KR101312300B1 - Girder using upper and under member and bridge construction method - Google Patents

Abstract

PURPOSE: A girder using upper and lower members and a bridge production and construction method using the same are provided to obtain economical and structural efficient cross sections by using standardized shaped steel and to minimize the cross-sectional height. CONSTITUTION: A girder (100) using upper and lower members is integrally formed with an upper member which is standardized I-type shape steel and a lower member which is standardized T-type shape steel. The lower member is welded to the lower surface of the lower flange of the upper member. The lower member is made of a steel material with higher intensity than the upper member. The upper and lower parts of the girder are introduced with residual compressive stress around a neutral axis in advance. [Reference numerals] (100) Girder of the present invention; (20) Existing girder; (AA,BB,EE,GG,KK) Tension; (DD,HH,II,LL) Compression; (FF) Permissible stress of a steel material with high intensity; (JJ) Introduce residual compressive stress

Description

Girder using upper and lower members and bridge construction and construction method using same {GIRDER USING UPPER AND UNDER MEMBER AND BRIDGE CONSTRUCTION METHOD}

The present invention relates to a girder using the upper and lower members, and a bridge manufacturing and construction method using the same. More specifically, the present invention relates to girders using upper and lower members, which are advantageous for stiffness reinforcement and fabrication by introducing residual stress (compressive stress) in advance, and a bridge manufacturing and construction method using the same.

Figure 1a shows a process step view of the temporary bridge using the steel plate girder 20.

First, the temporary bridge is a girder 20 is installed in the temporary vent 30 located in three points, it can be seen that the girder 20 is a steel plate girder.

These steel plate girders are cross-sectional I-shaped cross sections, which are formed of an upper flange, an abdomen and a lower flange.

In this case, the temporary bridges in the form of continuous bridges determine the cross section of the girder 20 because the magnitude of the bending parent moment (-M) generated at each point portion is much larger than the bending constant moment (+ M) between the point portions.

The point portion is to use a girder 20 (B-B cross-section) having a relatively large cross-sectional height (H1).

Therefore, the factory can not use the I-shaped steel standardized, the upper girder, the abdomen and the lower flange to weld the steel plate made of I-shaped cross section to use the girder 20.

Generally, these girders are called built-up girders, and they are customized to the required cross-sectional height by welding in the factory.

However, because the size of the bending constant moment is smaller than the size of the bending subbore between the points, the section height (H2) is not large, so the standard I-shaped steel product (40, AA) without using the built-up girder is used. Cross section) can be used.

However, in the case of the normalized I-shaped steel as well as the built-up girder, there is a fear of local buckling in the lower part of the abdomen when the load is applied. Often installed.

The built-up girder or standardized I-shaped steel has its advantages and disadvantages, but it is not easy to reduce the cost of manufacturing the girder due to the addition of a process for forming the stiffener.

Furthermore, the reason for using a lot of built-up girders is that it is not possible to provide girders with various cross-sectional heights that users want as standardized I-shaped steel products. If the I-shaped steel fabrication equipment is not provided, it will not be able to suggest a solution otherwise.

Therefore, even if the girder is manufactured by the built-up girder method, girders are introduced that can secure the necessary bending stiffness while reducing the possible cross-sectional height based on the same extension length. Introduced in FIG. 1B.

This girder is a layer girder 10 in which the upper and lower members are separated.

That is, as the upper structure of the temporary bridge, H is formed so that the upper member 11 and the lower member 12 made of the rolled steel including the I beam are separated at a predetermined interval so that the cross-sectional structure is formed as the upper and lower layer structures. However, the girder 10 in which stress generated in the upper and lower members is dispersed by the strong connecting member by the strong connecting members 13a, 13b, and 13c, which are rigid between the upper and lower members 11 and 12, respectively. ) Is introduced.

At this time, the strong connecting members 13a, 13b, and 13c serve to transfer internal energy due to bending stress and axial stress to the upper member and the lower member.

In this case, the upper member and the lower member have the advantage of being able to use conventionally standardized I-shaped steel products, but in forming a strong connection member 13a, 13b, 13c such as manufacturing a steel plate in the form of a box through a separate manufacturing process In fact, it can be seen that such a conventional girder can not only be structurally efficient, but also to develop a method that can be economically manufactured.

