CN210104528U - A lightweight steel grid-UHPC composite bridge structure - Google Patents

Abstract

The utility model discloses a light steel net rack-UHPC combined bridge structure, which comprises a UHPC panel, a uniform distribution type welded short steel bar combined node and a light space steel net rack, wherein the UHPC panel and the light space steel net rack are connected into a whole through the uniform distribution type welded short steel bar combined node, the UHPC panel is formed by splicing prefabricated UHPC panels, the splicing surface of the prefabricated UHPC panel is provided with a perforated steel plate, cast-in-situ UHPC concrete is filled in a transverse seam after the prefabricated UHPC panel is spliced, the uniform distribution type welded short steel bar combined node is composed of a hollow hemisphere and a short steel bar welded on the top surface of the hollow hemisphere, the short steel bar passes through the perforated steel plate and extends into the cast-in-situ UHPC concrete, the light space steel net rack is composed of a belly pipe, a transverse connection pipe and a lower chord pipe, the utility model has the advantages of high prefabrication degree, the structure has the advantages of light dead weight, strong durability and the like, and can be widely applied to medium-span highway bridges.

Description

A lightweight steel grid-UHPC composite bridge structure

technical field

The utility model relates to a combined bridge structure, in particular to a light steel grid-UHPC combined bridge structure, which belongs to the technical field of bridge engineering.

Background technique

The steel grid-concrete composite bridge structure is a bridge structure in which a light-weight space steel grid is used to support the concrete panels, and the space steel grid and the concrete panels are connected as a whole through shear connectors, which are jointly stressed. As the upper chord, the concrete slab is subjected to the dual effects of axial force and bending moment, and there is a serious shear lag phenomenon, especially at the point-contact composite node position, the negative shear lag phenomenon is particularly serious. As a result, a large tensile stress occurs in the concrete panel near the node, which is easy to cause cracking of the concrete panel, thereby affecting the service performance and safety performance of the structure.

Given that ultra-high-performance cement-based material (UHPC) is a high-strength, high-toughness, low-porosity ultra-high-strength cement-based material, its mechanical properties are excellent, especially with high tensile strength, which can be effectively avoided or reduced. The problem of concrete cracking in tension, and the weight of the structure can be reduced. Therefore, it is reasonable to use prefabricated UHPC panels to replace traditional concrete panels. However, how to effectively connect the prefabricated UHPC panel with the steel grid is a technical problem that needs to be solved.

Utility model content

In order to solve the above problems, the utility model provides a light steel grid-UHPC composite bridge structure with a simple and light structure, clear mechanical properties, and a high degree of industrialized manufacturing. As the upper chord of the steel mesh frame, the prefabricated UHPC panel is connected to the steel mesh frame through uniformly distributed composite nodes composed of welded short steel bars.

For achieving the above object, the technical scheme of the present utility model is as follows:

A light steel grid frame-UHPC composite bridge structure includes UHPC panels, uniform welded short steel bar composite nodes and light space steel grid frames from top to bottom. The UHPC panels and the light space steel grid frames pass through the The joints of short welded steel bars are connected into a whole. The UHPC panel is spliced by prefabricated UHPC panels. The splicing surface of the prefabricated UHPC panel is provided with a perforated steel plate. One end of the perforated steel plate extends into the prefabricated UHPC panel. In the transverse joint after the UHPC panels are spliced, the evenly distributed welded short steel bar composite joint is composed of a hollow hemisphere and short steel bars welded on the top surface of the hollow hemisphere. The light-duty space steel grid frame is composed of three parts: the web tube, the lateral connection tube and the lower chord tube, which are formed by cast steel nodes to form a whole. The core concrete is filled in the inner part of the lower chord tube. ordinary concrete.

The hollow hemisphere is formed by welding a small hemispherical notch and a horizontal cover plate, and the width of the horizontal cover plate is consistent with the transverse width of the bridge.

The grid arrangement of the light space steel grid is one of a quadrangular pyramid type, a cross truss type and a triangular pyramid type.

The perforated steel plate is provided with circular perforations both in the part located in the prefabricated UHPC panel and in the part in the cast-in-place UHPC concrete.

