A highway tunnel initial support collapse treatment reinforcing device and a construction method thereof

Abstract

The application discloses a kind of highway tunnel initial support collapse treatment reinforcing device and its construction method, including highway tunnel portal, the inside of highway tunnel portal is provided with arch guide wall, the outside of arch guide wall is evenly provided with odd guide hole and even guide hole.The steel arch and several guide steel pipes are arranged in the inside of arch guide wall, and the several guide steel pipes are welded on the outside of steel arch, and the compression resistance of arch guide wall is enhanced to some extent by the combination of the two;By inserting the pipe shed steel pipe into the inside of several odd guide holes and several even guide holes, inserting the reinforcement cage into the inside of pipe shed steel pipe, grouting in the grouting filling part between reinforcement cage and pipe shed steel pipe, and filling mortar in the mortar filling part between pipe shed steel pipe and each odd guide hole or each even guide hole, so that the arch guide wall and the pipe shed steel pipe in its inside can be combined to form strong support to prevent the collapse of working face.

Description

A reinforcement device for treating collapse of initial support in highway tunnels and its construction method Technical Field

[0001] This invention relates to the field of tunnel collapse treatment technology, and in particular to a strengthening device for treating collapses in the initial support of highway tunnels and its construction method. Background Technology

[0002] Initial support collapse in highway tunnels is a common risk. Common treatment measures for initial support collapse in highway tunnels include grouting anchoring, large-pipe roof grouting pre-support (small pilot tunnel method), and collapse pit grouting. Grouting anchoring uses "non-casing drilling technology" and "medium-high pressure grouting." "Non-casing drilling technology" can ensure the stability of the borehole, and "medium-high pressure grouting" can expand the effective grouting radius. Connecting the pre-support long anchor rods makes them an organic whole with the pressure grouting reinforced body, which can maximize the support effect of the pre-support anchor rods. However, this method requires driving ultra-long anchor rods (30 meters) above the collapse area. The construction difficulty is quite high (above m). The large pipe roof grouting pre-support method (small guide tunnel method) mainly uses grouting large pipe roofs supplemented by grouting small guide pipes to pre-support the collapsed body. It adopts short advance and staged excavation, and the support of the collapsed body is carried out as excavation. However, the construction of pipe roof and grouting must achieve the expected effect, that is, to form a shell that can support the loose rock above. The collapse pit grouting method uses the surface collapse pit to grout the collapsed body for reinforcement before the excavation of the collapsed body. However, this method is too costly and the quality is not easy to control. After comprehensive technical and economic comparison, the pipe roof grouting pre-support method (small guide tunnel method) is more ideal for treating the collapse of the initial support.

[0003] A search revealed a Chinese utility model patent with patent number CN 216922142 U, which discloses a strengthening device for treating collapses in the initial support of highway tunnels. The device includes a tunnel body comprising a collapsed cavity and uncollapsed portions at both ends of the cavity. A backfill of collapsed slag is placed on the slag within the tunnel body. A concrete layer is provided on the collapsed cavity surface within the tunnel body. A support device is also provided within the tunnel body, and concrete is filled between the support device and the collapsed cavity surface. Compared with existing technologies, this utility model patent with patent number CN 216922142 U effectively ensures construction quality and safety, accelerates construction progress, generates higher economic benefits, and significantly improves the level of initial support collapse treatment in highway tunnels, thereby meeting construction requirements.

