An assembled arched tunnel structure with an extra-large cross-section for highways and its construction method

Abstract

The present invention discloses a super-large cross-section highway prefabricated arched tunnel structure and its construction method, belonging to the technical field of tunnel construction. The structure includes annular prefabricated structures spliced in sequence longitudinally. Each annular prefabricated structure includes a cast-in-place inverted arch structure, a tunnel prefabricated structure A, and a tunnel prefabricated structure B. The upper ends of the tunnel prefabricated structure A and the tunnel prefabricated structure B cooperate with each other to form an arch shape, and the lower ends of the tunnel prefabricated structure A and the tunnel prefabricated structure B are respectively connected to both ends of the cast-in-place inverted arch structure; adjacent two annular prefabricated structures are spliced with each other through a concave-convex tenon and groove structure. The structure and construction method of the present invention can not only ensure the stiffness and stability of the tunnel, but also have certain economy and aesthetics, and adopt the method of segment prefabrication and on-site assembly for construction. The tunnel structure is in a segmented form, which can ensure the waterproof effect and will not affect the normal operation and service life of the prefabricated tunnel in the whole life cycle.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel construction, and particularly relates to a super-large-section highway assembled arched tunnel structure and a construction method thereof. Background Art

[0002] With the rapid development of the economy, the traffic demand has also increased accordingly. As a convenient and efficient structural form, tunnels are developing faster and faster, with an increasing number of constructions, and the scale is gradually developing from single-hole two-lane tunnels to double-hole four-lane, six-lane, and eight-lane tunnels. Among them, in order to meet the current demand for the increasing traffic volume, two-way eight-lane and above tunnels with large cross-sections and multiple lanes are often adopted in municipal engineering. When a tunnel passes through a relatively thin overlying soil layer, the open-cut method is often used for construction. The open-cut method refers to a construction method for underground engineering in which the ground is first excavated, the lining is built in the open air, and then backfilled. It is mostly used for shallow-buried tunnels. The open-cut method is the most basic and commonly used method in urban underground engineering construction. The in-situ casting method is a relatively traditional and conservative construction method. However, in the context of the rapid development of urbanization, the in-situ casting method has attracted the attention and discussion in the industry due to factors such as a long construction period and a greater impact on the existing traffic. In contrast, assembled tunnels have gradually come into view and been accepted because of their advantages such as convenient construction, economic efficiency, short cycle, quality assurance, and strong adaptability of the lining. As a result, many scholars have carried out relevant research and applied it to actual projects. Moreover, assembled tunnels can save raw materials and reduce carbon emissions, which is a positive response to the country's "dual carbon" strategy and has good environmental and social benefits; at the same time, assembled tunnels also conform to the country's policy orientation of building "quality projects", and an important measure to build "quality projects" is to "pay attention to overall design and promote the standardization of project construction". However, in terms of current applications, more are rectangular assembled tunnels used in subway projects. If applied to highway municipal tunnels, although it will not affect the driver's vision, its cross-sectional area is often larger than that of arched tunnels.

[0003] Therefore, it is necessary to propose a super-large-section highway assembled arched tunnel structure and a construction method thereof, which can not only ensure the stiffness and stability of the tunnel, but also have certain economy and aesthetics, and use the method of prefabricating segments and assembling them on-site for construction. The tunnel structure is in a segmented form, which can ensure the waterproof effect and will not affect the normal operation and service life of the assembled tunnel during its whole life cycle. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a super-large-section highway assembled arched tunnel structure and a construction method thereof to meet the relevant requirements of strong assembly splicing stability, prevention of groundwater infiltration, and structural economy and aesthetics.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An assembled arched tunnel structure for extra-large cross-section highway of the present invention comprises annular precast structures spliced in sequence longitudinally. Each annular precast structure includes a cast-in-place inverted arch structure, a tunnel precast structure A and a tunnel precast structure B. The upper ends of the tunnel precast structure A and the tunnel precast structure B cooperate with each other to form an arch shape, and the lower ends of the tunnel precast structure A and the tunnel precast structure B are respectively connected to both ends of the cast-in-place inverted arch structure; adjacent two annular precast structures are spliced with each other through a concave-convex tenon and groove structure.

