Double-layer steel truss bridge drag construction technology of continuous double-layer cast-in-situ box girder

Abstract

This invention provides a towing construction process for a double-layer steel truss bridge with sequentially connected double-layer cast-in-place box girders. The steps are as follows: construct the bridge's pile foundations and abutments, construct the piers, erect assembly supports, hoist the guide beam, and assemble the steel truss section; first, hoist the guide beam and the assembled steel truss section, then perform the first towing; after completion, hoist the remaining sections for subsequent towing construction; after the first towing is completed, construct the unaffected cast-in-place box girder section on the left; after the steel truss reaches the assembly supports above the fourth pier, the guide beam can be removed, and the unaffected cast-in-place box girder section on the right can be constructed; after the overall towing is completed, construct the upper piers, construct the auxiliary structures, and dismantle the assembly supports. This overcomes the limitations of existing technologies where the steel truss cannot be installed on the piers at the junction of the truss section and the cast-in-place box girder section. Furthermore, by constructing the cast-in-place box girder during the towing and assembly process, the construction period is significantly shortened, and traffic control time is reduced.

Description

Technical Field

[0001] This invention relates to double-layer steel truss bridges, specifically the drag-and-pull construction process for double-layer steel truss bridges with sequentially connected double-layer cast-in-place box girders. Background Technology

[0002] During the towing of a double-layer steel truss bridge, the piers of the substructure can obstruct its movement, a problem that current technology cannot solve. Towing presents two main challenges: First, the steel truss bridge needs to be assembled within the cast-in-place area, and the piers of the cast-in-place box girder will hinder its movement. Second, the need for assembly within the cast-in-place area impacts the construction of the cast-in-place box girder, often preventing the construction of the entire section of the cast-in-place structure, significantly affecting the project's progress. Summary of the Invention

[0003] The purpose of this invention is to provide a drag-and-pull construction process for a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder to solve the problems in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] The construction process of a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder.

[0006] The bridge comprises a steel truss section in the middle and cast-in-place box girder sections at both ends. Below the steel truss section, from left to right, are the first and second piers. Below the junction of the steel truss section and the cast-in-place box girder sections, from left to right, are the third and fourth piers.

[0007] Includes the following steps:

[0008] Construction of the bridge's pile foundations and abutments.

[0009] Construct the piers below the cast-in-place box girder section; construct the first pier and the second pier below the steel truss section;

[0010] The construction includes the third and fourth piers located below the junction of the steel truss section and the cast-in-place box girder section.

[0011] Erect the assembly support for the steel truss, hoist the guide beam, and assemble the steel truss section;

[0012] If the sum of the length of the guide beam and the length of the assembly range is greater than the distance between the first pier and the second pier, and the guide beam, after being pulled into place, only exceeds the distance of one span of the cast-in-place box girder of the fourth pier, the assembly bracket only occupies one section of the cast-in-place box girder within the assembly range, and can be completed by one pull; otherwise, first hoist the guide beam and the steel truss of the assembly part, and then perform the first pull; after completion, hoist the remaining section for subsequent pull construction; after the first pull is completed, construct the cast-in-place box girder section on the left side that is not affected;

[0013] After the steel truss reaches the assembly support above the fourth pier, the guide beam can be removed, and the cast-in-place box girder section on the right side, which is not affected, can be constructed.

[0014] After the overall towing is completed, construct the upper piers of the cast-in-place box girder section, the upper piers at the connection between the steel truss section and the cast-in-place box girder section, and the remaining cast-in-place box girder section;

[0015] Construction of auxiliary structures and dismantling of assembly supports.

[0016] Furthermore, the towing process involves first assembling the steel truss and guide beams, and then using a system composed of jacks and steel strands to tow the entire steel truss to the target point.

[0017] Furthermore, after the construction of the third and fourth piers is completed, the concrete surface is roughened and the reinforcing bars are treated with rust prevention.

[0018] Furthermore, the single-span cast-in-place box girder has 2-3 spans.

[0019] Furthermore, the third and fourth piers are constructed to the pad stone near the steel truss, with a height of H on the side near the cast-in-place box girder;

[0020] H = Elevation of the first pier column - Height of the steel truss frame - Height of the towing slider - Height of the towing track beam - 35 times the spacing of the vertical main reinforcement of the third pier column - 2cm.

