Up-down split type prefabricated inverted arch structure of tunnel

Abstract

The utility model relates to the technical field of tunnel inverted arches, in particular to an up-down split type prefabricated inverted arch structure of a tunnel. Comprising a secondary lining and an inverted arch structure, the inverted arch structure comprises a first split block and a second split block, supporting structures are arranged at the two ends of the first split block, one end of each supporting structure abuts against the first split block, the other end of each supporting structure abuts against the end of the secondary lining, and a cast-in-place arch foot is arranged between the first split block and the secondary lining. A first connecting block is vertically arranged in the middle of the second split block, second connecting blocks are obliquely arranged at the two ends of the second split block, a first connecting groove is formed in the first split block, and a second connecting groove is formed in the first split block. According to the utility model, the first connecting groove and the second connecting groove are arranged on the first split block, and the first connecting block and the second connecting block are arranged on the second split block, so that the first split block and the second split block can be quickly connected, the splicing process is simple, the number of joints is small, the overall waterproof effect is good, and the construction efficiency is high.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel invert, in particular to an upper and lower split precast tunnel invert structure. Background Technique

[0002] In recent years, many high-speed railways have been built in China. The construction procedures for tunnel invert and invert filling are as follows: construction preparation → bottom excavation of the tunnel → construction of the invert primary support steel frame → shotcrete for the invert primary support → tying of invert steel bars → installation of the water stop belt → installation of the formwork → pouring of invert concrete → waiting for the concrete to reach the required strength → removal of the invert formwork → pouring of invert filling concrete. This construction method is not ideal because after the invert concrete is poured, the formwork cannot be removed until the concrete strength reaches the formwork removal condition, and then the invert filling concrete can be poured. As a result, 15 - 20 hours are wasted for each block of invert concrete pouring.

[0003] Chinese invention patent CN116733492A discloses a precast invert design and construction method for preventing tunnel floor heave deformation. The precast invert includes a left precast block, a right precast block, and a central precast block. The left precast block is laid on the left side of the tunnel base, the right precast block is laid on the right side of the tunnel base, and the central precast block is laid between the left precast block and the right precast block. The sum of the lengths of the top surfaces of the left precast block, the right precast block, and the central precast block is the width of the tunnel horizontal plane. Precast assembled joints are respectively provided on the contact surfaces between the left precast block, the right precast block, and the central precast block. Each precast block is positioned and butt - jointed through the precast assembled joints and then connected by grouting.

[0004] The above - mentioned patent forms an invert structure by splicing multiple precast blocks left and right, which can effectively shorten the construction period, but there are still some problems:

[0005] 1. The complete invert structure at the bottom of the tunnel cannot be formed at one time and needs to be installed in stages. During the installation process, the lower invert and the upper secondary lining structure cannot be closed into a loop in a timely and effective manner, and the overall structural stress risk is higher.

[0006] 2. There are multiple joints in the left - middle - right split precast invert, and the overall waterproof effect is poor. Water at the lower part of the invert is easily seeped into the structure along the joints. Content of the Utility Model

[0007] The technical problem to be solved by the utility model is to provide an upper and lower split precast tunnel invert structure, which reduces the on - site installation and splicing procedures, reduces the difficulty of specific operations, ensures the overall waterproof effect, guarantees the safety of the overall structure, improves the construction operation efficiency, significantly shortens the construction period, and improves the treatment efficiency and engineering quality of the tunnel bottom of the operating highway tunnel.

[0008] The technical solution adopted by the present utility model to solve its technical problems is a tunnel upper and lower split-type precast inverted arch structure, which includes a secondary lining and an inverted arch structure. The inverted arch structure includes a first split block and a second split block arranged above the first split block. Support structures are arranged at both ends of the first split block. One end of the support structure abuts against the first split block, and the other end abuts against the end of the secondary lining. A cast-in-place arch foot covering the support structure is arranged between the first split block and the secondary lining. The secondary lining, the cast-in-place arch foot, and the inverted arch structure enclose an annular structure. A first connecting block is vertically arranged in the middle of the second split block, and second connecting blocks are obliquely arranged at both ends of the second split block. A first connecting groove for cooperating with the first connecting block is arranged on the first split block, and a second connecting groove for cooperating with the second connecting block is arranged on the first split block.

[0009] Further, a connecting steel plate is arranged on the side wall of the first connecting block, a screw hole is arranged on the side wall of the first split block, and the connecting steel plate and the screw hole are connected by bolts.