[0007] Furthermore, first shear keys, first positioning pin holes and fixed ends of pre-tightening devices embedded parts are arranged on the upper sides of both ends of the cast-in-place inverted arch structure. The first positioning pin holes are opened at the tops of the first shear keys. The lower ends of the tunnel precast structure A and the tunnel precast structure B are correspondingly provided with first shear grooves, second positioning pin holes and first pre-tightening device holes. The second positioning pin holes are opened at the bottoms of the first shear grooves. Grouting holes are also opened at both ends of the cast-in-place inverted arch structure; the upper end of the tunnel precast structure A is provided with a second shear key, a third positioning pin hole and a second pre-tightening device hole. The third positioning pin holes are opened at the tops of the second shear keys. The upper end of the tunnel precast structure B is correspondingly provided with a second shear groove, a fourth positioning pin hole and a third pre-tightening device hole. The fourth positioning pin holes are opened at the bottoms of the second shear grooves. Vent holes are opened at the upper ends of the tunnel precast structure B.

[0008] Furthermore, the concave-convex tenon and groove structure includes a groove and a tenon. Annular grooves are arranged on one side surface of the tunnel precast structure A and the tunnel precast structure B, and tenons corresponding to the grooves are arranged on the other side surface of the tunnel precast structure A and the tunnel precast structure B.

[0009] Furthermore, reserved steel bar installation holes are opened on both the tunnel precast structure A and the tunnel precast structure B. The reserved steel bar installation holes are opened outside the concave-convex tenon and groove structure. Prestressed steel bars are installed in the reserved steel bar installation holes, and adjacent two annular precast structures are tensioned through the prestressed steel bars.

[0010] Further, a slurry storage cavity is provided on the lower side of the groove. The slurry storage cavity is communicated with a grouting port and a slurry outlet. A pressing groove is provided in the groove. A bottom plate is arranged in the pressing groove. The bottom plate is connected to a piston plate through a guiding column. A guiding hole matching with the guiding column is provided at the bottom of the pressing groove. The piston plate is located in the slurry storage cavity. A tenon groove cavity ballast plate is arranged above the pressing groove. The lower end of the tenon groove cavity ballast plate is rotatably matched in the groove. When the convex tenon is matched with the groove, the tenon groove cavity ballast plate can be pressed into the pressing groove. The tenon groove cavity ballast plate applies a force to the piston plate through the bottom plate. The piston plate extrudes the slurry in the slurry storage cavity from the slurry outlet to fill the fitting gap of the concave-convex tenon groove structure.

[0011] Further, an outer arc surface is formed on one inner wall of the pressing groove. An inner arc surface corresponding to the outer arc surface is formed on the tenon groove cavity ballast plate. A ball groove is further provided on one side of the pressing groove. A rotating shaft is arranged in the ball groove. A ball head is formed at one end of the tenon groove cavity ballast plate. The ball head is rotatably matched with the rotating shaft. A return torsion spring is arranged between the tenon groove cavity ballast plate and the rotating shaft. A clamping groove is provided on the ball head. A clamping block corresponding to the clamping groove is connected in the groove through a spring.

[0012] Further, a vertical storage cavity is formed in the slurry storage cavity. A pushing block is arranged in the vertical storage cavity. A wedge block is formed on the upper part of the pushing block. The wedge block extends out of the vertical storage cavity through a sliding hole in the pressing groove. The wedge block can be matched with the tenon groove cavity ballast plate at the same time.

[0013] Further, a rubber block is arranged in the slurry outlet. The rubber block is extrusion-fitted with the slurry outlet to form a certain pre-tightening force on the slurry in the slurry storage cavity.

[0014] A construction method for an assembled arch tunnel structure with an extra-large cross-section highway includes the following steps:

[0015] 1) Precast tunnel precast structure A and tunnel precast structure B respectively in a factory;

[0016] 2) Construct the cast-in-place inverted arch structure on site in sequence;

[0017] 3) Dock and fix a group of tunnel precast structure A and tunnel precast structure B to form a ring-shaped precast structure;

[0018] 4) Dock and fix the assembled ring-shaped precast structure with the cast-in-place inverted arch structure;

[0019] 5) The ring-shaped precast structure and the next group of ring-shaped precast structures are spliced with each other through a concave-convex tenon groove structure;

[0020] 6) Control the lateral spacing between the front and rear rings of the prefabricated tunnel in the straight and curved sections of the tunnel.

