CN219605296U

CN219605296U - Construction structure suitable for steel construction skeleton preliminary bracing of large-section tunnel

Info

Publication number: CN219605296U
Application number: CN202320101626.6U
Authority: CN
Inventors: 马磊; 付航; 梅江涛; 刘丹
Original assignee: Third Construction Co Ltd of China Construction Eighth Engineering Divison Co Ltd
Current assignee: Third Construction Co Ltd of China Construction Eighth Engineering Divison Co Ltd
Priority date: 2023-02-02
Filing date: 2023-02-02
Publication date: 2023-08-29
Anticipated expiration: 2033-02-02

Abstract

The utility model discloses a construction structure of a steel structure framework primary support suitable for a large-section tunnel, and belongs to the technical field of tunnel construction; the construction structure has the advantages of high construction speed, low construction cost, safety and reliability; the construction structure can effectively solve the defects that primary support cannot be applied to a large-section tunnel and is time-consuming and labor-consuming in the prior art; the construction structure is suitable for primary support of a large-section tunnel and has good popularization and application values.

Description

Construction structure suitable for steel construction skeleton preliminary bracing of large-section tunnel

Technical Field

The utility model belongs to the technical field of tunnel construction, and particularly relates to a construction structure of a steel structure framework primary support suitable for a large-section tunnel.

Background

At present, in order to prevent soil collapse at the upper part and left and right parts after tunnel excavation, the outline surface of the excavation needs to be supported and protected in time. In a general supporting form, a framework with certain strength and rigidity is precisely attached to an outline surface of excavation, then a reinforcing mesh is hung in a gap between the framework and the framework, and then dry and hard concrete is sprayed, so that the collapse of soil around a tunnel is effectively prevented. In the prior art, a commonly used framework is formed by welding large-diameter steel bars exceeding 22mm, and then the framework is erected on an excavated profile surface in a segmented mode, but the method is complex in processing technology, multiple in working procedures, time-consuming and labor-consuming to manufacture and install, and cannot be suitable for large-section tunnels exceeding 10m in width, and the application range is limited. Therefore, development of a steel structure skeleton construction structure suitable for a large-section tunnel is required.

Disclosure of Invention

The utility model aims to: aiming at the defects of the prior art, the utility model provides a construction structure suitable for the primary support of a steel structure skeleton of a large-section tunnel, which has the advantages of high construction speed, low manufacturing cost, safety and reliability; the construction structure can effectively solve the defects that primary support cannot be applied to a large-section tunnel and is time-consuming and labor-consuming in the prior art; the construction structure is suitable for primary support of a large-section tunnel and has good popularization and application values.

The technical scheme is as follows: the utility model relates to a construction structure suitable for primary support of a steel structure skeleton of a large-section tunnel, which comprises a section steel arch;

the section steel arch comprises a side wall section steel arch and a vault section steel arch; the bottom of the side wall section steel arch frame is in girth welding connection with a connecting steel plate, and two ends of the arch roof section steel arch frame are respectively connected with the connecting steel plate in girth welding; and two ends of the arch-top section steel arch are respectively connected with the side wall section steel arch on two sides of the tunnel through connecting steel plates by bolts.

Preferably, the side wall section steel arch bottom is supported on hard rock.

Preferably, a pin locking anchor pipe is arranged on the section steel arch near the connecting steel plate, and the pin locking anchor pipe is welded with the section steel arch.

Preferably, the diameter of the foot locking anchor pipe is not less than 35mm, the length of the foot locking anchor pipe is not less than 2500mm, and the pipe body of the foot locking anchor pipe is provided with quincuncial small holes.

Preferably, each two profile steel arches are welded and connected by adopting connecting steel bars, so that the profile steel arches are longitudinally connected into a whole.

Preferably, the diameter of the connecting steel bar is not less than 25mm.

Preferably, the steel reinforcement mesh is fully hung on the section steel arch, a primary spraying concrete layer is sprayed on the outer side of the steel reinforcement mesh, and a secondary lining concrete layer is poured on the outer side of the primary spraying concrete layer.

