Flue plate structure for shield tunnel and construction method thereof

Abstract

The application discloses a flue plate structure for a shield tunnel and a construction method thereof, and the flue plate structure comprises a plurality of flue plates which are arranged along the length direction of the shield tunnel and are prestressed concrete hollow plates. The flue plate structure adopts the prestressed concrete hollow plates as the flue plates, thereby ensuring the overall bearing strength of the flue plates, reducing the quality of the flue plates, greatly reducing the transportation and construction difficulty, and ensuring the construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of shield tunnel construction, and more specifically to a flue slab structure for shield tunnels and its construction method. Background Technology

[0002] In existing technologies, flue slab structures are typically constructed from multiple solid reinforced concrete flue slabs. However, in shield tunnels, to meet the load-bearing requirements of the flue slab structure, the size and camber height of the flue slabs are usually designed to be larger.

[0003] However, since the flue slab is made of solid reinforced concrete, its larger size increases its weight, requiring special equipment for transportation and installation, which greatly increases the difficulty of transportation and installation. At the same time, the larger arch height reduces the distance between the flue slab and the top segments of the shield tunnel, compressing the construction space for workers and making construction difficult. Summary of the Invention

[0004] The first objective of this invention is to provide a lightweight flue plate structure that is easy to transport and install.

[0005] The second objective of this invention is to provide a construction method for the above-mentioned flue plate structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A flue slab structure for shield tunnels is installed on the top of the shield tunnel. The flue slab structure includes multiple flue slabs laid along the length of the shield tunnel. The flue slabs are prestressed concrete hollow slabs.

[0008] Preferably, the arch height of the flue plate is h, where h ≤ 5cm.

[0009] Preferably, the flue plate has a top surface and a bottom surface on its upper and lower sides, a first connecting end face at each end in the length direction, and a second connecting end face at each end in the width direction. The flue plate is connected to the shield tunnel through the first connecting end face, and two adjacent flue plates are connected through the second connecting end face.

[0010] More preferably, the second connecting end face includes a first groove section and a facing section arranged sequentially along the direction from the top surface to the bottom surface. When two adjacent flue plates are connected, the two adjacent facing sections of the two plates are bonded to each other, and a first keyway is formed between the two adjacent first groove sections. The flue plate structure also includes a fireproof strip disposed in the first keyway, a sealing slurry injected into the first keyway, and a fireproof sealant disposed at the end of the first keyway away from the facing section.

[0011] More preferably, the second connecting end face further includes a second groove section located between the first groove section and the facing section. When two adjacent flue plates are connected, a second keyway is formed between the two adjacent second groove sections. The diameter of the second keyway is larger than the diameter of the first keyway, and a reinforcing cage is provided in the second keyway.

[0012] More preferably, the second connecting end face also includes a concave corner segment located at the end of the facing section away from the first groove section. When two adjacent flue plates are connected, the two concave corner segments that are close to each other form an angle, wherein the angle is α, and 30° < α < 60°.

[0013] Preferably, the flue plate comprises:

[0014] The first flue plate, multiple first flue plates are arranged sequentially along the length of the shield tunnel to form a first flue plate group, and multiple first flue plate groups are arranged at intervals along the length of the shield tunnel.

[0015] The second flue plate is provided between each two adjacent groups of the first flue plate. The arrangement direction of the two second flue plates is perpendicular to the length direction of the shield tunnel. The two second flue plates and the two adjacent groups of the first flue plate form a flue opening for installing a smoke exhaust valve.

[0016] The third flue plate has a reinforcing layer attached to one side surface and an installation plate for mounting a fan embedded on the other side surface. At least two of the third flue plates are respectively arranged at both ends of the multiple first flue plate groups.

[0017] More preferably, one side surface of the third flue plate is a rough surface, and the reinforcing layer includes a steel mesh laid on the rough surface and a concrete composite layer poured on the steel mesh.

[0018] More preferably, the flue plate structure further includes a connector for connecting the first flue plate group and the second flue plate. The connector includes a support beam extending along the arrangement direction of the two adjacent first flue plate groups and two support plates respectively disposed at both ends of the support beam. The two support plates respectively support the lower part of the two adjacent first flue plate groups, and the support beam supports the lower part of the second flue plate.

