Tunnel structure laterally penetrating karst cave and construction method thereof

Abstract

The invention relates to the technical field of underground engineering, in particular to a tunnel structure laterally penetrating a karst cave and a construction method of the tunnel structure laterally penetrating the karst cave. The bearing platform is connected to the top of the stand column; the secondary lining is erected on the bearing platform; the primary supporting steel frame is located on the outer side of the secondary lining, the primary supporting steel frame comprises a hollowed-out section and a supporting section which are connected with each other, the hollowed-out section is located in the top area of the karst cave, the supporting section is located in a soil layer, and a permeable cavity is formed between the hollowed-out section and the secondary lining; and the access door is arranged on the secondary lining and used for communicating the permeable cavity with the interior of the tunnel. The top of the karst cave is protected through the hollowed-out section of the primary support steel frame, the stand columns and the bearing platform are arranged at the bottom of the karst cave to support the tunnel, the traditional procedure of blocking and filling the karst cave is avoided, it is guaranteed that water in the karst cave is smooth, air in the karst cave can be introduced into the tunnel, tunnel ventilation is assisted, and the tunnel ventilation efficiency is improved. And construction procedures are reduced, and the tunnel construction progress is accelerated.

Description

Technical Field

[0001] The present invention relates to the technical field of underground engineering, and particularly relates to a tunnel structure passing through a karst cave laterally and a construction method thereof. Background Art

[0002] A karst cave is an underground cavity formed by the dissolution, erosion, and collapse of soluble rocks (such as limestone) under the action of water. Its formation is closely related to rock solubility, hydrogeological conditions, climate, and geological structure. Karst water is groundwater stored in the dissolution fissures, karst caves, and underground rivers of soluble rocks, and has the characteristics of strong fluidity and uneven water volume. Karst caves and karst water depend on each other. Karst water shapes the morphology of karst caves, and karst caves provide runoff channels for karst water.

[0003] During the tunnel construction process, special geology such as karst caves is often encountered. Especially when constructing in the southwestern region of China, the styles and situations of karst caves are more complex and changeable. Currently, the traditional method is to backfill the karst cave area. For example, a Chinese patent with the patent number CN111485901A discloses a method for constructing a tunnel across a long and narrow shallow-bottom karst cave section without filling. The cavity under the tunnel excavation surface is backfilled with tunnel muck, the side cavity of the tunnel is backfilled with concrete, and a drain pipe is set. The water above the karst cave is introduced into the backfilled tunnel muck below the karst cave through the drain pipe for drainage.

[0004] However, the above method requires a large amount of backfilling work, and the backfilled tunnel muck is easy to block the original drainage channel of the karst cave, affecting the drainage effect of the karst cave. At the same time, when the current tunnel passes through a karst cave, the karst cave is treated as a kind of bad geology. In fact, there is an obvious natural wind inside and outside the karst cave due to the large temperature difference, and there is currently no structural design considering the application of the natural wind in the karst cave. Summary of the Invention

[0005] The purpose of the present invention is to provide a tunnel structure passing through a karst cave laterally and a construction method thereof for the problems in the background art that the conventional method requires a large amount of backfilling work, the backfilled tunnel muck is easy to block the original drainage channel of the karst cave, affecting the drainage effect of the karst cave, and there is currently no consideration of applying the natural wind in the karst cave.

[0006] In a first aspect, the present invention provides a tunnel structure passing through a karst cave laterally, including:

[0007] Columns, anchored to the bottom of the karst cave;

[0008] A bearing platform, connected to the top of the column;

[0009] A secondary lining, erected on the bearing platform;

[0010] The primary support steel frame is located outside the secondary lining. The primary support steel frame includes an open section and a support section that are connected to each other. The open section is located in the top area of the karst cave, and the support section is located in the soil layer. A permeable cavity is formed between the open section and the secondary lining.

[0011] An inspection door is provided on the secondary lining for connecting the permeable cavity with the inside of the tunnel.

