KR101634313B1 - Steel box girder with reinforced rigidity and resisting power of moment, and method for constructing bridge thereof - Google Patents

Abstract

The present invention relates to a steel box girder with an improved cross-sectional stiffness and a moment resistance, and a method to construct a bridge using the same, comprising: a panel-shaped lower flange unit on which a reinforced concrete is cured; a panel-shaped web panel formed lengthwise in both side units of the lower flange unit; a panel-shaped upper flange unit installed to connect web panels located to face one another; and a panel shaped perforated shear connection unit installed in a line extended from the web panel. The present invention has effects of reducing the number of work processes, decreasing a work time, remarkably increasing resistance to a moment applied to the steel box girder and saving construction costs by forming a plurality of through-holes in the perforated shear connection unit in the longitudinal direction, extending a shearing connection member on the top surface of the steel box girder of which cross section is approximately rectangular.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel box girder having increased cross-sectional stiffness and moment resistance and a bridge construction method using the steel box girder,

The present invention relates to a bridge using a steel box girder, more particularly, to a bridge girder having a shear connection portion formed in a steel box girder and a steel box girder in which a reinforced concrete is cured in a lower flange portion, To a steel box girder with increased moment resistance and to a bridge construction method using the same.

Generally, a girder is a structural member for bridges that supports the weight of a slab and a load acting on a slab, and has a function of transmitting an acting load to a column or a bridge, which is a bridge substructure.

According to the recent report on the status of road bridges and tunnels (Ministry of Land, Transport and Maritime Affairs, 2008), the total length of bridges built on the expressway of Korea is 904,905m, and the steel box girder bridges (Kang Sang Hyun Bridge) account for 34.4% at 311,305m. In addition, the total extension of the steel box girder bridges on other national roads and general roads amounts to approximately 721,058 m. Since such a steel box girder is mainly manufactured by using a thin steel plate having a large slenderness ratio, the flange portion or the bump plate to be compressed may be destroyed by local buckling. Therefore, it is very important in designing steel box girders to prevent local buckling that may occur in thin plate elements before the bending strength that a steel box girder can achieve.

Such a conventional steel box girder 10 is manufactured by assembling a lower flange portion 11, both side portions 12 and an upper flange portion 13 as shown in Fig.

The lower flange portion 11 is formed of a double bottom plate member and the upper and the lower bottom plate members 11a and 11b are spaced apart from each other to form a hollow portion S.

The abdomen portion 12 is a member connecting the lower flange portion 11 and the side surfaces of the upper flange portion 13. The lower portion is provided at each of the four corners of the lower flange portion 11, 13) was installed.

The upper flange portion 13 is a member on which a slab die plate 14 for placing and curing a slab (not shown) is seated. The upper flange portion 13 is provided on the upper portion of the abdomen portion 12 so that both side edge portions of the slab die plate 14 are seated. Installed.

However, since the abdomen portion 12 and the upper flange portion 13 are made of the L-shaped steel member and the lower flange portion 11 is made of the double bottom plate member, a number of separate members for fastening and reinforcing the rigidity As the number of working hours increased, work time became longer.

The provision of the upper and lower bottom plate members 11a and 11b is intended to increase the rigidity of the lower flange portion 13 but is independent of the mutual interval or the height variation of the hollow portion S. [

Further, in order to reinforce the stiffness of the abdominal region 12, a separate member is required to additionally provide the abdomen inclined reinforcing member 16, which increases the difficulty of the operation.

Korean Patent No. 10-0943823 (Bulletin of Feb. 25, 2010) Korean Patent No. 10-0569028 (2006.04.10. Announcement) Korean Registered Patent No. 10-0545490 (2006.04. Announcement) Korean Patent No. 10-0947306 (Bulletin of Mar. 16, 2010)

SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the problems described above, and the lower flange portion, the abdomen portion, and the upper flange portion are formed in a panel shape so that the members for fastening are minimized or removed, And to provide a method of constructing a steel box girder with increased cross-sectional rigidity and moment resistance and a method of constructing a bridge using the same.

Also provided is a steel box girder having increased cross-sectional rigidity and moment resistance to improve the resistance of a moment applied to a steel box girder by curing a reinforced concrete having a predetermined height on the upper surface of the lower flange portion, and a bridge construction method using the same. There is another purpose in.

Still another object of the present invention is to provide a steel box girder having increased cross-sectional stiffness and moment resistance, and a bridge construction method using the steel box girder, in which a conventional steel box girder can be reused because a shear connection member can additionally be installed on the steel box girder .