Accordingly, the present invention provides a steel plate girder, even if the standardized I-shaped steel product is not provided in the desired cross-sectional size, but can be manufactured in a desired cross-sectional size by combining the standardized I-shaped steel products to minimize the possible cross-sectional height It is a task to solve the provision of steel girders using residual stress, a method of manufacturing the same, and a bridge manufacturing and construction method using the same.

In order to achieve the above object,

First, the upper member and the lower member of the steel plate girder are manufactured by fixing the upper and lower integrally with each other, each of the upper member and the lower member is to use the standardized I and T-shaped steel as it is.

In other words, if the required cross-sectional height is determined, conventionally manufactured standard built-up girders (Built-Up Girder) cannot be used when I-shaped steel is used. In this case, the manufacturing cost increases, and thus the present invention can be secured. Standardized I-shaped steel is prepared as an upper member, and the cut abdomen of standardized T-shaped steel (cutting the abdomen of standardized I-shaped steel) is integrated at the center of the bottom surface of the lower flange of the upper member to eventually be standardized with standardized I-shaped steel. Girder is made using T-beam.

In this case, the standardized T-shaped steel is made of steel having a greater strength than standardized I-shaped steel to minimize the cross-sectional height of the standardized T-shaped steel to minimize the cross-sectional height of the entire girder.

Second, since the girder fabricated using the standardized I-shaped steel and the standardized T-shaped steel different from each other in strength is a bending member installed at the point portion, the upper part of the tensile stress under the neutral axis receives the compressive stress.

In this case, the tension member may be used to effectively reduce the cross-sectional height while effectively resisting the tensile stress, but the present invention allows the upper member to be retained by the compressive stress as a residual stress when the upper member and the lower member are integrated with each other. By effectively resisting the tensile stress occurring in the girder, the cross-sectional height of the entire girder can be further minimized.

Third, when fabricating the girder of the present invention, that is, in order to manufacture such that the compressive stress remains in the upper member, the upper member and the lower member are first welded (non-synthesized) to each other, and then the compressive stress is applied to the upper member by applying a vertical load. If this occurs, the integrated welding (composite) to completely integrate the upper member and the lower member at this time.

This releases the applied vertical load so that the compressive stress is introduced to the upper member by the elastic restoring force of the upper member and the lower member.

Fourth, in the girder fabrication of the present invention, the welding, integral welding of the upper member and the lower member is provided with a manufacturing device for the operator to weld downward, and when using such a manufacturing device is released after applying a vertical load during girder production When loading, stable load transfer is possible and welding work is easy to provide more girder that can introduce more precise residual stress.

To this end,

An upper member which is a standard I-shaped steel; And a lower member which is a standardized T-shaped steel welded to the bottom surface of the lower flange of the upper member. The lower member is configured to include the upper member and the lower member to be integrated with each other. One made of steel having a higher strength is used, and the girder is provided with a girder using upper and lower members to form residual stresses, which are compressive stresses, are pre-introduced to the upper member and the lower part based on the neutral axis.

Also preferably,

The residual stress is

The upper member and the lower member are integrated with each other in a state where the upper member and the lower member are bent by applying a load to the non-synthetic girder which is welded to each other, thereby forming a non-synthetic girder as a synthetic girder, and It provides a girder using the upper and lower members to remove the load to release the composite girder to introduce the residual stress by the elastic restoring force of the girder.

Also preferably,

The non-synthetic girder welded is installed so that both ends of the girder are supported by the lower support in an upside down state, both ends of the girder are fixed and fixed to the lower support by an anchor fixing device, and fixedly fixed to the lower support. The upper member and the lower member are completely welded to each other in a state in which the vertical load is applied upward to the upper member of the girder, and the residual stress is introduced by the elastic restoring force of the synthesized upper and lower members by removing the vertical load. It provides a girder using the upper and lower members.

Also preferably,

The girder using the upper and lower members of the synthesized state is prepared and placed in the point portion,

Connect the standard I-shaped steel between the girder and the girder disposed in the point portion,

It provides a bridge fabrication and construction method using the girders and the girder using the upper and lower members is installed on the upper surface of the standard I-shaped steel plate.

Steel plate girder according to the present invention can be manufactured by using a standard shaped steel product to reduce the manufacturing cost, by using the strength of the lower member than the strength of the upper member in the upper member and the lower member constituting the girder The cross section height of the girder can be reduced in response to the stress applied, and the compressive stress remains as residual stress in the upper part of the girder (neutral axis basis) in the manufacturing process, thereby minimizing the cross section height of the girder to provide more economical and efficient girder This becomes possible.