[0019] Another technical solution adopted in this invention is as follows:

[0020] A construction method for the above-mentioned flue slab structure includes the following steps:

[0021] (1) Prefabricate multiple flue slabs and transport them into the shield tunnel, wherein the flue slabs include a first flue slab, a second flue slab and a third flue slab;

[0022] (2) Multiple first flue plates are laid sequentially along the length of the shield tunnel, and the multiple first flue plates are combined into a first flue plate group. Multiple first flue plate groups are arranged along the length of the shield tunnel, and an installation gap is reserved between two adjacent first flue plate groups.

[0023] (3) The second flue plates are laid in the installation gaps, and two second flue plates are laid in each installation gap. A smoke exhaust valve is installed between the two second flue plates. The arrangement direction of the two second flue plates is consistent with the extension direction of the installation gap.

[0024] (4) At least two of the third flue plates are laid at both ends of the arrangement direction of the plurality of first flue plate groups, and a fan is hung on the lower part of the third flue plate.

[0025] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: The flue slab structure of the present invention uses prestressed concrete hollow slabs as flue slabs, which not only ensures the overall load-bearing strength of the flue slabs, but also reduces the weight of the flue slabs, greatly reducing the difficulty of transportation and construction, and ensuring construction efficiency. Attached Figure Description

[0026] Appendix Figure 1 A schematic diagram of the radial section of a shield tunnel equipped with the flue plate structure of a specific embodiment of the present invention;

[0027] Appendix Figure 2 This is a schematic diagram illustrating the arrangement of multiple flue plates in a specific embodiment of the present invention;

[0028] Appendix Figure 3 This is a cross-sectional schematic diagram of the flue plate in the thickness direction in a specific embodiment of the present invention;

[0029] Appendix Figure 4 This is a schematic diagram showing the connection between two adjacent flue plates in a specific embodiment of the present invention;

[0030] Appendix Figure 5 This is a schematic diagram showing the connection between the first flue plate and the second flue plate in a specific embodiment of the present invention;

[0031] Appendix Figure 6 This is a cross-sectional schematic diagram of the thickness direction of the third flue plate in a specific embodiment of the present invention.

[0032] In the diagram: 1. Flue plate; 11. Top surface; 12. Bottom surface; 13. First connecting end face; 14. Second connecting end face; 14a. First groove section; 14b. Facing section; 14c. Second groove section; 14d. Inside corner section; 14e. Transition section;

[0033] 1a. First flue plate; 1b. Second flue plate; 1c. Third flue plate;

[0034] 2. First keyway; 3. Second keyway; 4. Flue opening; 5. Reinforcing layer; 6. Connector; 6a. Support beam; 6b. Support plate; 7. Mounting plate; 8. Internal corner joint;

[0035] 100. Shield tunnel. Detailed Implementation

[0036] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0037] See Figure 1-2 As shown, a flue slab structure for a shield tunnel is installed on the top of the shield tunnel 100. It includes multiple flue slabs 1 laid along the length of the shield tunnel 100. The flue slabs 1 are prestressed concrete hollow slabs.

[0038] In this example, after calculating the bearing capacity, deflection, and other parameters of the flue slab required for the shield tunnel, the SP18A8710 type prestressed concrete hollow slab was ultimately selected as the flue slab. This flue slab has a mass of 2.71 t / m, which is about 40% of the mass of a traditional solid reinforced concrete flue slab. Using this flue slab effectively reduces the difficulty of transportation and installation. The length of the flue slab depends on the specific dimensions of the shield tunnel.

[0039] Furthermore, combined Figure 1As shown, the arch height of flue slab 1 is h, where h ≤ 5cm. By designing the arch height of flue slab 1 to not exceed 5cm, the installation position of flue slab 1 can be raised during construction. While ensuring sufficient exhaust space above and driving space below the flue slab 1, the raised installation position effectively reduces the length of flue slab 1, given the circular radial cross-section of the shield tunnel 100. Simultaneously, the smaller arch height of flue slab 1 expands the working space for construction personnel, improving construction efficiency. In this example, the installation position of flue slab 1 is raised by 48cm, reducing the length of flue slab 1 to 8.7m, and the distance between the highest point of the arch of flue slab 1 and the top segment is 1.915m.

