model box, test soil, rectangular tunnel lining, built-in unit rectangular rubber bag, external unit rectangular ring rubber bag, zinc chloride inner liquid, polyvinyl chloride foam, organic solvent, inner liquid injection and discharge pipe, organic solvent injection pipe, outer liquid discharge pipe and liquid collecting tank;By discharging zinc chloride inner liquid in built-in unit rectangular rubber bag to simulate the soil weight loss caused by tunnel excavation, by injecting organic solvent to dissolve polyvinyl chloride foam in external unit rectangular ring rubber bag to simulate the soil volume loss caused by tunnel excavation.The present application can realize three-dimensional simulation excavation while simulating soil volume loss and weight loss, fully considers the time-space effect of rectangular tunnel excavation, has the characteristics of strong operability, good simulation effect, convenient installation and removal, high test precision, etc., suitable for rectangular tunnel simulation excavation in indoor scale test.

Description

Technical Field

[0001] The present invention relates to the field of geotechnical model testing, and in particular to a three-dimensional rectangular tunnel excavation model testing device and method, which is suitable for simulating the excavation of a rectangular tunnel in an indoor scale-down test. Background Art

[0002] Shield tunneling, the predominant construction method for subway tunnels today, boasts advantages such as high mechanization, minimal environmental impact, rapid construction, and safety. However, traditional single-circular shield machines often encounter technical challenges when constructing tunnels under narrow roads in older urban areas, such as being unable to fit within the tunnel and unable to touch the tunnel. After decades of development, my country's shield tunneling technology and equipment have significantly improved. The cross-sectional shape of existing shields has evolved from the original circular shape to include horseshoe-shaped, rectangular, and rectangular pipe jacking machines. Quasi-rectangular shield cross-sections offer the advantages of excellent structural strength and high space utilization. During construction, dual-track tunnels can be formed in a single excavation, maximizing the conservation of underground space resources and significantly improving the tunnel's ability to pass through narrow roads or between high-rise buildings. This has gradually become a new option for underground shield projects.

[0003] Indoor model testing of tunnels is difficult to fully replicate every construction process due to the complexity of actual tunnel excavation processes. Ground deformation caused by tunnel excavation is related to multiple factors, including face excavation, shield machine advancement, shield tail voids, lining deformation, and soil reconsolidation. The impact of these factors on ground deformation is typically defined as volume loss. Therefore, using volume loss as a control parameter to simulate tunnel excavation has become the most commonly used and recognized method. However, actual tunnel construction also causes a certain amount of weight loss due to soil excavation within the lining, a factor rarely considered in existing model tests. However, studies using centrifuge model tests have shown that the test results differ by approximately 10% between conditions with and without weight loss simulation. Furthermore, existing tunnel model test devices primarily operate under plane strain conditions, simulating a single excavation phase while neglecting the three-dimensional tunnel excavation process. Therefore, for indoor model testing of rectangular tunnels, a three-dimensional excavation simulation device that can simultaneously simulate both soil volume loss and weight loss is urgently needed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a three-dimensional excavation model test device and method for a quasi-rectangular tunnel.

[0005] The three-dimensional excavation model test device of the quasi-rectangular tunnel comprises a model box, test soil, a quasi-rectangular tunnel lining, an internal unit quasi-rectangular rubber bag, an external unit quasi-rectangular ring rubber bag and a liquid collecting tank;

[0006] The quasi-rectangular tunnel lining is buried in the test soil in the model box, and the excavation area of ​​the quasi-rectangular tunnel lining includes a plurality of segments;

[0007] The inner unit rectangular rubber bag is arranged in sections inside the rectangular tunnel lining, and the inner unit rectangular rubber bag is filled with zinc chloride liquid, and the density of the zinc chloride liquid is consistent with that of the test soil; the bottom of the inner unit rectangular rubber bag is connected to an inner liquid injection and discharge pipe;

[0008] The external rectangular annular rubber bag is arranged in sections outside the quasi-rectangular tunnel lining, and the interior of the external rectangular annular rubber bag is filled with polyvinyl chloride foam; an organic solvent injection pipe is connected to one corner of the external rectangular annular rubber bag, and an external liquid discharge pipe is connected to the other opposite corner below; the cross-sectional shape of the polyvinyl chloride foam conforms to the displacement convergence mode of the quasi-rectangular tunnel, and the cross-sectional area size is consistent with the soil volume loss rate caused by the excavation of the quasi-rectangular tunnel;

[0009] The external liquid drain pipe and the internal liquid injection and discharge pipe are respectively connected to the liquid collecting tank, which includes an internal liquid tank and an external liquid tank.