[0021] The beneficial effects of the present invention are as follows:

[0022] An ultra-large cross-section highway prefabricated arched tunnel structure of the present invention includes annular precast structures spliced in sequence longitudinally. Each annular precast structure includes a cast-in-place inverted arch structure, a tunnel precast structure A, and a tunnel precast structure B. The cast-in-place inverted arch structure is cast on-site, which can adapt to the on-site tunnel structure, without redundant correction work, and can ensure the tight connection accuracy with the tunnel precast structure A and the tunnel precast structure B. Moreover, the tunnel precast structure A and the tunnel precast structure B can be directly prefabricated and formed in the factory, and directly assembled after being transported to the site, which can greatly improve the assembly efficiency. Sealing at the joints can ensure the waterproof effect and will not affect the normal operation and service life of the prefabricated tunnel throughout its life cycle.

[0023] In the device of the present invention, the upper ends of the tunnel precast structure A and the tunnel precast structure B cooperate with each other to form an arch shape, which can meet the relevant requirements of strong assembly splicing stability, structural economy and beauty. The lower ends of the tunnel precast structure A and the tunnel precast structure B are respectively connected to both ends of the cast-in-place inverted arch structure; adjacent two annular precast structures are spliced with each other through a concave-convex tenon groove structure, which can unify the standards and improve the construction efficiency.

[0024] Other advantages, objectives and features of the present invention will be described in the subsequent specification, and to some extent will be obvious to those skilled in the art, or those skilled in the art can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the objectives, technical solutions and beneficial effects of the present invention clearer, the present invention provides the following drawings for description:

[0026] Figure 1 It is a schematic structural diagram of the tunnel of the present invention;

[0027] Figure 2 It is an exploded view of the annular precast structure of the present invention;

[0028] Figure 3 It is a schematic structural diagram of the tunnel precast structure A;

[0029] Figure 4 It is a schematic structural diagram of the tunnel precast structure B;

[0030] Figure 5 It is a top view of the tunnel precast structure A;

[0031] Figure 6For Figure 2 and Figure 4 An enlarged view at B;

[0032] Figure 7 It is a schematic installation diagram of the tenon groove cavity ballast plate;

[0033] Figure 8 For Figure 7 An enlarged view at A;

[0034] Figure 9 It is a schematic diagram of the cooperation between the groove and the tenon.

[0035] The markings in the attached drawings are as follows: cast-in-place inverted arch structure 1, tunnel precast structure A 2, tunnel precast structure B 3, first shear key 4, first positioning pin hole 5, fixed end embedded part of the pre-tightening device 6, first shear groove 7, second positioning pin hole 8, first pre-tightening device hole 9, grouting hole 10, second shear key 11, third positioning pin hole 12, second pre-tightening device hole 13, second shear groove 14, fourth positioning pin hole 15, third pre-tightening device hole 16, exhaust hole 17, groove 18, tenon 19, reserved steel bar installation hole 20, slurry storage cavity 21, grouting port 22, slurry outlet 23, pressure groove 24, bottom plate 25, guide post 26, piston plate 27, tenon groove cavity ballast plate 28, outer arc surface 29, inner arc surface 30, ball groove 31, rotating shaft 32, ball head 33, reset torsion spring 34, card slot 35, block 36, spring 37, vertical storage cavity 38, pushing block 39, wedge block 40, rubber block 41, hanging nail 42, open ditch 43, open slot 44. Detailed implementation manners

[0036] As Figures 1 - 2 shown, an ultra-large cross-section highway assembled arch tunnel structure of the present invention includes annular precast structures spliced in sequence along the longitudinal direction. Each annular precast structure includes a cast-in-place inverted arch structure 1, a tunnel precast structure A 2, and a tunnel precast structure B 3. The cast-in-place inverted arch structure 1 is poured in an open ditch 43 dug in advance along the highway route. The upper ends of the tunnel precast structure A 2 and the tunnel precast structure B 3 cooperate with each other to form an arch shape. They are of the same scale and size, and only have slight differences in the connection structure and are directly prefabricated and formed in the factory. The lower ends of the tunnel precast structure A 2 and the tunnel precast structure B 3 are respectively connected to both ends of the cast-in-place inverted arch structure 1; adjacent two annular precast structures are spliced with each other through a tenon and groove structure.

