Tunnel inverted arch structure and construction method

Abstract

According to the tunnel inverted arch structure and the construction method, inverted arch prefabricated modules are manufactured in advance, then the inverted arch prefabricated modules conduct cast-in-place construction on the left side and the right side to form pouring modules, and the whole construction time can be shortened; the curvature value of the area, corresponding to the pouring module, of the tunnel inverted arch structure is large, cast-in-place construction is adopted, the excavation radian, the structure size and the like of the inverted arch structure can be guaranteed, and therefore the construction quality of the inverted arch structure is guaranteed; the number of splicing gaps is reduced, the leakage risk is reduced, the later maintenance difficulty of the tunnel is reduced, and the service life of the tunnel is prolonged; the inverted arch prefabricated module can be divided into a plurality of parts, and the weight of each part is controlled within a preset weight range, so that a truck crane can be selected for hoisting operation, and the construction cost of the hoisting operation is reduced; meanwhile, hoisting in a narrow tunnel space is flexible and convenient; d2 is equal to 1 / 2D1, so that the curvature precision of the inverted arch structure can be ensured, and the construction time can be shortened.

Description

Technical Field

[0001] The present invention generally relates to the technical field of tunnels and underground engineering, and in particular to a tunnel invert structure and a construction method. Background Art

[0002] The inverted arch in the secondary lining of a highway tunnel is an upward-arching arc-shaped structure installed at the bottom of the tunnel to improve the stress conditions of the tunnel superstructure. It forms a closed loop with the arch ring lining, improving the overall stress state of the tunnel. In highway tunnel engineering, the inverted arch is a key component of the tunnel structure, and its design and construction technology directly affect the tunnel's stability, durability, and construction efficiency.

[0003] Currently, the construction process for highway tunnel inverts primarily involves pouring concrete on-site after excavation and curing it. This requires formwork support, rebar tying, and curing, with a steel trestle installed overhead as a temporary access route. This results in long construction times and low efficiency. With the advancement of prefabricated structure technology, fully prefabricated structures are being explored for highway tunnel inverts. While these structures offer advantages such as factory-based production and intelligent assembly, they also have disadvantages such as poor adaptability to the curvature of the tunnel axis, numerous joints, difficulty waterproofing the connections between prefabricated blocks, and the need for heavy lifting equipment. Summary of the Invention

[0004] The present invention provides a tunnel invert structure, comprising:

[0005] The inverted arch prefabricated module is used to be arranged corresponding to the middle part of the tunnel inverted arch structure in the left and right directions. Several inverted arch prefabricated modules are arranged along the tunnel axis. The inverted arch prefabricated module is divided into at least two prefabricated parts that are spliced ​​together. The size of the inverted arch prefabricated module in the left and right directions is D1.

[0006] Casting modules: The two casting modules are respectively located on the left and right sides of the inverted arch prefabricated module. The size of the casting module in the left and right directions is D2, and D2=1 / 2D1.

[0007] As an implementable manner, the inverted arch prefabricated module includes an upper prefabricated part and a lower prefabricated part spliced ​​together, and the weight of the lower prefabricated part matches the weight of the upper prefabricated part, or the weight of the lower prefabricated part is less than the weight of the upper prefabricated part.

[0008] As an achievable approach, the weight of the lower preform matches that of the upper preform, and is between 20 tons and 50 tons. The left-right dimensions of the lower preform match those of the upper preform, and the dimension L1 of the lower preform along the tunnel axis is smaller than the dimension L2 of the upper preform along the tunnel axis.

[0009] As an achievable method, the inverted arch prefabricated module includes an upper prefabricated part and multiple lower prefabricated parts. Adjacent upper prefabricated parts are spliced ​​to form an upper splicing seam, and adjacent lower prefabricated parts are spliced ​​to form a lower splicing seam. The lower splicing seam and the upper splicing seam are staggered in the direction of the tunnel axis.

[0010] As an achievable method, the upper prefabricated part includes an upper prefabricated plate, and a first splicing boss is protruding from the surface of the upper prefabricated plate facing the lower prefabricated part. The prefabricated part includes a lower prefabricated plate, and a second splicing boss is protruding from the surface of the prefabricated plate facing the upper prefabricated part. The second splicing bosses are spliced ​​with the second splicing bosses, and the splicing seam is a broken line splicing seam to locate the relative position between the upper prefabricated part and the lower prefabricated part.

