Composite girder and bridge construction method

Abstract

The present invention relates to a composite girder installed in the longitudinal direction of a bridge on a bridge substructure, comprising: a plate portion (110) including an upper flange (101), a lower flange (102), and a web (103); a cross-sectional change portion (120) integrally provided at both ends in the longitudinal direction of the plate portion (110); and a box portion (130) integrally provided on one side and the other side in the longitudinal direction of the cross-sectional change portion (120), and a bridge using the same and a method for constructing a bridge.

Description

Technology Field

[0001] The present invention relates to a composite girder used in bridge construction and a bridge construction method using the same.

[0002] This invention is based on the support of the following national research and development project.

[0003] Item name Details Project Unique Number 2025-RISE-14-004 Assignment Number 2025-RISE-14-004 Buddha name Ministry of Education Project Management (Specialized) Agency Name Jeollanam-do RISE Center Research Project Name Jeonnam Regional Innovation Center University Support System (RISE) Research Project Title R. Regional Innovation Challenge Project implementing organization name Dongshin University Research period 2025. 08. 01. ~ 2030. 02. 28. Background Technology

[0004] Bridges are civil engineering structures that connect spaces and provide passageways for the movement of people, vehicles, trains, water resources, and cargo. Among these, girder bridges and plate girder bridges are types of bridges that allow for the simple fabrication of the superstructure (the structure installed on top of the substructure, such as abutments and piers) based on girders. Because they are not structurally complex and have a clean appearance, they are widely applied to small-scale bridges in Korea.

[0005] However, girder bridges and plate girder bridges had the problem of increasing manufacturing and construction costs because the large number of members relative to the size of the bridge prolongs the time required for on-site assembly and joining, and the inefficient connection structure of each member.

[0006] Therefore, there was a need to develop composite girders and bridge construction methods that are structurally superior while making bridge construction work easier. Prior art literature

[0007] Korean Patent Publication No. 10-2895966 The problem to be solved

[0008] To improve upon the problems of the prior art described above, the present invention aims to provide a composite girder and a bridge construction method that are structurally superior and easy to construct. means of solving the problem

[0009] The present invention provides a composite girder that is installed in the longitudinal direction of a bridge on a bridge substructure, comprising: a plate portion (110) including an upper flange (101), a lower flange (102), and a web (103); a cross-sectional change portion (120) integrally provided at both ends in the longitudinal direction of the plate portion (110); and a box portion (130) integrally provided on one side and the other side in the longitudinal direction of the cross-sectional change portion (120).

[0010] The cross-sectional change portion (120) includes an upper flange (101), a lower flange (102), a web (103), a partial side plate (121), and a lower plate (122), and the box portion (130) includes an upper flange (101), a lower flange (102), a web (103), and a full side plate (131).

[0011] The above-mentioned partial side plate (121) has a vertical length smaller than the web (103) of the cross-sectional change portion (120) and is integrally formed with the upper flange (101) of the cross-sectional change portion (120); the above-mentioned lower plate (122) is integrally formed with the lower end of the partial side plate (121) and the web (103); and the above-mentioned full side plate (131) has a vertical length equal to the web (103) of the box portion (130) and is integrally formed with the upper flange (101) and lower flange (102) of the box portion (130).

[0012] The vertical length of the above-mentioned partial side plate (121) is characterized by gradually increasing from the plate portion (110) to the box portion (130).

[0013] It is characterized in that a web (103) is not provided in a portion of the above box section (130).

[0014] A concrete section (132) is provided at the bottom of the above box section (130).

[0015] The above box portion (130) is provided in the branch portion, and the above plate portion (110) and cross-sectional change portion (120) are provided in the span portion, wherein the above plate portion (110) is located in the center of the span and the above cross-sectional change portion (120) is located at both ends in the longitudinal direction of the plate portion (110) provided in the center of the span.

[0016] The present invention provides a bridge construction method comprising the steps of: (a) installing a plurality of substructures spaced apart in the bridge axis direction; (b) installing the composite girder (100) on the upper part of the substructures; and (c) constructing a deck plate on the upper part of the composite girder (100).

