A reinforcement support structure for collapsible loess tunnels

Abstract

The present application relates to the technical field of tunnel construction and discloses a reinforcement support structure for collapsible loess tunnels, which solves the problem of arch sinking caused by poor support effect of related tunnel support structures. The structure comprises a steel mesh arranged in contact with the tunnel soil wall, a steel arch frame is provided on the side of the steel mesh away from the tunnel soil wall, a plurality of anchor rods are interspersed between the steel arch frame and the steel mesh, one end of the anchor rod is inserted into the tunnel soil wall, the other end of the anchor rod is threadedly connected with a fixing bolt, and the fixing bolt abuts against the side of the steel arch frame away from the steel mesh, and a plurality of support frames are further provided between the steel arch frame and the steel mesh, the support frames comprising a first support rod and a second support rod, one end of the first support rod and the second support rod are both abutted against the steel mesh, the other ends of the first support rod and the second support rod are both abutted against the steel arch frame, and the first support rod and the second support rod are inclined to each other, thereby reducing the sinking of the arch.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel construction, and in particular to a reinforcement and support structure for collapsible loess tunnels. Background Art

[0002] When tunnel construction passes through some adverse geological structures, such as collapsible loess geology, which has the characteristics of collapsibility and expansion, it is easy to cause adverse effects on tunnel construction.

[0003] Tunnel support structures can reduce the deformation or collapse of tunnels caused by the destruction of the original ground structure balance around the tunnel after tunnel excavation. Tunnel support structures include initial support and permanent support. Initial support can ensure the continuous progress of excavation work. After a certain length of excavation, the location of the initial support is concrete lined to achieve permanent support. On the one hand, it is necessary to effectively transfer the ground pressure above the tunnel to the underground through the tunnel side wall structure or the load on the road surface, and on the other hand, it is necessary to effectively resist the reaction force from the ground below the tunnel.

[0004] At present, relevant tunnel support structures, such as the Chinese patent "Tunnel Support Structure and Tunnel" with authorization announcement number CN209604018U, discloses a tunnel support structure, including a tunnel body, a bottom arch cast at the bottom of the inner wall of the tunnel body, the bottom of the bottom arch is plugged with equidistantly distributed reinforcement piles, and the outer wall of the reinforcement pile is connected to the equidistantly distributed triangular mounting blocks by bolts, the inner wall of the reinforcement pile is provided with a cavity, and the outer wall of the reinforcement pile is provided with equidistantly distributed second grouting holes, the outer wall of the tunnel body is connected to a first steel mesh by fixing nails, and the bottom of the first steel mesh is sprayed with an outer layer of sprayed concrete, and the bottom of the outer layer of sprayed concrete is connected to a second steel mesh by bolts.

[0005] The above-mentioned related technologies have the following deficiencies: when the related tunnel support structure faces poor settlement geology, the arch sinking problem caused by poor support effect is easy to occur. Summary of the Invention

[0006] In order to improve the supporting effect of the support structure and reduce the sinking of the arch, the present application provides a reinforced support structure for a collapsible loess tunnel.

[0007] The present application provides a reinforcement support structure for a collapsible loess tunnel using the following technical solutions:

[0008] A reinforcement support structure for a collapsible loess tunnel comprises a steel mesh fitted against the tunnel soil wall, a steel arch frame is provided on the side of the steel mesh away from the tunnel soil wall, a plurality of anchor rods are interspersed between the steel arch frame and the steel mesh, one end of the anchor rod is inserted into the tunnel soil wall, the other end of the anchor rod is threadedly connected to a fixing bolt, and the fixing bolt abuts against the side of the steel arch frame away from the steel mesh, a plurality of support frames are further provided between the steel arch frame and the steel mesh, the support frames comprise a first support rod and a second support rod, one end of the first support rod and the second support rod are both abutted against the steel mesh, the other ends of the first support rod and the second support rod are both abutted against the steel arch frame, and the first support rod and the second support rod are arranged obliquely to each other.

[0009] By adopting the above technical solution, the support frame can further enhance the supporting stability of the support structure. When the steel arch frame is fixed by fixing bolts and anchor rods, the support frame can also be fixed between the steel arch frame and the steel mesh. The first support rod and the second support rod are arranged at an angle to each other, forming a stable structure that is approximately triangular between the steel mesh and the steel arch frame, thereby enhancing the stability of the support structure. Moreover, when concrete lining is carried out after the support is completed, the support frame can also enhance the internal strength of the concrete, thereby improving the supporting strength of the support structure and reducing the sinking of the arch.

