Recyclable temporary cross brace structure for tunnel excavation through benching method

Abstract

The utility model relates to a turnover temporary cross-brace structure for tunnel benching method excavation, which is arranged in a tunnel and comprises a plurality of supporting rods horizontally arranged in the tunnel at intervals along the direction of the tunnel. The two ends of the supporting rod are arranged on the two opposite sides of the tunnel in a supported mode. And the fixing rods are arranged between the two supporting rods which are arranged up and down at intervals, the structure is simple, and construction is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel construction, in particular to a temporary cross-bracing structure capable of excavating a rotatable tunnel using a step method. Background Art

[0002] Currently, tunnel excavation operations in highway and railway sectors generally utilize the New Austrian Tunneling Method (NATM). Excavation methods are further determined based on the tunnel's hydrogeological conditions, surrounding rock conditions, and tunnel depth. Conventional excavation methods include the full-face method, two-bench method, three-bench method, three-bench core soil method, three-bench temporary cross-bracing method, three-bench temporary invert arch method, and CRD method. In Grade V surrounding rock areas with shallow, biased depth, the three-bench temporary cross-bracing method is generally used.

[0003] The three-bench method uses mechanical excavation, with temporary steel frames and temporary vertical supports erected immediately after excavation. Excavation openings are generally set up at regular intervals on the temporary horizontal supports to facilitate excavation of the upper steps. However, the temporary horizontal supports have low rigidity and poor stability, making them unsuitable for rapid and stable movement after excavation. Single-track temporary horizontal supports also have low rigidity and can significantly deform during removal, resulting in low turnover rates. Utility Model Content

[0004] The purpose of the utility model is to overcome the defects of the prior art and provide a temporary cross-bracing structure that can be used for tunnel step excavation. By setting multiple support rods in the tunnel and setting fixed rods between two adjacent support rods, it is ensured that the support rods set in the tunnel have a certain stability and strength, and the support rods are not easily deformed when dismantled.

[0005] The technical solution to achieve the above object is a temporary cross-bracing structure for excavation of a revolving tunnel step method, which is arranged in the tunnel, and the cross-bracing structure includes:

[0006] A plurality of support rods are horizontally arranged in the tunnel, wherein the plurality of support rods are spaced apart along the direction of the tunnel, and two ends of the support rods are supported on two opposite sides of the tunnel; and

[0007] A plurality of fixing rods are arranged at intervals between the two upper and lower support rods.

[0008] Furthermore, a supporting plate is fixedly installed on the end of the support rod.

[0009] Furthermore, the support plate is fixed to the support rod by welding.

[0010] Furthermore, threaded holes are formed on the support plate, and bolts are passed through the threaded holes to fix the support plate to the tunnel.

[0011] Furthermore, a connecting steel plate is fixedly installed on the end of the fixing rod.

[0012] Furthermore, the connecting steel plate is fixed to the end of the fixing rod by welding.

[0013] Furthermore, the connecting steel plate is fixed to the support rod by welding.

[0014] Furthermore, support steel frames are provided on opposite sides of the tunnel, and the support rods are connected between the two oppositely provided support steel frames.

[0015] Furthermore, the length of the support rod is adapted to the width of the tunnel.

[0016] Furthermore, the length of the fixing rod is determined according to construction requirements.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] By setting up multiple support rods in the tunnel and setting fixing rods between two adjacent support rods, it is ensured that the support rods set up in the tunnel have a certain stability and strength, and the support rods are not easily deformed when being dismantled. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an overall structural diagram of a temporary cross bracing structure for excavating a revolving tunnel using the step method according to the present invention.

[0020] Figure 2 This is a front view of a temporary cross bracing structure for excavating a revolving tunnel using the step method, in which support rods are fixed to a supporting steel frame.

[0021] Figure 3 The utility model is a top view of a temporary cross bracing structure for excavating a revolving tunnel using the step method, in which support rods are fixed to a supporting steel frame.

[0022] Legend: 1. Support rod; 11. Support plate; 12. Bolt; 2. Fixing rod; 21. Connecting steel plate; 3. Support steel frame. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] See Figure 1 A temporary cross-bracing structure for revolving tunnel step excavation is set in the tunnel. The cross-bracing structure includes: support rods 1 and fixed rods 2. Several support rods 1 are horizontally arranged in the tunnel, and several support rods 1 are arranged at intervals along the direction of the tunnel. The two ends of the support rods 1 are supported on two opposite sides of the tunnel; and several fixed rods 2 are arranged at intervals between two support rods 1 arranged above and below.

[0025] In the present invention, a preferred embodiment is as follows: the top part of the tunnel is excavated by weak blasting, and after each part of the position is excavated downward, steel frames are set on both sides of the tunnel, and the tunnel face is sprayed with 10 cm thick concrete for sealing; after the construction of the upper step of the tunnel is completed, a support rod 1 is set between the two opposite steel frames of the upper step. Preferably, there are two support rods 1, and the fixing rod 2 is set at intervals between the two support rods 1, and a system anchor rod is driven on the inner wall of the tunnel; the middle step of the tunnel is continued to be excavated by weak blasting. At the same time, after each downward excavation, steel frames are set up on both sides of the tunnel, and the peripheral part of the tunnel pilot pit is sprayed with 4cm thick concrete to seal it and a steel mesh is set up. After the construction of the middle step is completed, a support rod 1 is set up between the two opposite steel frames of the middle step; continue to excavate the lower step of the tunnel with weak blasting, and initially spray 4cm thick concrete on the surrounding area and the bottom of the tunnel, set up a steel frame (steel mesh), and set up a locking foot anchor pipe, spray concrete to the designed thickness, and set up a system anchor rod. After the construction of the lower step is completed, a support rod 1 is set up between the two opposite steel frames of the lower step.