[0021] The beneficial effect of this invention is that the construction process of this invention solves the problem of pier columns hindering the forward movement of steel trusses in conventional dragging construction processes.

[0022] The construction process of this invention combines in-situ assembly with conventional towing construction, minimizing the impact of towing on the cast-in-place area and enabling continuous construction of steel truss bridges and seamlessly connected cast-in-place box girders, which can significantly improve overall construction efficiency.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the initial construction of the present invention.

[0025] Figure 2 This is a schematic diagram of the construction steps of the present invention.

[0026] Figure label:

[0027] 1-First pier, 2-Second pier, 3-Third pier, 4-Fourth pier, 5-Steel truss, 6-Guide beam, 7-Assembly support, 8-Trail beam. Detailed Implementation

[0028] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate preferred embodiments of the application. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of this application more thorough and complete.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] It should be understood that although the terms first, second, third, etc., may be used to describe various components, these components should not be limited by these terms. These terms are only used to distinguish a component. Therefore, the components discussed below are those that do not depart from the teachings of this application.

[0031] Spatial relation terms such as “below,” “under,” “below,” “below,” “above,” “on the left,” “left side,” “on the right,” and “on the right side” are used herein for convenience of description to describe the relationship between one component or feature shown in the figure and other components or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of components in use and operation. For example, if a component in the figure is flipped, then a component or feature described as “below,” “under,” or “below” other components or features would be oriented “above” other components or features. Thus, the exemplary terms “below” and “under” can include both upper and lower orientations. “On the left” and “on the left” can include both left and right orientations.

[0032] The construction process of a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder is described.

[0033] The bridge comprises a central steel truss section (5) and cast-in-place box girder sections at both ends. Below the steel truss section (5), from left to right, are the first pier (1) and the second pier (2). Below the junction of the steel truss section (5) and the cast-in-place box girder sections, from left to right, are the third pier (3) and the fourth pier (4).

[0034] Includes the following steps:

[0035] Construction of the bridge's pile foundations and abutments.

[0036] Construct the piers below the cast-in-place box girder section; construct the first pier 1 and the second pier 2 below the steel truss 5 section;

[0037] The third pier 3 and the fourth pier 4 are constructed below the connection between the steel truss 5 section and the cast-in-place box girder section. After the construction of the third pier 3 and the fourth pier 4 is completed, the concrete surface is roughened and the reinforcing steel is treated with rust prevention. The third pier 3 and the fourth pier 4 are constructed up to the pad stone near the steel truss 5 section, and the height of the side near the cast-in-place box girder is H.

[0038] H = Elevation of the first pier column 1 - Height of the steel truss 5 frame - Height of the towing slider - Height of the towing track beam 8 - 35 times the spacing of the vertical main reinforcement bars of the third pier column 3 - 2cm. The towing slider is located on the towing track beam 8, not shown in the diagram, and represents existing technology.

[0039] Erect the assembly support 7 for the steel truss 5, hoist the guide beam 6, and assemble the steel truss 5.

[0040] If the sum of the length of the guide beam 6 and the length of the assembly range is greater than the distance between the first pier 1 and the second pier 2, and the guide beam 6, after being dragged into place, only exceeds the distance of one span of the cast-in-place box girder of the fourth pier 4; the assembly bracket 7 occupies only one span of the cast-in-place box girder within the assembly range, and the span of the cast-in-place box girder consists of 2-3 spans. This can be completed with a single dragging operation.

[0041] Otherwise, please refer to Figure 1 First, hoist the guide beam 6 and the assembled steel truss 5, and then carry out the first towing; after that, hoist the remaining sections and carry out subsequent towing construction; after the first towing is completed, construct the cast-in-place box girder section on the left side that is not affected.

[0042] Please see Figure 2 The towing process involves first assembling the steel truss 5 and guide beam 6, and then using a system consisting of jacks and steel strands to tow the steel truss 5 as a whole to the target point.