[0010] Optionally, the first support rod and the second support rod are hinged at one end close to each other, and the support frame also includes a third support rod, the third support rod is hinged to the end of the first support rod away from the second support rod, the third support rod is overlapped and fixed to the end of the second support rod away from the first support rod, the end of the second support rod away from the first support rod is provided with a overlap block, the overlap block is provided with an overlap groove, and the end of the third support rod close to the second support rod is overlapped and fixed to the overlap groove.

[0011] By adopting the above technical solution, when the support frame is supported between the steel arch frame and the support net, the first support rod, the second support rod and the third support rod together form a triangular stable structure to resist the pressure of the arch sinking, and when the end of the third support rod is away from the overlap groove, the support frame can be folded and stored, which is convenient for transportation of the support frame, and the support frame can be installed quickly during installation, thereby improving construction efficiency.

[0012] Optionally, a first fixing mechanism is provided on the side of the first support rod close to the anchor rod, and a second fixing mechanism is provided on the side of the second support rod close to the other anchor rod. The first support rod is fixed to the anchor rod through the first fixing mechanism, and the second support rod is fixed to the other anchor rod through the second fixing mechanism.

[0013] By adopting the above technical solution, since the support frame is located between two adjacent anchor rods, one side of the support frame is fixed to the anchor rod through a first fixing mechanism, and the other side of the support frame is fixed to another anchor rod through a second fixing mechanism, so that the support frame can be stably fixed between two adjacent anchor rods, further increasing the stability of the support structure.

[0014] Optionally, the first fixing mechanism includes a gear and a sliding rack meshing with the gear, the gear is fixed to the end of the third support rod close to the first support rod, and the axis of the gear and the rotation axis of the third support rod are located in the same straight line, the sliding rack is slidably installed on the first support rod, a receiving plate is fixed to one end of the first support rod close to the third support rod, the sliding rack is located between the gear and the receiving plate, and a first plug hole is opened on the side of the anchor rod close to the first fixing mechanism, and the end of the sliding rack is plugged and fixed to the first plug hole.

[0015] By adopting the above technical solution, when the third support rod rotates, the gear rotates accordingly. When the third support rod rotates to overlap and fix with the second support rod, the sliding rack engaged with the gear slides out in the direction away from the gear and plugs into the first plug hole, thereby achieving fixation between the first support rod and the anchor rod and enhancing the support stability of the support frame.

[0016] Optionally, a sliding member is provided between the receiving plate and the sliding rack to reduce the sliding rack from detaching from the receiving plate. The sliding member includes a sliding bar fixed to the side of the sliding rack close to the receiving plate. The sliding bar is parallel to the sliding direction of the sliding rack. A sliding groove is provided on the side of the receiving plate close to the sliding rack, and the sliding bar is slidably connected to the sliding groove.

[0017] By adopting the above technical solution, the sliding bar is slidably connected to the sliding groove, so that the sliding rack is not easy to fall out from between the receiving plate and the gear, thereby enhancing the stability during sliding.

[0018] Optionally, the second fixing mechanism includes a plug-in strip slidably installed in the overlap block, a second plug-in hole is provided on the side of the anchor rod close to the overlap block, the plug-in strip is plugged into the second plug-in hole, and the end of the plug-in strip away from the second plug-in hole abuts against the end of the third support rod.

[0019] By adopting the above technical solution, when the third support rod abuts against the plug-in strip, the other end of the plug-in strip is plugged and fixed into the second plug-in hole, thereby achieving a stable connection between the anchor rod and the support frame.

[0020] Optionally, the end of the connecting strip close to the third support rod has an inclined surface that gradually slopes downward from a side away from the third support rod to a side close to the third support rod.

[0021] By adopting the above technical solution, when the end of the third support rod overlaps with the overlapping groove, the end of the third support rod slides along the inclined surface of the plug-in strip and pushes the plug-in strip out, so that the other end of the plug-in strip is plugged and fixed with the second plug-in hole. At the same time, the triangular structure of the support frame makes it difficult for the plug-in strip to fall out of the second plug-in hole, thereby enhancing the stability between the support frame and the anchor rod.

