Arch frame structure of tunnel buckle arch

Abstract

The arch frame structure of the tunnel buckling arch comprises a connecting steel plate, a buckling arch grating frame and U-shaped steel bars, the connecting steel plate is arranged on the outer side of a tunnel pilot tunnel grating, the connecting steel plate is pre-buried in side hole primary support concrete of a side hole in early-stage construction, and one side of the connecting steel plate is connected with a steel frame in the side hole; the buckling arch grating frame comprises upper main reinforcements, lower main reinforcements and stirrups, the upper main reinforcements, the lower main reinforcements and the stirrups form an arch frame body through erection and binding, and the arch frame structure of the tunnel buckling arch is reliable in connection, good in construction quality and high in construction efficiency and has good engineering benefits.

Description

Technical Field

[0001] The utility model relates to an arch frame structure node of a tunnel arch using a hole-pile method, in particular to an arch frame structure of a tunnel arch. Background Art

[0002] In the tunnel-pile method of station construction, the side and middle guide tunnels are constructed first, and then piles are built in the tunnels. Side and middle longitudinal beams are constructed on the piles, followed by side arching and backfilling in the tunnels. After the middle longitudinal beam reaches the design strength, the arching between the guide tunnels is excavated. Entering the arching excavation stage, the biggest risk in the construction process of the rectification station is the arching excavation construction risk. The quality of the arch connection directly affects the risk level and probability of occurrence. The traditional design of the arching is to embed steel plates and connecting bolts in the guide tunnel construction stage, and then use connecting foot plates for bolt connection during the arch excavation. Affected by construction errors, the embedded steel plates and bolts are not in the same section on the left and right, and the elevations are not at the same height. As a result, when connecting the arch feet, it is impossible to align the holes, and the connection is difficult. Additional processing is required during the operation, and connections are made through supplementary welding methods. The operating space is small, the operation is difficult, and it takes a long time, which will increase the operation time of each cycle and increase the construction risk. After the excavation is completed, untimely support and poor connection quality may lead to face collapse. In severe cases, it may cause ground depression, resulting in casualties and major social impacts. Summary of the Invention

[0003] In view of the problems existing in the above-mentioned prior art, the utility model provides an arch frame structure for a tunnel arch, which can drill and expand the hole in one step, effectively increasing construction efficiency and reducing construction time.

[0004] In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0005] A tunnel arch frame structure includes a connecting steel plate, an arch grid frame and U-shaped steel bars, wherein the connecting steel plate is arranged on the outside of the tunnel pilot hole grid, and the connecting steel plate is embedded in the primary support concrete of the side hole of the side hole constructed in the early stage and one side is connected to the steel frame in the side hole; the arch grid frame includes upper main bars, lower main bars and stirrups, and the upper main bars, lower main bars and stirrups are erected and tied to form an arch frame body; the U-shaped steel bars include at least one short-leg U-shaped steel bar and one long-leg U-shaped steel bar, wherein the upper main bar is welded to the connecting steel plate through the short-leg U-shaped steel bar, the two ends of the short-leg U-shaped steel bar are welded to the upper main bar, and the bottom end of the short-leg U-shaped steel bar is welded to the connecting steel plate, and the lower main bar is welded to the connecting steel plate through the long-leg U-shaped steel bar, the two ends of the long-leg U-shaped steel bar are welded to the lower main bar, and the bottom end of the long-leg U-shaped steel bar is welded to the connecting steel plate.

[0006] The spacing between the stirrups is 120 mm.

[0007] The welding length of the upper main reinforcement and the U-shaped reinforcement is greater than 10d, where d is the diameter of the upper main reinforcement.

[0008] The welding length of the lower main reinforcement 22 and the U-shaped reinforcement 32 is greater than 12d, where d is the diameter of the upper main reinforcement.

[0009] By means of the above solution, the present invention has at least the following advantages:

[0010] 1. The present invention sets U-shaped steel bars according to the different forces of the support, and sets short-leg U-shaped steel bars and long-leg U-shaped steel bars, which adapts to the installation and centering requirements of the upper and lower steel bars and is convenient for installation and force bearing;

[0011] 2. The tunnel buckle arch of the present invention has reliable arch frame structure connection, good construction quality, high construction efficiency and good engineering benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is an overall schematic diagram of the tunnel buckle arch of the present invention;

[0013] Figure 2 is a cross-sectional view of the arch structure of the present invention;