[0012] In the tunnel structure of this embodiment, the columns are anchored to the bottom of the karst cave, the bearing platform is connected to the top of the columns, and the secondary lining is erected on the bearing platform. A support system is formed through the columns and the bearing platform to ensure that the bottom of the tunnel can be effectively supported at the karst cave, guarantee the bearing capacity of the tunnel bottom. Further, the primary support steel frame adopts a form combining an open section and a support section. The open section is located in the top area of the karst cave, and there is a permeable cavity between the open section and the secondary lining. It can not only prevent falling rocks from entering the karst cave through the open section, but also ensure that the karst cave water above can reach the bottom of the karst cave through the permeable cavity, avoiding water accumulation at the top of the tunnel from eroding the structure. And only columns are provided at the bottom of the karst cave without blocking the karst cave, allowing the karst cave water to flow out through the original water passage of the karst cave, ensuring the smooth drainage of the karst cave, realizing the natural diversion of karst water, reducing the water damage risk of the tunnel structure at the karst cave. Further, the permeable cavity is connected to the inside of the tunnel through the inspection door on the secondary lining, which is convenient for the tunnel structure to use the natural wind in the karst cave for ventilation during the construction period and the operation period, reducing the construction and operation ventilation costs and achieving economic savings.

[0013] Preferably, the open section covers the top of the karst cave.

[0014] The top of the karst cave is protected through the open section, and at the same time, it is also convenient for lava water and wind to enter the karst cave through the open section.

[0015] Preferably, it further includes a steel mesh, and the steel mesh is laid on the open section.

[0016] By laying a steel mesh on the open section, the stiffness of the open section is enhanced, and smaller falling rocks and rock blocks are intercepted by the steel mesh to reduce the risk of falling rocks.

[0017] Preferably, it further includes locking foot anchor pipes, and the locking foot anchor pipes are arranged on the open section and the support section.

[0018] Preferably, it further includes cross braces, and the cross braces are used to connect the open section and the secondary lining.

[0019] In a second aspect, the present invention provides a construction method for a tunnel structure passing through a karst cave laterally. When constructing the tunnel structure passing through a karst cave laterally as described in this application, the following steps are included:

[0020] S1: Construct columns at the bottom of the karst cave;

[0021] S2: Construct a bearing platform at the top of the column.

[0022] S3: Construct the primary support steel frame. The primary support steel frame includes a hollowed-out section and a support section. The hollowed-out section is located at the top of the karst cave, and the support section is located in the soil layer. Spray concrete on the support section.

[0023] S4: Carry out the casting of the secondary lining, and make the secondary lining located in the karst cave be erected on the bearing platform.

[0024] S5: Open the inspection door on the secondary lining located in the karst cave area.

[0025] For the construction method of a tunnel structure passing through a karst cave laterally according to the present invention, a rigid support system is formed by the column and the bearing platform to ensure the bearing capacity of the tunnel bottom and avoid the settlement or collapse of the tunnel structure caused by the karst cave. The hollowed-out section of the primary support steel frame is not sprayed with concrete, which is convenient for guiding the karst water at the top of the karst cave to naturally flow into the bottom of the karst cave, avoiding the erosion of the tunnel structure by accumulated water. At the same time, opening the inspection door can utilize the ventilation of the karst cave to improve the environment inside the tunnel.

[0026] Preferably, in S: Set up a temporary steel plate in the karst cave area. One end of the temporary steel plate is fixed on the karst cave, and the other end of the temporary steel plate is connected to the bearing platform.

[0027] Preferably, in S2: Lay a steel mesh on the hollowed-out section.

[0028] Preferably, in S3: Set up locking foot anchor pipes at both ends of the primary support steel frame.

[0029] Preferably, in S4: First make the outer formwork and inner formwork of the secondary lining. The outer formwork of the secondary lining is located below the hollowed-out section, and the outer formwork of the secondary lining is connected to the support section.

[0030] Compared with the prior art, the beneficial effects of the present invention:

[0031] A tunnel structure passing through a karst cave laterally according to the present application, where columns are anchored to the bottom of the karst cave, a bearing platform is connected to the top of the columns, and a secondary lining is erected on the bearing platform. A support system is formed by the columns and the bearing platform to ensure that the bottom of the tunnel can be effectively supported at the karst cave, guarantee the bearing capacity of the tunnel bottom. Further, the primary support steel frame adopts a form combining a hollowed-out section and a support section. The hollowed-out section is located in the area of the top of the karst cave, and there is a permeable cavity between the hollowed-out section and the secondary lining. It can not only prevent falling rocks from entering the karst cave through the hollowed-out section, but also ensure that the karst cave water above can reach the bottom of the karst cave through the permeable cavity, avoiding water accumulation at the top of the tunnel from eroding the structure. Moreover, only columns are arranged at the bottom of the karst cave, and the karst cave is not blocked, so that the karst cave water flows out through the original water passage of the karst cave, ensuring smooth drainage of the karst cave, realizing natural diversion of karst water, and reducing the water damage risk of the tunnel structure at the karst cave. Further, the permeable cavity is connected to the inside of the tunnel through a maintenance door on the secondary lining, enabling the tunnel structure to utilize the natural wind in the karst cave during the construction period and the operation period to reduce the ventilation cost and achieve economic savings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the construction steps of the present application Figure 1 .

[0033] Figure 2 is a schematic diagram of the construction steps of the present application Figure 2 .

[0034] Figure 3 is a schematic diagram of the construction steps of the present application Figure 3 .

[0035] Figure 4 is a schematic diagram of the construction steps of the present application Figure 4 .

[0036] Figure 5 is a schematic diagram of the construction steps of the present application Figure 5 .

[0037] Figure 6 is a top view of the primary support steel frame of the present application.

[0038] Figure 7 is a front view of the primary support steel frame.

[0039] Figure 8 is a layout schematic diagram of the foot-locking anchor pipes.

[0040] Figure 9 is Figure 8 the sectional view taken along A-A of

[0041] Figure 10 is Figure 8 the sectional view taken along B-B of

[0042] Markings in the figure:

[0043] 1 - Column

[0044] 2 - Raft

[0045] 3 - Secondary lining

[0046] 4 - Primary support steel frame, 41 - Hollowed - out section, 42 - Support section

[0047] 5 - Inspection door

[0048] 6 - Steel mesh

[0049] 7 - Temporary steel plate

[0050] 8 - Lock - foot anchor pipe

[0051] 9 - Connecting steel bar

[0052] 10 - Backfill part

[0053] 20 - External formwork of lining

[0054] 30 - Cross brace

[0055] 100 - Karst cave

[0056] 200 - Permeable cavity Specific implementation mode

[0057] The present invention will be further described in detail below in conjunction with specific embodiments. However, this should not be construed as limiting the scope of the above - mentioned subject matter of the present invention to the following embodiments. All technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0058] In the description of the specific embodiments of the present invention, without special explanation, the expression terms indicating the orientation or positional relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the invention product / device / equipment is usually used and placed. These terms of orientation or positional relationship are only for the convenience of describing the solution of the present invention or simplifying the description in the specific embodiments, facilitating technicians to quickly understand the solution, rather than indicating or implying that a specific device / component / element must have a specific orientation or be constructed and operated in a specific positional relationship. Therefore, it should not be construed as a limitation to the present invention.

[0059] In addition, for terms such as "horizontal", "vertical", "hanging", "parallel", and "coaxial", it does not mean that the corresponding device / component / element is required to be absolutely horizontal or vertical or hanging or parallel or coaxial. Instead, it can be slightly inclined or deviated as long as the normal functions of the relevant components are not affected. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and it does not mean that the structure must be completely horizontal but can be slightly inclined; "coaxial" means that two components are arranged as coaxial as possible and move in a coaxial or approximately coaxial manner when the relative position changes. Or, it can be simply understood that the corresponding device / component / element is arranged in directions such as "horizontal", "vertical", "hanging", "parallel", "coaxial", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2 - 1 mm, preferably within 0.2 - 0.5 mm. As long as the corresponding device / component / element is within the error / deviation range, it can still play its role in the solution of the present invention.

[0060] In addition, for expressions such as "first", "second", "third", etc. that appear in the terms, they are only used to distinguish the descriptions of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0061] In addition, in the description of the embodiments of the present invention, "several", "multiple", and "a number of" represent at least 2. It can be any situation such as 2, 3, 4, 5, 6, 7, 8, 9, etc., and even more than 9.

[0062] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, for places where terms such as "set", "installed", "connected", "linked", "provided with", "laid", and "arranged" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection, and can be connection means commonly used in the art such as welding, riveting, bolting, and threaded connection. Such a connection can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two components.