[0022] Optionally, a limiting component is provided between the plug-in strip and the overlapping block to reduce the complete disengagement of the plug-in strip, and the limiting component includes a limiting block fixed on the plug-in strip, and a limiting groove is provided on the side wall of the overlapping block close to the plug-in strip, and the length direction of the limiting groove is parallel to the length direction of the plug-in strip, and the limiting groove is connected to the overlapping groove, and the limiting block is slidably connected to the limiting groove.

[0023] By adopting the above technical solution, the limiting component makes the sliding of the plug-in strip more stable, so that the plug-in strip can be stably inserted into the second plug-in hole, thereby achieving the fixation of the support frame and the anchor rod.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. The support frame can further enhance the support stability of the supporting structure. When the steel arch frame is fixed with fixing bolts and anchor rods, the support frame can also be fixed between the steel arch frame and the steel mesh. The first support rod and the second support rod are arranged at an angle to each other, forming a stable structure that is approximately triangular between the steel mesh and the steel arch frame, thereby enhancing the stability of the supporting structure. Moreover, when the concrete lining is carried out after the support is completed, the support frame can also enhance the internal strength of the concrete, thereby improving the support strength of the supporting structure and reducing the sinking of the arch crown.

[0026] 2. When the support frame is supported between the steel arch frame and the support net, the first support rod, the second support rod and the third support rod together form a triangular stable structure to resist the pressure of the arch top sinking. When the end of the third support rod is away from the overlap groove, the support frame can be folded and stored, which is convenient for transportation of the support frame and can be installed quickly during installation, thereby improving construction efficiency.

[0027] 3. Since the support frame is located between two adjacent anchor rods, one side of the support frame is fixed to the anchor rod through a first fixing mechanism, and the other side of the support frame is fixed to another anchor rod through a second fixing mechanism, so that the support frame can be stably fixed between the two adjacent anchor rods, further increasing the stability of the support structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural diagram of the support structure.

[0029] Figure 2 It is a structural diagram of the support frame and anchor rods.

[0030] Figure 3 It is a structural diagram of the support frame.

[0031] Figure 4 The first fixing mechanism is Figure 3 A partial enlarged view of point A in the middle.

[0032] Figure 5 It is a structural schematic diagram of the second fixing mechanism.

[0033] Explanation of the accompanying drawings: 1. Steel mesh; 2. Support frame; 21. First support rod; 22. Second support rod; 221. Overlap block; 2211. Overlap groove; 222. Locking bolt; 2221. Threaded hole; 23. Third support rod; 3. Steel arch frame; 31. Through hole; 4. Anchor rod; 41. Fixing bolt; 42. First plug hole; 43. Second plug hole; 5. First fixing mechanism; 51. Gear; 52. Sliding rack; 53. Socket plate; 531. Slide groove; 54. Slide bar; 6. Second fixing mechanism; 61. Plug bar; 62. Limiting assembly; 621. Limiting block; 622. Limiting groove. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-5 This application is described in further detail.

[0035] The embodiment of the present application discloses a reinforcement support structure for a collapsible loess tunnel.

[0036] Reference Figure 1 A reinforcement support structure for a collapsible loess tunnel includes a steel mesh 1 that is fitted and fixed to the arched tunnel soil wall. The side of the steel mesh 1 away from the tunnel soil wall is abutted against a support frame 2, and the side of the support frame 2 away from the steel mesh 1 is abutted against a steel arch frame 3, and an anchor rod 4 and a fixing bolt 41 for fixing are provided between the steel arch frame 3, the support frame 2 and the steel mesh 1. One end of the anchor rod 4 is the fixed end, and the other end of the anchor rod 4 is the installation end. The fixed end of the anchor rod 4 is inserted into the tunnel soil wall, and the fixing bolt 41 is threadedly connected to the installation end of the anchor rod 4. The fixing bolt 41 is tightly fixed to the side of the steel arch frame 3 away from the support frame 2. By arranging the support frame 2 between the steel arch frame 3 and the steel mesh 1, the support effect of the support structure is further improved, and the occurrence of arch top sinking is reduced.

[0037] Reference Figure 1 and Figure 2There are multiple anchor rods 4, which are spaced apart axially along the tunnel wall. Each anchor rod 4 penetrates both the steel mesh 1 and the steel arch 3. The steel arch 3 is provided with a through hole 31 for the anchor rod 4 to penetrate. The axis of the through hole 31 is aligned with the axis of the anchor rod 4. A support frame 2 is provided between every two adjacent anchor rods 4 to ensure the strength of the support structure, enabling it to withstand pressure at different locations on the tunnel vault and reduce the risk of the vault sinking.