[0004] However, in actual use, the compressive strength of the aforementioned highway tunnel initial support collapse treatment reinforcement device needs to be improved, and it cannot form strong support in time to prevent the tunnel face from collapsing, thus failing to guarantee construction safety. Therefore, a highway tunnel initial support collapse treatment reinforcement device and its construction method that can guarantee construction safety are needed. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies, such as insufficient compressive strength and inability to form strong support in a timely manner to prevent tunnel face collapse, thereby compromising construction safety. The invention proposes a device for strengthening the initial support collapse treatment of highway tunnels and its construction method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A reinforcement device for treating initial support collapse in highway tunnels includes a highway tunnel entrance; an arched guide wall is provided inside the highway tunnel entrance, and a plurality of odd-numbered guide holes and a plurality of even-numbered guide holes are evenly provided on the outside of the arched guide wall. The plurality of odd-numbered guide holes and the plurality of even-numbered guide holes are distributed at intervals on the outside of the arched guide wall. A pipe roof steel pipe is provided inside the plurality of odd-numbered guide holes and the plurality of even-numbered guide holes, and a reinforcing cage is provided inside the pipe roof steel pipe. A grouting filling part is formed between the pipe roof steel pipe and the reinforcing cage, and a mortar filling part is formed between the pipe roof steel pipe and each of the odd-numbered guide holes or each of the even-numbered guide holes.

[0008] The above technical solution further includes:

[0009] The arched guide wall includes a steel arch frame erected inside the entrance of the highway tunnel. Several guide steel pipes are uniformly welded to the outside of the steel arch frame. A concrete layer is provided on the outside of the steel arch frame and the several guide steel pipes. The arrangement of the guide steel pipes can not only enhance the compressive strength of the arched guide wall, but also provide guidance for the several odd-numbered guide holes and the several even-numbered guide holes.

[0010] Several odd-numbered guide holes and several even-numbered guide holes are respectively aligned with several guide steel pipes. The diameter of each odd-numbered guide hole and each even-numbered guide hole is 20-30mm larger than the outer diameter of each pipe roof steel pipe. The pipe roof steel pipe is a Ф108×6mm hot-rolled seamless steel pipe. The distribution range of the odd-numbered guide holes and the even-numbered guide holes is 150° from the middle of the arched guide wall. The distance between each odd-numbered guide hole and each even-numbered guide hole is 40cm.

[0011] The steel pipes for the pipe roof are all composed of a head steel pipe, several middle steel pipes, and a tail steel pipe. The head steel pipe is 3m or 6m long, the several middle steel pipes are 6m long, and the tail steel pipe is 3m long. The head steel pipe of the pipe roof steel pipe inserted into the odd-numbered guide holes is 3m long, and the head steel pipe of the pipe roof steel pipe inserted into the even-numbered guide holes is 6m long.

[0012] Several middle steel pipes and tail steel pipes are connected by a Ф102×6mm threaded steel pipe, the threaded steel pipe being 30cm long; the head steel pipe, several middle steel pipes and tail steel pipes can be connected manually.

[0013] The front end of the first steel pipe is tapered for 10cm. Several grouting holes of Ф10mm are opened on the outside of the first steel pipe and several middle steel pipes. The grouting holes are distributed in a quincunx pattern on the outside of the first steel pipe and several middle steel pipes. The distance between two adjacent grouting holes is 20cm.

[0014] The inner sides of the head steel pipe, the several middle steel pipes, and the tail steel pipe are all provided with sliding groove groups, and the inner sides of the head steel pipe, the several middle steel pipes, and the tail steel pipe are all provided with fastening groove groups evenly distributed. The sliding groove groups and the fastening groove groups do not interfere with each other. Each sliding groove group includes four sliding grooves, and each fastening groove group includes four axisymmetric fastening grooves.

[0015] The outer side of the reinforcing cage is uniformly provided with sliding components that cooperate with the sliding groove assembly. Each sliding component includes a sleeve welded to the outside of the reinforcing cage, and a connecting rod welded to the outside of the sleeve. A pulley is rotatably connected to the end of the connecting rod away from the sleeve. The cooperation between the sliding component and the sliding groove assembly can prevent the reinforcing cage from rubbing against the inside of the pipe roof steel pipe due to its own weight when it is inserted into the pipe roof steel pipe, thereby reducing the difficulty of inserting the reinforcing cage.

