A highway tunnel excavation construction process

Abstract

The application relates to the technical field of tunnel construction, in particular to a highway tunnel excavation construction process, which comprises the following steps: S1, hole opening excavation, first hole opening excavation is carried out, and side and inverted slopes at a tunnel hole opening are subjected to construction; S2, hole opening support, anchor rods are drilled and installed on the upper end wall of the hole opening, a protective net is installed, concrete is sprayed, then advanced large pipe shed construction is carried out, and advanced small guide pipe drilling and grouting are carried out; S3, hole body excavation, the hole body is subjected to step excavation, and advanced small guide pipe construction is carried out; S4, tunnel protection and inverted arch construction, tunnel inner wall concrete protection is carried out, and inverted arch formwork pouring concrete is carried out. The application has the effect of improving construction safety.

Description

Technical Field

[0001] This application relates to the technical field of tunnel construction, and in particular to an excavation and construction process for a highway tunnel. Background Technology

[0002] Currently, with the rapid development of high-speed railways and highways, people have increasingly higher requirements for the quality standards of construction. During highway construction, due to the high requirements for horizontal alignment and longitudinal slope, direct construction on mountainsides often requires a large amount of earthwork and can damage the ecological environment. Therefore, tunnel excavation plays a crucial role when highways pass through mountainous areas.

[0003] First, the tunnel entrance is excavated, then the entrance is supported. The tunnel is then excavated inwards from the entrance, and the excavated sand and gravel are removed. Next, the side and uphill slopes at the tunnel entrance are constructed, followed by the construction of the advanced large pipe roof. After this, drilling and grouting are carried out to complete the preliminary preparations for tunnel excavation. Then, tunnel excavation begins. During excavation, initial shotcrete is applied to the tunnel interior walls, steel support frames are erected, anchor bolts and steel mesh are installed, and shotcrete is applied again. Finally, the lining and invert arch are constructed.

[0004] In the process of developing this application, the inventors discovered that the technology has at least the following problems: when performing support treatment at the tunnel entrance, some rock masses are affected by weathering or the geological conditions themselves, and rocks may fall during the support process, causing injury to construction workers and thus reducing safety. Summary of the Invention

[0005] To improve construction safety, this application provides an excavation and construction process for highway tunnels.

[0006] This application provides a construction method for the excavation of a highway tunnel, which adopts the following technical solution:

[0007] A construction process for excavating a highway tunnel includes the following steps:

[0008] S1. Excavation of the tunnel entrance: The tunnel entrance is excavated first, and the side slopes and the tunnel entrance are excavated.

[0009] S2. For the opening support, anchor rods are drilled and installed on the upper wall of the opening, and a protective net is installed and concrete is sprayed. Then, the advanced large pipe roof construction is carried out, and the advanced large pipe drilling and grouting are carried out.

[0010] S3. Tunnel excavation: The tunnel body is excavated using the bench method, and advanced small guide pipe construction is carried out.

[0011] S4. Tunnel protection and invert construction: spray concrete to protect the inner wall of the tunnel and pour concrete for the invert.

[0012] By adopting the above technical solution, the excavation of highway tunnels first involves excavating the slopes and back slopes, then pouring concrete for slope support, reserving the location for the tunnel entrance, and then excavating the entrance. Anchor bolts are drilled at the entrance, and protective netting is installed. Concrete is then sprayed onto the surface of the protective netting to form a protective layer, reducing the fall of debris at the entrance during construction. Next, advanced large-diameter pipe roofs are installed, and boreholes are drilled. Grouting is then performed on the advanced large-diameter pipes, followed by the excavation of the tunnel body using a step-by-step method. During the excavation process, advanced small-diameter pipes are constructed. As each section of excavation is completed, the inner wall of the tunnel is reinforced with steel mesh, sprayed, and then formwork erected and poured. The protective measures implemented at the tunnel entrance reduce the risk of injury to construction workers from falling debris or soil during the construction of the advanced large-diameter pipe roofs, improving safety. Simultaneously, the construction of advanced small-diameter pipes enhances the stability of the tunnel body, further improving safety.