[0037] In this embodiment, as Figure 3 、 4As shown in FIGS. 6, first shear tenons 4, first positioning pin holes 5 and fixed-end embedded parts 6 of pre-tightening devices are provided on the upper sides at both ends of the cast-in-place inverted arch structure 1. The first positioning pin holes 5 are opened at the tops of the first shear tenons 4. Corresponding first shear grooves 7, second positioning pin holes 8 and first pre-tightening device holes 9 corresponding to the first shear tenons 4, first positioning pin holes 5 and fixed-end embedded parts 6 of pre-tightening devices are respectively provided at the lower ends of the tunnel precast structure A2 and the tunnel precast structure B3. The second positioning pin holes 8 are opened at the bottoms of the first shear grooves 7. Grouting holes 10 are also opened at both ends of the cast-in-place inverted arch structure 1; finally, grouting is completed through the grouting holes 10 pre-set on the cast-in-place inverted arch structure 1 to ensure the integrity of the structure and the reliability of waterproofing.

[0038] Specifically, a second shear tenon 11, a third positioning pin hole 12 and a second pre-tightening device hole 13 are provided at the upper end of the tunnel precast structure A2. The third positioning pin hole 12 is opened at the top of the second shear tenon 11. Corresponding second shear grooves 14, fourth positioning pin holes 15 and third pre-tightening device holes 16 are provided at the upper end of the tunnel precast structure B3. The fourth positioning pin holes 15 are opened at the bottoms of the second shear grooves 14. An exhaust hole 17 is opened at the upper end of the tunnel precast structure B3. It is communicated with the atmospheric pressure through the exhaust hole 17 pre-set on the tunnel precast structure B3 to ensure the sealing between the tunnel precast structure A2 and the tunnel precast structure B3. In this embodiment, joint connecting bolts are provided at the external convex platform parts of the circumferential joints, and bolt holes are reserved through embedded PVC pipes at the corresponding positions on the precast components. Four qualified lifting nails 42 are respectively provided on the tunnel precast structures A2 and B for later transportation hoisting and installation hoisting.

[0039] In this embodiment, as Figure 5 shown, the concave-convex tenon 19 groove structure includes a groove 18 and a tenon 19. Annular grooves 18 are provided on one side surface of the tunnel precast structure A2 and the tunnel precast structure B3. Tenons 19 corresponding to the grooves 18 are provided on the other side surface of the tunnel precast structure A2 and the tunnel precast structure B3.

[0040] In this embodiment, reserved steel bar installation holes 20 are provided on both the tunnel precast structure A2 and the tunnel precast structure B3. The reserved steel bar installation holes 20 are opened outside the concave-convex tenon 19 groove structure. Prestressed steel bars are installed in the reserved steel bar installation holes 20. Adjacent two ring-shaped precast structures are tensioned by the prestressed steel bars. The holes are all arranged at the non-cavity parts of the components, avoiding the concave-convex tenon 19 groove as much as possible. After the tensioning is completed, the tensioning orifice is blocked. The present invention can also be provided with longitudinal positioning pin bars between adjacent front and rear rings; circumferential positioning pin bars are arranged at the joints between each precast component in the circumferential direction, which is convenient for quick assembly positioning and restricting the dislocation deformation of the component joints; the above-mentioned positioning pin bars are spindle-shaped standardized products, which are inserted into the holes reserved in the components in advance during assembly. The reserved holes for the positioning pin bars are all arranged in the concave-convex tenon grooves of the joints. Among them, the circumferential double-tenon joint is arranged in only one of the concave-convex tenon grooves.

[0041] In this embodiment, 4 waterproof structural measures are adopted for each joint seam. First, 2 completely closed waterproof material installation grooves 18 are provided at the joint for attaching waterproof rubber gaskets; second, grouting is carried out in the later stage of the joint; finally, waterproof caulking grooves are provided at the joints of each precast component on the inner arc surface of the lining ring for embedding waterproof materials. The joints between the assembled structure components all adopt the grouting type tenon groove connection method, and joint grouting needs to be carried out at an appropriate time after the structure assembly is completed for all circumferential and longitudinal joints.