[0017] The present invention provides a bridge constructed by the above bridge construction method.

[0018] The present invention provides a bridge comprising: a plurality of substructures installed spaced apart in the longitudinal direction; a composite girder (100) provided on the upper part of the substructures; and a deck plate provided on the upper part of the composite girder (100). Effects of the invention

[0019] The composite girder and bridge construction method of the present invention allows for the construction of a durable and economical bridge by organically and efficiently arranging the plate section, the cross-sectional change section, and the box section, taking into account the structure of the girder and the deformation of the girder due to load.

[0020] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description in the claims. Brief explanation of the drawing

[0021] FIG. 1 is a side view, a top view, and an enlarged cross-sectional view of a composite girder according to an embodiment of the present invention (an embodiment in which the web is integrally connected over the entire length of the composite girder). FIG. 2 is a side view, a plan view, and an enlarged cross-sectional view of an embodiment of the present invention (an embodiment in which the web is integrally connected over the entire length of the composite girder) when applied to a simple bridge. FIG. 3 is a side view of an embodiment of the present invention (an embodiment in which the web is integrally connected over the entire length of the composite girder) when applied to a multi-span continuous bridge. FIG. 4 is a side view, a top view, and an enlarged cross-sectional view of a composite girder according to another embodiment of the present invention (an embodiment in which a web is not provided on a portion of both ends of the composite girder). FIG. 5 is a side view, a top view, and an enlarged cross-sectional view of another embodiment of the present invention (an embodiment in which a web is not provided on some of the ends of the composite girder) when applied to a simple bridge. FIG. 6 is a side view of another embodiment of the present invention (an embodiment in which a web is not provided on parts of both ends of the composite girder) when applied to a multi-span continuous bridge. Specific details for implementing the invention

[0022] Embodiments of the present invention are described in detail below with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are given similar reference numerals. Throughout the specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0023] First, the composite girder of the present invention will be described, and subsequently, a bridge construction method using the composite girder and the bridge will be described.

[0024] The composite girder (100) of the present invention is provided with its longitudinal direction parallel to the longitudinal direction (bridge axis direction) of the bridge. The left-right direction of the girder shown in the drawing becomes the longitudinal direction of the bridge.

[0025] The composite girder (100) of the present invention is installed in the longitudinal direction of the bridge on a bridge substructure and includes a plate portion (110), a cross-sectional change portion (120), and a box portion (130).

[0026] A bridge substructure is a structure that supports the bridge superstructure and transmits the load of the superstructure to the ground, and includes abutments, piers, foundations, etc.

[0027] The configuration and arrangement of the above plate section (110), cross-sectional change section (120), and box section (130) are provided in consideration of the load applied to the bridge and the deformation of the bridge caused by the load.

[0028] The above box portion (130) may be provided in the branch portion, and the above plate portion (110) and cross-sectional change portion (120) may be provided in the span portion.

[0029] In the span section, the plate section (110) is located at the center of the span, and the cross-sectional change section (120) is located at both ends in the longitudinal direction of the plate section (110) provided at the center of the span.

[0030] The above plate portion (110) includes an upper flange (101), a lower flange (102), and a web (103).

[0031] The upper flange (101), lower flange (102), and web (103) are integrally provided with each other and may be integrally connected over the entire length of the composite girder. However, there is another embodiment in which the web (103) is not provided in a portion of the box section (130), and in the other embodiment, the web (103) may not be provided in a portion of both ends of the composite girder (100).

[0032] The above cross-sectional change portion (120) is integrally provided at both ends in the longitudinal direction of the plate portion (110).

[0033] The cross-sectional change portion (120) includes an upper flange (101), a lower flange (102), and a web (103) extending from the plate portion (110), and additionally includes a partial side plate (121) and a lower plate (122).

[0034] The above-mentioned partial side plate (121) is provided on both sides of the web (103) and is formed integrally with the upper flange (101) of the cross-sectional change portion (120) by welding, and its vertical length is smaller than that of the web (103) of the cross-sectional change portion (120).