[0013] Optionally, in step S3, during the construction of the advance small guide pipe, a fixing frame is installed in the tunnel body, and drilling holes are opened on the fixing frame. The advance small guide pipe is drilled according to the hole positions and is drilled crosswise. It is connected above the large guide pipe of the advance large pipe shed, and the drilling of the advance small guide pipe hole positions is inclined along the excavation direction of the tunnel body.

[0014] By adopting the above technical solution, a fixed frame needs to be installed after each section of tunnel excavation. Pre-drilled holes for advance guide pipes are then drilled on the fixed frame. The holes for the two advance guide pipes in each group are tangent and connected. The advance guide pipes are then inserted into the holes and welded to the fixed frame, followed by grouting. The connection between the holes of the two adjacent advance guide pipes allows the poured concrete to be connected into a whole, making it easier to fix the tunnel roof. At the same time, the force can be applied to the advance guide pipes, further enhancing the stability of the tunnel roof and thus improving safety.

[0015] Optionally, two interconnected small guide pipe holes above the large guide pipe of the large pipe shed are grouped into one group, and multiple groups are set along the circumference of the tunnel body, with adjacent groups of small guide pipes staggered along the excavation direction of the tunnel body.

[0016] By adopting the above technical solution, multiple fixing frames are set up, and multiple holes for inserting advanced small guide pipes are opened on the fixing frames. Each pair of holes for inserting advanced small guide pipes is a group, and adjacent groups are set at intervals. The above arrangement can reduce the drilling of too many holes and excessive damage to the upper structure of the tunnel body, thereby enhancing the stability of the tunnel body and further improving safety. At the same time, the fixing frames fix the advanced small guide pipes, which facilitates grouting.

[0017] Optionally, in step S3, before the pre-construction of the small guide pipe, an arch frame is first installed to support and fix the tunnel body. The arch frame includes an upper arch section, a side arch section, a lower arch section, and a connecting mechanism. The side arch sections are arranged sequentially at both ends of the upper arch section, and the lower arch section is arranged at the end of the side arch section away from the upper arch section. The upper arch section and the side arch section are connected by the connecting mechanism, and the side arch section is connected to the lower arch section by the connecting mechanism.

[0018] By adopting the above technical solution, the tunnel body is excavated using a step-by-step method. After each step is excavated, the corresponding part of the arch frame is installed. After the next section is completed, the corresponding part of the arch frame is installed and connected by a connecting mechanism. The arch frame is then welded and fixed. The arch frame is divided into multiple sections, which makes the construction of the tunnel body more convenient. At the same time, the step-by-step construction method facilitates the support of the steel mesh and the installation of the arch frame, thereby improving work efficiency.

[0019] Optionally, the connecting mechanism includes a fixing block, a slider, and a locking assembly. The fixing blocks are provided at both ends of the upper arch section and at the end of the side arch section away from the upper arch section. The fixing blocks have sliding grooves. The sliders are provided at the end of the side arch section near the upper arch section and at the end of the lower arch section near the side arch section. The sliders are slidably connected in adjacent sliding grooves. The locking assembly is provided on the fixing block and connected to the slider.

[0020] By adopting the above-mentioned technical solution, the step method of excavation generally prioritizes the excavation of the upper arch, followed by the excavation of the side arches and lower arches in sequence. After the upper arch is excavated, anchor bolt holes are drilled and anchor bolts are installed. Then, the upper arch section is installed and fixed. Next, advance guide pipe holes are drilled and advance guide pipes are installed for grouting. Then, steel mesh support is installed and concrete is poured. Excavation continues, and the sliders on the adjacent side arch sections are slid into the grooves of the fixed blocks. The sliders are then fixed with locking components to reduce slider slippage, thereby improving the stability of the arch frame. The sliders slide into the grooves from the side, providing a certain degree of support for the arch top of the tunnel and improving safety.