[0042] In this embodiment, as Figure 7 and 8As shown in the figure, in order to achieve synchronous grouting after the cooperation of each groove 18 and the tenon 19, the construction efficiency and assembly accuracy are improved. In this embodiment, a slurry storage cavity 21 is provided on the lower side of the groove 18. The slurry storage cavity 21 is communicated with a grouting port 22 and a slurry outlet 23. A pressure groove 24 is provided in the groove 18. A bottom plate 25 is arranged in the pressure groove 24. The bottom plate 25 is connected to a piston plate 27 through a guide post 26. A guide hole matching the guide post 26 is provided at the bottom of the pressure groove 24. The piston plate 27 is located in the slurry storage cavity 21. A tenon groove cavity ballast plate 28 is arranged above the pressure groove 24. The lower end of the tenon groove cavity ballast plate 28 is rotatably matched in the groove 18. When the tenon 19 is matched with the groove 18, the tenon groove cavity ballast plate 28 can be pressed into the pressure groove 24. The tenon groove cavity ballast plate 28 applies a force to the piston plate 27 through the bottom plate 25. The piston plate 27 extrudes the slurry in the slurry storage cavity 21 from the slurry outlet 23 to fill the matching gap of the concave-convex tenon 19 groove structure. An outer arc surface 29 is formed on one inner wall of the pressure groove 24. An inner arc surface 30 corresponding to the outer arc surface is formed on the tenon groove cavity ballast plate 28. A ball groove 31 is further provided on one side of the pressure groove 24. A rotating shaft 32 is arranged in the ball groove 31. One end of the tenon groove cavity ballast plate 28 forms a ball head 33. The ball head 33 is rotatably matched with the rotating shaft 32. A return torsion spring 34 is arranged between the tenon groove cavity ballast plate 28 and the rotating shaft 32. A clamping groove 35 is provided on the ball head 33. A clamping block 36 corresponding to the clamping groove 35 is connected in the groove 18 through a spring 37. A vertical storage cavity 38 is formed in the slurry storage cavity 21. A pushing block 39 is arranged in the vertical storage cavity 38. A wedge block 40 is formed on the upper part of the pushing block 39. The wedge block 40 extends out of the vertical storage cavity 38 through a sliding hole in the pressure groove 24. The wedge block 40 can be matched with the tenon groove cavity ballast plate 28 at the same time. A rubber block 41 is arranged in the slurry outlet 23. The rubber block 41 is extrusion-matched with the slurry outlet 23 to form a certain pre-tightening force on the slurry in the slurry storage cavity 21. After the groove 18 and the tenon 19 are matched, the tenon 19 presses the tenon groove cavity ballast plate 28 to rotate. The tenon groove cavity ballast plate 28 is pressed into the pressure groove 24. The tenon groove cavity ballast plate 28 applies a force to the piston plate 27 through the bottom plate 25. The piston plate 27 extrudes the slurry in the slurry storage cavity 21 from the slurry outlet 23 to fill the matching gap of the concave-convex tenon 19 groove structure, achieving the synchronous grouting effect of each concave-convex tenon 19 groove structure. Affected by the slurry storage cavity 21, the grouting in each groove 18 is uniform, and misalignment is not likely to occur, saving the later adjustment and maintenance costs.

[0043] Figure 9 Fig. is a schematic diagram of the cooperation between the groove 18 and the tenon 19. By providing an opening groove 44 on the side wall of the tenon, the problem of difficult slurry discharge caused by the tenon blocking the rubber block 41 can be avoided.

[0044] A construction method for an extra-large cross-section highway prefabricated arched tunnel structure includes the following steps:

[0045] Excavate the foundation pit in layers according to the road route plan, lay the concrete cushion, and pour the gantry crane track foundation in the open ditch 43. Then, pour the cast-in-place inverted arch structure 1 in segments according to the design, and reserve the connection joints with the tunnel precast structure A2; erect and assemble the trolley to ensure accurate positioning.