[0011] As an achievable method, one of the first splicing boss and the second splicing boss is provided with a first positioning protrusion, and the other is provided with a first positioning groove adapted to the first positioning protrusion, and one of the end surface of the first positioning protrusion and the bottom surface of the first positioning groove is provided with a threaded connection hole and a threaded matching hole, and a fastener passes through the threaded matching hole and is connected to the threaded connection hole to connect the upper prefabricated part and the lower prefabricated part, wherein the fold line splicing seam is close to the surface of the upper prefabricated plate facing away from the lower prefabricated part.

[0012] As an implementable manner, the upper prefabricated plate is provided with three first splicing bosses arranged along the left-right direction, wherein two first splicing bosses are located at the left and right ends of the upper prefabricated plate, the vertical side walls of the first splicing bosses are planes, and the vertical side walls of the first splicing bosses close to the casting module are provided with a plurality of first embedded steel bars; the lower prefabricated plate is provided with three second splicing bosses arranged along the left-right direction, wherein two second splicing bosses are located at the left and right ends of the lower prefabricated plate, the vertical side walls of the second splicing bosses are planes, and the vertical side walls of the second splicing bosses close to the casting module are provided with a plurality of second embedded steel bars;

[0013] The space between adjacent first splicing convex columns and the space between adjacent second splicing columns form a weight-reducing hollow area.

[0014] As an achievable method, the surface of the lower prefabricated plate facing the upper prefabricated part is recessed toward the area of ​​the second splicing boss near the middle position, and the surface of the lower prefabricated plate facing the upper prefabricated part is provided with threaded connection parts in the areas of the second splicing bosses near the left and right positions, and the adjacent lower prefabricated parts are spliced ​​and connected through the threaded connection parts.

[0015] As an implementable manner, a positioning portion is provided on the surface of the lower prefabricated plate facing away from the upper prefabricated member, and the positioning portion is used to match the surface of the lower prefabricated plate facing away from the upper prefabricated member with the corresponding area of ​​the primary support structure after casting.

[0016] As an achievable method, a flat area is provided on the surface of the lower prefabricated plate facing away from the upper prefabricated member near the casting module, and a flat positioning area adapted to the flat portion is provided on the primary support structure, or at least two second positioning protrusions are provided on the surface of the lower prefabricated plate facing away from the upper prefabricated member, and two second positioning grooves adapted to the second positioning protrusions are provided on the primary support structure.

[0017] The present invention also provides a construction method for a tunnel invert structure, comprising:

[0018] Construct the primary support structure and pour the inverted arch cushion concrete. Apply precision leveling to the contact surface between the preset position of the primary support structure and the prefabricated inverted arch module after pouring.

[0019] Placing the lower prefabricated parts of the inverted arch prefabricated module at a preset position, splicing and connecting two adjacent lower prefabricated parts, and then placing the upper prefabricated part of the inverted arch prefabricated module, splicing and connecting the upper prefabricated part and the lower prefabricated parts;

[0020] Based on the inverted arch prefabricated module, the casting module is obtained by casting construction on the left and right sides of the inverted arch prefabricated module. A drainage channel, a cable channel and a weight reduction channel extending along the tunnel axis are provided in the casting module. The weight reduction channel, the drainage channel and the cable channel are arranged in sequence from the inverted arch prefabricated module to the casting module. The cable channel is higher than the drainage channel, and the weight reduction channel is set away from the curved surface of the primary support structure after casting.

[0021] In the above scheme, this embodiment prefabricates the inverted arch prefabricated modules, which are then used to form casting modules for on-site casting construction on the left and right sides, thereby shortening the entire construction time. The curvature value of the area corresponding to the tunnel inverted arch structure and the casting modules is large, and on-site casting construction can ensure the excavation curvature and structural dimensions of the inverted arch structure, thereby ensuring the construction quality of the inverted arch structure. The number of splicing gaps is reduced, which helps to reduce the risk of leakage, ease the difficulty of tunnel maintenance in the later stage, and extend the service life of the tunnel. The inverted arch prefabricated modules can be divided into several parts, and the weight of each part is controlled within a preset weight range. In this way, a mobile crane can be used for lifting operations, reducing the construction cost of the lifting operations. At the same time, lifting is flexible and convenient in narrow tunnel spaces. D2=1 / 2D1, which can achieve both ensuring the curvature accuracy of the inverted arch structure and shortening the construction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present application will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0023] Figure 1 A schematic front view of a tunnel invert structure provided by an embodiment of the present invention;