[0035] Since the support structure is not sturdy if the above-mentioned partial side plate (121) is welded only to the upper flange (101), a lower plate (122) is welded between the bottom of the above-mentioned partial side plate (121) and the web (103).

[0036] The lower plate (122) is integrally formed with the lower end and web (103) of the partial side plate (121) by welding.

[0037] In order to form an efficient support structure, save materials, and reduce self-weight, the vertical length of the above-described side plate (121) can be configured to gradually increase from the plate portion (110) to the box portion (130).

[0038] The drawing illustrates an embodiment in which the vertical length of the partial side plate (121) increases in a curved manner from the plate portion (110) to the box portion (130), but it may also increase in a linear manner.

[0039] When the vertical length of the partial side plate (121) is curved, the lower plate (122) can be a curved plate, and when the vertical length of the partial side plate (121) is linear, the lower plate (122) can be a flat plate.

[0040] The above box portion (130) is integrally provided on one side and the other side in the longitudinal direction of the above cross-sectional change portion (120).

[0041] The above box section (130) includes an upper flange (101), a lower flange (102), and a web (103) that extend from the plate section (110) and the cross-sectional change section (120), and additionally includes an overall side plate (131).

[0042] The above-mentioned full side plate (131) is provided on both sides of the web (103).

[0043] The above-mentioned entire side plate (131) has the same vertical length as the web (103) of the box section (130) and is integrally formed with the upper flange (101) and lower flange (102) of the box section (130) by welding.

[0044] The above box section (130) forms a box structure with a rectangular cross-sectional edge shape by means of an upper flange (101), a lower flange (102), and an overall side plate (131).

[0045] Since the above cross-sectional change section (120) is provided in a section where the bending moment acts relatively smaller than that of the box section (130), a partial side plate (121) shorter than the vertical length of the web (103) is used to save material and form an efficient structure, and since a relatively large negative bending moment (bending moment that causes upward convex deformation) may act on the box section (130), a full side plate (131) equal to the vertical length of the web (103) is used.

[0046] As previously explained, the box section (130) can be provided at the support section. When the composite girder of the present invention is applied to a multi-span continuous bridge, a concrete section (107) can be provided at the bottom of the box section (130) located at the support section, excluding the starting and ending sections.

[0047] In a multi-span continuous bridge, a negative bending moment acts on the support sections excluding the starting and ending sections, and compressive stress acts on the lower part of the box section (130). Therefore, to improve strength against compression, a concrete section (132) may be provided on the lower part of the box section (130).

[0048] The concrete section (132) can be provided by pouring concrete into the internal space of the box section (130). To improve the adhesion of the concrete, a stud can be provided on the upper part of the lower flange (102) inside the box section (130).

[0049] The box portion (130) of the present invention can have two embodiments.

[0050] One embodiment (Figs. 1 to 3) in which the web (103) is integrally connected to the upper flange (101) and lower flange (102) over the entire length of the composite girder, and another embodiment (Figs. 4 to 6) in which the web (103) is not provided only at parts of both ends of the composite girder (100) are possible.

[0051] That is, in one embodiment, the box portion (130) is provided with a web (103) over the entire box portion (130), and in another embodiment, the box portion (130) is provided with a web (103) partially.

[0052] Referring to FIG. 4, another embodiment is described. In FIG. 4, the DD section of the right box portion (130) is provided with a web (103), but the D'-D' section, which is the end side of the composite girder, is provided in a box shape without a web (103).

[0053] The composite girder (100) of the present invention can be applied not only to simple bridges shown in FIG. 2 and 5, but also to multi-span continuous bridges such as 2-span and 3-span bridges.

[0054] The specifications, such as the longitudinal length of each of the above-mentioned plate section (110), cross-sectional change section (120), and box section (130), can be determined according to the specifications, load, etc. of the bridge.

[0055] The following describes a bridge construction method using the composite girder described above.

[0056] To construct the bridge, multiple substructures are first installed so as to be spaced apart in the longitudinal direction.

[0057] The composite girder (100) can be manufactured simultaneously with the installation process of the substructure.

[0058] When the construction of the substructure is completed, one or more composite girders (100) are installed on the upper part of the substructure in a direction perpendicular to the bridge axis.