[0046] 1) Prefabricate the tunnel precast structure A2 and the tunnel precast structure B3 in the factory respectively;

[0047] 2) Construct the cast-in-place inverted arch structure 1 on-site in sequence;

[0048] 3) Dock and fix a group of tunnel precast structures A2 and tunnel precast structures B3 to form a circular precast structure; transport the first ring of tunnel precast structures A2 and B to the designated position, and hoist them onto the trolley by the gantry crane. Align and lock the tunnel precast structures A2 and B, and gradually move them close to the predetermined position;

[0049] 4) Dock and fix the assembled circular precast structure with the cast-in-place inverted arch structure 1; make the shear key grooves on the first ring of tunnel precast structure A2 correspond and fit with the shear key grooves on the cast-in-place inverted arch structure 1, install the longitudinal pre-tightening device for precise position adjustment, lock it after being completely in place, and implement the arch limit device at the same time;

[0050] 5) The circular precast structure and the next group of circular precast structures are spliced with each other through the concave-convex tenon 19 groove structure; continue to assemble the second ring of tunnel precast structures A2 and B. When the end faces of the tunnel precast structures A2 and B are at a certain distance from the end face of the previous ring of components, lower the hydraulic system of the upper trolley, control the tunnel precast structures A2 and B to drop to a certain distance from the cast-in-place inverted arch structure 1, move the upper trolley forward. Before it is about to be close to the top slab of the previous ring, place the tunnel precast structures A2 and B on the cast-in-place inverted arch structure 1, and then lock the front and rear tunnel precast structures A2 and B through the longitudinal pre-tightening device, and implement the arch limit device at the same time;

[0051] 6) Repeat the above steps to complete the assembly of the subsequent tunnel precast structures A2, and control the lateral spacing of the front and rear rings of the assembled tunnel in the straight section and the curved section of the tunnel. Backfill the gap between the two tunnels with rubble concrete. Backfill the side of the tunnel near the slope with rubble concrete to the designated position from the bottom of the foundation pit, and pour the internal structure of the tunnel at the same time; tamp and fill the foundation pit with earth and rock, use a clay impermeable layer at a certain distance below the ground, restore the ground, and the backfill material, its compaction degree and bearing capacity meet the relevant requirements of the later project.

[0052] The structure and construction method of the present invention adopt a unique arched tunnel structure form, which achieves the beneficial effects of high applicability, economy and beauty compared with the rectangular tunnels commonly used in subway projects.

[0053] The pre - set shear - resistant tenon grooves and pre - tightening device holes facilitate the installation and fixation during the later assembly process, ensure the installation accuracy, and achieve the beneficial effects of strong assembly stability, convenient and efficient construction.

[0054] The waterproof structural measures at the joint seams can ensure the sealing performance and overall force - bearing of the tunnel structure, and achieve the beneficial effect of preventing the infiltration of groundwater.

[0055] The void between the two tunnels is backfilled with rubble concrete, and the side of the tunnel near the slope is backfilled with rubble concrete to a specified position from the bottom of the foundation pit. At the same time, the internal structure of the tunnel is poured, achieving the beneficial effects of stable operation of the tunnel in the later stage and reducing the maintenance cost.

[0056] Finally, it should be noted that the above - mentioned preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail through the above - mentioned preferred embodiments, those skilled in the art should understand that various changes can be made in terms of form and details without departing from the scope defined by the claims of the present invention.

Claims

1. An assembled arch tunnel structure for extra-large cross-section highway, characterized in that: It includes annular precast structures spliced sequentially along the longitudinal direction. Each annular precast structure includes a cast-in-place inverted arch structure, a tunnel precast structure A and a tunnel precast structure B. The upper ends of the tunnel precast structure A and the tunnel precast structure B cooperate with each other to form an arch shape. The lower ends of the tunnel precast structure A and the tunnel precast structure B are respectively connected to both ends of the cast-in-place inverted arch structure; adjacent two annular precast structures are spliced with each other through a concave-convex tenon and groove structure; on the upper sides of both ends of the cast-in-place inverted arch structure, there are provided first shear keys, first positioning pin holes and fixed ends of pre-tightening devices embedded parts. The first positioning pin holes are opened at the top of the first shear keys. The lower ends of the tunnel precast structure A and the tunnel precast structure B are respectively provided with corresponding first shear grooves, second positioning pin holes and first pre-tightening device holes. The second positioning pin holes are opened at the bottom of the first shear grooves. On both ends of the cast-in-place inverted arch structure, there are also opened grouting holes; on the upper end of the tunnel precast structure A, there are provided second shear keys, third positioning pin holes and second pre-tightening device holes. The third positioning pin holes are opened at the top of the second shear keys. The upper end of the tunnel precast structure B is correspondingly provided with a second shear groove, a fourth positioning pin hole and a third pre-tightening device hole. The fourth positioning pin hole is opened at the bottom of the second shear groove. On the upper end of the tunnel precast structure B, there is opened an exhaust hole.