In addition, the welding operation of the upper member and the lower member during the manufacturing of the girder enables the downward welding to significantly increase the girder manufacturing workability, and to provide an efficient girder by introducing a more precise stress by the stable vertical load and release. do.

1A is a cross-sectional view of a construction step of a conventional temporary bridge and a girder cross section between a branch part and a branch part of the temporary bridge;
1b is a perspective view of a conventional steel plate girder,
Figure 2a and Figure 2b is a girder manufacturing and conceptual diagram using the upper and lower members of the present invention,
3a, 3b, 3c and 3d is a front view and a cross-sectional view of the girder fabrication apparatus of the present invention,
4a and 4b is a conceptual diagram of the girder fabrication of the present invention,
5a and 5b is a girder manufacturing flow chart of the present invention,
6 is a cross-sectional view of the construction process of the temporary bridge using the upper and lower members of the present invention and the girder cross section between the point and the branch of the temporary bridge.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Girder 100 using the upper and lower members of the present invention

Figure 2a shows a girder 100 and a conventional steel plate girder 20 of the present invention.

First, it can be seen that the conventional steel plate girder 20 is formed as an I-shaped cross section including an upper flange, an abdomen, and a lower flange as a built-up girder.

Therefore, the conventional steel plate girder 20 must be manufactured by welding the upper flange, the abdomen, and the lower flange to each other, thereby increasing the manufacturing cost of the girder by the welding operation.

Furthermore, since the conventional steel plate girder 20 is a bending member installed at a point, the upper part acts as a tensile stress and the compressive stress acts as shown in FIG. Side effect).

In this case, according to FIG. 2b, the allowable stress of the steel is indicated by a dotted line. If the tensile stress and the compressive stress exceeding the allowable stress (indicated by NG) are applied, the steel plate girder 20 has a large cross section or a horizontal reinforcement. You need to install more. However, in this case, the manufacturing cost of the girder increases and there is a problem that the cross section cannot be enlarged in the case where the height of the cross section is limited.

Accordingly, the girder 100 of the present invention integrates the lower member 120, which is also standardized T-shaped steel, up and down by welding to the bottom of the upper member 110, which is the standardized I-shaped steel, as shown in FIG. 2A. (See the middle picture)

First, since the upper member 110 can be purchased as a factory product as a standard I-shaped steel, the manufacturing cost can be reduced.

Next, the lower member 120, which is the standardized T-shaped steel, may be used as a standardized T-shaped steel, which is also purchased as a factory product, thereby reducing manufacturing costs. At this time, the T-shaped steel may be used to cut the abdomen of the I-shaped steel.

In this state, the abdomen of the upper member 110 and the lower member 120, which is a standard T-shaped steel, are positioned on the same vertical line with each other, and the lower part of the lower member and the lower part of the upper member are welded together to be integrated with each other. One with strength is used.

Accordingly, the lower flange 113 of the upper member 110 serves as a horizontal reinforcement of the girder, which is advantageous in flexural rigidity reinforcement.

At this time, it can be seen that the sum of the cross-sectional heights of the upper member and the lower member is the same as that of the conventional steel plate girder 20.

In this case, the girder manufacturing cost can be reduced because it is not manufactured in the built-up method, but there is no difference in the cross-sectional height, so the present invention is particularly effective in reducing the overall cross-sectional height. It is to use the lower member 130 produced as.

Accordingly, the lower member 130 having increased strength can reduce the cross-sectional height in securing bending rigidity for the same load action.

As a result, as shown in FIG. 2a, the girder 100 manufactured by integrating the upper member 110 and the lower member 130 having a greater strength than the upper member of the present invention is integrated with each other.

It can be seen that the cross section height can be secured to the same bending rigidity with a smaller cross-sectional height compared to the girder using the standardized I-shaped steel and the standardized T-shaped steel and the same as the conventional steel plate girders.

In this regard, the stress of the girder 100 manufactured by integrating the upper member 110 and the lower member 130 having a greater strength (higher strength) than the upper member is shown in FIG. It will have a larger allowable stress than the member, but the tensile stress generated in the upper member also causes a problem that exceeds the allowable stress.