[0063] Embodiment 1

[0064] As Figure 5 、 Figure 6 shown, a tunnel structure for side-piercing a karst cave in this embodiment includes:

[0065] Column 1, anchored at the bottom of the karst cave 100;

[0066] The bearing platform 2 is connected to the top of the column 1;

[0067] The secondary lining 3 is erected on the bearing platform 2;

[0068] The primary support steel frame 4 is located outside the secondary lining 3. The primary support steel frame 4 includes a hollowed-out section 41 and a support section 42 that are connected to each other. The hollowed-out section 41 is located in the top area of the karst cave 100, and the support section 42 is located in the soil layer. There is a permeable cavity 200 between the hollowed-out section 41 and the secondary lining 3;

[0069] The inspection door 5 is arranged on the secondary lining 3 and is used to connect the permeable cavity 200 with the inside of the tunnel.

[0070] In the tunnel structure of this embodiment, the column 1 is anchored to the bottom of the karst cave, the bearing platform 2 is connected to the top of the column 1, and the secondary lining 3 is erected on the bearing platform 2. A support system is formed by the column 1 and the bearing platform 2 to ensure that the bottom of the tunnel can be effectively supported at the karst cave 100 and guarantee the bearing capacity of the tunnel bottom. Further, the primary support steel frame 4 adopts a form combining the hollowed-out section 41 and the support section 42. The hollowed-out section 41 is located in the top area of the karst cave 100, and there is a permeable cavity 200 between the hollowed-out section 41 and the secondary lining 3. It can not only prevent falling rocks from entering the karst cave 100 through the hollowed-out section 41, but also ensure that the water above the karst cave can reach the bottom of the karst cave 100 through the permeable cavity 200, avoiding water accumulation at the top of the tunnel from eroding the structure. And only the column 1 is arranged at the bottom of the karst cave 100, without blocking the karst cave 100, so that the karst cave water flows out from the original water passage of the karst cave 100, ensuring the smooth drainage of the karst cave 100, realizing the natural diversion of karst water, reducing the water damage risk of the tunnel structure at the karst cave 100. Further, the inspection door 5 on the secondary lining 3 is used to connect the permeable cavity 200 with the inside of the tunnel, which is convenient for the tunnel structure to use the natural wind in the karst cave for ventilation during the construction period and the operation period, reducing the construction and operation ventilation costs and achieving economic savings;

[0071] Compared with the existing method of blocking and filling the karst cave 100, in the tunnel structure of this embodiment, the top of the karst cave 100 is protected by the hollowed-out section 41 of the primary support steel frame 4, and columns 1 and bearing platforms 2 are constructed at the bottom of the karst cave 100 to support the tunnel, avoiding the traditional process of blocking and filling the karst cave 100. That is, it ensures the smooth flow of karst cave water and can introduce the wind in the karst cave 100 into the tunnel to assist tunnel ventilation, realizing construction and operation ventilation by using the natural wind in the karst cave 100. The tunnel structure of this embodiment reduces the construction process, reduces the construction risk, and effectively speeds up the tunnel construction progress.

[0072] In this embodiment, the large space existing between the primary support steel frame 4 and the secondary lining 3 measured by using the karst cave 100 is used as the permeable cavity 200, so as to ensure that the karst cave water above can reach the bottom of the karst cave 100 through the permeable cavity 200, to realize the natural diversion of karst water, and it is also convenient to introduce the natural wind in the karst cave 100 into the tunnel interior subsequently.

[0073] In this embodiment, the karst cave 100 can also be inspected at any time through the inspection door 5, such as inspecting the drainage condition of the karst cave 100 during the flood season.

[0074] A preferred way, as Figure 5 、 Figure 6 shown, the hollowed-out section 41 covers the top of the karst cave 100.

[0075] Wherein, the hollowed-out section 41 is anchored on the side wall of the karst cave 100.

[0076] In an alternative embodiment, as Figure 4 shown, it further includes a steel mesh 6, and the steel mesh 6 is laid on the hollowed-out section 41.

[0077] By laying the steel mesh 6 on the hollowed-out section 41, the stiffness of the hollowed-out section 41 is enhanced, and smaller falling rocks and rock blocks are intercepted by the steel mesh to reduce the risk of falling rocks.