[0024] Figure 2A schematic top view of a tunnel invert structure provided by an embodiment of the present invention;

[0025] Figure 3 A schematic front view of an inverted arch prefabricated module provided in an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of the structure of the upper prefabricated part provided in an embodiment of the present invention Figure 1 ;

[0027] Figure 5 Schematic diagram of the structure of the upper prefabricated part provided in an embodiment of the present invention Figure 2 ;

[0028] Figure 6 A schematic structural diagram of a lower prefabricated component provided in an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of the positioning and coordination of a lower prefabricated component and a primary support structure after casting provided by an embodiment of the present invention;

[0030] Figure 8 A schematic diagram of the positioning and coordination of another lower prefabricated component and the primary support structure after casting provided by an embodiment of the present invention;

[0031] Inverted arch prefabricated module 10, upper prefabricated part 11, upper prefabricated plate 111, first splicing protrusion 112, first positioning protrusion 1121, threaded matching hole 113, first embedded steel bar 114;

[0032] Lower prefabricated part 12, lower prefabricated plate 121, second splicing boss 122, first positioning groove 1221, threaded connection portion 123, connection block 124, flat area 125, second positioning protrusion 126, second embedded steel bar 127, threaded connection hole 128;

[0033] Weight loss hollow area 101;

[0034] Casting module 20, weight reduction channel 21, drainage channel 22, cable channel 23;

[0035] Primary support structure 30, preset position 301, plane positioning area 301a, second positioning groove 301b. DETAILED DESCRIPTION

[0036] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0037] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] like Figures 1-8 As shown, the present application provides a tunnel inverted arch structure, comprising an inverted arch prefabricated module 10 and a casting module 20. Several inverted arch prefabricated modules 10 are arranged along the tunnel axis C1. The inverted arch prefabricated modules 10 are divided into at least two prefabricated parts that are spliced ​​together. The inverted arch prefabricated module 10 has a left-right dimension D1. Two casting modules 20 are located on the left and right sides of the inverted arch prefabricated module 10, respectively. The casting module 20 has a left-right dimension D2, where D2 = 1 / 2 D1.

[0039] Among them, such as Figure 1 As shown, the inverted arch prefabricated module 10 is used to be arranged corresponding to the middle part of the tunnel inverted arch structure in the left and right directions. The middle part of the tunnel inverted arch structure has a small curvature value and is suitable for prefabrication. In this way, the prefabricated parts are prefabricated in a factory and standardized manner, which can shorten the entire construction time.

[0040] The inverted arch prefabricated module 10 can be spliced ​​up and down, or the inverted arch prefabricated module 10 can be spliced ​​left and right. The up-down splicing is convenient and difficult. This embodiment is described by splicing the inverted arch prefabricated module 10 up and down:

[0041] For example, the inverted arch prefabricated module 10 includes an upper prefabricated part 11 and a lower prefabricated part 12, which are spliced ​​and connected to form the inverted arch prefabricated module 10. Alternatively, the inverted arch prefabricated module 10 may include an upper prefabricated part 11 and at least two lower prefabricated parts 12, which are spliced ​​and connected to form the inverted arch prefabricated module 10. Alternatively, the inverted arch prefabricated module 10 may include at least two upper prefabricated parts 11 and one lower prefabricated part 12, which are spliced ​​and connected to form the inverted arch prefabricated module 10. In this way, the inverted arch prefabricated module 10 can be divided into several parts, and the weight of each part is controlled within a preset weight range. This allows for the use of a truck crane for lifting operations, reducing construction costs and making lifting flexible and convenient in narrow tunnel spaces.