[0040] Meanwhile, since the flue slab 1 in this example is relatively light and has a small arch height, more flue slabs 1 can be stacked in the same position when stacking, which greatly reduces the site occupation and improves the convenience of construction.

[0041] like Figure 2 As shown, the flue plate 1 has a top surface 11 and a bottom surface 12 on its upper and lower sides, respectively; a first connecting end surface 13 at each end along its length; and a second connecting end surface 14 at each end along its width. The flue plate 1 is connected to the shield tunnel 100 through the first connecting end surface 13, and two adjacent flue plates 1 are connected through the second connecting end surface 14. The top surface 11 is smooth, which reduces wind resistance and improves ventilation.

[0042] Furthermore, such as Figure 3-4 As shown, the second connecting end face 14 includes a first groove section 14a and a facing section 14b arranged sequentially along the direction from the top surface 11 to the bottom surface 12. When two adjacent flue plates 1 are connected, the two adjacent facing sections 14b of the two are attached to each other, and a first keyway 2 is formed between the two adjacent first groove sections 14a. The flue plate structure also includes a fireproof strip provided in the first keyway 2, a sealing slurry injected into the first keyway 2, and a fireproof sealant provided at the end of the first keyway 2 away from the facing section 14b.

[0043] In this example, the fireproof strip is a polyethylene foam strip, and the sealing grout is cast-in-place concrete or cement mortar. The cast-in-place concrete is fine aggregate concrete with a strength grade of not less than C20. After two adjacent flue plates 1 are connected, the fireproof strip is filled into the first keyway 2, followed by pouring concrete or cement mortar, and finally sealing with fireproof sealant, ensuring the reliability of the connection between the two adjacent flue plates 1 and the sealing between them.

[0044] As a preferred embodiment, the second connecting end face 14 further includes a second groove section 14c located between the first groove section 14a and the facing section 14b. When two adjacent flue plates 1 are connected, a second keyway 3 is formed between the two adjacent second groove sections 14c. The diameter of the second keyway 3 is larger than the diameter of the first keyway 2, and a reinforcing cage is provided inside the second keyway 3. By setting the reinforcing cage, the overall connection strength of the two adjacent flue plates 1 can be greatly increased.

[0045] An inclined transition section 14e is also provided between the second groove section 14c and the first groove section 14a, and between the second groove section 14c and the facing section 14b.

[0046] Combination Figure 4 As shown, the second connecting end face 14 also includes a concave corner section 14d located at the end of the facing section 14b away from the first groove section 14a. When two adjacent flue plates 1 are connected, the two adjacent concave corner sections 14d form an angle α between them, where 30° < α < 60°. In this embodiment, α = 45°. This setting allows a V-shaped concave corner seam 8 to be formed between the two adjacent corners at the lower ends of two adjacent flue plates 1. This avoids shrinkage cracks caused by direct contact between the two corners and also appropriately covers the appearance defects caused by the inconsistent bottom heights of the two flue plates 1.

[0047] In this embodiment, the flue plate 1 includes a first flue plate 1a, a second flue plate 1b, and a third flue plate 1c.

[0048] Multiple first flue slabs 1a are arranged sequentially along the length of the shield tunnel 100 to form a first flue slab group. Multiple first flue slab groups are arranged at intervals along the length of the shield tunnel 100, and multiple first flue slab groups constitute the main body of the flue slab structure.

[0049] Combination Figure 5 As shown, two second flue slabs 1b are respectively set between each pair of adjacent first flue slab groups. The arrangement direction of the two second flue slabs 1b is perpendicular to the length direction of the shield tunnel 100. The two second flue slabs 1b and the adjacent two first flue slab groups form a flue opening 4 for installing the smoke exhaust valve. By setting two shorter second flue slabs 1b between the two first flue slab groups, the installation space for the smoke exhaust valve can be directly formed between the two second flue slabs 1b and the adjacent two first flue slab groups, eliminating the need to prefabricate flue slabs 1 with flue openings, saving costs and improving construction efficiency.

[0050] Combination Figure 6As shown, the top surface 11 of the third flue plate 1c is covered with a reinforcing layer 5, and the bottom surface 12 is pre-embedded with an installation plate 7 for hanging the fan. The installation plate 7 is a steel plate, and at least two third flue plates 1c are respectively set at both ends of the arrangement direction of multiple first flue plates 1a groups.