[0021] Optionally, the locking assembly includes a plug, the fixing block having a first slot communicating with the slide groove, the slider having a second slot, the axis of the first slot being parallel to the axis of the second slot, and the plug being inserted into the first slot and the second slot.

[0022] By adopting the above technical solution, after the slider is slid into the groove, the insert blocks are then inserted into the first and second slots in sequence and welded to fix them. The insert blocks can reduce the lateral force applied to the arch frame, allowing the two sections of the arch frame to separate. The insert blocks also block the sliding direction of the slider, reducing the separation of the slider from the fixed block, thereby further improving safety. At the same time, it can reduce the welding length and reduce the difficulty of welding construction. Furthermore, the weld seam far from the top wall of the tunnel is easier to weld, and the stress point is on the slider and the fixed block, which facilitates the distribution of stress and reduces the stress that is entirely concentrated at the weld seam during ordinary welding construction.

[0023] Optionally, the locking assembly further includes a limiting bolt, which is threaded onto the fixing block and abuts against the insert block.

[0024] By adopting the above technical solution, after the slider is slid into the groove, the insert is then inserted into the first slot, and the insert is tapped with a hammer to fix its position. Then, the limiting bolt is rotated, and the limiting bolt abuts against the insert and restricts the insertion from sliding. The limiting bolt can fix the insert and reduce the loosening of the abutment between the insert and the first slot caused by the release of force during welding, thereby maintaining the stability of the locking assembly for fixing the arch frame.

[0025] Optionally, the arch frame is provided with an anchoring assembly, which includes an anchor rod, a tension bolt, and a tension nut. Multiple anchor rods are provided and embedded into the periphery of the tunnel by drilling and grouting. Each anchor rod is provided with a tension bolt, which passes through the arch frame and is threadedly connected to the tension nut.

[0026] By adopting the above technical solution, when installing the arch frame, anchor holes can be opened on the upper top wall of the tunnel body. Then, anchor rods are sequentially inserted into the anchor holes and grouting is performed for fixation. After the upper arch section of the arch frame is installed, the tension bolts are passed through the upper arch section, and then the tension nuts are threaded onto the tension bolts. The tension nuts drive the arch frame to press against the tunnel body. The anchor components provide support for the tunnel body and allow the anchor rods to provide a certain tensile fixation for the arch frame, thereby improving the support and fixation of the arch frame.

[0027] Optionally, a bearing plate is integrally provided on the arch frame, which is used to connect adjacent steel meshes and support the steel meshes.

[0028] By adopting the above technical solution, when installing the steel mesh, a portion of anchor rods are first drilled and installed on the fixed wall of the tunnel. Then, the steel mesh is suspended, and part of the steel mesh is supported on a bearing plate and welded in place. The bearing plate and anchor rods work together to suspend the steel mesh. On the one hand, this reduces the number of anchor rods that need to be drilled. On the other hand, the anchor rods and bearing plate work together to support the steel mesh, reducing its downward deflection. This ensures that the steel mesh provides a stable support for the tunnel, thereby further improving safety.

[0029] In summary, this application includes the following beneficial technical effects:

[0030] 1. The excavation of highway tunnels begins with the excavation of the slopes and back slopes, followed by concrete pouring for slope support, reserving space for the tunnel entrance. The entrance is then excavated, anchor bolts are drilled, and protective netting is installed. Concrete is then sprayed onto the protective netting to form a protective layer, reducing the risk of debris falling into the tunnel entrance during construction. Next, large-diameter pipe roofs are installed, and boreholes are drilled. Grouting is then performed on the large-diameter pipes, followed by tunnel body excavation using a step-by-step method. During excavation, small-diameter pipes are constructed. As each section of excavation is completed, the inner tunnel wall is reinforced with steel mesh, sprayed, and then formwork erected and poured. The protective measures implemented at the tunnel entrance reduce the risk of injury to workers from falling debris or soil during the construction of the large-diameter pipe roofs, improving safety. Simultaneously, the construction of small-diameter pipes enhances the stability of the tunnel body, further improving safety.