Another object of the present invention is to provide a steel box girder in which the thickness of the flange portion can be adjusted according to the installation position of the upper flange portion, and a bridge construction method using the steel box girder.

Another object of the present invention is to provide a steel box girder in which a slab concrete is placed on an upper surface of a steel box girder, and a bridge construction method using the same.

According to another aspect of the present invention, there is provided a steel box girder comprising: a panel-shaped lower flange portion; A panel-shaped abdomen provided in the longitudinal direction on both side portions of the lower flange portion; An upper flange portion in the form of a panel provided so as to connect opposite abdominal portions; And a perforated shear connection portion formed on the extension line of the abdomen and having a panel-like shape, and a plurality of through holes are formed in the longitudinal direction at the perforation front end connection portion, Reinforced concrete.

Here, the height h of the perforated shear connection portion is calculated by calculating the section rigidity EI having a certain range through the second-order momentum formula of the end portion, and the upper flange portion is positioned at a predetermined position according to the calculated height h of the perforated shear connection portion Respectively.

In addition, the height h of the piercing shear connection portion has a ratio of H: h = 1: 0.03 to 0.2 in comparison with the height H from the lower flange portion to the upper flange portion.

Also, the perforation shear connection portion is formed integrally with the abdomen, and both ends of the upper flange portion are formed by being spaced apart from the upper end of the abdomen by a predetermined distance, and have a height from the position where the upper flange portion is provided at the abdomen to the upper end.

A stiffener having a rectangular cross section and a width larger than the width of the upper surface of the through hole connecting portion is provided on the upper surface of the through hole connecting portion.

In the embodiment of the through hole connecting portion, the cross section is formed in a "T" shape and is fixed in a "T" shape so that the lower surface is located at the end of the upper surface of the upper flange portion.

In another embodiment of the through hole connecting portion, the cross section is "C " shaped and is fixed in the shape of" A ", and the refracted upper portion is installed outward while the lower surface is located at the end of the upper surface of the upper flange portion.

Meanwhile, a method of constructing a bridge using girder box girder constructed as described above includes a step (S10) in which a lower flange portion is provided at regular intervals, and a belly portion is provided in a longitudinal direction on both sides of each lower flange portion; A step (S20) of forming a perforation shear connection with an upper flange portion to connect the abutments positioned opposite to each other; (S30) in which a plurality of through holes are formed in the longitudinal direction at the piercing shear connection portion; Curing the reinforced concrete on the upper surface of the lower flange portion (S40); A step (S50) in which the formwork is installed to receive the perforation shear connection portion; And a step (S60) in which slab concrete is placed and cured in the formwork.

Here, in step S40 in which the mold is installed, the inner bottom surface of the mold is installed so as to coincide with the upper surface of the upper flange portion.

In addition, the slab concrete is poured into the inner bottom surface of the formwork and the upper surface of the upper flange portion at the time of pouring and curing (S40), and the through hole is filled with the pore transfer connection portion.

As described above, according to the present invention, the lower flange portion, the abdomen portion, and the upper flange portion are replaced with the panel shape in the conventional shape steel, so that the fasteners and the folding members for the conventional fastening are removed, And the operation cost is reduced.

Also, since the reinforced concrete is cured at a predetermined height on the upper surface of the lower flange portion, the resistance of the moment applied to the steel box girder is improved.

Further, the thickness of the flange portion and the abdomen is taken into account in the allowable range of the moment of moment of inertia of the steel box girder, which is required according to the installation place and the work environment, so that the thickness of the flange portion and the abdomen is made thin So that the material cost of the steel box girder can be reduced. At this time, since the flange portion and the abdomen portion are in a panel shape and the shear connecting member also has a certain length, the thickness of the flange portion and the abdomen portion can be further thinned.

In addition, it is possible to determine the thickness of the flange portion and the abdomen according to the height of the shear connection member in a state in which the moment of moment of inertia required for the steel box girder is always satisfied according to the work site and construction, .

Further, the upper flange portion is provided so as to connect the opposite abdomen portions, and the upper end portion of the abdomen portion to the upper end portion of the abdomen is the shear connecting member. That is, the upper portion of the abdomen is the shear connecting member. The number of working hours is reduced, and the convenience of the work is improved.

In addition, since a separate shear connection member can be installed and used in a conventional steel box girder having a substantially rectangular shape, the already manufactured steel box girder can be reused and the manufacturing cost at this time is very low, .

