Steel arch for tunnel excavation

Abstract

The utility model discloses a steel arch for tunnel excavation, which relates to the technical field of steel arches and comprises arches connected through longitudinal connecting steel bars. The feet-lock anchor pipe is inserted into the tunnel wall; the U-shaped connecting rib is obliquely arranged on the arch frame in a sleeving manner and is respectively welded with the feet-lock anchor pipe and the arch frame; the reinforcing mesh is arranged above the arch frame and is connected with the tunnel wall through the fixing anchor rods; according to the steel arch frame, the arch frame of a splicing structure is arranged, the arch frame is fixed in the tunnel wall through the feet-lock anchor pipes and the U-shaped connecting ribs, meanwhile, the arch frame is arranged above the arch frame and fixed to the tunnel wall through the fixing anchor rods, the steel arch frame is installed, the strength of the steel arch frame is high, and the steel arch frame is simple in structure and convenient to install and construct. And effective supporting can be carried out in the tunnel excavation process, the problem of tunnel excavation collapse is reduced, and the operation safety is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of plastic box technology, specifically to a steel arch frame for tunnel excavation. Background Technology

[0002] A steel frame is a support skeleton structure made of steel profiles and steel grids, which is laid out according to the tunnel excavation outline in the initial support of tunnel excavation to keep the surrounding rock stable.

[0003] Currently, steel arch structures used for tunnel excavation are quite complex, and their installation and construction are difficult. For example, the publicly available number is...

[0004] A steel arch frame for tunnel support, as disclosed in CN223004042U, includes a curved steel frame and vertical steel frames. Two vertical steel frames are provided, and two moving devices are provided at the lower ends of each of the two vertical steel frames. An auxiliary device is provided between the two vertical steel frames. First connecting seats are provided at the front and rear ends of each of the two vertical steel frames. Telescopic support rods are movably mounted inside each of the four first connecting seats via movable pins. Fixed seats are movably mounted at the lower ends of each of the four telescopic support rods via movable pins. Fixed bolts are threaded into the front and rear ends of the upper ends of each of the four fixed seats.

[0005] The steel arch frame structure used for tunnel support mentioned above is relatively complex, making it difficult to install and resulting in low installation and construction efficiency. Therefore, this application proposes a steel arch frame for tunnel excavation with a simple structure. Utility Model Content

[0006] The purpose of this utility model is to address the shortcomings of the above-mentioned technologies by proposing a steel arch frame for tunnel excavation, aiming to solve the problems of the complex structure and difficult installation and construction of the above-mentioned steel arch frame.

[0007] This utility model provides a steel arch frame for tunnel excavation, comprising:

[0008] The arch frame is connected by longitudinal reinforcing bars.

[0009] Anchor pipes are inserted into the tunnel wall;

[0010] U-shaped connecting bars are obliquely fitted onto the arch frame and welded to the locking foot anchor pipe and the arch frame respectively;

[0011] The steel mesh is placed above the arch frame and is connected to the tunnel wall by fixed anchor bolts.

[0012] Preferably, the arch frame includes an upper arch frame and a lower arch frame. Connecting plates are welded to both ends of the upper arch frame and the upper end of the lower arch frame. The upper arch frames are connected to each other, and the upper and lower arch frames are connected by connecting plates. The upper and lower arch frames are I-shaped steel.

[0013] Preferably, the connecting plates are provided with through holes, and the connecting plates are connected by bolts.

[0014] Preferably, the longitudinal connecting steel bars are spaced 1m apart along the circumferential direction of the arch frame.

[0015] Preferably, it also includes a steel plate support, connected to the end of the lower arch frame.

[0016] Preferably, the resultant force direction of the anchor pipe is at an angle of 15 to 30° to the axis of the steel arch frame.

[0017] Compared with existing technologies, it has the following beneficial effects:

[0018] This utility model uses a spliced ​​arch frame, which is fixed to the tunnel wall by anchor pipes and U-shaped connecting bars. Simultaneously, it is fixed to the tunnel wall by anchor rods located above the arch frame. This allows for the installation of the steel arch frame, which has high strength. The steel arch frame structure of this utility model is simple, easy to install and construct, and can effectively support tunnel excavation, reducing the risk of tunnel collapse and significantly improving operational safety. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a steel arch frame for tunnel excavation according to the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a steel arch frame for tunnel excavation according to the present invention;

[0022] Figure 3 This is a schematic diagram of the arch frame structure of this utility model;

[0023] Figure 4 for Figure 3 Enlarged schematic diagram of part A in the middle.