[0042] Several precast inverted arch modules 10 are spliced ​​and connected along the tunnel axis C1. Reinforced concrete is then poured on the left and right sides of the precast inverted arch modules 10 to form casting modules 20. The area corresponding to the tunnel inverted arch structure and casting modules 20 has a large curvature. Using on-site casting ensures the excavation curvature and structural dimensions of the inverted arch structure, thereby ensuring the construction quality of the inverted arch structure.

[0043] In addition, compared with the related art in which a tunnel arch structure is formed by splicing multiple prefabricated modules in the left and right directions, this embodiment reduces the number of splicing gaps, which are the weak link in tunnel waterproofing. The fewer the number of gaps, the more it helps to reduce the risk of leakage, reduce the difficulty of later maintenance of the tunnel, and extend the service life of the tunnel.

[0044] Among them, D2=1 / 2D1, D1 is the size of the inverted arch prefabricated module 10 in the left and right direction, and D2 is the size of the casting module 20 in the left and right direction. This can ensure the curvature accuracy of the inverted arch structure and shorten the construction time.

[0045] In summary, the tunnel inverted arch structure provided in this embodiment can shorten the entire construction time by prefabricating the inverted arch prefabricated module 10 and then forming the casting module 20 by on-site casting construction on the left and right sides of the inverted arch prefabricated module 10. The curvature value of the area corresponding to the tunnel inverted arch structure and the casting module 20 is large. The on-site casting construction can ensure the excavation curvature and structural dimensions of the inverted arch structure, thereby ensuring the construction quality of the inverted arch structure. The number of splicing gaps is reduced, which helps to reduce the risk of leakage, reduce the difficulty of tunnel maintenance in the later stage, and extend the service life of the tunnel. The inverted arch prefabricated module 10 can be divided into several parts, and the weight of each part is controlled within a preset weight range. In this way, a mobile crane can be used for lifting operations, reducing the construction cost of the lifting operation. At the same time, lifting is flexible and convenient in a narrow tunnel space. D2=1 / 2D1 can take into account both ensuring the curvature accuracy of the inverted arch structure and shortening the construction time.

[0046] The following examples describe the tunnel invert structure in detail:

[0047] The weight of the lower preform 12 matches the weight of the upper preform 11 , or the weight of the lower preform 12 is less than the weight of the upper preform 11 .

[0048] It should be noted that the weight of the lower prefabricated part 12 can be between 20t and 50t, and the weight of the upper prefabricated part 11 can be between 20t and 50t, which is suitable for lifting operations using a truck crane. The weight of the lower prefabricated part 12 matches the weight of the upper prefabricated part 11, that is, the weight of the lower prefabricated part 12 is close to the weight of the upper prefabricated part 11, and the difference between the two is small. When performing the lifting operation of the upper prefabricated part 11 and the lower prefabricated part 12, the crane parameters and movement speed are the same, avoiding the need to switch crane parameters and adjust movement speed, which helps to standardize the lifting operation; operators do not need to repeatedly adjust the lifting plan for different weights, simplifying the process, reducing the probability of misjudgment, and suppressing safety hazards.

[0049] Of course, it is understandable that the weight of the lower prefabricated member 12 is also less than that of the upper prefabricated member 11, meaning that there is a significant weight difference between the lower prefabricated member 12 and the upper prefabricated member 11. The lower prefabricated member 12 serves as the reference for the upper prefabricated member 11. When placing the lower prefabricated member 12, it is necessary to ensure that the inverted arch prefabricated module 10 matches the preset position 301 of the cast primary support structure 30. The lower prefabricated member 12, being lighter in weight, greatly increases the flexibility of its hoisting, thereby easily meeting the construction requirement of matching the inverted arch prefabricated module 10 with the preset position 301 of the cast primary support structure 30.

[0050] Among them, when the weight of the lower preform 12 matches the weight of the upper preform 11, the size of the lower preform 12 in the left and right directions matches the size of the upper preform 11 in the left and right directions, and the size L1 of the lower preform 12 in the tunnel axis direction C1 is smaller than the size L2 of the upper preform 11 in the tunnel axis direction C1.

[0051] It should be noted that the left-right dimensions of the lower preform 12 match those of the upper preform 11 , and the upper and lower preforms 12 can share the left-right mold, which can reduce mold development costs.