[0038] The support frame 2 includes a first support rod 21, a second support rod 22 and a third support rod 23, and the length of the first support rod 21 and the second support rod 22 is greater than the distance between the steel arch frame 3 and the steel mesh 1, so that the first support rod 21 and the second support rod 22 are inclined to each other and are arranged between the steel arch frame 3 and the steel mesh 1, one end of the first support rod 21 is hinged to the second support rod 22, and one end of the third support rod 23 is rotatably installed on the first support rod 21, and the other end of the third support rod 23 is overlapped with the second support rod 22. When the support frame 2 is needed for support, the first support rod 21, the second support rod 22 and the third support rod 23 can be quickly spliced ​​into a stable triangular frame and installed between the steel arch frame 3 and the steel mesh 1, which helps to improve construction efficiency and quickly realize the installation of the support structure. When the support frame 2 is no longer needed for support, the first support rod 21, the second support rod 22 and the third support rod 23 can be folded and retracted, which is convenient for transportation of the support frame 2.

[0039] The end of the third support rod 23 close to the second support rod 22 is the movable end, and a lap block 221 is fixed on the second support rod 22, and a lap groove 2211 is vertically opened on the lap block 221, and the movable end of the third support rod 23 overlaps the lap groove 2211, and the lap length of the third support rod 23 is less than the length of the lap groove 2211, so that the movable end of the third support rod 23 can vertically slide into the lap groove 2211, and the side wall of the lap block 221 is also installed with a locking bolt 222, and the side wall of the lap block 221 is provided with a threaded hole 2221, and the threaded hole 2221 is perpendicular to the length direction of the lap groove 2211. After the movable end of the third support rod 23 slides into the lap groove 2211, the locking bolt 222 passes through the threaded hole 2221 and is tightened against the third support rod 23, so that the movable end of the third support rod 23 is fixed to the second support rod 22, thereby forming a stable triangular structure of the support frame 2.

[0040] Since the support frame 2 is located between two adjacent anchor rods 4, a first fixing mechanism 5 is provided on the side of the first support rod 21 close to the anchor rod 4, and a second fixing mechanism 6 is provided on the side of the second support rod 22 close to the other anchor rod 4. The first fixing mechanism 5 and the second fixing mechanism 6 jointly fix the support frame 2 to the anchor rod 4, thereby enhancing the supporting stability of the support frame 2.

[0041] Reference Figure 3 and Figure 4The first fixing mechanism 5 includes a gear 51 fixed on the third support rod 23. The end of the third support rod 23 hinged to the first support rod 21 is a hinged end. The gear 51 is fixedly installed on the hinged end of the third support rod 23, and the axis of the gear 51 is located in the same straight line as the axis of the third support rod 23. When the third support rod 23 rotates, the gear 51 rotates at the same time.

[0042] The first fixing mechanism 5 also includes a sliding rack 52 engaged with the gear 51. The sliding rack 52 is engaged with the lower side of the gear 51. A receiving plate 53 is provided on the side of the sliding rack 52 away from the gear 51. The receiving plate 53 is fixed on the first support rod 21, and the sliding rack 52 is slidably connected to the receiving plate 53.

[0043] In order to further improve the sliding stability of the sliding rack 52 and reduce the sliding rack 52 from falling off the receiving plate 53, a sliding member is provided between the sliding rack 52 and the receiving plate 53. The sliding member is a slide bar 54. The slide bar 54 is fixed to the side of the sliding rack 52 close to the receiving plate 53, and the length direction of the slide bar 54 is the same as the length direction of the sliding rack 52. A slide groove 531 is provided on the side of the receiving plate 53 close to the sliding rack 52. The slide groove 531 is opened along the length direction of the receiving plate 53. The slide bar 54 is plugged into the slide groove 531, and the slide bar 54 can slide along the length direction of the slide groove 531.

[0044] A first insertion hole 42 is defined on the side of the anchor rod 4 near the first support rod 21, and the end of the sliding rack 52, away from the gear 51, can be plugged and fixedly engaged with the first insertion hole 42. When the third support rod 23 rotates toward the second support rod 22, the gear 51 rotates simultaneously, driving the sliding rack 52 to slide toward the first insertion hole 42, causing the end of the sliding rack 52 to be inserted into the first insertion hole 42, thereby achieving plug-and-slot securement between one side of the support frame 2 and the anchor rod 4.