[0024] In the diagram, 1-arch frame; 11-upper arch frame; 12-lower arch frame; 13-connecting plate; 2-anchor pipe; 3-U-shaped connecting bar; 4-steel mesh; 5-longitudinal connecting bar; 6-steel plate support. Detailed Implementation

[0025] To better understand the structure, functional features, and advantages of this utility model, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings:

[0026] Example:

[0027] like Figures 1 to 4 As shown, this utility model provides a steel arch frame 1 for tunnel excavation, comprising:

[0028] Arch frame 1, which is connected by longitudinal connecting steel bars 5;

[0029] Anchor pipe 2 is inserted into the tunnel wall;

[0030] U-shaped connecting ribs 3 are obliquely sleeved on the arch frame 1 and welded to the locking foot anchor pipe 2 and the arch frame 1 respectively;

[0031] Reinforcing mesh 4, located above arch frame 1, is connected to the tunnel wall via fixed anchor bolts. A8 steel bars are used for the reinforcing mesh 4 support, with a spacing of 15cm. Adding reinforcing mesh 4 to the shotcrete prevents the sprayed surface from collapsing due to the spraying force, reduces rebound and cracking of the shotcrete layer, and enhances the overall effect of the initial support. It is usually welded to the fixed anchor bolts or arch frame 1 as a whole. Reinforcing mesh 4 is laid after the initial shotcrete application, forming a unified structure with the shotcrete. The protective layer thickness of reinforcing mesh 4 is greater than 2cm.

[0032] Furthermore, during the construction of the steel arch frame 1, two 4m long, 50mm diameter seamless steel pipes are installed at each of the upper and lower arch frames 12. After the anchor pipes 2 are arranged, grouting is required, and the grout should fill the anchor pipes 2 and the surrounding gaps.

[0033] See Figure 4 The arch frame 1 includes an upper arch frame 11 and a lower arch frame 12. Connecting plates 13 are welded to both ends of the upper arch frame 11 and the upper end of the lower arch frame 12. The upper arch frames 11 are connected to each other, and the upper arch frames 11 and lower arch frames 12 are connected by the connecting plates 13. When the arch foot excavation is too deep, steel plates or concrete pads are added, and after installation, anchor pipes 2 are used for positioning. When the over-excavation is significant, the arch back is sprayed with the same grade of concrete to ensure close contact between the support and the surrounding rock, controlling further deformation of the surrounding rock. The two rows of arch frames 1 are firmly connected by longitudinal connecting steel bars 5 to form an integral load-bearing structure. During the installation of the arch frame 1, a 20cm settlement allowance is reserved to prevent intrusion into the lining clearance. The gap between the arch frame 1 and the surrounding rock must be filled tightly with sprayed concrete, and the inclination is controlled within ±2°.

[0034] See Figure 4 The connecting plate 13 has through holes, and the connecting plates 13 are connected by bolts.

[0035] See Figure 3 The longitudinal connecting steel bars 5 are spaced 1m apart along the circumferential direction of the arch frame 1. The steel frames are connected longitudinally with threaded steel bars of 25mm diameter and spaced 1m apart in the circumferential direction to enhance the overall stability of the steel arch frame 1.

[0036] See Figure 2 The upper arch frame 11 and the lower arch frame 12 are I-shaped steel.

[0037] See Figure 1 It also includes steel plate supports 6, which are connected to the ends of the lower arch frame 12. Specifically, the over-excavated part at the foot of the arch frame 1 is filled with C20 concrete or steel plate supports 6, and shotcrete of the same grade. Each arch frame 1 is connected into a whole by C25 longitudinal connecting steel bars 5 with a spacing of no more than 1m to enhance the overall support capacity of the steel arch frame 1.

[0038] The above description is merely a preferred embodiment of this utility model and does not constitute any limitation on this utility model. Any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this utility model. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technology of this utility model without departing from the scope of the technical solution of this utility model shall fall within the protection scope of this technical solution.

Claims

1. A steel arch (1) for tunnel excavation, characterized in that, include: The arch frame (1) is connected by longitudinal connecting steel bars (5); Anchor pipe (2) is inserted into the tunnel wall; U-shaped connecting ribs (3) are obliquely sleeved on the arch frame (1) and welded to the locking foot anchor pipe (2) and the arch frame (1) respectively; A steel mesh (4) is placed above the arch frame (1) and is connected to the tunnel wall by a fixed anchor rod.

2. Steel arch (1) for tunnel excavation according to claim 1, characterized in that The arch frame (1) includes an upper arch frame (11) and a lower arch frame (12). Connecting plates (13) are welded to both ends of the upper arch frame (11) and the upper end of the lower arch frame (12). The upper arch frames (11) are connected to each other, and the upper arch frames (11) and the lower arch frames (12) are connected by the connecting plates (13).

3. A steel arch (1) for tunnel excavation according to claim 2, characterized in that, The connecting plate (13) is provided with through holes, and the connecting plates (13) are connected to each other by bolts.

4. The steel arch (1) for tunnel excavation according to claim 1, characterized in that, The longitudinal connecting steel bars (5) are spaced 1m apart along the circumferential direction of the arch frame (1).

5. The steel arch (1) for tunnel excavation according to claim 2, characterized in that, The upper arch frame (11) and the lower arch frame (12) are I-shaped steel.

6. The steel arch (1) for tunnel excavation according to claim 2, characterized in that, It also includes a steel plate support (6) connected to the end of the lower arch frame (12).

7. A steel arch (1) for tunnel excavation according to claim 1, characterized in that, The resultant force direction of the anchor pipe (2) forms an angle of 15 to 30° with the axis of the steel arch frame (1).

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