[0052] like Figure 3 As shown, since the surface of the lower preform 12 facing away from the upper preform 11 is a curved surface, shortening the dimension of the lower preform 12 in the axial direction helps to control the curvature accuracy of the curved surface. When adjacent lower preforms 12 are spliced, the curvature of the splicing seam is completely fitted, reducing the risk of splicing misalignment.

[0053] like Figure 2 As shown, 2L1 = L2. The inverted arch prefabricated module 10 includes an upper prefabricated component 11 and three lower prefabricated components 12. After the three lower prefabricated components 12 are spliced ​​together, the upper prefabricated component 11 is placed and then spliced ​​together with the three lower prefabricated components 12 simultaneously. The upper prefabricated components 11 are spliced ​​together to form an upper splicing seam A, while the lower prefabricated components 12 are spliced ​​together to form a lower splicing seam B. The lower splicing seams B and the upper splicing seams A are staggered along the tunnel axis C1.

[0054] If the lower joint B and the upper joint A were aligned along the tunnel axis C1, a longitudinal line of weakness would form across the entire tunnel cross-section, resulting in poor structural strength and prone to cracking. This embodiment, by staggering the lower joint B and the upper joint A along the tunnel axis C1, distributes the load, improves structural strength, and avoids these problems. Furthermore, the staggered joints prevent water from flowing straight through and into the space between the upper and lower prefabricated members 12, slowing the flow of water into the space through the gap.

[0055] like Figure 4-Figure 6As shown, the upper prefabricated member 11 includes an upper prefabricated plate 111, with a first splicing boss 112 protruding from the surface of the upper prefabricated plate 111 facing the lower prefabricated member 12. The lower prefabricated member 12 includes a lower prefabricated plate 121, with a second splicing boss 122 protruding from the surface of the lower prefabricated plate 121 facing the upper prefabricated member 11. The second splicing bosses 122 are spliced ​​together, and the splicing seam is a broken line splicing seam E.

[0056] A first positioning protrusion 1121 is provided on the end surface of the first splicing boss 112, and a threaded mating hole 113 is provided on the end surface of the first positioning protrusion 1121. A first positioning groove 1221 is provided on the end surface of the second splicing boss 122, which is adapted to fit within the first positioning protrusion 1121. A threaded connection hole 128 is provided on the bottom surface of the first positioning groove 1221, which matches the threaded mating hole 113. After the first positioning protrusion 1121 is inserted and mated with the first positioning groove 1221, a fastener passes through the threaded mating hole 113 and is connected to the threaded connection hole 128, thereby connecting the upper preform 11 and the lower preform 12.

[0057] The first positioning protrusion 1121 fits into the first positioning groove 1221 to position the upper preform 11 relative to the lower preform 12, ensuring that the vertical sidewalls of the first splicing protrusion 112 align with the vertical sidewalls of the second splicing protrusion 122. This helps to improve the strength of the threaded connection between the upper preform 11 and the lower preform 12. Furthermore, the folded seam E prevents water from entering the space between the upper and lower preforms 12 through the seam.

[0058] It should be noted that the first positioning groove 1221 and the first positioning protrusion 1121 can be guided and matched, one is gradually contracted and the other is gradually expanded, which helps to assemble the first positioning protrusion 1121 and the first positioning groove 1221 and shorten the assembly time.

[0059] A seal is installed at the open portion of the threaded fitting hole 113 facing the external environment. The seal can inhibit water from entering the threaded fitting hole 113 to avoid corrosion of the fasteners, thereby ensuring the connection stability between the upper prefabricated part 11 and the lower prefabricated part 12.

[0060] The fold line joint E is close to the surface of the upper prefabricated plate 111 facing away from the lower prefabricated member 12. This can shorten the vertical dimension of the threaded fitting hole 113, thereby shortening the length of the fastener and improving its ability to resist bending and flexing.

[0061] Of course, it is understandable that the end surface of the first splicing boss 112 is provided with a first positioning groove 1221 , and the end surface of the second splicing boss 122 is provided with a first positioning protrusion 1121 , and this embodiment does not limit this.

[0062] like Figure 4-Figure 6As shown, three first splicing bosses 112 are arranged along the left and right directions on the upper precast plate 111, wherein two first splicing bosses 112 are located at the left and right ends of the upper precast plate 111, the vertical side walls of the first splicing bosses 112 are plane, and a number of first embedded steel bars 114 are provided on the vertical side walls of the first splicing bosses 112 close to the casting module 20.