Preferably, the reinforcing mesh is arranged in a double-layer bidirectional manner with the diameter of not less than 8 mm.

Preferably, the thickness of the primary sprayed concrete layer is not less than 220mm.

The beneficial effects are that: (1) The construction speed of the construction structure suitable for the primary support of the steel structure skeleton of the large-section tunnel is high, and the construction work can be improved by 20% through calculation; the construction structure has the advantages of low cost, safety and reliability; the construction structure can effectively solve the defects that primary support cannot be applied to a large-section tunnel and is time-consuming and labor-consuming in the prior art; the construction structure is suitable for primary support of a large-section tunnel and has good popularization and application values.

Drawings

Fig. 1 is an elevation view of a construction structure of an initial support of a steel structure skeleton suitable for a large-section tunnel.

FIG. 2 is a longitudinal joint plan view (section I-I) of a steel structure skeleton.

Fig. 3 is an enlarged view of node a and node B.

Reference numerals:

1-section steel arch centering; 2-joining the steel plates; 3-bolts; 4-connecting the reinforcing steel bars; 5-welding seams; 6-locking the pin anchor tube; 7-primary spraying a concrete layer; 8-secondary lining concrete layer.

Detailed Description

The technical scheme of the utility model is described in detail below through the drawings, but the protection scope of the utility model is not limited to the embodiments.

Example 1:

as shown in fig. 1-3, the construction structure suitable for the primary support of the steel structure skeleton of the large-section tunnel comprises a section steel arch 1; the section steel arch 1 comprises a side wall section steel arch and a vault section steel arch; the bottom of the side wall section steel arch is connected with the connecting steel plate 2 in a girth welding mode, and the bottom of the side wall section steel arch is supported on hard rocks. The two ends of the arch-shaped steel arch are respectively welded with a connecting steel plate 2 in a surrounding manner; the arch-top steel arch is respectively connected with side wall steel arch bolts 3 at two sides of the tunnel through connecting steel plates 2 at two ends.

As shown in fig. 1 to 3, a pin locking anchor pipe 6 is inserted into the section steel arch 1 near the connecting steel plate 2, and the pin locking anchor pipe 6 is welded with the section steel arch 1. The diameter of the foot locking anchor pipe 6 is not less than 35mm, the length of the foot locking anchor pipe 6 is not less than 2500mm, and the whole pipe body of the foot locking anchor pipe 6 is provided with quincuncial small holes.

As shown in fig. 1-3, each two profile steel arches 1 are welded and connected by adopting a connecting steel bar 4, so that the profile steel arches 1 are longitudinally connected into a whole; the diameter of the connecting steel bar 4 is not less than 25mm. The steel reinforcement meshes are fully hung on the section steel arch 1, and the steel reinforcement meshes are arranged in a double-layer bidirectional manner with the diameter of not less than 8 mm. The outside of the reinforcing mesh is sprayed with a primary spraying concrete layer 7 with the thickness not less than 220mm, and a secondary lining concrete layer 8 is poured outside the primary spraying concrete layer 7.

In a specific implementation process, the construction steps of the steel structure framework primary support suitable for the large-section tunnel are as follows:

(1) And processing the section steel arch 1 according to the section of the tunnel in a sectioning way, wherein the section steel arch 1 comprises a side wall section steel arch and a vault section steel arch, and the section steel adopts I16b I-steel. The bottom of the side wall steel arch is girth welded with the connecting steel plates 2, the size of the connecting steel plates 2 is 250 x 20mm, the weld width is 8mm, and the bottom of the side wall steel arch is supported on hard rocks.

(2) And hoisting the arch-shaped steel arch frame by adopting small equipment, welding the two ends of the arch-shaped steel arch frame in a girth manner, connecting steel plates 2, and then connecting the arch-shaped steel arch frame with side wall shaped steel arch frames on two sides of a tunnel through the connecting steel plates 2 on the two ends of the arch-shaped steel arch frame by adopting M16 high-strength bolts 3 during connection.