[0010] Further, a first installation groove for placing the connecting steel plate is arranged on the side wall of the first connecting block, a second installation groove for placing the connecting steel plate is arranged on the side wall of the first split block, and the screw hole is arranged on the groove wall of the second installation groove.

[0011] Further, a mortar filling layer is arranged between the second connecting block and the second connecting groove.

[0012] Further, the mortar filling layer is high-strength concrete.

[0013] Further, the support structure is a hydraulic jack.

[0014] The beneficial effects of the present utility model are:

[0015] 1. By arranging the first split block and support structures at both ends of the first split block, the connection between the inverted arch structure and the secondary lining is realized, and the overall structure is quickly formed to ensure the stability of the overall structure.

[0016] 2. By arranging the first connecting groove and the second connecting groove on the first split block, and the first connecting block and the second connecting block on the second split block, the quick connection of the first split block and the second split block can be realized. The splicing process is simple, the joints are few, the overall waterproof effect is good, and the construction efficiency is high. Description of the Drawings

[0017] Figure 1 is the structural schematic diagram of the present utility model;

[0018] Figure 2 is the exploded view of the inverted arch structure.

[0019] Reference numerals: 1 - secondary lining; 2 - invert structure; 3 - first split block; 4 - second split block; 5 - support structure; 6 - cast-in-place arch foot; 7 - first connection block; 8 - second connection block; 9 - first connection groove; 10 - second connection groove; 11 - connection steel plate; 12 - mortar filling layer; 13 - first installation groove; 14 - second installation groove. Detailed implementation mode

[0020] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0021] As Figure 1 and Figure 2 shown, the tunnel upper and lower split precast invert structure of the present invention includes a secondary lining 1 and an invert structure 2. The invert structure 2 includes a first split block 3 and a second split block 4 arranged above the first split block 3. Support structures 5 are arranged at both ends of the first split block 3. One end of the support structure 5 abuts against the first split block 3, and the other end abuts against the end of the secondary lining 1. A cast-in-place arch foot 6 covering the support structure 5 is arranged between the first split block 3 and the secondary lining 1. The secondary lining 1, the cast-in-place arch foot 6 and the invert structure 2 enclose an annular structure. A first connection block 7 is vertically arranged in the middle of the second split block 4, and second connection blocks 8 are obliquely arranged at both ends of the second split block 4. A first connection groove 9 for cooperating with the first connection block 7 is arranged on the first split block 3, and a second connection groove 10 for cooperating with the second connection block 8 is arranged on the first split block 3.

[0022] Among them, the secondary lining 1 is a cast-in-place concrete or reinforced concrete lining constructed on the inner side of the initial support of the tunnel, which together with the initial support of the tunnel forms a composite lining; the inverted arch structure 2 is precast from reinforced concrete and hoisted into the tunnel during use; the lower surface of the first split block 3 is an arc surface, and the upper surface of the second split block 4 is a flat surface. The support structure 5 can adopt a hydraulic cylinder or a telescopic rod. One end of the support structure 5 abuts against the first split block 3 and the other end abuts against the end of the secondary lining 1, and is used to provide a supporting force to support the secondary lining 1 after the first split block 3 is installed; the cast-in-place arch footing 6 is a concrete structure formed by pouring between the first split block 3, the support structure 5 and the secondary lining 1 after they are installed, and is used to connect the first split block 3 and the secondary lining 1. After the construction is completed, the secondary lining 1, the cast-in-place arch footing 6 and the first split block 3 form an annular structure. The first connecting block 7 is a rectangular block and is integrally formed with the second split block 4. Similarly, the second connecting block 8 is also a rectangular block and is integrally formed with the second split block 4; the second connecting block 8 is inclined, and the distance from the upper end of the second connecting block 8 to the center of the second split block 4 is less than the distance from the lower end of the second connecting block 8 to the center of the second split block 4. Since during the operation of the tunnel, the gravity provided by the vehicle will cause the middle part of the first split block 3 to be subjected to a vertical force, but the edge part will be subjected to a force in an inclined direction, the second connecting block 8 is inclined, and the included angle formed by the center line of the second connecting block 8 and the upper surface of the second split block 4 is between 100° and 120°. The first connecting groove 9 is a rectangular groove. After the installation is completed, one side wall of the first installation groove 13 abuts against one side of the first connecting block 7; the second installation groove 14 is used in cooperation with the second connecting block 8. When the first split block 3 and the second split block 4 are connected, the hoisting method is adopted. The first time ensures that the first installation groove 13 and the first connecting block 7 are opposite. Since the second connecting block 8 is inclined, the second connecting groove 10 needs to be larger than the cross-sectional size of the second connecting block 8. After the installation is completed, the side wall of the second connecting block 8 close to the center of the second split block 4 needs to abut against the side wall of the second connecting groove 10 close to the center of the first split block 3. In this way, the quick connection between the first split block 3 and the second split block 4 can be realized, and the stability after connection can also be ensured.