[0063] Three second splicing bosses 122 are arranged in the left and right directions on the lower precast plate 121, of which two second splicing bosses 122 are located at the left and right ends of the lower precast plate 121. The vertical side walls of the second splicing bosses 122 are flat, and several second embedded steel bars 127 are provided on the vertical side walls of the second splicing bosses 122 close to the casting module 20.

[0064] The first and second embedded steel bars are used to connect the casting module 20, so that the casting module 20 is integrated with the inverted arch prefabricated module 10; the vertical side walls of the first and second splicing bosses are flat, which can reduce the complexity of the mold and reduce the mold development cost.

[0065] The spaces between adjacent first splicing bosses 112 and adjacent second splicing bosses form a weight-reducing hollowed-out area 101. Removing the raw material from the non-load-bearing areas between adjacent splicing bosses helps reduce the weight of the upper and lower preforms 12. The hollowed-out design also reduces the raw material usage and manufacturing costs of the upper and lower preforms 12.

[0066] like Figure 6 As shown, the surface of the lower prefabricated plate 121 facing the upper prefabricated part 11 is recessed toward the area of ​​the second splicing boss 122 near the middle position, and the surface of the lower prefabricated plate 121 facing the upper prefabricated part 11 near the areas of the second splicing boss 122 at the left and right positions is provided with a threaded connection portion 123, and the adjacent lower prefabricated parts 12 are spliced ​​and connected through the threaded connection portion 123.

[0067] Connecting blocks 124 are located at the corners formed by the left and right second splicing bosses 122 and the surfaces of the lower precast plate 121 facing the upper precast member 11. These blocks are positioned near the splicing locations of the lower precast member 12. Connecting holes extending along the tunnel axis C1 are provided in these blocks, each configured as a threaded connection 123. Fasteners pass through adjacent connecting holes to connect adjacent lower precast members 12.

[0068] Since the surface of the lower prefabricated plate 121 facing the upper prefabricated part 11 is recessed toward the area of ​​the second splicing boss 122 near the middle position, after flowing into the weight-reducing hollow area 101, water is concentrated in the area of ​​the second splicing boss 122 near the middle position, and the position of the connecting through-hole is higher, so it is not easy for water to enter the connecting through-hole and contact the fasteners, thereby avoiding corrosion of the fasteners and ensuring the connection stability between adjacent lower prefabricated parts 12.

[0069] A positioning portion is protruded on the surface of the lower precast plate 121 facing away from the upper precast member 11 , and the positioning portion is used to match the surface of the lower precast plate 121 facing away from the upper precast member 11 with the corresponding area of ​​the primary support structure 30 after casting.

[0070] During the actual construction process, when placing the lower prefabricated part 12, it is necessary to ensure that the arch prefabricated module 10 matches the preset position 301 of the primary support structure 30 after casting, that is, it is necessary to ensure that the surface of the lower prefabricated plate 121 facing the upper prefabricated part 11 is in contact with the upper surface of the preset position 301 of the primary support structure 30 after casting. This process wastes a lot of time and is difficult to construct.

[0071] In a specific embodiment, if Figure 7 As shown, a plane area 125 is provided on the surface of the lower precast plate 121 facing away from the upper precast part 11 near the casting module 20, and a plane positioning area 301a adapted to the plane portion is provided on the primary support structure 30. The lower precast part 12 is positioned by fitting the plane area 125 of the lower precast plate 121 with the plane positioning area 301a of the primary support structure 30 after casting, ensuring that the surface of the lower precast plate 121 facing away from the upper precast part 11 fits with the upper surface of the preset position 301 of the primary support structure 30 after casting, thereby reducing the construction difficulty and shortening the construction time.

[0072] In another specific embodiment, Figure 8 As shown, the surface of the lower precast panel 121 facing away from the upper precast member 11 is provided with at least two second positioning protrusions 126, and the primary support structure 30 is provided with two second positioning grooves 301b that match the second positioning protrusions 126. The second positioning grooves 301b interlock with the second positioning protrusions 126 to position the lower precast member 12, ensuring that the surface of the lower precast panel 121 facing away from the upper precast member 11 aligns with the upper surface of the pre-cast primary support structure 301 after casting, thereby reducing construction difficulty and shortening construction time.