(3) And a pin anchor pipe 6 is inserted near the connecting steel plate 2, namely near each connecting point of the side wall section steel arch and the vault section steel arch, and the pin anchor pipe 6 is welded and connected with the section steel arch 1. The diameter of the foot locking anchor pipe 6 is 35mm, the length of the foot locking anchor pipe 6 is 2500mm, and the whole pipe body of the foot locking anchor pipe 6 is provided with plum blossom-shaped small holes. Then, a cement slurry having a cement ratio of 0.6 was injected into the foot locking anchor pipe 6.

(4) The two adjacent steel arches 1 are welded by connecting steel bars 4 with the diameter of 25mm, and the steel arches 1 are longitudinally connected into a whole. After the section steel arch 1 is installed and connected, the section steel arch 1 is fully hung with the steel bar net sheets, and the steel bar net sheets are arranged in a double-layer bidirectional manner with the diameter of 8 mm. And then spraying 220mm thick dry and hard concrete to the outer side of the reinforcing mesh to obtain a primary sprayed concrete layer 7, and pouring a secondary lining concrete layer 8 on the outer side of the primary sprayed concrete layer 7.

As described above, although the present utility model has been shown and described with reference to certain preferred embodiments, it is not to be construed as limiting the utility model itself. Various changes in form and details may be made therein without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims

1. The construction structure suitable for the primary support of the steel structure skeleton of the large-section tunnel is characterized by comprising a section steel arch (1);

the profile steel arch (1) comprises a side wall profile steel arch and a vault profile steel arch; the bottom of the side wall section steel arch frame is connected with a connecting steel plate (2) in a girth welding manner, and two ends of the arch roof section steel arch frame are respectively connected with the connecting steel plate (2) in a girth welding manner;

and two ends of the arch-top steel arch are respectively connected with side wall steel arch bolts at two sides of the tunnel through connecting steel plates (2).

2. The construction structure for preliminary bracing of steel structure skeleton for large-section tunnel according to claim 1, wherein the side wall type steel arch bottom is supported on hard rock.

3. The construction structure for the primary support of the steel structure skeleton of the large-section tunnel according to claim 1, wherein a foot locking anchor pipe (6) is inserted on the section steel arch near the connecting steel plate (2), and the foot locking anchor pipe (6) is welded with the section steel arch (1).

4. The construction structure for the primary support of the steel structure skeleton applicable to the large-section tunnel according to claim 3, wherein the diameter of the foot locking anchor pipe (6) is not less than 35mm, the length of the foot locking anchor pipe is not less than 2500mm, and quincuncial small holes are formed in the whole body of the foot locking anchor pipe (6).

5. The construction structure for the primary support of the steel structure skeleton of the large-section tunnel according to claim 1, wherein the two steel arches (1) are welded by adopting connecting steel bars (4), so that the steel arches (1) are longitudinally connected into a whole.

6. The construction structure for preliminary bracing of steel structure skeleton applicable to large-section tunnel according to claim 5, wherein the diameter of the connecting steel bar (4) is not less than 25mm.

7. The construction structure for primary support of steel structure skeleton applicable to large-section tunnel according to claim 1, wherein the steel reinforcement net piece is hung fully by the steel reinforcement arch, a primary spraying concrete layer (7) is sprayed on the outer side of the steel reinforcement net piece, and a secondary lining concrete layer (8) is poured on the outer side of the primary spraying concrete layer (7).

8. The construction structure for primary support of steel structure skeleton of large-section tunnel of claim 7, wherein the steel bar net sheet is double-layer bidirectional arrangement with diameter not less than 8 mm.

9. The construction structure for preliminary supporting of steel structure skeleton of large-section tunnel according to claim 7, wherein the thickness of the preliminary spraying concrete layer (7) is not less than 220mm.