[0078] A preferred way, as Figure 7 shown, it further includes a locking foot anchor pipe 8, and the locking foot anchor pipe 8 is arranged at the lower parts of both ends of the primary support steel frame 4, and the locking foot anchor pipe 8 is used for anchoring in the rock stratum or soil layer.

[0079] Wherein, at least one group of locking foot anchor pipes 8 is connected to the lower part of the hollowed-out section 41 and the lower part of the support section 42;

[0080] As Figure 8 、 Figure 9 shown, each group of locking foot anchor pipes 8 includes two locking foot anchor pipes 8, and the two locking foot anchor pipes 8 are on both sides of the primary support steel frame 4.

[0081] Furthermore, as Figure 10 shown, it further includes a connecting steel bar 9, one end of the connecting steel bar 9 is welded to the primary support steel frame 4, and the other end of the connecting steel bar 9 is welded together with the locking foot anchor pipe 8;

[0082] Furthermore, the connecting steel bar 9 is arc-shaped.

[0083] In an alternative embodiment, the column 1 is a reinforced concrete column.

[0084] In an alternative embodiment, the bearing platform 2 is a reinforced concrete bearing platform.

[0085] In an alternative embodiment, a cross brace 30 is provided between the hollowed-out section 41 and the secondary lining 3 to enhance the strength of the hollowed-out section 41 through the cross brace 30;

[0086] Among them, the cross brace 30 can first select a steel structure cross brace. For example, an I-beam is selected as the cross brace 30, and both ends of the cross brace 30 are anchored to the hollowed-out section 41 and the secondary lining 3 respectively.

[0087] Embodiment 2

[0088] As Figures 1 - 5 shown, on the basis of Embodiment 1, this embodiment discloses a construction method for a tunnel structure passing through a karst cave laterally. The tunnel structure passing through a karst cave described in Construction Embodiment 1 includes the following steps:

[0089] S1: Construct columns 1 at the bottom of the karst cave 100 as the bottom support of the tunnel structure.

[0090] S2: Construct a bearing platform 2 on the top of the column 1;

[0091] Specifically, a 40 cm reinforced concrete bearing platform is constructed within the tunnel structure range of the karst cave 100 to support the tunnel structure.

[0092] S3: Construct the primary support steel frame 4. The primary support steel frame 4 includes a hollowed-out section 41 and a support section 42. The hollowed-out section 41 is located at the top of the karst cave 100, and the support section 42 is located within the soil layer, and shotcrete is sprayed on the support section 42;

[0093] Among them, shotcrete is not sprayed on the hollowed-out section 41. On the one hand, the risk of falling rocks at the top of the karst cave 100 is placed through the hollowed-out section 41, and on the other hand, it is also convenient for the karst water at the top of the karst cave 100 to flow into the bottom of the karst cave.

[0094] S4: Pour the secondary lining 3 and make the secondary lining 3 located within the karst cave 100 be erected on the bearing platform 2;

[0095] S5: Open a maintenance door 5 on the secondary lining 3 within the area of the karst cave 100. By setting the maintenance door 5, it is convenient for the natural wind within the karst cave 100 to blow into the tunnel, and at the same time, it is also convenient to check the condition of the karst cave 100 through the maintenance door 5.

[0096] A rigid support system is formed through the columns and the bearing platform to ensure the bearing capacity at the bottom of the tunnel and avoid the settlement or collapse of the tunnel structure caused by the karst cave 100; Shotcrete is not sprayed on the hollowed-out section 41 of the primary support steel frame 4, which is convenient for guiding the karst water at the top of the karst cave 100 to naturally flow into the bottom of the karst cave 100, avoiding the erosion of the tunnel structure by accumulated water. At the same time, opening the maintenance door 5 can utilize the ventilation of the karst cave 100 to improve the environment within the tunnel.

[0097] In an alternative embodiment, in S2: A temporary steel plate 7 is arranged within the area of the karst cave 100. One end of the temporary steel plate 7 is fixed to the karst cave 100, and the other end of the temporary steel plate 7 is connected to the bearing platform 2.

[0098] The temporary steel plate 7 forms a temporary barrier to prevent the surrounding rock from loosening and falling or materials such as concrete from falling into the bottom of the karst cave 100 during the construction process, and to avoid blocking the drainage channel of the karst cave 100.

