Semi-prefabricated highway tunnel inverted arch structure

Abstract

An inverted arch is divided into a middle prefabricated part and cast-in-place parts on the two sides in the longitudinal direction of the tunnel, tunnel drainage ditches are located on the cast-in-place parts on the two sides, the middle prefabricated part is divided into a plurality of prefabricated blocks in the transverse direction of the tunnel, and a plurality of connecting ribs extend out of the two sides of each prefabricated block in the transverse direction of the tunnel. The cast-in-place parts on the two sides are integrally poured, and the connecting ribs on the two sides of the precast block are poured in concrete of the cast-in-place parts on the two sides The inverted arch middle part prefabricated structure is high in installation speed, construction vehicles can pass through the inverted arch middle part prefabricated structure after the inverted arch middle part prefabricated structure is installed, cast-in-place construction of arch feet on the two sides can be conveniently and rapidly carried out, the cast-in-place parts of the arch feet are integrally poured, the stress performance of the arch feet can be guaranteed, the problems of slab staggering, leakage and the like are avoided, and the inverted arch quality is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of highway tunnel construction, relates to tunnel invert construction, and specifically relates to a semi-prefabricated highway tunnel invert structure. Background Art

[0002] The invert is part of the tunnel secondary lining composite structure and bears a certain proportion of the surrounding rock load. Its construction quality directly affects the safety of the tunnel throughout its life cycle. Traditional highway tunnel inverts are mostly cast-in-place, with a large amount of cast-in-place concrete in the tunnel, which has the disadvantages of complex construction organization, long construction period, poor construction environment, and difficulty in construction quality control.

[0003] Prefabricated concrete structures have unique advantages in terms of ensuring project quality, saving resources, shortening construction periods, and reducing labor costs. They have now begun to be used in tunnel invert construction. Prefabricated inverts are structures that divide the invert into multiple segments along the tunnel transverse direction, and each segment is further divided into multiple prefabricated blocks, which are connected by bolts.

[0004] The cross-section of a highway tunnel is generally flat, and the arch foot is subject to greater stress. Ancillary facilities such as tunnel cable troughs and drainage ditches are also installed near the arch foot. However, the existing fully prefabricated inverted arch structure has joints at the arch foot and has poor integrity, which not only affects the stress on the arch foot, but is also prone to problems such as misalignment and leakage. Summary of the invention

[0005] The utility model aims to solve the above problems and provide a semi-prefabricated highway tunnel invert structure, which ensures the construction quality of the invert while retaining the advantages of prefabricated assembly construction technology.

[0006] The technical solution of the utility model is as follows:

[0007] A semi-prefabricated highway tunnel invert structure, characterized in that: the invert is divided into a middle prefabricated part and cast-in-place parts on both sides along the longitudinal direction of the tunnel, and the tunnel drainage ditch is located on the cast-in-place parts on both sides; the middle prefabricated part is divided into a plurality of prefabricated blocks along the transverse direction of the tunnel, a plurality of connecting bars are extended from both sides of each prefabricated block along the transverse direction of the tunnel, the cast-in-place parts on both sides are cast as a whole respectively, and the connecting bars on both sides of the prefabricated block are cast in the concrete of the cast-in-place parts on both sides.

[0008] The driving lane part in the middle of the inverted arch of the utility model adopts a prefabricated assembled structure, and the arch foot parts on both sides adopt a cast-in-place structure; the prefabricated structure in the middle part has a fast installation speed, and after the installation is completed, it can be used for construction vehicles to pass, which is convenient for the rapid cast-in-place construction of the arch feet on both sides; the cast-in-place part of the arch foot is cast in one piece, which can ensure the stress performance of the arch foot, avoid problems such as misalignment and leakage, and ensure the quality of the inverted arch. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1It is a schematic diagram of the cross-sectional structure of the utility model along the transverse direction of the tunnel;

[0010] Figure 2 It is a schematic diagram of the plane structure of the utility model;

[0011] Figure 3 It is a schematic diagram of the cross-sectional structure of a prefabricated block segment;

[0012] Figure 4 This is a schematic diagram of the installation status of the first prefabricated block;

[0013] Figure 5 is a schematic diagram of the installation state of the second prefabricated block and its connection structure with the first prefabricated block;

[0014] Figure 6 is a schematic diagram of the installation state of the third prefabricated block and its connection structure with the second prefabricated block;

[0015] Figure 7 It is a schematic diagram of the installation status of the steel frame of the cast-in-place parts on both sides;

[0016] Figure 8 This is a schematic diagram of the status after the cast-in-place parts on both sides are completed. DETAILED DESCRIPTION

[0017] like Figure 1 , Figure 2 , Figure 3 As shown, the inverted arch of the utility model is divided into a middle prefabricated part and cast-in-place parts on both sides along the longitudinal direction of the tunnel, and the tunnel drainage ditch is located on the cast-in-place parts on both sides; the middle prefabricated part is divided into multiple prefabricated blocks along the transverse direction of the tunnel, and multiple connecting bars extend from both sides of each prefabricated block along the transverse direction of the tunnel. The cast-in-place parts on both sides are cast as a whole respectively, and the connecting bars on both sides of the prefabricated blocks are cast in the concrete of the cast-in-place parts on both sides.