To this end, but also to install a horizontal reinforcing material corresponding to the excess tensile stress, in order to solve the present invention, the compressive stress is introduced to the upper and lower parts based on the neutral axis of the girder during the integration of the upper member and the lower member (residual stress introduced) When the (public) load action, the girder 100 can be seen that the tensile, compressive stress due to the working load to act within the final allowable stress.

As a result, the girder 100 according to the present invention is

First, standardized I- and T-shaped steels are used as the upper and lower members, respectively.

Second, the lower member 130 is manufactured by integrating with the upper member 110 using a T-shaped steel having a greater strength than the upper member 110,

Third, when manufacturing the girder, the compressive stress is introduced into the upper and lower parts as the residual stress based on the neutral axis of the upper and lower members.

While minimizing the height of the cross section, it is possible to produce a girder with a more economical and structurally efficient cross section by using standard shaped steel.

Girder manufacturing method of the present invention

Previously, the present invention has been made so that the compressive stress is introduced into the upper and lower portions of the upper member and the lower member of high strength based on the neutral axis as residual stress.

3A and 3B, the girder fabrication method in which such residual stress is introduced will be described.

First, as shown in FIG. 3a, the upper member 110 and the lower member 130 are welded vertically to each other to restrain each other.

At this time, the lower member 130 may have a length smaller than the upper member 110, and both ends (a) of the lower member 130 are installed to be simply supported.

The upper and lower members are to use the standardized I-shaped steel and T-shaped steel as described above, the lower member of the T-shaped steel is made of a steel material having a greater strength than the upper member.

Fusible welding means that the upper member 110 and the lower member 130 are coupled to each other to the extent that the upper member 110 and the lower member 130 are not integrated with each other but be constrained to each other. It can be seen that only the center parts are welded to each other to maintain a soluble welding state.

The state in which the soluble welded upper and lower members are simply installed on the floor will be referred to as a non-synthetic girder.

Since the girder in such a non-synthetic state does not have a working load excluding its own weight, it can be seen that no stress occurs in the upper and lower members.

When the load P1 is applied to the non-synthetic girder 100, the upper member 110 and the lower member 130 do not be integrated with each other, so the loads P1 are acted on the upper member 110 and the lower portion, respectively. The members generate compressive and tensile stresses based on their respective neutral axes.

Although the load P1 is not shown as a vertical load, it can be applied using a hydraulic jack or the like, and when such a load is applied to the girder, the girder is bent downwardly.

In this non-synthetic state, the upper member 110 has a compressive stress in the upper portion of the lower portion based on the neutral axis, and the lower portion of the upper member 110 has a compressive stress in the upper portion of the compressive portion on the basis of the neutral axis.

Next, as shown in FIG. 3b, the upper and lower members welded to each other are completely welded to each other to be structurally integrated with each other, that is, to be synthesized. The girder is a state in which the upper member 110 and the lower member 130 are synthesized with each other, but there is no change in stress.

Therefore, when the load (P1) is removed, that is, when released, the synthesized girder 100 has a compressive stress in the upper portion of the lower tensile stress based on the neutral axis of the entire girder by elastic restoring force. It can be seen that the compressive stress remains in the upper and lower portions of the girder 100 based on the connection portion.

Therefore, the residual stress is introduced into the upper and lower portions of the girder 100 by the release of the final load, and when the common load is applied, the compressive stress cancels the tensile stress generated at the upper portion due to the common load, Since the compressive stress generated in the lower portion is increased, the lower member uses a high strength steel having a large allowable force.

As a result, the girder 100 of the present invention further reduces the cross-sectional height by a process of manufacturing the compressive stress into the upper and lower parts based on the neutral axis of the upper member and the lower member as residual stresses when manufacturing the girder according to the present invention. It can be seen that it is possible to use the elastic restoring force of the girder 100 itself and it can be seen that using a high-strength lower member.

Girder making apparatus of the present invention

Since the residual stress of the girder 100 described above is to use the elastic restoring force of the girder, the cross-sectional height of the desired girder should be minimized to be introduced as precisely as possible.

The residual stress of the girder 100 is generated in the process of applying and releasing the vertical load to the girder 100, it can be seen that is formed in the process of making the non-synthetic girder into a synthetic girder.

Thus, an apparatus for introducing such residual stress into the girder more effectively is disclosed in Figs. 4a to 4c.