[0026] Furthermore, the support rod 1 is made of I-18 steel.

[0027] Furthermore, the length of the fixing rod 2 is adapted to the height of each step during tunnel construction.

[0028] Furthermore, a support plate 11 is fixedly mounted on the end of the support rod 1. Preferably, the support plate 11 is made of steel, which increases the stress-bearing area between the support rod 1 and the inner wall of the tunnel to avoid stress concentration that may deteriorate the stability of the tunnel structure.

[0029] See Figure 2 and Figure 3 Furthermore, the support plate 11 is fixed to the support rod 1 by welding. Preferably, the support plate 11 is fixed to the support rod 1 by welding to ensure a stable connection between the support plate 11 and the support rod 1.

[0030] Furthermore, a threaded hole is formed on the support plate 11, and a bolt 12 is passed through the threaded hole to fix it to the tunnel. By using the bolt 12 to fix the support plate 11 to the tunnel, the support plate 11 can be detachably arranged in the tunnel, thereby ensuring that the support rod 1 can be used rotatably.

[0031] Furthermore, a connecting steel plate 21 is fixedly mounted on the end of the fixing rod 2. Preferably, the connecting steel plate 21 is used to increase the force bearing area of the fixing rod 2 and the support rod 1 to avoid stress concentration that may cause the structural stability of the tunnel to deteriorate.

[0032] Furthermore, the connecting steel plate 21 is fixed to the end of the fixing rod 2 by welding. Preferably, the connecting steel plate 21 is fixed to the fixing rod 2 by welding, so that the connecting steel plate 21 and the fixing rod 2 are stably connected.

[0033] Furthermore, the connecting steel plate 21 is fixed to the support rod 1 by welding. Preferably, the connecting steel plate 21 is fixed to the support rod 1 by welding, so that the connecting steel plate 21 and the support rod 1 are stably connected.

[0034] Furthermore, support steel frames 3 are provided on opposite sides of the tunnel, and the support rods 1 are connected between the two opposing support steel frames 3. Preferably, during construction of the tunnel, in order to ensure the stability of the tunnel walls and the tunnel face, steel frames or steel mesh are sandwiched around the tunnel pilot pit. The steel frames ensure that the tunnel is not easily collapsed and increase the stability of the tunnel's inner surface.

[0035] Furthermore, the length of the support rod 1 is adapted to the width of the tunnel.

[0036] Furthermore, the length of the fixing rod 2 is determined according to construction requirements.

[0037] The following describes the use of a temporary cross bracing structure for excavating a turnaround tunnel using the step method according to the present invention.

[0038] The top part of the tunnel is excavated in sections by weak blasting. At the same time, steel frames are set on both sides of the tunnel after each downward excavation, and the tunnel face is sprayed with 10 cm thick concrete for sealing; after the construction of the upper step of the tunnel is completed, a support rod 1 is set between the two opposite steel frames of the upper step. Preferably, two support rods 1 are provided, and the fixing rod 2 is arranged at intervals between the two support rods 1, and a system anchor rod is driven on the inner wall of the tunnel; the middle step of the tunnel is continued to be excavated by weak blasting. At the same time, steel frames are set on both sides of the tunnel after each downward excavation, and the peripheral part of the tunnel pilot pit is sprayed with 4 cm thick concrete for sealing and a steel mesh is set up. After the construction of the middle step is completed, a support rod 1 is set between the two opposite steel frames of the middle step; the lower step of the tunnel is continued to be excavated by weak blasting, and 4 cm thick concrete is initially sprayed around and at the bottom of the tunnel. A steel frame (steel mesh) is set up, and a locking anchor pipe is set up. Concrete is sprayed to the designed thickness, and a system anchor rod is driven. After the construction of the lower step is completed, a support rod 1 is set between the two opposite steel frames of the lower step.

[0039] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. A person skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention. The scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. A temporary cross bracing structure for excavation of a revolving tunnel using the step method, arranged in a tunnel, characterized by: The cross bracing structure comprises: A plurality of support rods are horizontally arranged in the tunnel, wherein the plurality of support rods are spaced apart along the direction of the tunnel, and two ends of the support rods are supported on two opposite sides of the tunnel; and A plurality of fixing rods are arranged at intervals between the two upper and lower support rods.

2. The temporary cross bracing structure for tunnel step excavation according to claim 1 is characterized by: A supporting plate is fixedly installed on the end of the supporting rod.

3. The temporary cross bracing structure for tunnel step excavation according to claim 2 is characterized by: The supporting plate is fixed to the supporting rod by welding.

4. The temporary cross bracing structure for tunnel step excavation according to claim 2 is characterized by: The supporting plate is formed with threaded holes, and is fixed to the tunnel by passing bolts through the threaded holes.

5. The temporary cross bracing structure for tunnel step excavation according to claim 1 is characterized by: A connecting steel plate is fixedly installed on the end of the fixing rod.

6. The temporary cross bracing structure for tunnel step excavation according to claim 5 is characterized by: The connecting steel plate is fixed to the end of the fixing rod by welding.

7. The temporary cross bracing structure for tunnel step excavation according to claim 5 is characterized by: The connecting steel plate is fixed to the supporting rod by welding.

8. The temporary cross bracing structure for tunnel step excavation according to claim 1 is characterized by: Support steel frames are arranged on opposite sides of the tunnel, and the support rods are connected between the two oppositely arranged support steel frames.

9. The temporary cross bracing structure for tunnel step excavation according to claim 1 is characterized by: The length of the support rod is adapted to the width of the tunnel.

10. The temporary cross bracing structure for tunnel step excavation according to claim 1, characterized in that: The length of the fixing rod is determined according to construction requirements.

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