[0059] When there are multiple installed composite girders (100), a cross beam can be installed between adjacent composite girders.

[0060] Once the installation of the composite girder (100) or the installation of the composite girder (100) and the cross beam is completed, a bridge deck is constructed on top of the composite girder (100).

[0061] The bridge deck can be provided as any one of a PC deck, cast-in-place concrete, or half deck.

[0062] The bridge of the present invention can be used as an application facility for utilizing drones.

[0063] One way to utilize drones on bridges is for safety inspections and maintenance. Since bridges are often difficult for humans to access directly, drones can solve this problem.

[0064] Drones can take close-up shots of blind spots that are difficult for humans to see directly, such as the underside of bridge superstructures and the tops of piers, and use high-resolution cameras to detect minute defects, allowing for the precise identification of concrete cracks, exposed rebar, corrosion, and loosened bolts. Additionally, drones equipped with thermal imaging cameras can detect invisible internal bridge damage, leaks, and concrete spalling through temperature differences.

[0065] In addition, a drone can fly over the entire bridge to perform photogrammetry and build a 3D digital model based on the photogrammetry data. Through this 3D model, data can be constructed to accurately determine the current condition of the bridge and measure the location and size of damaged areas in millimeters. Additionally, the 3D model can be updated regularly to manage the history of the bridge.

[0066] The present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom.

[0067] Therefore, the true scope of technical protection of the present invention should be determined by the technical concept of the appended claims. Explanation of the symbols

[0068] 100. Composite girder 101. Upper flange 102. Bottom flange 103. Webb 110. Plate section 120. Section change section 121. Partial side panel 122. Bottom plate 130. Box section 131. Full side panel 132. Concrete section

Claims

Claim 1 A girder installed in the longitudinal direction of a bridge on a bridge substructure, comprising: a plate portion (110) including an upper flange (101), a lower flange (102), and a web (103); and cross-sectional change portions (120) integrally provided at both ends in the longitudinal direction of the plate portion (110). The above cross-sectional change section (120) includes a box section (130) integrally provided on one side and the other side in the longitudinal direction, wherein the cross-sectional change section (120) includes an upper flange (101), a lower flange (102), a web (103), a partial side plate (121), and a lower plate (122), and the box section (130) includes an upper flange (101), a lower flange (102), a web (103), and a full side plate (131), wherein the partial side plate (121) has a vertical length smaller than the web (103) of the cross-sectional change section (120) and is integrally provided with the upper flange (101) of the cross-sectional change section (120), and the lower plate (122) is integrally provided with the bottom of the partial side plate (121) and the web (103), and the full side plate (131) A composite girder characterized in that the upper and lower lengths of the web (103) of the box section (130) are the same, and the upper flange (101) and lower flange (102) of the box section (130) are integrally formed, and the upper and lower lengths of the partial side plate (121) gradually increase from the plate section (110) to the box section (130). Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A composite girder according to claim 1, characterized in that a web (103) is not provided in a portion of the box section (130). Claim 6 A composite girder according to claim 1, wherein a concrete section (132) is provided at the bottom of the box section (130). Claim 7 A composite girder according to claim 1, wherein the box portion (130) is provided in the branch portion, and the plate portion (110) and the cross-sectional change portion (120) are provided in the span portion, wherein the plate portion (110) is located in the center of the span, and the cross-sectional change portion (120) is located at both ends in the longitudinal direction of the plate portion (110) provided in the center of the span. Claim 8 A bridge construction method comprising: (a) a step of installing a plurality of substructures spaced apart in the bridge axis direction; (b) a step of installing a composite girder (100) of any one of claims 1, 5 to 7 on the upper part of the substructures; and (c) a step of constructing a deck plate on the upper part of the composite girder (100). Claim 9 A bridge constructed by the construction method of Paragraph 8. Claim 10 A bridge comprising: a plurality of substructures installed spaced apart in the longitudinal direction; a composite girder (100) of any one of claims 1, 5 to 7 provided on the upper part of the substructures; and a deck plate provided on the upper part of the composite girder (100).

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