The perforated steel plate is provided with circular openings in the part located in the prefabricated UHPC panel and the part in the cast-in-place UHPC concrete, and the gap w between adjacent perforated steel plates is not less than 3cm.

The utility model includes the following beneficial effects:

1. The UHPC panel is used as the upper chord of the steel grid in this utility model, and the high tensile strength of the UHPC material is fully utilized to avoid or reduce the cracking problem of the panel in the node area, improve the durability of the structure, and can be widely used in medium-span highway bridges.

2. The use of cast-in-place UHPC concrete for the transverse joints of prefabricated UHPC panels in the present invention can effectively enhance the strength of the connecting section, and the UHPC material is dense and has self-leveling pouring performance, avoiding the problem of vibration at the joints.

3. The perforated steel plate in the utility model is pre-embedded in the prefabricated UHPC panel to facilitate the hoisting and transportation in the actual project.

4. The horizontal cover plate with the same transverse width as the bridge in the present invention can provide better supporting effect for the prefabricated UHPC panel, and provide the bottom formwork for the concrete pouring at the transverse joint.

5. The hollow hemisphere of the uniformly distributed welded short steel bar composite node in the present invention can adapt to the abdominal tubes from various directions.

Description of drawings

The following drawings are only intended to illustrate and explain the present invention schematically, and do not limit the scope of the present invention.

Figure 1 is an overall schematic diagram of a lightweight steel grid-UHPC composite bridge structure.

Figure 2 is a schematic cross-sectional view of the bridge along the longitudinal direction of the bridge.

Figure 3 is a schematic cross-sectional view of the bridge along the lateral direction of the bridge.

Figure 4 is a schematic cross-sectional view of the bridge along the horizontal plane.

Figure 5 is a schematic diagram of the construction of a prefabricated UHPC panel.

Figure 6 is a schematic diagram of the structure of the transverse seam when prefabricated UHPC panels are spliced.

Figure 7 is a schematic diagram of the structure of the uniformly distributed welded short steel bar composite node.

Figure 8 is a front view of a light steel grid using a cross truss type.

Figure 9 is a side view of the light steel grid using the cross truss type.

Figure 10 is a front view of a light steel grid using a quadrangular pyramid.

Figure 11 is a side view of a light steel grid using a quadrangular pyramid.

Figure 12 is the front view of the light steel grid using the triangular cone type.

Figure 13 is a side view of the light steel grid using the triangular cone type.

Detailed ways:

The specific embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

As shown in Figures 1 to 13, a lightweight steel grid-UHPC composite bridge structure includes UHPC panels 1, uniformly welded short steel bar composite nodes 2 and light space steel grids 3. The three parts are shared from top to bottom. The composition is characterized in that the UHPC panel 1 and the light space steel grid 3 are connected into a whole by the uniformly welded short steel bar combination nodes 2, the UHPC panel 1 is spliced by the prefabricated UHPC panel 11, and the splicing surface of the prefabricated UHPC panel 11 is provided with The perforated steel plate 111, one end of the perforated steel plate 111 protrudes into the prefabricated UHPC panel 11, the cast-in-place UHPC concrete 112 is filled in the transverse joint 113 after the prefabricated UHPC panel 11 is spliced, and the uniformly welded short steel bar composite node 2 consists of a hollow hemisphere. The body 21 and the short steel bar 22 welded on the top surface of the hollow hemisphere 21 are formed. The short steel bar 22 extends through the perforated steel plate 111 into the cast-in-place UHPC concrete 112. It consists of three parts and the lower chord 33 , and the core concrete 331 is filled in the interior of the lower chord 33 .

The hollow hemisphere 21 is formed by welding a small hemispherical notch 211 and a horizontal cover plate 212; so that the hollow hemisphere 21 can adapt to the webs 31 from all directions, and the width of the horizontal cover plate 212 is the same as that of the bridge. The horizontal width is the same, which can provide better support for the prefabricated UHPC panels, and provide bottom formwork for the concrete pouring at the lateral joints; One of the triangular cone type; the web tube 31, the lateral connection tube 32 and the lower chord tube 33 are formed by cast steel nodes to form a whole, which overcomes the adverse effects of the stress caused by a large number of concentrated welding on the structure; the openings The steel plate 111 is provided with circular openings 114 in both the part located in the prefabricated UHPC panel 11 and the part in the cast-in-place UHPC concrete 112 , which not only ensures the formation of concrete tenons at the transverse joint 113 , but also enables the prefabricated UHPC panel 11 The concrete tenon is formed to enhance the reliability of the connection between the steel plate and the concrete; the gap w between the adjacent perforated steel plates 111 is not less than 3cm, so that the cast-in-place UHPC concrete 112 can penetrate into the bottom of the transverse joint 113; the core concrete 331 adopts a strength of C40 Ordinary concrete of ~C60.