[0031] 2. After the slider is slid into the groove, the insert blocks are then inserted into the first and second slots in sequence, and the insert blocks are welded and fixed. The insert blocks reduce the lateral force applied to the arch frame, allowing the two sections of the arch frame to separate. The insert blocks also block the sliding direction of the slider, reducing the separation of the slider from the fixed block, thereby further improving safety. At the same time, it can reduce the welding length and reduce the difficulty of welding construction. Furthermore, the weld seam far from the top wall of the tunnel is easier to weld, and the stress point is on the slider and the fixed block, which facilitates the distribution of stress and reduces the stress that is entirely concentrated at the weld seam during ordinary welding construction.

[0032] 3. When installing the arch frame, anchor holes can be opened on the upper top wall of the tunnel. Then, anchor rods are inserted into the anchor holes one by one, and grouting is performed for fixation. After the upper arch section of the arch frame is installed, the tension bolts are passed through the upper arch section, and then the tension nuts are threaded onto the tension bolts. The tension nuts cause the arch frame to press against the tunnel body. The anchor components provide support for the tunnel body and allow the anchor rods to provide a certain tensile fixation for the arch frame, thereby improving the support and fixation of the arch frame.

[0033] 4. When installing the steel mesh, first drill and install a portion of anchor rods on the fixed wall of the tunnel. Then suspend the steel mesh, while a portion of the steel mesh is supported on a bearing plate and welded in place. The bearing plate and anchor rods together suspend the steel mesh. This reduces the number of anchor rods required and, moreover, the anchor rods and bearing plate together support the steel mesh, reducing its downward deflection. This ensures the steel mesh maintains its fixed support effect on the tunnel, further improving safety. Attached Figure Description

[0034] Figure 1 This is a flowchart of the excavation and construction process of a highway tunnel in the embodiments of this application;

[0035] Figure 2 This is a schematic diagram of the tunnel structure in an embodiment of this application;

[0036] Figure 3 This is a structural schematic diagram showing the installation position of the advanced small catheter in an embodiment of this application;

[0037] Figure 4 This is a schematic diagram of the arch frame structure in an embodiment of this application;

[0038] Figure 5 This is a schematic diagram of the locking component in an embodiment of this application;

[0039] Figure 6 This is a schematic diagram of the anchoring component in an embodiment of this application.

[0040] Reference numerals: 100, opening; 200, tunnel body; 300, advanced large pipe shed; 400, advanced small pipe; 500, arch frame; 510, upper arch section; 520, side arch section; 530, lower arch section; 540, connecting mechanism; 541, fixing block; 542, slider; 543, sliding hole; 544, first slot; 550, locking assembly; 551, insert block; 552, limit bolt; 553, fixing plate; 554, abutting block; 560, anchoring assembly; 561, anchor rod; 562, tension bolt; 563, tension nut; 564, bearing plate; 565, anchoring plate; 566, snap-fit ​​groove; 567, clearance groove. Detailed Implementation

[0041] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0042] This application discloses an excavation and construction process for a highway tunnel.

[0043] refer to Figure 1 , Figure 2 and Figure 3The excavation and construction process of a highway tunnel includes the following steps: S1. Excavation of the tunnel entrance 100: First, the tunnel entrance 100 is excavated, including the side slopes and the excavation of the tunnel entrance 100 itself; S2. Support of the tunnel entrance 100: Anchor bolt holes 561 are drilled in the upper wall of the tunnel entrance 100, then the anchor bolts 561 are installed and grouting is performed. A protective net is then installed on the top wall of the tunnel entrance 100 and connected to the anchor bolts 561. Concrete spraying is then performed, and a protective net is installed before concrete spraying. Then, a pre-installed large pipe shed 300 is installed, and a steel mesh is installed between the tunnel entrance 100 and the large pipe shed. Concrete is poured, and after solidification, pre-installed large pipe grouted; S3. Excavation of the tunnel body 200: The tunnel body 200 is excavated using the step method. After each small section is excavated, an arch frame 500 is installed to support the tunnel body 200. A fixing frame is installed between two adjacent arch frames 500, and holes for advanced small guide pipes 400 are drilled. The holes of two adjacent advanced small guide pipes 400 are drilled crosswise and connected above the advanced large guide pipe. The axes of the two advanced small guide pipe 400 holes are parallel and the two advanced small guide pipes 400 are tangentially connected, without hindering the installation of the advanced small guide pipes 400. The holes of two advanced small guide pipes 400 connected above the advanced large guide pipe are grouped together and staggered with the holes of the adjacent group of advanced small guide pipes 400 along the excavation direction of the tunnel body 200. Multiple groups of advanced small guide pipe 400 holes are equally spaced along the circumference of the tunnel body 200, and each advanced small guide pipe 400 hole is inclined along the excavation direction. Then, the advanced small guide pipes 400 are inserted into the holes for grouting. S4, Tunnel protection and invert construction: spray concrete protection is carried out on the inner wall of the tunnel, and concrete is poured for the invert formwork.