[0045] Reference Figure 5 The second fixing mechanism 6 includes a plug-in strip 61 slidably installed in the overlapping block 221. The plug-in strip 61 can slide horizontally along the length direction of the overlapping block 221. When the movable end of the third support rod 23 is overlapped and fixed with the overlapping block 221, the plug-in strip 61 abuts against the third support rod 23. The side of the plug-in strip 61 close to the third support rod 23 has an inclined surface that gradually tilts downward from the side away from the third support rod 23 to the side close to the third support rod 23. In the process of the movable end of the third support rod 23 sliding into the overlapping groove 2211, the movable end of the third support rod 23 slides along the inclined surface of the plug-in strip 61 and pushes the plug-in strip 61 in the direction away from the third support rod 23.

[0046] Reference Figure 2 and Figure 5A second plug hole 43 is opened on the side of the anchor rod 4 close to the second support rod 22. The plug strip 61 slides out in the direction away from the third support rod 23 and is plugged and fixed with the second plug hole 43 to realize the plug-in fixation of the other side of the support frame 2 with the other anchor rod 4.

[0047] In order to reduce the situation where the plug-in strip 61 is completely separated from the overlapping block 221, a limit assembly 62 is further provided between the plug-in strip 61 and the overlapping block 221. The limit assembly 62 includes a limit block 621 fixed on the plug-in strip 61 and a limit groove 622 opened in the overlapping block 221. The number of limit blocks 621 is two, and the two limit blocks 621 are respectively fixed on the two parallel side walls of the plug-in strip 61. The number of limit grooves 622 is the same as that of limit blocks 621. The limit grooves 622 are respectively opened on the side walls of the overlapping block 221 close to the plug-in block strip, so that the limit grooves 622 and the overlapping grooves 2211 are interconnected. The length direction of the limit groove 622 is parallel to the sliding direction of the plug-in strip 61. The limit block 621 is slidably connected to the limit groove 622 to ensure that the plug-in strip 61 is normally inserted into the second plug hole 43.

[0048] After the installation of the support structure is completed, it is necessary to spray concrete into the support structure for lining to achieve permanent support of the support structure. The existence of the support frame 2 ensures the stability and support strength of the support structure. At the same time, after the concrete lining, it is beneficial to improve the internal strength of the concrete, thereby improving the support strength of the support structure and reducing the sinking of the arch.

[0049] The implementation principle of the reinforcement support structure of a collapsible loess tunnel in the embodiment of the present application is as follows:

[0050] When installing the support structure, first dig out the arched tunnel soil wall, then fit the steel mesh 1 to the tunnel soil wall for fixing, and then insert the anchor rod 4 so that the fixed end of the anchor rod 4 is inserted into the tunnel soil wall, and the installation end of the anchor rod 4 is used to install the steel arch frame 3 and locked by the fixing bolt 41. Finally, install the support frame 2 between the steel arch frame 3 and the steel mesh 1. The support frame 2 can be folded and retracted during transportation. When the support frame 2 is needed for support, the first support rod 21 and the second support rod 22 are rotated and opened to be inclined to each other, so that one end of the first support rod 21 and the second support rod 22 abuts against the steel mesh 1, and the other end of the first support rod 21 and the second support rod 22 abuts against the steel mesh 1. The steel arch frame 3 is in contact, and then the third support rod 23 is rotated so that the movable end of the third support rod 23 is overlapped with the overlapping block 221. During the rotation of the third support rod 23, the sliding rack 52 slides in the direction close to the first plug hole 42 and is finally plugged and fixed with the first plug hole 42. When the movable end of the third support rod 23 is overlapped and fixed with the overlapping block 221, the plug-in bar 61 is pushed to slide in the direction close to the second plug hole 43 and is finally plugged and fixed with the second plug hole 43, so that the support frame 2 has a stable support effect, the support frame 2 is installed conveniently and quickly, the tightening effect between the steel arch frame 3 and the steel mesh 1 is enhanced, and the occurrence of arch top sinking is reduced.