[0014] Figure 3 It is a plan view of the arch structure of the present invention. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0017] like Figures 1 to 2As shown, in order to achieve the above-mentioned purpose, the utility model is implemented through the following technical solutions: an arch frame structure of a tunnel buckle arch, comprising a connecting steel plate 1, a buckle arch grid frame 2 and a U-shaped steel bar 3, wherein the connecting steel plate 1 is arranged on the outside of the tunnel guide hole grid 4, and the connecting steel plate 1 is pre-embedded in the primary support concrete 6 of the side hole constructed in the early stage and one side is connected to the steel frame 7 in the side hole; The buckled arch grid frame 2 includes an upper main reinforcement 21, a lower main reinforcement 22 and stirrups 5, and the upper main reinforcement 21, the lower main reinforcement 22 and the stirrups 5 are erected and tied to form an arch frame; the U-shaped steel bar 3 includes at least one short-limb U-shaped steel bar 31 and one long-limb U-shaped steel bar 32, wherein the upper main reinforcement 21 is welded to the connecting steel plate 1 through the short-limb U-shaped steel bar 31, the two ends of the short-limb U-shaped steel bar are welded to the upper main reinforcement 21, and the bottom end of the short-limb U-shaped steel bar is welded to the connecting steel plate, and the lower main reinforcement 22 is welded to the connecting steel plate 1 through the long-limb U-shaped steel bar 32, the two ends of the long-limb U-shaped steel bar are welded to the lower main reinforcement, and the bottom end of the long-limb U-shaped steel bar 32 is welded to the connecting steel plate.

[0018] The spacing between the stirrups 5 is 120 mm.

[0019] The welding length of the upper main reinforcement 21 and the U-shaped reinforcement 31 is greater than 10d, where d is the diameter of the upper main reinforcement.

[0020] The welding length of the lower main reinforcement 22 and the U-shaped reinforcement 32 is greater than 12d, where d is the diameter of the upper main reinforcement.

[0021] The specific construction process is as follows:

[0022] Step 1: After excavation and under-excavation are completed to expose the embedded steel plates, the arch frame is erected and the U-shaped reinforcement on the tunnel face side is positioned. Then, the inner side (on the tunnel face side) reinforcement is welded using a two-way welding machine. The U-shaped reinforcement is fully welded on both sides where it contacts the steel plate, and welded on one side to the main reinforcement of the grid steel frame. The welding length is not less than 10d (d is the diameter of the reinforcement).

[0023] Step 2: Based on the location of the main reinforcement of the grid on the outside (away from the tunnel face), weld the outside reinforcement in the same way as the inside.

[0024] Step 3: For the welded steel frame, stirrups are placed near the arch foot section to strengthen the stability of the steel frame. The spacing between the stirrups is 300mm, and all contact points with the arch frame need to be spot welded. The stirrups (3 on one side) are processed in advance and passed through the normal section of the arch frame for temporary binding and fixation.

[0025] The above description is only a preferred embodiment of the present invention and does not limit the structure of the present invention in any form. Any simple modification, equivalent change or modification of the above embodiment based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A tunnel arch frame structure, comprising a connecting steel plate (1), an arch grid frame (2) and a U-shaped steel bar (3), wherein the connecting steel plate (1) is arranged on the outside of the tunnel guide hole grid (4), the connecting steel plate (1) is pre-embedded in the primary support concrete (6) of the side hole constructed in the early stage and one side is connected to the steel frame (7) in the side hole; Its characteristics are: The buckled arch grid frame (2) comprises an upper main reinforcement (21), a lower main reinforcement (22) and stirrups (5), wherein the upper main reinforcement (21), the lower main reinforcement (22) and the stirrups (5) are erected and tied to form an arch frame body; the U-shaped steel bar (3) comprises at least one short-limb U-shaped steel bar (31) and one long-limb U-shaped steel bar (32), wherein the upper main reinforcement (21) is welded to the connecting steel plate (1) through the short-limb U-shaped steel bar (31), two limb ends of the short-limb U-shaped steel bar are welded to the upper main reinforcement (21), and the bottom end of the short-limb U-shaped steel bar is welded to the connecting steel plate; the lower main reinforcement (22) is welded to the connecting steel plate (1) through the long-limb U-shaped steel bar (32), two limb ends of the long-limb U-shaped steel bar are welded to the lower main reinforcement, and the bottom end of the long-limb U-shaped steel bar (32) is welded to the connecting steel plate.

2. The tunnel arch structure according to claim 1, characterized in that: The spacing between the stirrups (5) is 120 mm.

3. The tunnel arch structure according to claim 1, characterized in that: The welding length of the upper main reinforcement (21) and the U-shaped reinforcement (3) is greater than 10d, where d is the diameter of the upper main reinforcement.

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