[0010] Preferably, in each rectangular tunnel lining segment, the inner unit rectangular rubber bag is fitted with the inner wall of the rectangular tunnel lining, and the outer unit rectangular annular rubber bag is fitted with the outer wall of the rectangular tunnel lining; the longitudinal lengths of the inner unit rectangular rubber bag and the outer unit rectangular annular rubber bag are consistent.

[0011] As a preference, an inner liquid discharge valve is provided on the inner liquid injection and discharge pipe, an organic solvent injection valve is provided on the organic solvent injection pipe, and an outer liquid discharge valve is provided on the outer liquid discharge pipe.

[0012] Preferably: a first reserved pipe opening is provided at the bottom center axis of each rectangular tunnel lining segment; the external unit rectangular annular rubber bag includes an inner membrane and an outer membrane, and a second reserved pipe opening is provided at the bottom center of the inner membrane and the outer membrane; the first reserved pipe opening and the second reserved pipe opening are distributed on the same axis, the inner diameters of the first reserved pipe opening and the second reserved pipe opening are consistent, and the inner diameters of the first reserved pipe opening and the second reserved pipe opening are larger than the outer diameter of the internal liquid injection and discharge pipe; one end of the internal liquid injection and discharge pipe is connected to the bottom of the built-in unit rectangular rubber bag, and the other end passes through the first reserved pipe opening and the second reserved pipe opening to be connected to the liquid collecting tank.

[0013] The test method of the three-dimensional excavation model test device of the quasi-rectangular tunnel comprises the following steps:

[0014] S1. Divide the quasi-rectangular tunnel lining into several segments and drill the first reserved pipe opening;

[0015] S2. Prepare an external unit-type rectangular ring rubber bag with a second reserved pipe port, an organic solvent injection pipe, and an external liquid discharge pipe, and fill it with polyvinyl chloride foam; prepare an internal unit-type rectangular rubber bag with an internal liquid injection and discharge pipe;

[0016] S3. Install the external unit-like rectangular ring rubber bag and the internal unit-like rectangular rubber bag in sections, fill the internal unit-like rectangular rubber bag with zinc chloride internal liquid, and close the internal liquid drain valve to form a rectangular tunnel model;

[0017] S4. Laying test soil in the model box and burying a rectangular tunnel model, the organic solvent injection pipe horizontally penetrates the model box, and the external liquid drainage pipe and the internal liquid injection and drainage pipe downwardly penetrate the model box to the liquid collecting tank;

[0018] S5. Simulate the excavation of the first tunnel section. Open the organic solvent injection valve and the external liquid discharge valve. Inject the organic solvent into the external unit-like rectangular ring rubber bag. Dissolve the polyvinyl chloride foam to form a mixed liquid and discharge it into the external liquid tank. Simultaneously open the internal liquid discharge valve and discharge the zinc chloride internal liquid into the internal liquid tank. Carry out three-dimensional simulated excavation of the remaining tunnel sections in sequence.

[0019] Preferably, in step S3, a plurality of external unit rectangular annular rubber bags are first installed in sequence on the outer wall of the rectangular tunnel lining, ensuring that the second reserved pipe opening is aligned with the first reserved pipe opening; then, the internal unit rectangular rubber bags are installed in sequence inside the rectangular tunnel lining, wherein the internal liquid injection and discharge pipes pass through the first reserved pipe opening and the second reserved pipe opening in sequence and leak out to the outside of the rectangular tunnel lining; and a syringe is used to fill the internal unit rectangular rubber bags with zinc chloride internal liquid through the internal liquid injection and discharge pipes.

[0020] Preferably, in step S3, cylindrical restraining blocks are filled in the lining of the quasi-rectangular tunnel in the trenchless sections at both ends of the quasi-rectangular tunnel.

[0021] Preferably, in step S5, an organic solvent is injected into the external unit-like rectangular ring-shaped rubber bag through an organic solvent injection tube using a syringe; the organic solvent is tetrahydrofuran, dioxane or cyclohexanone.