[0044] refer to Figure 4 and Figure 5The arch frame 500 includes an upper arch section 510, which abuts against the upper arch of the tunnel body 200. Both ends of the upper arch section 510 abut against side arch sections 520, which abut against the side arches of the tunnel body 200. The end of the side arch section 520 away from the upper arch section 510 abuts against a lower arch section 530. Connecting mechanisms 540 are provided at the abutments of the lower arch section 530, upper arch section 510, and side arch sections 520. Each connecting mechanism 540 includes multiple fixing blocks 541. Fixing blocks 541 are fixedly connected to both ends of the upper arch section 510 and to the end of the side arch section 520 away from the upper arch section 510. A sliding groove is provided on each fixing block 541 along its length. Each side arch section 520 has a sliding hole 543 on its side wall that communicates with the chute. Both the chute and the sliding hole 543 have a T-shaped cross-section. A slider 542 is fixedly connected to the end of the side arch section 520 near the upper arch section 510 and the end of the lower arch section 530 near the side arch section 520. The slider 542 has a T-shaped cross-section and can slide into the chute through the sliding hole 543. After each step is excavated, the side arch section 520 is first moved closer to the upper arch section 510, and the slider 542 slides into the chute through the sliding hole 543, so that the upper arch section 510 and the side arch section 520 are connected into a whole. This connection method has a simple structure, can be quickly connected, is easy to install, has uniform stress, and can reduce the welding length.

[0045] refer to Figure 5 To reduce the sliding of the slider 542, a locking component 550 is provided on the fixing block 541. The locking component 550 includes an insert block 551. A first slot 544 is formed on the side wall of the fixing block 541 away from the tunnel body 200. The first slot 544 penetrates the upper arch section 510, and the cross-sectional area of ​​the first slot 544 gradually decreases along the axis of the first slot 544 towards the side wall of the tunnel body 200. A second slot is formed on the slider 542. The second slot smoothly transitions with the first slot 544. The insert block 551 is inserted into the first slot 544 and the second slot in sequence, and respectively into the first slot 542. 4. The inner wall of the second slot is press-fitted; two fixing plates 553 are fixedly connected to the fixing block 541, and limit bolts 552 are threadedly connected to the fixing plates 553. The two limit bolts 552 are set facing each other; a clamping block 554 is fixedly connected to the side wall of the insert block 551 away from the hole 200. The clamping block 554 has abutting surfaces on the two side walls near the locking bolt. The two abutting surfaces are inclined and the end away from the fixing block 541 is inclined towards the direction of approach. The limit bolt 552 abuts against the abutting surface; the abutting point between the insert block 551 and the fixing block 541 can be welded to balance the force.