[0016] The outside of the reinforcing cage is also uniformly provided with fasteners that cooperate with the fastening groove assembly. The fasteners include a sleeve welded to the outside of the reinforcing cage, and a fastening block slidably connected inside the sleeve. The side of the fastening block near the bottom of the reinforcing cage is arc-shaped. A rust-proof spring is fixedly connected between the sleeve and the fastening block. The cooperation between the fastening block and the fastening groove assembly can achieve the initial fastening of the reinforcing cage at the same time as it is inserted, thereby strengthening the connection strength between the reinforcing cage and the steel pipe of the pipe shed.

[0017] A construction method for a reinforcement device for treating collapses in the initial support of a highway tunnel, implemented according to the aforementioned reinforcement device for treating collapses in the initial support of a highway tunnel, includes the following steps:

[0018] Step 1: Construct the arched guide wall. Set up the steel arch frame at the junction of the open and closed areas. Evenly weld several guide steel pipes to the outside of the steel arch frame. Set up formwork and pour concrete to form the concrete layer.

[0019] Step 2: Drilling is carried out on several odd-numbered guide holes and several even-numbered guide holes. The pipe roof drilling rig is moved to the entrance of the highway tunnel and fixed and positioned. The pipe roof drilling rig is positioned and drilled according to the reserved guide steel pipe positions. The drilling sequence is from high hole position to low hole position. During the drilling process, the skip-hole drilling method is adopted. Several odd-numbered guide holes are constructed first, and then several even-numbered guide holes are constructed.

[0020] The drilling speed should be fixed at the beginning. After drilling to a depth of 20cm, switch to normal speed. During the drilling process, use an inclinometer to measure the drilling deviation. If the deviation exceeds the design requirements, stop drilling immediately and correct the deviation. After the hole is formed, use a rotating rod in conjunction with high-pressure air to blow out the debris in the hole while retracting the rod.

[0021] Step 3: Install the steel pipes for the pipe roof by using a drilling rig to push the connected steel pipes into the interior of several odd-numbered guide holes and several even-numbered guide holes.

[0022] Step 4: Insert the reinforcing cage. After the steel pipe of the pipe shed is in place, insert the reinforcing cage inside the steel pipe of the pipe shed.

[0023] Step 5: Perform grouting construction of the grouting filling part. Use steel plates to seal the opening of the steel pipe in the pipe roof, weld the grouting guide pipe and pre-embed the exhaust pipe. Grouting starts from both ends and advances towards the tunnel arch. Grouting is carried out from bottom to top according to the odd number first, then even number of alternate holes grouting method.

[0024] Grouting is pumped into the hole using a grouting pump. The grouting is then closed under pressure for 10 minutes to ensure that the grout can quickly penetrate into the surrounding rock fissures through several grouting holes. Grouting is stopped when grout is discharged from the vent.

[0025] Step Six: Perform mortar application on the mortar filling section, using M30 cement mortar to fill the mortar filling section;

[0026] Step 7: Conduct testing and acceptance. The testing personnel need to test the grouting effect. After the test is qualified, the next construction process can only be carried out when the strength of the grout reaches 70%.

[0027] The present invention has the following beneficial effects:

[0028] 0. In this invention: by setting a steel arch frame and several guide steel pipes inside the arched guide wall, and welding the guide steel pipes to the outside of the steel arch frame, the combination of the two enhances the compressive strength of the arched guide wall to a certain extent; by inserting the pipe roof steel pipe into the interior of several odd-numbered guide holes and several even-numbered guide holes, inserting the reinforcing cage into the interior of the pipe roof steel pipe, grouting the grouting filling part between the reinforcing cage and the pipe roof steel pipe, and filling the mortar filling part between the pipe roof steel pipe and each odd-numbered guide hole or each even-numbered guide hole, the arched guide wall and the pipe roof steel pipe inside can be combined to form a strong support to prevent the collapse of the working face.