[0022] Preferably, in step S5, the mixed solution and the zinc chloride inner solution are respectively recovered and harmlessly treated.

[0023] The beneficial effects of the present invention are:

[0024] 1) The present invention flexibly adjusts the size of the polyvinyl chloride foam according to the displacement convergence mode and volume loss rate of the quasi-rectangular tunnel, and dissolves the polyvinyl chloride foam in the external unit quasi-rectangular annular rubber bag by injecting an organic solvent, thereby simulating the soil volume loss caused by the excavation of the quasi-rectangular tunnel.

[0025] 2) The present invention uses zinc chloride liquid with the same density as the test soil and discharges the zinc chloride liquid from the built-in rectangular rubber bags to simulate the weight loss of soil in the lining caused by the excavation of the rectangular tunnel. By considering multiple influencing factors, the simulation accuracy of the rectangular tunnel is improved.

[0026] 3) The present invention adopts independent external unit rectangular annular rubber bags and internal unit rectangular rubber bags, and realizes three-dimensional excavation simulation of rectangular tunnels by setting multiple unit segments. Compared with the one-time excavation simulation under plane strain conditions, the present invention fully considers the time and space effects of rectangular tunnel excavation during the three-dimensional excavation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a transverse cross-sectional view of a three-dimensional excavation model test device for a quasi-rectangular tunnel according to an embodiment of the present invention;

[0028] Figure 2 2. It is a top view of a three-dimensional excavation model test device for a quasi-rectangular tunnel according to one embodiment of the present invention;

[0029] Figure 3 is a longitudinal cross-sectional view of a three-dimensional excavation model test device for a quasi-rectangular tunnel according to an embodiment of the present invention;

[0030] Figure 4 is a schematic cross-sectional view of a quasi-rectangular tunnel lining according to an embodiment of the present invention;

[0031] Figure 5 is a cross-sectional schematic diagram of an external unit-like rectangular ring-shaped rubber bag according to one embodiment of the present invention;

[0032] Figure 6 yes Figure 5 Detailed schematic diagram of the second reserved nozzle in area A;

[0033] Figure 7 2 is a schematic cross-sectional view of a rectangular rubber bag with built-in units according to an embodiment of the present invention.

[0034] In the figure: 1-model box; 2-test soil; 3-rectangular tunnel lining; 4-internal unit rectangular rubber bag; 5-external unit rectangular ring rubber bag; 501-inner membrane; 502-outer membrane; 6-zinc chloride inner liquid; 7-polyvinyl chloride foam; 8-organic solvent; 9-inner liquid injection and discharge pipe; 10-organic solvent injection pipe; 11-external liquid discharge pipe; 12-syringe; 13-collecting tank; 131-inner liquid tank; 132-external liquid tank; 133-partition; 14-first reserved pipe opening; 15-inner liquid discharge valve; 16-second reserved pipe opening; 17-organic solvent injection valve; 18-external liquid discharge valve; 19-mixed liquid; 20-column constraint block. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0036] Example 1

[0037] As an example, Figures 1 to 7 As shown, a quasi-rectangular tunnel three-dimensional excavation model test device includes a model box 1, test soil 2, a quasi-rectangular tunnel lining 3, an internal unit quasi-rectangular rubber bag 4, an external unit quasi-rectangular ring rubber bag 5, a zinc chloride internal solution 6, polyvinyl chloride foam 7, an organic solvent 8, an internal solution injection and discharge pipe 9, an organic solvent injection pipe 10, an external solution discharge pipe 11, a syringe 12, and a liquid collecting tank 13;

[0038] like Figure 2 and Figure 3 As shown, the quasi-rectangular tunnel lining 3 is an aluminum alloy structure, and the quasi-rectangular tunnel lining 3 is buried in the test soil 2 in the model box 1. The excavation area of ​​the quasi-rectangular tunnel lining 3 includes several segments; a first reserved pipe opening 14 is arranged at the bottom central axis of each segment.

[0039] like Figures 1 to 3 As shown, the internal rectangular rubber bag 4 is segmented and placed inside the rectangular tunnel lining 3, closely attached to the inner wall of the lining. It is filled with zinc chloride internal solution 6, and its bottom is connected to an internal solution injection and discharge pipe 9 equipped with an internal solution drain valve 15. The zinc chloride internal solution 6 is made of zinc chloride powder and clean water in a certain proportion, and its density is consistent with that of the test soil 2.