[0043] After the steel truss 5 reaches the assembly support 7 above the fourth pier 4, the guide beam 6 can be removed, and the cast-in-place box girder section on the right side can be constructed without being affected.

[0044] After the overall towing is completed, construct the upper piers of the cast-in-place box girder, the upper piers at the connection between the steel truss 5 and the cast-in-place box girder, and the remaining cast-in-place box girder.

[0045] Construction of auxiliary structures, dismantling of assembly supports 7.

[0046] Working principle:

[0047] First, construct the pile foundation and pile cap, then construct the piers. Install the assembly support frame 7 and the towing track beam 8 on top of the piers.

[0048] The guide beam 8 has a slider. A crane is used to lift the guide beam 6 and the steel truss 5 for assembly. Then, the guide beam 6 is dragged to the second pier 2. At the same time, the cast-in-place box girder on the left side is constructed without being affected. The steel truss 5 is assembled and then dragged again until the steel truss 5 reaches the fourth pier 4. The guide beam 6 is removed and the cast-in-place box girder on the right side is constructed without being affected. The steel truss 5 on the left side is assembled until the steel truss 5 is on the third pier 3 on the left and on the fourth pier 4 on the right. The upper pier of the cast-in-place box girder (not shown), the upper pier at the connection between the steel truss 5 and the cast-in-place box girder (not shown), and the remaining cast-in-place box girder (not shown) are constructed.

[0049] This invention overcomes the limitation in existing technologies where the steel truss 5 cannot be installed on the pier (third pier 3) at the junction of the truss section and the cast-in-place box girder section. At the same time, the cast-in-place box girder is constructed during the towing and assembly process, which greatly shortens the construction period and reduces the time for traffic control.

[0050] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A construction method for a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder, characterized in that: The bridge comprises a steel truss section in the middle and cast-in-place box girder sections at both ends. Below the steel truss section, from left to right, are the first and second piers. Below the junction of the steel truss section and the cast-in-place box girder sections, from left to right, are the third and fourth piers. Includes the following steps: Construction of the bridge's pile foundations and abutments. Construct the piers below the cast-in-place box girder section; construct the first pier and the second pier below the steel truss section; The construction includes the third and fourth piers located below the junction of the steel truss section and the cast-in-place box girder section. Erect the assembly support for the steel truss, hoist the guide beam, and assemble the steel truss section; If the sum of the length of the guide beam and the length of the assembly range is greater than the distance between the first pier and the second pier, and the guide beam, after being pulled into place, only exceeds the distance of one span of the cast-in-place box girder of the fourth pier, the assembly bracket only occupies one section of the cast-in-place box girder within the assembly range, and can be completed by one pull; otherwise, first hoist the guide beam and the steel truss of the assembly part, and then perform the first pull; after completion, hoist the remaining section for subsequent pull construction; after the first pull is completed, construct the cast-in-place box girder section on the left side that is not affected; After the steel truss reaches the assembly support above the fourth pier, the guide beam can be removed, and the cast-in-place box girder section on the right side, which is not affected, can be constructed. After the overall towing is completed, construct the upper piers of the cast-in-place box girder section, the upper piers at the connection between the steel truss section and the cast-in-place box girder section, and the remaining cast-in-place box girder section; Construction of auxiliary structures and dismantling of assembly supports.

2. The construction method for a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder as described in claim 1, characterized in that, The towing process involves first assembling the steel truss and guide beams, and then using a system consisting of jacks and steel strands to tow the entire steel truss to the target point.

3. The construction method for a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder as described in claim 1, characterized in that, After the construction of the third and fourth piers was completed, the concrete surface was roughened and the reinforcing steel was treated with rust prevention.

4. The construction method for a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder as described in claim 1, characterized in that, The cast-in-place box girder has 2-3 spans.

5. The construction method for a double-layer steel truss bridge with a continuous double-layer cast-in-place box girder as described in claim 3, characterized in that, The third and fourth piers were constructed to the pad stone near the steel truss, with a height of H on the side near the cast-in-place box girder. H = Elevation of the first pier column - Height of the steel truss frame - Height of the towing slider - Height of the towing track beam - 35 times the spacing of the vertical main reinforcement bars of the third pier column - 2cm.

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