Also, since the shear connection member is embedded in the slab concrete, the slab concrete is filled in the plurality of fastening holes formed in the shear connection member, thereby maximizing the fastening force between the shear connection member and the slab concrete.

Further, since the slab concrete is installed on the upper surface of the upper flange portion, the upper surface of the upper flange portion replaces a part of the entire inner bottom surface of the conventional formwork, thereby reducing the manufacturing cost of the formwork.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description, serve to further the understanding of the technical idea of the invention, It should not be interpreted.
1 is a perspective view schematically showing a conventional steel box girder.
2 is a perspective view schematically showing a steel box girder with increased section and moment resistance according to a preferred embodiment of the present invention.
3 is a perspective view showing a modification of Fig.
4 and 5 are perspective views showing the first and second embodiments of the steel box girder shown in FIG.
FIG. 6 is a partially exploded perspective view of a bridge constructed using the steel box girder of FIG. 2. FIG.
7 is a partial cross-sectional side view of the bridge shown in Fig.
FIG. 8 is a perspective view showing a construction process of a bridge using the steel box girder of FIG. 2. FIG.
Fig. 9 is a flow chart of Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the detailed description of known functions and configurations incorporated herein will be omitted when it may unnecessarily obscure the subject matter of the present invention.

<Configuration>

Fig. 2 is a perspective view schematically showing a steel box girder having increased sectional rigidity and moment resistance according to a preferred embodiment of the present invention, and Fig. 3 is a perspective view showing a modification of Fig.

2, the steel box girder 100 according to the present invention includes a lower flange portion 110, a belly portion 120, an upper flange portion 130, and a helix shear connection portion 140 .

The lower flange portion 110 is formed in a panel shape and is positioned on the upper surface of a pier (not shown) to support the steel box girder 100. Since the length b of the lower flange portion 110 is closely related to the moment of inertia I described later, it is seriously considered together with the height of the hole shear connection member 140. A reinforcing concrete 111 having a predetermined height is placed and cured on the upper surface of the lower flange portion 110. The length of the reinforced concrete 111 may be equal to or shorter than the length of the lower flange portion 110. [ The height and length of the reinforced concrete 111 may vary depending on the degree of the moment applied to the steel box girder 100. The reinforced concrete 111 significantly increases the resistance against the moment applied to the steel box girder 100. Of course, the reinforced concrete 111 can be cured also in the steel box girder 100 of Figs. 3 to 5 described later.

The abdomen (120) is formed in a panel shape and is installed so as to be longitudinally and mutually opposed to both side portions of the lower flange portion (110). Here, the abdomen 120 is provided at a position shifted inward by a predetermined length from the terminating end of the lower flange portion 110, and one side surface shape at this time is roughly "ㅛ" shape. Of course, the abdomen 120 may be provided in correspondence with the end of the lower flange portion 110.

The upper flange portion 130 is formed in a panel shape, and both ends are installed inside the abdomen portion 120 so that the mutually opposed abdomen portions 120 are connected. Here, both end portions of the upper flange portion 130 are respectively positioned and fixed on the mutually facing surfaces of the abdomen portion 120. Of course, the upper flange portion 130 may be positioned on the upper surface of the abdomen 120 and may be fastened to the abdomen 120 in the same size and shape as the lower flange portion 110. The installation height H of the upper flange portion 130 is closely related to the following moment of inertia I, so it should be considered carefully.

6, the piercing shear connection part 140 is a part embedded in the slab concrete 200 and is a part for fastening the steel box girder 100 and the slab concrete 200. The perforation shear connection part 140 is a part for fastening the slab concrete 200, Method is adopted. Accordingly, the upper flange portion 130 is formed long along the longitudinal direction, and a plurality of through holes 141 are formed along the length. The through hole 141 is filled with the slab concrete 200 to improve the tightening force between the stiffener shear connection 140 and the concrete box girder 100 and the slab concrete 200. At this time, the length of the through-hole 141 and the length of the through hole 141, the shortest length to the end of the through-hole 141 and the end of the through hole connection 140, So as to prevent the perforation shear connection portion 140 from being broken by the external force within a certain range. As the number of the through holes 141 increases, the amount of the slab concrete 200 to be filled increases to increase the fastening force. However, as the distance between the through holes 141 becomes narrower, the through holes 141 The number of the through holes 141 and the distance between the through holes 141 are considered.