[0018] When the utility model is implemented, in order to reduce the weight of each prefabricated block and save the amount of concrete, a row of circular weight-reducing holes can be set in each prefabricated block along the longitudinal direction of the tunnel. The arched structure of the circular hole has strong compressive resistance and can meet the driving load requirements of the top of the inverted arch.

[0019] During the specific implementation of the utility model, in order to ensure the firm connection between the prefabricated blocks, four pin rod insertion holes are provided in each prefabricated block along the longitudinal direction of the tunnel. The four pin rod insertion holes are symmetrically arranged on both sides of the longitudinal center line of the tunnel. Adjacent prefabricated blocks are connected by prestressed pin rods inserted into the pin rod insertion holes.

[0020] Furthermore, to facilitate the installation of prestressed pins in adjacent prefabricated blocks, prestressed pins can be inserted into the two pin holes on both sides of the first prefabricated block and the second prefabricated block, the two pin holes in the middle of the second prefabricated block and the third prefabricated block can be inserted into the prestressed pins, and the pin holes on both sides of the third prefabricated block and the fourth prefabricated block can be inserted into the prestressed pins. The prestressed pins in subsequent prefabricated blocks are installed in a cycle in the above manner; the length of each prestressed pin is equal to the length of the two prefabricated blocks along the longitudinal direction of the tunnel, and anchor nuts are installed at both ends of each prefabricated block.

[0021] The above structure can also be implemented by inserting pins into the two middle pin rod insertion holes of the first and second prefabricated blocks, and inserting prestressed pins into the pin rod insertion holes on both sides of the second and third prefabricated blocks, as long as the pins are inserted alternately into the pin rod insertion holes on both sides and in the middle.

[0022] The construction method of the utility model is as follows:

[0023] like Figure 4 As shown, after the first prefabricated block is installed in place, prestressed pins are respectively inserted into the pin insertion holes on both sides thereof, the length of each prestressed pin is equal to the length of the two prefabricated blocks, and anchor nuts are installed at the rear ends of the pins;

[0024] like Figure 5 As shown, when installing the second prefabricated block, first insert the prestressed pins into the two pin holes in the middle, install the anchor nuts at the rear end of the pins, then insert the two prestressed pins at the front end of the first prefabricated block into the pin holes on both sides of the second prefabricated block, and install the anchor nuts at the front end of the two pins, so as to tighten and fix the second prefabricated block and the first prefabricated block;

[0025] like Figure 6 As shown, when the third prefabricated block is installed, first insert the prestressed pins into the pin holes on both sides thereof and install the anchor nuts at the rear end, then insert the two prestressed pins at the front end of the second prefabricated block into the two pin holes in the middle of the third prefabricated block, and install the anchor nuts at the front end of the pins to tighten and fix the third prefabricated block to the second prefabricated block.

[0026] The subsequent prefabricated blocks are installed cyclically in the above manner until all the prefabricated blocks in the middle part of the invert are installed.

[0027] like Figure 7 As shown, the steel skeleton of the cast-in-place part on both sides of the invert is installed and connected with the steel skeleton of the prefabricated block;

[0028] like Figure 8 As shown, the cast-in-place concrete is poured, and the connecting bars on both sides of the precast block are poured into the cast-in-place concrete to ensure the connection strength between the cast-in-place part and the precast part.

[0029] When constructing the cast-in-place part of the invert, the top of the prefabricated part of the invert can already accommodate the passage of construction vehicles, which can speed up the construction progress of the cast-in-place part.

Claims

1. A semi-prefabricated highway tunnel invert structure, characterized in that: The invert is divided into a middle prefabricated part and cast-in-place parts on both sides along the longitudinal direction of the tunnel, and the tunnel drainage ditch is located on the cast-in-place parts on both sides; the middle prefabricated part is divided into multiple prefabricated blocks along the transverse direction of the tunnel, and multiple connecting bars extend from both sides of each prefabricated block along the transverse direction of the tunnel. The cast-in-place parts on both sides are cast as a whole, and the connecting bars on both sides of the prefabricated blocks are cast in the concrete of the cast-in-place parts on both sides.

2. The semi-prefabricated highway tunnel invert structure according to claim 1 is characterized in that: A row of circular weight-reducing holes is provided in each prefabricated block along the longitudinal direction of the tunnel.

3. The semi-prefabricated highway tunnel invert structure according to claim 1, characterized in that: Each prefabricated block is provided with four pin rod insertion holes along the longitudinal direction of the tunnel. The four pin rod insertion holes are symmetrically arranged on both sides of the longitudinal center line of the tunnel. Adjacent prefabricated blocks are connected by prestressed pin rods inserted into the pin rod insertion holes.

4. The semi-prefabricated highway tunnel invert structure according to claim 3 is characterized in that: Prestressed pins are inserted into the two pin rod insertion holes on both sides of the first prefabricated block and the second prefabricated block, prestressed pins are inserted into the two pin rod insertion holes in the middle of the second prefabricated block and the third prefabricated block, prestressed pins are inserted into the pin rod insertion holes on both sides of the third prefabricated block and the fourth prefabricated block, and the prestressed pins in subsequent prefabricated blocks are installed cyclically in the above manner; the length of each prestressed pin is equal to the length of the two prefabricated blocks, and anchor nuts are installed at both ends of each prestressed pin.

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