2. The assembled arch tunnel structure for extra-large cross-section highway according to claim 1, characterized in that: The concave-convex tenon and groove structure includes a groove and a tenon. On one side surface of the tunnel precast structure A and the tunnel precast structure B, there are provided annular grooves. On the other side surface of the tunnel precast structure A and the tunnel precast structure B, there are provided tenons corresponding to the grooves.

3. The assembled arch tunnel structure for extra-large cross-section highway according to claim 2, characterized in that: On the tunnel precast structure A and the tunnel precast structure B, there are opened reserved steel bar installation holes. The reserved steel bar installation holes are opened outside the concave-convex tenon and groove structure. Prestressed steel bars are installed in the reserved steel bar installation holes. Adjacent two annular precast structures are tensioned through the prestressed steel bars.

4. The assembled arch tunnel structure for extra-large cross-section highway according to claim 3, characterized in that: On the lower side of the groove, there is provided a slurry storage cavity. The slurry storage cavity is communicated with a grouting port and a slurry outlet. In the groove, there is provided a pressing groove. In the pressing groove, there is provided a bottom plate. The bottom plate is connected to a piston plate through a guide post. At the bottom of the pressing groove, there are opened guide holes matching with the guide posts. The piston plate is located in the slurry storage cavity. Above the pressing groove, there is provided a tenon and groove cavity ballast plate. The lower end of the tenon and groove cavity ballast plate is rotatably matched in the groove. When the tenon is matched with the groove, the tenon and groove cavity ballast plate can be pressed into the pressing groove. The tenon and groove cavity ballast plate applies force to the piston plate through the bottom plate. The piston plate extrudes the slurry in the slurry storage cavity from the slurry outlet to fill the matching gap of the concave-convex tenon and groove structure.

5. The super-large cross-section highway prefabricated arched tunnel structure according to claim 4, characterized in that: One inner wall of the pressing groove forms an outer arc surface, an inner arc surface corresponding to the outer arc surface is formed on the ballast plate of the mortise groove cavity, a ball groove is further provided on one side of the pressing groove, a rotating shaft is arranged in the ball groove, one end of the ballast plate of the mortise groove cavity forms a ball head, the ball head is rotationally matched with the rotating shaft, a return torsion spring is arranged between the ballast plate of the mortise groove cavity and the rotating shaft, a clamping groove is formed on the ball head, and a clamping block corresponding to the clamping groove is connected in the groove through a spring.

6. The super-large cross-section highway prefabricated arched tunnel structure according to claim 5, characterized in that: A vertical storage cavity is formed in the slurry storage cavity, a pushing block is arranged in the vertical storage cavity, a wedge block is formed on the upper part of the pushing block, the wedge block extends out of the vertical storage cavity through a sliding hole in the pressing groove, and the wedge block can be matched with the ballast plate of the mortise groove cavity at the same time.

7. The super-large cross-section highway prefabricated arched tunnel structure according to claim 6, characterized in that: A rubber block is arranged in the slurry outlet, and the rubber block is extrusion-fitted with the slurry outlet to form a certain pre-tightening force on the slurry in the slurry storage cavity.

8. A construction method for a super-large cross-section highway prefabricated arched tunnel structure, characterized in that: The arched tunnel structure as described in any one of claims 1-7 is adopted, and the method includes the following steps: Precasting the tunnel precast structure A and the tunnel precast structure B in the factory respectively; Constructing the cast-in-place inverted arch structure on-site in sequence; Docking and fixing a group of the tunnel precast structure A and the tunnel precast structure B to form a ring-shaped precast structure; Docking and fixing the spliced ring-shaped precast structure with the cast-in-place inverted arch structure; The ring-shaped precast structure and the next group of ring-shaped precast structures are spliced with each other through the concave-convex mortise and tenon groove structure; Controlling the lateral spacing between the front and rear rings of the prefabricated tunnel in the straight section and the curve section of the tunnel.

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