[0073] The present application also provides a construction method for a tunnel inverted arch structure, the construction method comprising the following steps:

[0074] S1, constructing the primary support structure 30 and pouring the inverted arch cushion concrete, and performing fine leveling on the surface of the pre-set position 301 of the poured primary support structure 30 in contact with the inverted arch prefabricated module 10;

[0075] S2, placing the lower prefabricated parts 12 of the inverted arch prefabricated module 10 at the preset position 301, splicing and connecting two adjacent lower prefabricated parts 12, then placing the upper prefabricated part 11 of the inverted arch prefabricated module 10, and splicing and connecting the upper prefabricated part 11 and the lower prefabricated part 12;

[0076] S3. Based on the inverted arch prefabricated module 10, casting construction is carried out on the left and right sides of the inverted arch prefabricated module 10 to obtain a casting module 20. The casting module 20 is provided with a cable channel 23, a drainage channel 22, and a weight-reducing channel 21 extending along the tunnel axis direction C1. The weight-reducing channel 21, the drainage channel 22, and the cable channel 23 are arranged in sequence from the inverted arch prefabricated module 10 to the casting module 20. The cable channel 23 is higher than the drainage channel 22, and the weight-reducing channel 21 is arranged away from the curved surface of the primary support structure 30 after casting.

[0077] It should be noted that the cable channel 23 is higher than the drainage channel 22, which helps to avoid water and electricity cross contamination; the weight reduction channel 21 is close to the rigid inverted arch prefabricated module 10, and optimizes the stress distribution by utilizing the flexibility of the on-site casting area.

[0078] It should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used above to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "frame" and "cloth" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "frame" and "cloth" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0079] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A tunnel invert structure, characterized in that: include: An inverted arch prefabricated module (10) is used to be arranged corresponding to the middle portion of the tunnel inverted arch structure in the left-right direction. A plurality of the inverted arch prefabricated modules (10) are arranged along the tunnel axis direction (C1). The inverted arch prefabricated module (10) is divided into at least two prefabricated parts that are spliced ​​together. The size of the inverted arch prefabricated module (10) in the left-right direction is D1. Casting modules (20), two of the casting modules (20) are respectively located on the left and right sides of the inverted arch prefabricated module (10), and the size of the casting module (20) in the left and right directions is D2, where D2=1 / 2D1.

2. The tunnel invert structure according to claim 1, characterized in that: The inverted arch prefabricated module (10) comprises an upper prefabricated part (11) and a lower prefabricated part (12) which are spliced ​​together. The weight of the lower preform (12) matches the weight of the upper preform (11), or the weight of the lower preform (12) is less than the weight of the upper preform (11).

3. The tunnel invert structure according to claim 2, characterized in that: The weight of the lower preform (12) matches the weight of the upper preform (11), and the weight is between 20t and 50t. The size of the lower preform (12) in the left-right direction matches the size of the upper preform (11) in the left-right direction, and the size L1 of the lower preform (12) in the tunnel axis direction (C1) is smaller than the size L2 of the upper preform (11) in the tunnel axis direction (C1).

4. The tunnel invert structure according to claim 3, characterized in that: The inverted arch prefabricated module (10) comprises an upper prefabricated component (11) and a plurality of lower prefabricated components (12); adjacent upper prefabricated components (11) are spliced ​​to form an upper splicing seam (A); adjacent lower prefabricated components (12) are spliced ​​to form a lower splicing seam (B); the lower splicing seam (B) and the upper splicing seam (A) are staggered in the tunnel axis direction (C1).

5. The tunnel invert structure according to claim 2, characterized in that: The upper prefabricated part (11) comprises an upper prefabricated plate (111), and a first splicing boss (112) is protruded on the surface of the upper prefabricated plate (111) facing the lower prefabricated part (12). The lower prefabricated part (12) comprises a lower prefabricated plate (121), and a second splicing boss (122) is protruded on the surface of the lower prefabricated plate (121) facing the upper prefabricated part (11). The second splicing boss (122) is spliced ​​with the second splicing boss (122), and the splicing seam is a broken line splicing seam (E) to locate the relative position between the upper prefabricated part (11) and the lower prefabricated part (12).