[0040] like Figure 5 and Figure 6 As shown, the external rectangular annular rubber bag 5 comprises an inner membrane 501 and an outer membrane 502, which are arranged in sections outside the rectangular tunnel lining 3 and closely adhere to the lining's outer wall. The interior is filled with polyvinyl chloride foam 7. The cross-sectional shape of the polyvinyl chloride foam 7 conforms to the displacement convergence pattern of the rectangular tunnel, and the cross-sectional area is consistent with the soil volume loss rate caused by the excavation of the rectangular tunnel. A second reserved pipe opening 16 is provided at the bottom center of the inner and outer membranes 501, 502. The upper right corner of the outer membrane 502 is connected to the organic solvent injection pipe 10 equipped with an organic solvent injection valve 17, and the lower left corner is connected to the external liquid discharge pipe 11 equipped with an external liquid discharge valve 18.

[0041] like Figure 7As shown, the internal rectangular rubber bag 4 and the external rectangular annular rubber bag 5 have the same longitudinal length and are buried in the test soil 2 along with the rectangular tunnel lining 3. The first reserved nozzle 14 and the second reserved nozzle 16 are coaxially located, with the same inner diameter slightly larger than the outer diameter of the internal liquid injection and discharge pipe 9. One end of the internal liquid injection and discharge pipe 9 is connected to the bottom of the internal rectangular rubber bag 4, and the other end passes through the first reserved nozzle 14 and the second reserved nozzle 16 and connects to the liquid collection tank 13.

[0042] like Figure 1 As shown, the liquid collecting tank 13 is arranged outside the mold box 1, and includes an inner liquid tank 131, an outer liquid tank 132 and a partition 133. The outer liquid drain pipe 11 and the inner liquid injection and discharge pipe 9 are connected to the outer liquid tank 132 and the inner liquid tank 131 respectively.

[0043] Example 2

[0044] As another embodiment, the test method of the quasi-rectangular tunnel three-dimensional excavation model test device in the first embodiment includes the following steps:

[0045] S1: Making a quasi-rectangular tunnel lining. Divide the middle excavation area of ​​the quasi-rectangular tunnel lining 3 into several segments according to the simulated excavation length, and drill a first reserved pipe opening 14 at the center of the lining bottom of each segment.

[0046] S2: Fabricate an external unit-shaped rectangular annular rubber bag. The cross-sectional shape and dimensions of the polyvinyl chloride foam 7 are determined based on the dimensions of the rectangular tunnel lining, the displacement convergence pattern, and the soil volume loss rate. A dedicated mold is used to cast the external unit-shaped rectangular annular rubber bag 5, which is equipped with a second reserved nozzle 16, an organic solvent injection pipe 10, and an external liquid discharge pipe 11. The rubber bag is filled with polyvinyl chloride foam 7.

[0047] The cross-sectional shape and size of the built-in unit-like rectangular rubber bag 4 are determined according to the lining size of the quasi-rectangular tunnel, and the built-in unit-like rectangular rubber bag 4 with the internal liquid injection and discharge pipe 9 is cast using a special mold.

[0048] S3: Install the perfect rectangular tunnel model. In the excavation section of the rectangular tunnel, install the outer unit rectangular ring-shaped rubber bag 5 and the inner unit rectangular rubber bag 4 in segments. First, install several outer unit rectangular ring-shaped rubber bags 5 on the outer wall of the rectangular tunnel lining 3 in sequence, ensuring that the second reserved pipe opening 16 is aligned with the first reserved pipe opening 14. Then, install several inner unit rectangular rubber bags 4 inside the rectangular tunnel lining 3, wherein the inner liquid injection and drainage pipe 9 is sequentially passed through the first reserved pipe opening 14 and the second reserved pipe opening 16 and leaks outside the lining. Use the syringe 12 to fill the inner unit rectangular rubber bag 4 with the prepared zinc chloride inner liquid 6 through the inner liquid injection and drainage pipe 9, close the inner liquid drainage valve 15, and finally form a complete rectangular tunnel model. In the non-excavation section at both ends of the rectangular tunnel, fill the cylindrical constraint block 20 inside the rectangular tunnel lining 3 to prevent lateral deformation of the inner unit rectangular rubber bag 4.