That is, in the girder fabrication apparatus 200 according to FIG. 4A, the non-synthetic girder 100 of the present invention is installed upside down on the lower support 210. (The lower member 130 is positioned upward)

The girder manufacturing apparatus 200 is configured to include a lower support 210, anchor fixing device 220, end support frame 230, the support frame 240 and the hydraulic jack 250.

The lower support 210 so that the load (P1) is applied to the girder upward in the state that the girder 100 is fixed to the end support frame 230 installed between the lower support 210 by the anchor fixing device 220 is fixed. Hydraulic jack 250 is installed in the support frame 240 of the).

At this time, the anchoring device 220 is installed at the position of both ends (a) of the girder 100 as shown in Figure 3a, the loading frame 240 and the hydraulic jack 250 is a load (P1) as shown in Figure 3b It is installed in the position to be loaded.

First, the lower support 210 is arranged so that the two I-shaped steel support 211 on the floor spaced apart from each other in the lateral direction as shown in Figure 4b, it is installed so that both ends are supported by the support member on the floor.

The end support frame 230 and the support frame 240 described above are assembled between the lower support 210. To this end, two I-shaped steel supports 211 constituting the lower support 2 have a plurality of fastening holes 213 for fastening the end support frame 230 and the support frame 240 with bolts and nuts, as shown in Figure 4b It is.

That is, since the position of the end may be different for each girder 100 and the loading position of the load P1 may be changed, the position adjustment of the end supporting frame 240 and the supporting frame 240 according to the position of the end and the load is adjusted. The fastening hole 213 is formed so that a plurality of the upper flange, the abdomen and the lower flange of the two I-shaped steel support 211 is formed spaced apart from each other.

At this time, the end support frame 230 is formed to be fastened by a bolt and a nut between the upper flange, the abdomen and the lower flange inner surface between the two I-shaped steel support 211, as shown in Figure 4b 231 is fastened by using a bolt and a nut on the lower flange and the abdomen inner surface of the I-beam

An upper support frame 232 is integrally formed between the upper sides of both side vertical support frames 231 so that the upper bottom surface of the upper support frame 232 is set to contact the upper flange upper surfaces of the two I-shaped steel supports 211. .

The girder 100 in the center of the upper support frame 232 schematically constituting the end support frame 230 made of the c-shaped steel plate and the I-shaped steel between the two I-shaped steel support 211 by using bolts and nuts. It is to serve to support the bottom of the end of the).

The girder and the load acting on the girder is transmitted to the final bottom via the lower support 210 through the upper support frame 232 and both side vertical support frame 231 of the end support frame 230 and the lower support is Since it extends in the longitudinal direction at the bottom of the girder to effectively distribute the load to ensure the stability of the girder 100 upon loading of the load (P1) it is possible to introduce more precise residual stress.

In other words, if the girder moves or is unstable under load, the residual stress required by the design may not be precisely introduced, so structural uncertainty should be taken into consideration. However, when the girder fabrication apparatus according to the present invention is used, such concern is reduced.

Furthermore, the anchor fixing device 220 is installed so that both ends of the girder 100 installed to be supported by the upper support frame 232 constituting the end support frame 230 is fixed to the lower support 210.

The anchor fixing device 220 is a reaction force support frame 221 and the reaction force support is installed on the upper surface of the girder 100 is installed on the upper support frame 232 of the end support frame 230, as shown in Figure 4b Anchor 223 and the anchor hole 222 formed in the frame 221 and vertically penetrates the anchor hole 233 of the upper support frame 232 and

And fixing anchors 224 fixing the upper and lower ends of the anchors to the upper surface of the reaction force supporting frame 221 and the lower surface of the upper supporting frame 232, respectively.

Accordingly, the anchor fixing device 220 serves to fix both ends of the girder 100 to the end support frame 230 installed on the lower support 210.

Next, the loading support frame 240 is for restoring the load (P1) to the girder 100 fixed to the end support frame 230 installed in the lower support 210, the end support frame 230 and the end support The hydraulic jack 250 is installed on an upper surface of the frame 230 by being fastened and fixed to the lower support 210 such as the end support frame 230.