2, when the upper portion of the abdomen 120 is the helium front end connection portion 140, the upper flange portion 130 is formed on the opposite inner surface of the abdomen portion 120, Respectively. 3, a substantially rectangular stiffener 142 is additionally installed on the upper surface of the piercing shear connection part 140, as shown in FIG. At this time, the width of the reinforcing member 142 is formed to be wider than the width of the hole- Accordingly, the value of the moment of inertia I in the case where the reinforcing member 142 is provided is higher than that in the case where the reinforcing member 142 is not installed. Accordingly, the upper flange portion 130, the lower flange portion 110, The thickness of the substrate 120 can be reduced.

<Production>

Hereinafter, the manufacture of a steel box girder according to the present invention will be described with reference to a pierced shear connection portion.

Referring to FIG. 8, the steel box girder 100 of FIG. 2 is longitudinally and mutually opposed to both side portions of the lower flange portion 110 in the process of manufacturing the steel box girder 100 in the process of constructing the bridge, (120). The pair of abdomen portions 120 have a substantially "ㅛ" -shaped one side shape together with the lower flange portion 110. At this time, welding may be used or a separate 'c' bracket or the like may be used and installed through bolts or screws. Of course, considering the buckling applied to the steel box girder 100 after the bridge is installed, it is preferable that the entire contact surfaces of the lower flange portion 110 and the abdomen portion 120 are strongly adhered.

Next, the upper flange portion 130 is installed at a position spaced apart from the upper end of the abdomen portion 120 by a predetermined distance. At this time, both end portions of the upper flange portion 130 are provided on mutually facing surfaces of the abdomen portion 120. Here, the connection between the upper flange portion 130 and the abdomen portion 120 is preferably welded, and may be made through a bracket and a bolt or a screw if necessary.

When the through hole connection part 140 is formed as described above, a plurality of through holes 141 having a predetermined size in the longitudinal direction are formed in the through hole connection part 140. The through hole 141 is filled with the slab concrete 200 to maximize the coupling force of the slab concrete 200 of the piercing sheath connection part 140.

The height h of the piercing shear connection part 140 is selected in consideration of the second moment of inertia I required of the steel box girder 100. The second moment of inertia I is given by Equation 1 below: Respectively.

[Formula 1]

Where b is the length of the lower flange and h is the height of the hole shear connection. 3, H is the height from the lower flange portion to the upper flange portion. Accordingly, the value of the moment of inertia I is greatly influenced by the height h of the piercing shear connection portion 140, which greatly affects the sectional rigidity EI. That is, the higher the height h of the piercing sheath connection part 140 is, the more affected is the third power of the variable length. Of course, the higher the height h of the piercing shear connection part 140 is, the higher the value of the moment of inertia I will increase. However, if the depth of the piercing shear connection part 140 embedded in the slab concrete 200 becomes deeper, The thickness of the concrete 200 is increased. Therefore, the height (h) of the piercing shear connection portion 140 should be taken into account not only the base length but also the thickness of the slab concrete 200. Accordingly, it is preferable that the height h of the through hole connecting portion 140 is approximately 1: 0.03 to 0.2 with respect to the height H from the substantially lower flange portion 110 to the upper flange portion 130. Here, the second moment of inertia I is calculated by adding the second moment of inertia calculated through the base length b and the height H and the second moment of inertia calculated through the base length b and the height h . Of course, the moment of inertia of each section can be obtained by subtracting the empty space from the total space.

In addition, the sectional rigidity EI of the steel box girder 100 is ultimately obtained through this moment of inertia I. Here, since E is a constant according to the material, the section stiffness (EI) has a large change in the value of the moment of inertia (I). At this time, when the steel box girder 100 is manufactured, the range of the section rigidity EI of the steel box girder 100 is determined considering the length, width, size, etc. of the bridge, The moment of inertia (I) of the cross section is determined so as to be within the predetermined range. Further, when the moment of inertia I is set within a certain range, the height h of the through hole connecting portion 140 is determined. Here, the thickness of the upper flange portion 130, the lower flange portion 110, and the abdomen portion 120 can be changed by changing the height h of the piercing sheath connection portion 140. Therefore, in order to reduce the manufacturing cost of the steel box girder 100, the thickness of the upper flange portion 130, the lower flange portion 110, and the width of the abdomen portion 120, when the height h of the hole- Can be reduced.

3, the moment of inertia I is much higher than in the case of FIG. 2, so that the upper and lower flanges 130, The thickness of the body 110 and the abdomen 120 can be reduced.