[0029] 1. In this invention: by setting the length of the first steel pipe of the pipe roof steel pipe inserted into the odd-numbered guide holes to 3m, and setting the length of the first steel pipe of the pipe roof steel pipe inserted into the even-numbered guide holes to 6m, it is possible to ensure that the joints between two adjacent pipe roof steel pipes are staggered, thereby ensuring the compressive strength between several pipe roof steel pipes.

[0030] 2. In this invention: During the process of pushing the reinforcing cage, the reinforcing cage will drive its external pulleys to slide inside the sliding groove assembly, avoiding the reinforcing cage from tilting due to its own weight and contacting the inner wall of the pipe roof steel pipe, thus generating a large friction force. This can reduce the difficulty of inserting the reinforcing cage into the pipe roof steel pipe. At the same time, the reinforcing cage will drive its external fastening block into the interior of the pipe roof steel pipe and abut against the inner wall of the pipe roof steel pipe. When the reinforcing cage is completely pushed into the interior of the pipe roof steel pipe, the fastening block and the fastening groove assembly will engage, preventing the reinforcing cage from sliding outward, thereby achieving the initial fastening of the reinforcing cage to strengthen the connection strength between the reinforcing cage and the pipe roof steel pipe. Attached Figure Description

[0031] Figure 1 is a schematic diagram of the external structure of Embodiment 1 of the present invention;

[0032] Figure 2 is an enlarged schematic diagram of the structure at point A in Figure 1;

[0033] Figure 3 is an enlarged schematic diagram of the structure at point B in Figure 1;

[0034] Figure 4 is a schematic diagram of the internal structure of the arched guide wall in this embodiment 1;

[0035] Figure 5 is a schematic diagram of the first structure of the steel pipe for the pipe shed in this embodiment 1;

[0036] Figure 6 is a schematic diagram of the second structure of the pipe shed steel pipe in this embodiment 1;

[0037] Figure 7 is a schematic diagram of the threaded steel pipe in this embodiment 1;

[0038] Figure 8 is a structural schematic diagram of the steel pipe for the pipe shed in this embodiment 2;

[0039] Figure 9 is a schematic diagram of the external structure of the steel cage in this embodiment 2;

[0040] Figure 10 is a schematic diagram of the internal structure of the steel cage in this embodiment 2.

[0041] In the diagram: 1. Highway tunnel entrance; 2. Arched guide wall; 21. Steel arch frame; 22. Guide steel pipe; 23. Concrete layer; 3. Odd-numbered guide holes; 4. Even-numbered guide holes; 5. Pipe roof steel pipe; 51. Head steel pipe; 52. Middle steel pipe; 53. Tail steel pipe; 54. Threaded steel pipe; 55. Grouting hole; 56. Sliding groove assembly; 57. Fastening groove assembly; 6. Reinforcing cage; 61. Sliding component; 611. Sleeve; 612. Connecting rod; 613. Pulley; 62. Fastener; 621. Shell; 622. Fastening block; 623. Rust-proof spring; 7. Grouting filling section; 8. Mortar filling section. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] As shown in Figures 1-7, the present invention proposes a reinforcement device for the initial support collapse treatment of highway tunnels and its construction method, which includes a highway tunnel entrance 1. An arched guide wall 2 is set inside the highway tunnel entrance 1. The arched guide wall 2 includes a steel arch frame 21 erected inside the highway tunnel entrance 1. Several guide steel pipes 22 are uniformly welded to the outside of the steel arch frame 21. The setting of the guide steel pipes 22 can not only strengthen the compressive strength of the arched guide wall 2, but also provide guidance for several odd-numbered guide holes 3 and several even-numbered guide holes 4. A concrete layer 23 is set on the outside of the steel arch frame 21 and the several guide steel pipes 22.