[0051] Furthermore, the top surface 11 of the third flue plate 1c is a rough surface, and the protrusion height or depression depth of the rough surface is not less than 4mm. The reinforcing layer 5 includes a steel mesh laid on the rough surface and a concrete composite layer poured on the steel mesh. The reinforcing layer 5 and the third flue plate 1c form a whole, ensuring the load-bearing capacity of the third flue plate 1c after the fan is installed.

[0052] In this embodiment, combined with Figure 5 As shown, the flue plate structure also includes a connector 6 for connecting the first flue plate group and the second flue plate 1b. The connector 6 includes a steel support beam 6a extending along the arrangement direction of two adjacent first flue plate groups and two support plates 6b respectively located at both ends of the support beam 6a. The two support plates 6b support the lower part of the two adjacent first flue plate groups, and the support beam 6a supports the lower part of the second flue plate 1b. During installation, the two connectors 6 are respectively placed between the two adjacent first flue plate groups, and then the two second flue plates 1b are laid. One end of the two second flue plates 1b is connected to the shield tunnel 100, and the other end is supported on the support beam 6a.

[0053] After testing, the prestressed concrete hollow flue slab structure used in this embodiment has significant advantages in terms of quality, cost, storage area, construction convenience, and carbon emissions compared with the common solid concrete flue slabs and UHPC high-performance concrete flue slabs on the market, as shown in the table below.

[0054]

[0055] As can be seen from the table above, the flue plate of this embodiment, compared with Comparative Example 1 and Comparative Example 2, not only significantly reduces the cost, but also reduces the site area and investment in special equipment, while significantly reducing carbon emissions, making it more energy-efficient and environmentally friendly.

[0056] In summary, the flue plate structure of this embodiment has the following advantages:

[0057] (1) The flue slab is made of prestressed concrete hollow slab, which not only reduces the overall weight of the flue slab, but also saves costs;

[0058] (2) The flue slab can be transported and installed using a forklift, which reduces the difficulty of transporting and installing the flue slab structure and improves construction efficiency.

[0059] (3) In this example, the flue slab is lightweight and has a small arch height, so more flue slabs can be stacked in the same position when stacking, which greatly reduces the site occupation and improves the convenience of construction.

[0060] (4) In this example, since the flue plate is relatively light, the size of the bracket used to connect the flue plate can also be optimized accordingly, which effectively reduces the difficulty of casting the bracket, reduces the construction process, and speeds up the construction progress.

[0061] (5) In this example, the flue plate has a small arch height, which can significantly increase the working space of construction workers and improve the working environment of construction workers.

[0062] The construction method for the above-mentioned flue slab structure includes the following steps:

[0063] (1) Multiple prefabricated flue slabs 1 are transported to the shield tunnel 100 by forklift. The flue slabs 1 include a first flue slab 1a, a second flue slab 1b, and a third flue slab 1c. While the flue slabs 1 are being prefabricated, concrete removal of the top segments, chemical anchoring, and corbel pouring are carried out simultaneously in the shield tunnel 100. When pouring the corbels, neoprene rubber sheets are laid on the top surface of the corbel structure.

[0064] (2) Multiple first flue slabs 1a are laid sequentially along the length of the shield tunnel 100, and the two first connecting end faces 13 of the first flue slabs 1a are connected to the corbels on both sides of the shield tunnel 100. Multiple first flue slabs 1a are combined to form a first flue slab group, and multiple first flue slab groups are arranged along the length of the shield tunnel 100, with an installation gap reserved between two adjacent first flue slab groups.

[0065] (3) Multiple second flue plates 1b are laid in multiple installation gaps, with two second flue plates 1b laid in each installation gap, and a smoke exhaust valve is installed between the two second flue plates 1b. The arrangement direction of the two second flue plates 1b is consistent with the extension direction of the installation gap.

[0066] (4) At least two third flue plates 1c are laid at both ends of the arrangement direction of multiple first flue plate groups, and a fan is hung under the third flue plate 1c.

[0067] During the laying of the first flue plate 1a, the second flue plate 1b and the third flue plate 1c, fireproof strips can be installed between two adjacent flue plates 1, cement mortar can be poured and fireproof sealant can be applied to the top.