The reinforced concrete 111 is placed and cured at a height equal to or shorter than the length of the lower flange portion 110 at the upper surface of the lower flange portion 110. The height and length of the reinforced concrete 111 may vary depending on the degree of the moment applied to the steel box girder 100. This is because the weight of the steel box girder 100 This is to maximize the resistance to moment.

<Examples>

4 and 5 are perspective views showing the first and second embodiments of the steel box girder shown in Fig. 2. Here, Figs. 4 and 5 are schematic cross- There is shown an embodiment in which a connection portion is provided.

5 is a cross-sectional view of the upper flange portion 130 and the lower flange portion 110. The upper flange portion 130 and the abdomen portion 120 are coupled to each other in a substantially rectangular shape, And a reinforcing concrete 111 having a predetermined height and length is cured on the upper surface of the lower flange portion 110. [

do. At this time, the first auxiliary pneumatic front end connection portion 140a is welded to the upper end of the upper flange portion 130 by aligning the lower surface of the "T" Therefore, one side of the wing on the first auxiliary pneumatic shear connection portion 140a is located outside the extended range of the abdomen 120. Of course, a separate bolt or screw connection is also possible in addition to the welding connection. As a result of the arrangement of the first auxiliary pneumatic front end connection portion 140a, the value of the moment of inertia I further increases. A plurality of through holes 141 are formed in the longitudinal direction of the first auxiliary piercing shear connection part 140a. Of course, the upper flange portion 130, the lower flange portion 110, and the abdomen portion 120 are panel-shaped. Here, the first auxiliary porthole shear connection part 140a may be a T-shaped steel or an I-shape cut.

5 is a cross-sectional view of an upper flange portion 130 and a lower flange portion 120. The upper flange portion 130 and the lower flange portion 110 are coupled to each other in a substantially rectangular shape. The second auxiliary piercing shear connection part 140b is installed and the reinforced concrete 111 is cured at a predetermined height and length on the upper surface of the lower flange part 110. [ At this time, the second auxiliary piercing sheath connection portions 140b are arranged symmetrically with the upper bent portion facing outward, and the lower surface is aligned and welded to the end portion. Therefore, the bent portion of the upper portion of the second auxiliary piercing sheath connection portion 140b is located outside the extended range of the abdomen portion 120. [ As a result of the arrangement of the second auxiliary piercing shear connection portion 140b, the value of the second moment of inertia I further increases. A plurality of through holes 141 are formed in the longitudinal direction of the second auxiliary piercing shear connection part 140b. The upper flange portion 130, the lower flange portion 110, and the abdomen portion 120 have a panel shape.

Here, the height of the first auxiliary pneumatic front end connection portion 140a and the second auxiliary pneumatic front end connection portion 140b is set according to the value of the moment of inertia I, and the height thereof is about 1: 0.03 to 0.2 .

<Bridge construction method>

FIG. 6 is a partially exploded perspective view of the bridge constructed using the steel box girder of FIG. 2, FIG. 7 is a partial cross-sectional view of the bridge shown in FIG. 6, FIG. 9 is a process diagram of FIG. 8. FIG.

First, the lower flange portion 110 is installed at each bridge pier continuously arranged, and the abdomen portions 120 are installed on both sides of the lower flange portion 110 in a longitudinal direction and mutually symmetrically installed (S10). At this time, one side surface shape of the lower flange portion 110 and the abdomen portion 120 becomes approximately ".".

Next, both end portions of the upper flange portion 130 are provided on the inner side surfaces of the pair of abdomen portions 120 arranged opposite to each other, thereby forming the air hole front end connection portion 140 (S20). Since the height h of the perforated front end connection portion 140 varies depending on the position where the upper flange portion 130 is installed, the upper flange portion 130 may have a sectional moment of inertia I, And the position is set according to the value of.

Next, a plurality of through holes 141 are formed in the longitudinal direction of the perforated front end connection portion 140 (S30). When the upper flange part 130 is installed, the number and size of the through holes 141 are determined according to the height and the length of the through hole connecting part 140, and the holes are drilled.

Next, the reinforced concrete 111 is placed and cured (S40) on the upper surface of the lower flange portion 110 at a predetermined height and length. The height and length of the reinforced concrete 111 are calculated so as to obtain the minimum weight and the maximum moment resistance in consideration of the moment applied to the steel box girder 100 and the weight of the steel box girder 100.