[0044] The outer side of the arched guide wall 2 is evenly provided with a number of odd-numbered guide holes 3 and a number of even-numbered guide holes 4. The odd-numbered guide holes 3 and the even-numbered guide holes 4 are respectively aligned with a number of guide steel pipes 22. The distribution range of the odd-numbered guide holes 3 and the even-numbered guide holes 4 is 150° in the middle of the arched guide wall 2. The distance between each odd-numbered guide hole 3 and each even-numbered guide hole 4 is 40cm. The odd-numbered guide holes 3 and the even-numbered guide holes 4 are distributed alternately on the outer side of the arched guide wall 2.

[0045] A pipe roof steel pipe 5 is installed inside several odd-numbered guide holes 3 and several even-numbered guide holes 4. The diameter of each odd-numbered guide hole 3 and each even-numbered guide hole 4 is 20-30mm larger than the outer diameter of each pipe roof steel pipe 5. The pipe roof steel pipe 5 is made of Ф108×6mm hot-rolled seamless steel pipe. The commonly used lengths of the pipe roof steel pipe 5 are 16m, 28cm and 40cm respectively. Each pipe roof steel pipe 5 consists of a head steel pipe 51, several middle steel pipes 52 and a tail steel pipe 53. The head steel pipe 51 is 3m or 6m long. The head steel pipe 51 inserted into the odd-numbered guide holes 3 is 3m long, and the head steel pipe 51 inserted into the even-numbered guide holes 4 is 6m long. This ensures that the joints between two adjacent pipe roof steel pipes 5 are staggered, thereby ensuring the compressive strength of several pipe roof steel pipes 5.

[0046] Several middle steel pipes 52 are 6m long and several tail steel pipes 53 are 3m long. The middle steel pipes 52 and tail steel pipes 53 are connected by threaded steel pipes 54 with diameters of Ф102×6mm. The threaded steel pipes 54 are 30cm long and can be manually connected to the head steel pipe 51, several middle steel pipes 52 and tail steel pipes 53. The front end of the head steel pipe 51 is tapered for 10cm. Several grouting holes 55 with diameters of Ф10mm are opened on the outside of the head steel pipe 51 and several middle steel pipes 52. The grouting holes 55 are distributed in a quincunx pattern on the outside of the head steel pipe 51 and several middle steel pipes 52. The distance between two adjacent grouting holes 55 is 20cm.

[0047] The interior of each steel pipe 5 is equipped with a reinforcing cage 6. A grouting filling part 7 is formed between the steel pipe 5 and the reinforcing cage 6. A mortar filling part 8 is formed between the steel pipe 5 and each odd-numbered guide hole 3 or each even-numbered guide hole 4.

[0048] In this embodiment: First, the construction of the arched guide wall 2 is carried out. A steel arch frame 21 is erected at the junction of the open and closed areas. Several guide steel pipes 22 are welded evenly on the outside of the steel arch frame 21. A formwork is set up and concrete is poured to form a concrete layer 23. The steel arch frame 21 and the several guide steel pipes 22 welded on its outside enhance the compressive strength of the arched guide wall 2 to a certain extent.

[0049] Next, drilling is carried out on several odd-numbered guide holes 3 and several even-numbered guide holes 4. The pipe roof drilling rig is moved to the entrance 1 of the highway tunnel for fixing and positioning. The pipe roof drilling rig is positioned and drilled according to the reserved guide steel pipes 22. The drilling sequence is from high hole position to low hole position. During the drilling process, the skip drilling method is adopted. Several odd-numbered guide holes 3 are constructed first, followed by several even-numbered guide holes 4. The drilling speed should be fixed at the beginning. After drilling to a depth of 20cm, the normal speed is switched. During the drilling process, the inclinometer is used to measure the drilling deviation. If the deviation exceeds the design requirements, the drilling is stopped immediately and the deviation is corrected. After the hole is formed, the rotating rod is used in conjunction with high-pressure air to blow out the debris in the hole while retracting the rod.