[0068] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A flue plate structure for a shield tunnel, installed at the top of the shield tunnel, characterized in that, The flue plate structure comprises a plurality of flue plates laid along the length direction of the shield tunnel, and a connecting piece, wherein the flue plate is a prestressed concrete hollow plate; the rise height of the flue plate is h, and h≤5cm; the flue plate comprises first, second and third flue plates; the first flue plates are sequentially arranged to form a first flue plate group along the length direction of the shield tunnel; a plurality of first flue plate groups are arranged at intervals along the length direction of the shield tunnel; two second flue plates are arranged between each adjacent two first flue plate groups; the arrangement direction of the two second flue plates is perpendicular to the length direction of the shield tunnel; the two second flue plates and the adjacent two first flue plate groups enclose a flue port for mounting a smoke exhaust valve; the side surface of the third flue plate is provided with a reinforcing layer, and the other side surface is provided with a mounting plate for hanging a fan; at least two third flue plates are arranged at the two ends of the arrangement direction of the first flue plate groups; the connecting piece is used for connecting the first and second flue plates, and comprises a joist extending along the arrangement direction of the adjacent two first flue plate groups, and two supporting plates arranged at the two ends of the joist; the two supporting plates are supported at the lower parts of the adjacent two first flue plate groups, and the joist is supported at the lower part of the second flue plate.

2. The flue plate structure for a shield tunnel according to claim 1, characterized in that, The flue plate has a top surface and a bottom surface on the upper and lower sides thereof, first connecting end surfaces at the two ends in the length direction, and second connecting end surfaces at the two ends in the width direction; the flue plate is connected to the shield tunnel through the first connecting end surfaces, and adjacent two flue plates are connected through the second connecting end surfaces.

3. The flue plate structure for a shield tunnel according to claim 2, characterized in that, The second connecting end surface comprises a first groove surface section and a surface section arranged in sequence along the direction from the top surface to the bottom surface; when the adjacent two flue plates are connected, the two surface sections close to each other of the two flue plates are attached to each other, the first groove surface sections close to each other of the two flue plates form a first key groove, the flue plate structure further comprises a fireproof strip arranged in the first key groove, a sealing slurry filled in the first key groove, and a fireproof sealing glue arranged at one end of the first key groove away from the surface section.

4. The flue plate structure for a shield tunnel according to claim 3, characterized in that, The second connecting end surface further comprises a second groove surface section between the first groove surface section and the surface section; when the adjacent two flue plates are connected, the second groove surface sections close to each other of the two flue plates form a second key groove, the groove diameter of the second key groove is larger than that of the first key groove, and a steel reinforcement cage is arranged in the second key groove.

5. A flue plate structure for a tunneling shield according to claim 4, wherein The second connecting end surface further comprises a reentrant corner section at one end of the surface section away from the first groove surface section; when the adjacent two flue plates are connected, the reentrant corner sections close to each other of the two flue plates are at an angle to each other, and the angle is a, 30°<a<60°.

6. The flue plate structure for a shield tunnel according to claim 1, wherein The side surface of the third flue plate is a rough surface, and the reinforcing layer comprises a steel mesh laid on the rough surface and a concrete superimposed layer poured on the steel mesh.

7. A method of constructing a flue sheet structure as claimed in any one of claims 1 to 6, characterised in that, The method comprises the following steps: (1) prefabricating a plurality of flue plates and transporting the flue plates into the shield tunnel, wherein the flue plates comprise first, second and third flue plates; (2) A plurality of said first flue plates are sequentially laid along the length direction of the shield tunnel, said plurality of first flue plates are combined into a first flue plate group, a plurality of said first flue plate groups are arranged along the length direction of the shield tunnel, and installation gaps are reserved between two adjacent said first flue plate groups; (3) A plurality of said second flue plates are laid in a plurality of said installation gaps, two said second flue plates are laid in each said installation gap, and an exhaust valve is installed between said two second flue plates, wherein the arrangement direction of said two second flue plates is consistent with the extension direction of said installation gap; (4) At least two said third flue plates are laid at both ends of the arrangement direction of said plurality of first flue plate groups, and a fan is hung below said third flue plates.

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