[0046] refer to Figure 4 and Figure 6To facilitate the installation and fixation of the arch frame 500 and improve its stability, an anchoring assembly 560 is provided on the arch frame 500. The anchoring assembly 560 includes anchor rods 561. Multiple anchoring holes are provided on the tunnel body 200. The multiple anchoring holes are divided into two groups and are located on both sides of the width direction of the arch frame 500. The anchor rods 561 are inserted into the anchoring holes and fixed by grouting. A tension bolt 562 is integrally provided at the end of the anchor rod 561. The tension bolt 562 extends to the upper arch section 510, the side arch section 520 and the lower arch section. On the side of 530 away from the tunnel body 200, the upper arch section 510, the side arch section 520 and the lower arch section 530 away from the inner wall of the tunnel body 200 are provided with snap-fit ​​grooves 566. Anchor plates 565 are snapped into the snap-fit ​​grooves 566. Both ends of the anchor plates 565 are provided with insertion holes for tension bolts 562 to pass through. After the tension bolts 562 pass through the insertion holes, tension nuts 563 are threadedly connected. The tension nuts 563 press the anchor plates 565 against the snap-fit ​​grooves 566 and drive the arch frame 500 to press against the inner wall of the tunnel body 200.

[0047] refer to Figure 3 and Figure 6 Multiple anchor bolt holes are drilled in the inner wall of the tunnel body 200. Anchor bolts are inserted into the anchor bolt holes and fixed by grouting. The end of the anchor bolt away from the tunnel body 200 is fixedly connected to a steel mesh. The steel mesh is formed by binding multiple transverse and longitudinal bars with binding wire. Bearing plates 564 are fixedly connected to the side walls on both sides of the upper arch section 510, the side arch section 520 and the lower arch section 530 in the width direction. Multiple clearance grooves 567 are opened on the bearing plates 564 to avoid the transverse bars. The transverse bars can pass through the clearance grooves 567 and enter the side of the bearing plate 564 near the tunnel body 200. The transverse bars can be fixedly connected to the bearing plate 564 by spot welding. The bearing plate 564 supports the steel mesh and is used to reduce the downward deflection of the steel mesh.

[0048] The implementation principle of the excavation construction process for a highway tunnel according to an embodiment of this application is as follows: First, the tunnel entrance 100 is excavated, and the slope at the tunnel entrance 100 is excavated. After the tunnel entrance 100 is excavated, anchor bolt holes are drilled, anchor bolts are installed, and protective netting is installed. Then, a concrete protective layer is sprayed, followed by the construction of the advanced large pipe roof 300 and concrete pouring. Then, the advanced large pipe is drilled, installed, and grouted. Then, the tunnel body 200 is excavated using the step method, and the arch frame 500 is installed after each step is completed, followed by the installation and grouting of the advanced small pipe 400. When constructing the advanced small pipe 400, attention is paid to the position and inclination angle of the drill holes to ensure that the holes of the advanced small pipe 400 are staggered and connected. When installing the arch frame 500 in sections, first, according to each section... The length of the section is selected based on the excavation height of the step, and it is fixed during installation using anchor plates 565, tension bolts 562, and tension nuts 563. When installing the side arch section 520 or the lower arch section 530, the slider 542 is slid into the sliding hole 543 and into the groove. Then, the insert block 551 is inserted into the first slot 544 and hammered to fix it. Then, the limiting bolt 552 is rotated, and the limiting bolt 552 abuts against the abutment surface and restricts the insert block 551 from sliding out of the first slot 544. Then, the abutment joint between the insert block 551 and the first slot 544, and the abutment joint between the upper arch section 510 and the side arch section 520 are welded and fixed. The insert block 551 and the limiting bolt 552 respectively limit the slider 542 and the insert block 551, reducing the release of hard force during welding and preventing them from sliding.

[0049] The horizontal reinforcing bars are moved sequentially through the relief grooves 567 to the side of the bearing plate 564 near the tunnel body 200. Then, the horizontal reinforcing bars are slid and staggered with the relief grooves 567, and the horizontal reinforcing bars are fixedly connected to the anchor rods embedded in the tunnel body 200, so that there is a distance of 10 to 20 centimeters between the horizontal reinforcing bars and the inner wall of the tunnel body 200. Then, the longitudinal reinforcing bars are fixed to the horizontal reinforcing bars sequentially with binding wires. Then, the horizontal reinforcing bars are welded and fixed to the bearing plate 564. Then, the formwork is supported and the concrete is filled. After the concrete is filled, the formwork is removed and the decoration construction is carried out as needed.