[0051] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A reinforcement support structure for a collapsible loess tunnel, comprising a steel mesh (1) arranged in contact with the tunnel soil wall, a steel arch (3) being provided on the side of the steel mesh (1) away from the tunnel soil wall, a plurality of anchor rods (4) being intermittently provided on the steel arch (3) and the steel mesh (1), one end of the anchor rod (4) being inserted into the tunnel soil wall, the other end of the anchor rod (4) being threadedly connected to a fixing bolt (41), and the fixing bolt (41) being in contact with the side of the steel arch (3) away from the steel mesh (1), characterized in that: A plurality of support frames (2) are further provided between the steel arch frame (3) and the steel mesh (1), the support frame (2) comprising a first support rod (21) and a second support rod (22), one end of each of the first support rod (21) and the second support rod (22) being in contact with the steel mesh (1), the other ends of each of the first support rod (21) and the second support rod (22) being in contact with the steel arch frame (3), and the first support rod (21) and the second support rod (22) being arranged to be inclined relative to each other, the first support rod (21) and the second support rod (22) being hinged at their ends close to each other, and the support frame (2) further comprising a third support rod (23), the third support rod (23) and the first support rod (21) being away from the second support rod (22). One end of the third support rod (23) is hinged, the third support rod (23) is overlapped and fixed with the end of the second support rod (22) away from the first support rod (21), the end of the second support rod (22) away from the first support rod (21) is provided with a overlap block (221), the overlap block (221) is provided with an overlap groove (2211), the end of the third support rod (23) close to the second support rod (22) is overlapped and fixed with the overlap groove (2211), the first support rod (21) is provided with a first fixing mechanism (5) on the side close to the anchor rod (4), the second support rod (22) is provided with a second fixing mechanism (6) on the side close to the other anchor rod (4), the first support rod (21) is connected to the anchor rod through the first fixing mechanism (5). (4) plug-in fixation, the second support rod (22) is plug-in fixed with another anchor rod (4) through a second fixing mechanism (6), the first fixing mechanism (5) includes a gear (51) and a sliding rack (52) meshing with the gear (51), the gear (51) is fixed to the end of the third support rod (23) close to the first support rod (21), and the axis of the gear (51) and the rotation axis of the third support rod (23) are located in the same straight line, the sliding rack (52) is slidably installed on the first support rod (21), a receiving plate (53) is fixed at one end of the first support rod (21) close to the third support rod (23), and the sliding rack (52) is located between the gear (51) and the receiving plate ( 53), a first plug hole (42) is provided on a side of the anchor rod (4) close to the first fixing mechanism (5), and the end of the sliding rack (52) is plugged and fixed to the first plug hole (42). A sliding member is also provided between the receiving plate (53) and the sliding rack (52) to reduce the sliding rack (52) from separating from the receiving plate (53), and the sliding member includes a slide bar (54) fixed to a side of the sliding rack (52) close to the receiving plate (53), and the slide bar (54) is parallel to the sliding direction of the sliding rack (52). A sliding groove (531) is provided on a side of the receiving plate (53) close to the sliding rack (52), and the slide bar (54) is slidably connected to the slide groove (531).

2. The reinforcement and supporting structure for a collapsible loess tunnel according to claim 1, characterized in that: The second fixing mechanism (6) includes a plug-in strip (61) slidably mounted in the lap block (221); a second plug-in hole (43) is provided on a side of the anchor rod (4) close to the lap block (221); the plug-in strip (61) is plugged into the second plug-in hole (43); and an end of the plug-in strip (61) away from the second plug-in hole (43) abuts against an end of the third support rod (23).

3. The reinforcement and supporting structure for a collapsible loess tunnel according to claim 2, characterized in that: The end of the plug-in strip (61) close to the third support rod (23) has an inclined surface that gradually tilts downward from the side away from the third support rod (23) to the side close to the third support rod (23).

4. The reinforcement and supporting structure for a collapsible loess tunnel according to claim 3, characterized in that: A limiting assembly (62) is further provided between the plug-in strip (61) and the lap block (221) to reduce the possibility of the plug-in strip (61) being completely dislodged. The limiting assembly (62) comprises a limiting block (621) fixed on the plug-in strip (61). A limiting groove (622) is provided on a side wall of the lap block (221) close to the plug-in strip (61). The length direction of the limiting groove (622) is parallel to the length direction of the plug-in strip (61), and the limiting groove (622) is connected to the lap groove (2211). The limiting block (621) and the limiting groove (622) are slidably connected.

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