[0050] Then, the pipe roof steel pipe 5 is installed. The connected pipe roof steel pipe 5 is pushed into the interior of several odd-numbered guide holes 3 and several even-numbered guide holes 4 using a drilling rig. The pipe roof steel pipe 5 inside the arched guide wall 2 can form a strong support to prevent the working face from collapsing.

[0051] Subsequently, the steel cage 6 was inserted. After the steel pipe 5 of the pipe roof was in place, the steel cage 6 was inserted inside the steel pipe 5. The steel cage 6 can also enhance the compressive strength of the arched guide wall 2.

[0052] Subsequently, grouting construction of the grouting filling section 7 is carried out. Steel plates are used to seal the opening of the steel pipe 5 of the pipe roof, and grouting guide pipes are welded and vent pipes are pre-embedded. Grouting starts from both ends and advances towards the tunnel arch. Grouting is carried out from bottom to top according to the odd number first and then even number of alternate holes. Grouting pumps are used to pressurize the grout into the holes. It is necessary to pressurize and close the grout for 10 minutes to ensure that the grout can quickly penetrate into the surrounding rock crevices through several injection holes 55. Grouting is stopped when grout is discharged from the vent. After grouting is completed, the connection strength between the arched guide wall 2, the steel pipe 5 of the pipe roof, and the reinforcing cage 6 is enhanced.

[0053] Then, the mortar filling part 8 is filled with M30 cement mortar to make the mortar filling part 8 a sealed state.

[0054] Finally, testing and acceptance are carried out. The testing personnel need to test the grouting effect. After the test is qualified, the next construction process can only be carried out when the strength of the grout reaches 70%.

[0055] Example 2

[0056] As shown in Figures 8-10, based on Embodiment 1, sliding groove groups 56 are provided on the inner sides of the head steel pipe 51, several middle steel pipes 52 and tail steel pipe 53. Each sliding groove group 56 includes four sliding grooves. Fastening groove groups 57 are evenly provided on the inner sides of the head steel pipe 51, several middle steel pipes 52 and tail steel pipe 53. Each fastening groove group 57 includes four axisymmetric fastening grooves. The sliding groove group 56 and the fastening groove group 57 do not interfere with each other.

[0057] The outside of the reinforcing cage 6 is uniformly provided with sliding parts 61 that cooperate with the sliding groove assembly 56. The sliding parts 61 include a sleeve 611 welded to the outside of the reinforcing cage 6, a connecting rod 612 welded to the outside of the sleeve 611, and a pulley 613 rotatably connected to the end of the connecting rod 612 away from the sleeve 611. The cooperation between the sliding parts 61 and the sliding groove assembly 56 can prevent the reinforcing cage 6 from rubbing against the inside of the pipe roof steel pipe 5 due to its own weight when it is inserted into the pipe roof steel pipe 5, thereby reducing the difficulty of inserting the reinforcing cage 6.

[0058] The outside of the reinforcing cage 6 is also uniformly provided with fasteners 62 that cooperate with the fastening groove assembly 57. The fasteners 62 include a sleeve 621 welded to the outside of the reinforcing cage 6. A fastening block 622 is slidably connected inside the sleeve 621. The side of the fastening block 622 near the bottom of the reinforcing cage 6 is arc-shaped. A rust-proof spring 623 is fixedly connected between the sleeve 621 and the fastening block 622. The fastening block 612 cooperates with the fastening groove assembly 57 to achieve the initial fastening of the reinforcing cage 6 at the same time as it is inserted, thereby strengthening the connection strength between the reinforcing cage 6 and the pipe roof steel pipe 5.

[0059] In this embodiment: when inserting the reinforcing cage 6 into the steel pipe 5 of the pipe shed, it is necessary to use a lifting tool to align the pulley 613 on the reinforcing cage 6 with the sliding groove group 56 on the steel pipe 5 of the pipe shed, and at the same time align the fastening block 622 on the reinforcing cage 6 with the fastening groove group 57 on the steel pipe 5 of the pipe shed, and then push the reinforcing cage 6 in.