[0049] S4: Install the test device. Layered soil 2 is laid in the model box 1 during the laying process, and the above-mentioned rectangular tunnel model is buried at the designed depth. At the same time, the organic solvent injection pipe 10 is laid horizontally through the model box 1, and the outer liquid drainage pipe 11 and the inner liquid injection and drainage pipe 9 are laid downward through the model box 1 to the liquid collection tank 13.

[0050] S5: Simulate the first segment excavation of the tunnel. Open the organic solvent injection valve 17 and the outer liquid drainage valve 18, and use the syringe 12 to slowly inject the organic solvent 8 into the outer unit rectangular ring-shaped rubber bag 5 through the organic solvent injection pipe 10, until the organic solvent 8 completely dissolves the polyvinyl chloride foam 7 to form a mixed liquid 19 that is drained into the outer liquid tank 132 of the liquid collection tank 13; simultaneously open the inner liquid drainage valve 15 until the zinc chloride inner liquid 6 is completely drained into the inner liquid tank 131 of the liquid collection tank 13, thereby completing the three-dimensional simulation excavation of the first segment of the tunnel. The organic solvent 8 is preferably tetrahydrofuran, dioxane, or cyclohexanone.

[0051] Segmented simulation of the entire tunnel excavation. Repeat step S5 to sequentially complete the three-dimensional simulation excavation of the remaining tunnel segments, and the mixed liquid 19 and the zinc chloride inner liquid 6 are respectively recycled and harmlessly treated.

Claims

1. A test method for a three-dimensional rectangular tunnel excavation model test device, characterized by: A quasi-rectangular tunnel three-dimensional excavation model test device comprises a model box (1), test soil (2), a quasi-rectangular tunnel lining (3), an internal unit quasi-rectangular rubber bag (4), an external unit quasi-rectangular annular rubber bag (5), and a liquid collecting tank (13); A quasi-rectangular tunnel lining (3) is buried in the test soil (2) in the model box (1), and the excavation area of ​​the quasi-rectangular tunnel lining (3) includes a plurality of segments; The built-in unit-like rectangular rubber bag (4) is arranged in sections inside the quasi-rectangular tunnel lining (3); the built-in unit-like rectangular rubber bag (4) is filled with zinc chloride internal liquid (6), and the density of the zinc chloride internal liquid (6) and the test soil (2) are consistent; the bottom of the built-in unit-like rectangular rubber bag (4) is connected to an internal liquid injection and discharge pipe (9); The external unit rectangular annular rubber bag (5) is arranged in sections outside the quasi-rectangular tunnel lining (3), and the interior of the external unit rectangular annular rubber bag (5) is filled with polyvinyl chloride foam (7); an upper corner of the external unit rectangular annular rubber bag (5) is connected to an organic solvent injection pipe (10), and the other opposite lower corner is connected to an external liquid discharge pipe (11); the cross-sectional shape of the polyvinyl chloride foam (7) conforms to the displacement convergence mode of the quasi-rectangular tunnel, and the cross-sectional area size is consistent with the soil volume loss rate caused by the excavation of the quasi-rectangular tunnel; The external liquid discharge pipe (11) and the internal liquid injection and discharge pipe (9) are respectively connected to the liquid collecting tank (13), and the liquid collecting tank (13) includes an internal liquid tank (131) and an external liquid tank (132); The test method of the three-dimensional excavation model test device of the rectangular tunnel includes the following steps: S1, dividing the rectangular tunnel lining (3) into several sections and setting a first reserved pipe opening (14); S2, making an external unit-like rectangular annular rubber bag (5) provided with a second reserved pipe opening (16), an organic solvent injection pipe (10) and an external liquid discharge pipe (11) and filling it with polyvinyl chloride foam (7); making an internal unit-like rectangular rubber bag (4) provided with an internal liquid injection and discharge pipe (9); S3, installing the external unit-like rectangular ring rubber bag (5) and the internal unit-like rectangular rubber bag (4) in sections, filling the internal unit-like rectangular rubber bag (4) with the zinc chloride internal liquid (6), and closing the internal liquid drain valve (15) to form a rectangular tunnel model; S4. Laying test soil (2) in the model box (1) and burying a rectangular tunnel model, the organic solvent injection pipe (10) horizontally penetrates the model box (1), and the external liquid discharge pipe (11) and the internal liquid injection and discharge pipe (9) penetrate downwardly through the model box (1) to the liquid collecting tank (13); S5, simulate the excavation of the first section of the tunnel, open the organic solvent injection valve (17) and the external liquid discharge valve (18), inject the organic solvent (8) into the external unit-like rectangular annular rubber bag (5), dissolve the polyvinyl chloride foam (7) to form a mixed liquid (19) and discharge it into the external liquid tank (132); simultaneously open the internal liquid discharge valve (15), and discharge the zinc chloride internal liquid (6) into the internal liquid tank (131); sequentially perform three-dimensional simulated excavation of the remaining tunnel sections; use a syringe (12) to inject the organic solvent (8) into the external unit-like rectangular annular rubber bag (5) through the organic solvent injection pipe (10); the organic solvent (8) is tetrahydrofuran, dioxane or cyclohexanone.