6. The tunnel invert structure according to claim 5, characterized in that: One of the first splicing boss (112) and the second splicing boss (122) is provided with a first positioning protrusion (1121), and the other is provided with a first positioning groove (1221) adapted to the first positioning protrusion (1121); one of the end surface of the first positioning protrusion (1121) and the bottom surface of the first positioning groove (1221) is provided with a threaded connection hole (128) and a threaded matching hole (113); a fastener passes through the threaded matching hole (113) and is connected to the threaded connection hole (128) to connect the upper preform (11) and the lower preform (12); Wherein, the fold line joint seam (E) is close to the surface of the upper prefabricated plate (111) facing away from the lower prefabricated part (12).

7. The tunnel invert structure according to claim 5, characterized in that: The upper precast plate (111) is provided with three first splicing bosses (112) arranged in the left-right direction, wherein two of the first splicing bosses (112) are located at the left and right ends of the upper precast plate (111), the vertical side walls of the first splicing bosses (112) are plane, and a plurality of first embedded steel bars (114) are provided on the vertical side walls of the first splicing bosses (112) close to the casting module (20); The lower precast plate (121) is provided with three second splicing bosses (122) arranged in the left-right direction, wherein two of the second splicing bosses (122) are located at the left and right ends of the lower precast plate (121), the vertical side walls of the second splicing bosses (122) are plane, and a plurality of second embedded steel bars (127) are provided on the vertical side walls of the second splicing bosses (122) close to the casting module (20); The space between adjacent first splicing convex columns (112) and the space between adjacent second splicing columns form a weight-reducing hollow area (101).

8. The tunnel invert structure according to claim 7, characterized in that: The surface of the lower prefabricated plate (121) facing the upper prefabricated part (11) is recessed toward the area of ​​the second splicing boss (122) near the middle position, and the surface of the lower prefabricated plate (121) facing the upper prefabricated part (11) is provided with a threaded connection portion (123) in the area of ​​the second splicing boss (122) near the left and right positions, and the adjacent lower prefabricated parts (12) are spliced ​​and connected through the threaded connection portion (123).

9. The tunnel invert structure according to claim 5, characterized in that: A positioning portion is provided on the surface of the lower prefabricated plate (121) facing away from the upper prefabricated part (11), and the positioning portion is used to match the surface of the lower prefabricated plate (121) facing away from the upper prefabricated part (11) with a corresponding area of ​​the primary support structure (30) after casting.

10. The tunnel invert structure according to claim 9, characterized in that: The surface of the lower prefabricated plate (121) facing away from the upper prefabricated part (11) is provided with a plane area (125) near the casting module (20), and the primary support structure (30) is provided with a plane positioning area (301a) adapted to the plane portion, or, The surface of the lower prefabricated plate (121) facing away from the upper prefabricated part (11) is provided with at least two second positioning protrusions (126), and the primary support structure (30) is provided with two second positioning grooves (301b) adapted to the second positioning protrusions (126).

11. The method for constructing a tunnel invert structure according to claim 1, wherein: Constructing a primary support structure (30) and pouring concrete for an inverted arch cushion layer, and applying fine leveling to the surface of the pre-set position (301) of the poured primary support structure (30) in contact with the inverted arch prefabricated module (10); Placing the lower prefabricated part (12) of the inverted arch prefabricated module (10) at the preset position (301), splicing and connecting two adjacent lower prefabricated parts (12), and then placing the upper prefabricated part (11) of the inverted arch prefabricated module (10), splicing and connecting the upper prefabricated part (11) and the lower prefabricated part (12); Based on the inverted arch prefabricated module (10), a casting module (20) is obtained by casting construction on the left and right sides of the inverted arch prefabricated module (10). A drainage channel (22), a cable channel (23) and a weight reduction channel (21) extending along the tunnel axis direction (C1) are provided in the casting module (20). The weight reduction channel (21), the drainage channel (22) and the cable channel (23) are arranged in sequence along the direction from the inverted arch prefabricated module (10) to the casting module (20). The cable channel (23) is higher than the drainage channel (22). The weight reduction channel (21) is arranged away from the curved surface of the cast primary support structure (30).

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