[0060] During the process of pushing the reinforcing cage 6, the reinforcing cage 6 will drive the pulley 613 on its outside to slide inside the sliding groove group 56, so as to avoid the reinforcing cage 6 tilting due to its own weight and contacting the inner wall of the pipe roof steel pipe 5, thus generating a large friction force. This can reduce the difficulty of inserting the reinforcing cage 6 into the pipe roof steel pipe 5. At the same time, the reinforcing cage 6 will drive the fastening block 612 on its outside to enter the interior of the pipe roof steel pipe 5 and abut against the inner wall of the pipe roof steel pipe 5, so that the fastening block 612 can be engaged with or disengaged from the fastening groove group 57.

[0061] When the reinforcing cage 6 is fully pushed into the steel pipe 5 of the pipe shed, the fastening block 612 and the fastening groove group 57 engage, preventing the reinforcing cage 6 from sliding outward, thereby achieving the initial fastening of the reinforcing cage 6 to strengthen the connection strength between the reinforcing cage 6 and the steel pipe 5 of the pipe shed.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reinforcement device for treating initial support collapse in highway tunnels, comprising a highway tunnel entrance (1), characterized in that: An arched guide wall (2) is provided inside the entrance (1) of the highway tunnel. Several odd-numbered guide holes (3) and several even-numbered guide holes (4) are evenly provided on the outside of the arched guide wall (2). Several odd-numbered guide holes (3) and several even-numbered guide holes (4) are distributed at intervals on the outside of the arched guide wall (2). Pipe roof steel pipes (5) are provided inside the several odd-numbered guide holes (3) and several even-numbered guide holes (4). Reinforcing cages (6) are provided inside the pipe roof steel pipes (5). A grouting filling part (7) is formed between the pipe roof steel pipes (5) and the reinforcing cages (6). The pipe roof steel pipe (5) forms a mortar filling part (8) between each of the odd-numbered guide holes (3) or each of the even-numbered guide holes (4); the pipe roof steel pipe (5) is composed of a head steel pipe (51), several middle steel pipes (52) and a tail steel pipe (53). The head steel pipe (51) is 3m or 6m long, the several middle steel pipes (52) are 6m long, the tail steel pipe (53) is 3m long, and the several middle steel pipes (52) and the tail steel pipe (53) are connected by a Ф102×6mm threaded steel pipe (54). The threaded steel pipe (54) is 30cm long. The head steel pipe (51) is 3m or 6m long. 1) Sliding groove groups (56) are provided on the inner sides of several middle steel pipes (52) and tail steel pipes (53), and fastening groove groups (57) are uniformly provided on the inner sides of the head steel pipe (51), several middle steel pipes (52) and tail steel pipes (53). The sliding groove groups (56) and the fastening groove groups (57) do not interfere with each other. Sliding parts (61) that cooperate with the sliding groove groups (56) are uniformly provided on the outside of the reinforcing cage (6). The sliding parts (61) include sleeves (611) welded to the outside of the reinforcing cage (6). The sleeves (611) are welded to the outside of the sleeves. The connecting rod (612) is rotatably connected to a pulley (613) at one end away from the sleeve (611). The outside of the steel cage (6) is also uniformly provided with fasteners (62) that cooperate with the fastening groove group (57). The fasteners (62) include a sleeve (621) welded to the outside of the steel cage (6). A fastening block (622) is slidably connected inside the sleeve (621). The side of the fastening block (622) near the bottom of the steel cage (6) is an arc-shaped surface. A rust-proof spring (623) is fixedly connected between the sleeve (621) and the fastening block (622).