Next, a mold 210 is installed on the finished steel box girder 100 (S50). Here, the mold 210 is installed so as to include at least two steel box girders 100, which are wider than the width of the steel box girder 100 as shown in Figs. In addition, an inner bottom surface of the mold 210 is formed in an empty space between the steel box girders 100 and in an empty space of the steel box girder 100 by a predetermined length outside the abdomen 120. That is, a floor surface is formed at a portion of the inner bottom surface of the mold 210 in which the slab concrete 200 is installed except for the upper surface of the upper flange portion 130. At this time, the inner bottom surface of the mold 210 is flush with the upper surface of the upper flange 130. Here, the mold 210 may be fixed by a separate fixing member (not shown) fixed to the outward side surface of the abdomen 120.

Next, the slab concrete 200 is placed on the upper surface of the mold 210 and the upper flange 130, and cured (S60). As shown in FIG. 7, the slab concrete 200 is installed at a height above the upper surface of the upper flange portion 130 to a height at which the piercing shear connection portion 140 can be embedded, and the slab concrete 200, But it has a height of about 24 cm to 27 cm.

As described above, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the appended claims, rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalents of the claims are to be construed as being included within the scope of the present invention do.

100 ... Steel box girder
110 ... Lower flange portion
111 ... reinforced concrete
120 ... abdomen
130 ... upper flange portion
140 ... perforated shear connection
141 ... through hole
142 ... stiffener
200 ... Slab Concrete.

Claims (10)

In the steel box girder 100,
A panel-shaped lower flange portion 110;
A panel-shaped abdomen (120) longitudinally provided on both side portions of the lower flange portion (110);
A panel-shaped upper flange portion 130 installed to connect the abdomen portions 120 positioned opposite to each other;
A perforated-type perforated shear connection part 140 provided on an extension of the abdomen part 120, and a panel-
And a reinforcing concrete (111) integrally cured and having the same length as the length of the upper surface of the lower flange portion (110)
The height of the reinforced concrete 111 is selected according to the length of the reinforced concrete 111 and the weight and moment resistance of the steel box girder 100. The total length of the reinforced concrete 111 is equal to or shorter than the entire length of the bridge In addition,
A plurality of through holes 141 are formed in the longitudinal direction at the perforation front end connection portion 140,
The height h of the perforation front end connection portion 140 is calculated while calculating the sectional rigidity EI having a certain range through the second-order moment of inertia formula, and the height h of the perforated front end connection portion 140 The ratio of H: h = 1: 0.03 to 0.2 is set as a ratio of the height H from the lower flange portion 110 to the upper flange portion 130, And,
The perforation front end connection portion 140 is integrally formed with the abdomen portion 120 and both end portions of the upper flange portion 130 are formed by being spaced downward at a predetermined distance from the upper end of the abdomen portion 120. In the abdomen portion 120, Has a height from the position where the paper sheet 130 is installed to the top,
A stiffener 142 having a rectangular cross-section and a width larger than the width of the upper surface of the pore front end connection portion 140 is installed on the upper surface of the pore front end connection portion 140,
The perforation front end connection portion 140 is a T-shaped section and is fixed in a "T" shape so that the lower surface is positioned at the end of the upper surface of the upper flange portion 130, And the lower portion of the lower flange portion 130 is positioned at the end of the upper flange portion 130 while the upper portion of the bent portion is outwardly installed.
In the method of constructing a bridge using the steel box girder of claim 1,
(S10) in which the lower flange portion 110 is installed at regular intervals and the abdomen portions 120 are provided on both side portions of the respective lower flange portions 110, respectively;
A step (S20) in which the upper flange portion 130 is installed to connect the abutment portions 120 to be opposed to each other, and the perforation shear connection portion 140 is formed;
A plurality of through holes 141 are formed in the perforation front end connection portion 140 in the longitudinal direction S30;
Curing the reinforced concrete 111 on the upper surface of the lower flange portion 110 (S40);
A step (S50) in which the formwork (210) is installed to receive the perforation shear connection part (140); And
(S50) in which slab concrete (200) is placed and cured in the mold (210)
In step S40 in which the mold 210 is installed, the inner bottom surface of the mold 210 is installed to coincide with the upper surface of the upper flange part 130,
The slab concrete 200 is laid on the inner bottom surface of the mold 210 and the upper surface of the upper flange portion 130 and the through hole 141 The method for constructing a bridge using a steel box girder with increased cross-sectional stiffness and moment resistance. delete delete delete delete delete delete delete delete

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