[0099] In an alternative embodiment, in S3: A steel mesh 6 is laid on the hollowed-out section 41.

[0100] By laying the steel mesh 6 on the hollowed-out section 41, the stiffness of the hollowed-out section 41 is enhanced, and smaller falling rocks and rock blocks are intercepted by the steel mesh to reduce the risk of falling rocks.

[0101] In an alternative embodiment, in S3: Locking foot anchor pipes 8 are provided on both sides of the primary support steel frame 4.

[0102] In an alternative embodiment, in S4: First, the external formwork and internal formwork of the secondary lining 3 are fabricated. The external formwork of the secondary lining is located below the hollowed-out section 41 and is connected to the support section 42.

[0103] The secondary lining 3 is cast using the external formwork and internal formwork of the secondary lining to construct the internal structure of the tunnel, and an inspection door 5 is opened on the secondary lining 3 within the area of the karst cave 100.

[0104] In an alternative embodiment, in S4: The temporary steel plate 7 is removed, and the gap between the upper part of the bearing platform 2 and the secondary lining 3 is backfilled with C30 concrete to form a backfill part 10.

[0105] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A tunnel structure passing through a karst cave laterally, characterized in that, Including: A column (1), anchored at the bottom of a karst cave (100); A bearing platform (2), connected to the top of the column (1); A secondary lining (3), erected on the bearing platform (2); A primary support steel frame (4), located outside the secondary lining (3). The primary support steel frame (4) includes an openwork section (41) and a support section (42) connected to each other. The openwork section (41) is located in the top area of the karst cave (100), and the support section (42) is located in the soil layer. A permeable cavity (200) is formed between the openwork section (41) and the secondary lining (3); An inspection door (5), provided on the secondary lining (3) for communicating the permeable cavity (200) with the inside of the tunnel.

2. The tunnel structure for side-piercing karst caves according to claim 1, characterized in that, The openwork section (41) covers the top of the karst cave (100).

3. The tunnel structure passing through a karst cave laterally according to claim 1, wherein It further includes a steel mesh (6), and the steel mesh (6) is laid on the openwork section (41).

4. A tunnel structure for side-piercing a karst cave according to claim 1, characterized in that, It further includes locking foot anchor pipes (8), and the locking foot anchor pipes (8) are provided on the openwork section (41) and the support section (42).

5. A tunnel structure for side-piercing karst caves according to claim 1, characterized in that, It further includes a cross brace (30), and the cross brace (30) is used to connect the openwork section (41) and the secondary lining (3).

6. A construction method for a tunnel structure passing through a karst cave laterally, characterized in that, The construction of a tunnel structure passing through a karst cave laterally as described in any one of claims 1-5 includes the following steps: S1: Construct the column (1) at the bottom of the karst cave (100); S2: Construct the bearing platform (2) on the top of the column (1); S3: Construct the primary support steel frame (4). The primary support steel frame (4) includes an openwork section (41) and a support section (42). The openwork section (41) is located at the top of the karst cave (100), and the support section (42) is located in the soil layer, and spray concrete on the support section (42); S4: Pour the secondary lining (3), and make the secondary lining (3) located in the karst cave (100) erected on the bearing platform (2); S5: Open the inspection door (5) on the secondary lining (3) located in the area of the karst cave (100).

7. A construction method for a tunnel structure passing through a karst cave laterally according to claim 6, characterized in that, In S2: Set a temporary steel plate (7) in the area of the karst cave (100). One end of the temporary steel plate (7) is fixed on the karst cave (100), and the other end of the temporary steel plate (7) is connected to the bearing platform (2).

8. A construction method for a tunnel structure passing through a karst cave laterally according to claim 6, characterized in that, In S3: Lay the steel mesh (6) on the openwork section (41).

9. A construction method for a tunnel structure passing through a karst cave laterally according to claim 6, characterized in that, In S3: There are locking foot anchor pipes (8) at both ends of the primary support steel frame (4).

10. The construction method of a tunnel structure for side-piercing karst caves according to claim 6, characterized in that, In S4: First make the outer formwork and inner formwork of the secondary lining (3). The outer formwork of the secondary lining is located below the openwork section (41), and the outer formwork of the secondary lining is connected to the support section (42).

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