2. The reinforcement device for treating collapse of initial support in highway tunnels according to claim 1, characterized in that: The arched guide wall (2) includes a steel arch frame (21) erected inside the entrance (1) of the highway tunnel. Several guide steel pipes (22) are uniformly welded to the outside of the steel arch frame (21). A concrete layer (23) is provided on the outside of the steel arch frame (21) and the several guide steel pipes (22).

3. The reinforcement device for treating collapse of initial support in highway tunnels according to claim 2, characterized in that: Several odd-numbered guide holes (3) and several even-numbered guide holes (4) are respectively aligned with several guide steel pipes (22). The diameter of each odd-numbered guide hole (3) and each even-numbered guide hole (4) is 20-30mm larger than the outer diameter of each pipe roof steel pipe (5). The pipe roof steel pipe (5) is a Ф108×6mm hot-rolled seamless steel pipe. The distribution range of several odd-numbered guide holes (3) and several even-numbered guide holes (4) is 150° in the middle of the arched guide wall (2). The distance between each odd-numbered guide hole (3) and each even-numbered guide hole (4) is 40cm.

4. The reinforcement device for treating collapse of initial support in highway tunnels according to claim 3, characterized in that: The front end of the first steel pipe (51) is tapered for 10cm. The first steel pipe (51) and several middle steel pipes (52) are provided with several grouting holes (55) of Ф10mm on the outside. The several grouting holes (55) are distributed in a quincunx pattern on the outside of the first steel pipe (51) and several middle steel pipes (52). The distance between two adjacent grouting holes (55) is 20cm.

5. A construction method for a reinforcement device for treating collapse of initial support in highway tunnels, implemented according to claim 4, characterized in that: The steps include: Step 1: Construct the arched guide wall (2), erect the steel arch frame (21) at the junction of the open and closed sections, weld several guide steel pipes (22) evenly on the outside of the steel arch frame (21), set up formwork and pour concrete to form the concrete layer (23); Step 2: Drill several odd-numbered guide holes (3) and several even-numbered guide holes (4), move the pipe roof drilling machine to the entrance (1) of the highway tunnel for fixing and positioning, and drill the pipe roof drilling machine according to the reserved several guide steel pipes (22). 2) Positioning and drilling: Drilling sequence proceeds from high to low hole positions. During drilling, a skip-hole drilling method is used. First, construct several odd-numbered guide holes (3), then construct several even-numbered guide holes (4). The drilling speed should be fixed at the beginning. After drilling to a depth of 20cm, switch to normal speed. During drilling, use an inclinometer to measure the drilling deviation. If the deviation exceeds the design requirements, stop drilling immediately and correct the deviation. After the hole is formed, use the drill rod in conjunction with high-pressure air to blow out debris from the hole while retracting the rod. Step 3: Install the steel pipes (5) of the pipe roof. Use the drilling machine to connect the pipes. Step 4: Insert the steel pipe (5) into the interior of several odd-numbered guide holes (3) and several even-numbered guide holes (4); Step 5: Insert the steel cage (6) into the steel pipe (5) after it is in place; Step 6: Grout the filling part (7) into the grouting section (7). Use steel plates to seal the opening of the steel pipe (5), weld the grouting guide pipe and pre-embed the exhaust pipe. Grouting starts from both ends and proceeds towards the tunnel arch. Grouting is done in the order of odd-numbered holes first, then even-numbered holes. The grouting method is carried out from bottom to top; the grout is pumped into the hole using a grouting pump, and the grouting is closed under pressure for 10 minutes to ensure that the grout can quickly penetrate into the surrounding rock fissures through several grouting holes (55). Grouting is stopped when grout is discharged from the vent. Step six: carry out mortar construction of the mortar filling part (8) and fill the mortar filling part (8) with M30 cement mortar. Step seven: conduct inspection and acceptance. The inspection personnel need to inspect the grouting effect. After the inspection is qualified, the next process can be carried out only when the strength of the grout reaches 70%.

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