In the specific implementation, the uniformly distributed welded short steel bar combination node 2 and the light space steel grid frame 3 are pre-processed in the factory, wherein the light space steel grid frame 3 is formed as a whole by using cast steel nodes, and the core concrete 331 is poured into the lower chord 33. Then, the uniformly distributed welded short steel bar combination node 2 and the light space steel grid 3 are welded together and hoisted to the construction site. The welded overall structure can be erected on a specific pier by the jacking construction method. The prefabricated UHPC panel 11 is processed by the factory and transported to the construction site for assembly. During the assembly process, the short steel bars 22 of the uniformly welded short steel bar combination node 2 pass through the prefabricated UHPC panel 11. and ensure that the gap w between adjacent perforated steel plates 111 is not less than 3cm, so as to reserve space for concrete pouring at the joint, set pouring templates on both sides of the transverse joint 113, and pour UHPC concrete on site In order to fill the interior of the transverse seam 113, the lightweight space steel grid 3 and the prefabricated UHPC panel 11 are integrally connected.

Claims (8)

1. A light steel net rack-UHPC combined bridge structure comprises a UHPC panel (1), uniformly distributed welded short steel bar combined nodes (2) and a light space steel net rack (3) which are jointly formed from top to bottom, and is characterized in that the UHPC panel (1) and the light space steel net rack (3) are connected into a whole through the uniformly distributed welded short steel bar combined nodes (2), the UHPC panel (1) is formed by splicing prefabricated UHPC panels (11), the splicing surface of the prefabricated UHPC panel (11) is provided with perforated steel plates (111), one end of each perforated steel plate (111) extends into the prefabricated UHPC panel (11), cast-in-place UHPC concrete (112) is filled in transverse joints (113) formed after the prefabricated UHPC panels (11) are spliced, the uniformly distributed welded short steel bar combined nodes (2) are formed by hollow hemispheroids (21) and short steel bars (22) welded on the top surfaces of the hollow hemispheroids (21), and the short steel bars (22) extend into the cast-in-place UHPC concrete (112) through the perforated steel plates (111), the light space steel net rack (3) is composed of three parts, namely a belly pipe (31), a transverse connection pipe (32) and a lower chord pipe (33), and core concrete (331) is filled in the lower chord pipe (33).

2. The light steel net rack-UHPC combined bridge structure as claimed in claim 1, wherein the hollow hemispheroid (21) is formed by welding a small hemispheroid segment (211) and a horizontal cover plate (212).

3. The light steel grid structure-UHPC combined bridge structure of claim 2, characterized in that the width of the horizontal cover plate (212) is consistent with the transverse width of the bridge.

4. The light steel net rack-UHPC combined bridge structure of claim 1, characterized in that the net rack arrangement mode of the light space steel net rack (3) is one of a quadrangular pyramid type, a crossed truss type and a triangular pyramid type.

5. The light steel net rack-UHPC combined bridge structure of claim 1, wherein the web pipes (31), the transverse connecting pipes (32) and the lower chord pipes (33) are integrated by cast steel joints.

6. The light steel grid-UHPC combined bridge structure of claim 1, wherein the perforated steel plate (111) is provided with round openings (114) at the part positioned in the prefabricated UHPC panel (11) and the part positioned in the cast-in-place UHPC concrete (112).

7. The light steel grid-UHPC combined bridge structure of claim 1, wherein the clearance w between adjacent perforated steel plates (111) is not less than 3 cm.

8. The light steel grid-UHPC combined bridge structure of claim 1, wherein the core concrete (331) is common concrete with the strength of C40-C60.

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