[0023] To improve the stability between the first split block 3 and the second split block 4, further, see Figure 1 , a connecting steel plate 11 is arranged on the side wall of the first connecting block 7, a screw hole is arranged on the side wall of the first split block 3, and the connecting steel plate 11 is connected to the screw hole by a bolt. Among them, threaded holes can be manufactured on the side wall of the connecting steel plate 11 and the first connecting block 7. The first connecting block 7 is connected to the connecting steel plate 11 by a bolt, and the connecting steel plate 11 is also connected to the side wall of the first split block 3 by a bolt. Here, the bolt can adopt an expansion bolt or a high-strength bolt.

[0024] In order to reduce the axial dimension of the invert structure 2, further, refer to Figure 2 , a first installation groove 13 for placing the connecting steel plate 11 is provided on the side wall of the first connecting block 7, a second installation groove 14 for placing the connecting steel plate 11 is provided on the side wall of the first split block 3, and the screw hole is provided on the groove wall of the second installation groove 14. Wherein, the depths of the first installation groove 13 and the second installation groove 14 are consistent with the thickness of the connecting steel plate 11. After installation, the upper part of the connecting steel plate 11 is located in the first installation groove 13, and the lower part of the connecting steel plate 11 is located in the second installation groove 14.

[0025] In order to prevent the second connecting block 8 from shaking in the second connecting groove 10, further, refer to Figure 1 , a mortar filling layer 12 is provided between the second connecting block 8 and the second connecting groove 10. The mortar filling layer 12 is high-strength concrete.

[0026] Further, the support structure 5 is a hydraulic jack. The fixed end of the hydraulic jack is fixedly connected to the first split block 3, and the movable end of the hydraulic jack abuts against the secondary lining 1.

[0027] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A tunnel upper and lower split prefabricated inverted arch structure, comprising a secondary lining (1) and an inverted arch structure (2), characterized in that: The inverted arch structure (2) comprises a first split block (3) and a second split block (4) arranged above the first split block (3); support structures (5) are arranged at both ends of the first split block (3); one end of the support structure (5) is abutted against the first split block (3) and the other end is abutted against the end of the secondary lining (1); a cast-in-place arch foot (6) covering the support structure (5) is arranged between the first split block (3) and the secondary lining (1); the secondary lining (1), the cast-in-place arch foot (6) and the inverted arch structure (2) form an annular structure; a first connecting block (7) is vertically arranged in the middle of the second split block (4); second connecting blocks (8) are obliquely arranged at both ends of the second split block (4); a first connecting groove (9) used in conjunction with the first connecting block (7) is arranged on the first split block (3); and a second connecting groove (10) used in conjunction with the second connecting block (8) is arranged on the first split block (3).

2. The tunnel upper and lower split prefabricated invert structure according to claim 1, characterized in that: A connecting steel plate (11) is provided on the side wall of the first connecting block (7), a screw hole is provided on the side wall of the first split block (3), and the connecting steel plate (11) is connected to the screw hole by means of bolts.

3. The tunnel upper and lower split prefabricated invert structure according to claim 2, characterized in that: A first mounting groove (13) for placing a connecting steel plate (11) is provided on the side wall of the first connecting block (7), a second mounting groove (14) for placing a connecting steel plate (11) is provided on the side wall of the first split block (3), and the screw hole is provided on the groove wall of the second mounting groove (14).

4. The tunnel upper and lower split prefabricated invert structure according to claim 1, characterized in that: A mortar filling layer (12) is provided between the second connection block (8) and the second connection groove (10).

5. The tunnel upper and lower split prefabricated invert structure according to claim 4, characterized in that: The mortar filling layer (12) is high-strength concrete.

6. The tunnel upper and lower split prefabricated invert structure according to claim 1, characterized in that: The supporting structure (5) is a hydraulic jack.

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