[0050] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A construction process for excavating a highway tunnel, characterized in that, Includes the following steps: S1, Excavation of the tunnel entrance (100): First, the tunnel entrance (100) is excavated. Construction is carried out on the side slope and the tunnel entrance (100) at the tunnel entrance (100). S2, support of the opening (100), anchor rods are drilled and installed on the upper wall of the opening (100), and a protective net is installed for concrete spraying. Then, the advanced large pipe shed (300) is constructed, and the advanced large pipe is drilled and grouted. S3. Excavation of the tunnel body (200): The tunnel body (200) is excavated using the step method, and the advanced small guide pipe (400) is constructed. S4. Tunnel protection and invert construction: spray concrete to protect the inner wall of the tunnel and pour concrete for the invert. In step S3, before the pre-construction small guide pipe (400) is installed, an arch frame (500) is first installed to support and fix the tunnel body (200). The arch frame (500) includes an upper arch section (510), a side arch section (520), a lower arch section (530), and a connecting mechanism (540). The side arch sections (520) are arranged at both ends of the upper arch section (510), and the lower arch section (530) is arranged at the end of the side arch section (520) away from the upper arch section (510). The upper arch section (510) and the side arch section (520) are connected by the connecting mechanism (540), and the side arch section (520) is connected to the lower arch section (530) by the connecting mechanism (540). The connecting mechanism (540) includes a fixing block (541), a slider (542), and a locking assembly (550). The fixing blocks (541) are provided at both ends of the upper arch section (510) and at the end of the side arch section (520) away from the upper arch section (510). The fixing blocks (541) are provided with sliding grooves. The sliders (542) are provided at the end of the side arch section (520) near the upper arch section (510) and at the end of the lower arch section (530) near the side arch section (520). The sliders (542) are slidably connected in adjacent sliding grooves. The locking assembly (550) is provided on the fixing block (541) and connected to the slider (542). The locking assembly (550) includes a plug (551), a first slot (544) communicating with the slide groove is provided on the fixing block (541), a second slot is provided on the slider (542), the axis of the first slot (544) is parallel to the axis of the second slot, and the plug (551) is inserted into the first slot (544) and the second slot.

2. The excavation and construction technology for a highway tunnel according to claim 1, characterized in that, In step S3, when the advance small guide pipe (400) is constructed, a fixing frame is installed on the tunnel body (200), and drilling holes are opened on the fixing frame. The advance small guide pipe (400) is drilled according to the hole position and is drilled crosswise. It is connected above the large guide pipe of the advance large pipe shed (300), and the drilling of the holes of the advance small guide pipe (400) is inclined along the excavation direction of the tunnel body (200).

3. The excavation and construction technology for a highway tunnel according to claim 2, characterized in that, Two advanced small pipe holes (400) connected above the large pipe of the advanced pipe shed (300) are divided into a group, and multiple groups are set along the circumference of the tunnel body (200), and adjacent groups of advanced small pipes (400) are staggered along the excavation direction of the tunnel body (200).

4. The excavation and construction technology for a highway tunnel according to claim 1, characterized in that, The locking assembly (550) also includes a limiting bolt (552) which is threaded onto the fixing block (541) and abuts against the insert block (551).

5. The excavation and construction technology for a highway tunnel according to claim 1, characterized in that, An anchoring assembly (560) is provided on the arch frame (500). The anchoring assembly (560) includes an anchor rod (561), a tension bolt (562), and a tension nut (563). Multiple anchor rods (561) are provided and embedded into the periphery of the tunnel body (200) by drilling and grouting. Each anchor rod (561) is provided with a tension bolt (562). The tension bolt (562) passes through the arch frame (500) and is threadedly connected to the tension nut (563).

6. The excavation and construction process for a highway tunnel according to claim 4, characterized in that, The arch frame (500) is integrally provided with a bearing plate (564), which is used to connect adjacent steel mesh and support the steel mesh.

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