2. The test method of the quasi-rectangular tunnel three-dimensional excavation model test device according to claim 1, characterized in that: In each quasi-rectangular tunnel lining (3) segment, the internal unit quasi-rectangular rubber bag (4) is fitted to the inner wall of the quasi-rectangular tunnel lining (3), and the external unit quasi-rectangular annular rubber bag (5) is fitted to the outer wall of the quasi-rectangular tunnel lining (3); the longitudinal lengths of the internal unit quasi-rectangular rubber bag (4) and the external unit quasi-rectangular annular rubber bag (5) are consistent.

3. The test method of the quasi-rectangular tunnel three-dimensional excavation model test device according to claim 1, characterized in that: The inner liquid injection and discharge pipe (9) is provided with an inner liquid discharge valve (15), the organic solvent injection pipe (10) is provided with an organic solvent injection valve (17), and the outer liquid discharge pipe (11) is provided with an outer liquid discharge valve (18).

4. The test method of the quasi-rectangular tunnel three-dimensional excavation model test device according to claim 1, characterized in that: A first reserved pipe opening (14) is provided at the bottom center axis of each quasi-rectangular tunnel lining (3) segment; the external unit quasi-rectangular annular rubber bag (5) comprises an inner membrane (501) and an outer membrane (502), and a second reserved pipe opening (16) is provided at the bottom center of the inner membrane (501) and the outer membrane (502); the first reserved pipe opening (14) and the second reserved pipe opening (16) are distributed on the same axis, the first reserved pipe opening (14) and the second reserved pipe opening (16) have the same inner diameter, and the inner diameter of the first reserved pipe opening (14) and the second reserved pipe opening (16) is larger than the outer diameter of the internal liquid injection and discharge pipe (9); one end of the internal liquid injection and discharge pipe (9) is connected to the bottom of the internal unit quasi-rectangular rubber bag (4), and the other end passes through the first reserved pipe opening (14) and the second reserved pipe opening (16) and is connected to the collecting tank (13).

5. The test method of the quasi-rectangular tunnel three-dimensional excavation model test device according to claim 1, characterized in that: In step S3, a plurality of external unit-like rectangular annular rubber bags (5) are first installed and sleeved on the outer wall of the quasi-rectangular tunnel lining (3) in sequence, ensuring that the second reserved pipe opening (16) is aligned with the first reserved pipe opening (14); then, the internal unit-like rectangular rubber bags (4) are installed in sequence inside the quasi-rectangular tunnel lining (3), wherein the internal liquid injection and discharge pipe (9) passes through the first reserved pipe opening (14) and the second reserved pipe opening (16) in sequence and leaks outwardly to the outside of the quasi-rectangular tunnel lining (3); and a syringe (12) is used to fill the internal unit-like rectangular rubber bags (4) with zinc chloride internal liquid (6) through the internal liquid injection and discharge pipe (9).

6. The test method of the quasi-rectangular tunnel three-dimensional excavation model test device according to claim 1, characterized in that: In step S3, columnar restraining blocks (20) are filled in the quasi-rectangular tunnel lining (3) in the non-excavation section areas at both ends of the quasi-rectangular tunnel.

7. The test method of the quasi-rectangular tunnel three-dimensional excavation model test device according to claim 1, characterized in that: In step S5, the mixed solution (19) and the zinc chloride inner solution (6) are respectively recovered and harmlessly treated.

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