The loading frame 240 is to be installed in the position where the load (P1),

As shown in FIG. 4C, the upper flange, the abdomen, and the lower flange between the two I-shaped steel supports 211 are formed to be fastened by bolts and nuts. Both side vertical support frames 241 are lower flanges of the I-shaped steel. To the inner side of the abdomen using bolts and nuts

The central support frame 242 is integrally formed between the middle of the two side vertical support frame 241, the hydraulic jack 250 is installed on the upper surface of the central support frame 242.

The hydraulic jack 250 is operated so that the hydraulic cylinder is extended upward while contacting the bottom of the upper flange of the girder, the end of which is fixed and fixed so that the load (P1) is loaded on the girder (100).

As a result, it can be seen that the support frame 240 and the end support frame 230 is installed inside the I-shaped steel support 211 of the lower support 210.

At this time, the girder 100 is installed in the girder fabrication apparatus 200 so that the top and bottom is turned upside down, that is, the lower member is located upward and the upper member is disposed downward, so that the weld zone is exposed as it is. When performing welding to integrate the lower member and the upper member after loading, the operator can perform the downward welding work in the standing state, so the workability is very excellent.

In other words, if the welded part is not located below the worker but is located above, the welding work is very unstable and the quality control is difficult, but the downward welding work is easy and the quality control is easy. Since quality control is very important as an important process, the present invention uses a loading device so that the downward welding operation is possible and the loading is easy.

[Girder 100 manufacturing method using upper and lower members using the girder manufacturing apparatus 200 of the present invention]

5A and 5B illustrate a method of manufacturing the girder 100 using the upper and lower members using the girder fabrication apparatus 200 of the present invention.

First, as shown in FIG. 5a, the lower support 210 on which the hydraulic jack 250 is installed on the end support frame 230 and the support frame 240 is installed to be supported on the floor.

The end support frame 230 is installed so that both ends of the non-synthetic girder 100 upside down are supported.

Accordingly, the girder 100 is fixed to the lower support 210 using an anchor fixing device.

That is, the reaction force support frame 221 is installed on the upper surface of the girder 100 so as to contact, and the anchor 223, which is a steel bar, is anchor anchor 222 and the upper support frame 232 of the reaction force support frame 221. To vertically penetrate the anchor hole 233,

The upper and lower ends of the anchor 223 are fastened by using the fixing nut 224 to the upper surface of the girder and the lower surface of the upper support frame 232, respectively,

The girder 100 is fixed to the lower support 210.

Accordingly, the hydraulic jack 250 is set to be positioned below the lower surface of the upper member of the fixed girder.

Accordingly, when the hydraulic jack 250 is operated as shown in FIG. 5B, the girders 100 have both ends fixed and fixed to the lower support 210 by the anchor fixing device 220, so that vertical loads are bent upward in the weldable state. (P1) is introduced.

In this state, the upper member and the lower member constituting the girder are completely welded to each other to be integrated, and it can be seen that the composite girder 100 is manufactured.

At this time, the operator can ensure the workability enough because the welded portion is located below, the welding quality management becomes easy.

Next, when the hydraulic cylinder of the hydraulic jack is restored to its initial state (release), the synthesized girder 100 curved upward is a girder in which residual stress is introduced by elastic restoring force.

Accordingly, the girder of the present invention is completed by separating the synthesized girder 100 from the lower support 210 by releasing the fixing nut of the anchor fixing device 220 and introducing residual stress.

[Bridge construction method using the girder 100 of the present invention]

6 is a front view of a bridge constructed by a method of constructing a bridge, in particular, a temporary bridge using the girder 100 of the present invention.

That is, the synthesized girder 100 into which residual stress is introduced is separated from the girder fabrication apparatus 200 and installed above each point portion (section C-C) of the preliminary construction bridge in a state of upside down again.

Next, the girder 100 (cross section A-A), which is a standard I-shaped steel, is connected between the upper members of the present invention, which is installed first, by using a bolt and a nut, and the final girder is continuously installed in the longitudinal direction,

By installing the perforated plate 40 on the upper surface of the girder so that the final temporary bridge can be completed.

100: girder
110: upper member
120: standardized T-beam
130: lower member
200: girder manufacturing device
210: lower support
211: I-shaped steel support
220: anchor fixing device
221: reaction support frame
222: anchor hole
223: anchor
224: fixing nut
230: end support frame
231: vertical support frame on both sides
232: upper support frame
233: anchor hole
240: frame
241: vertical support frame on both sides
242: center support frame
250: hydraulic jack

Claims (4)

Upper member 110, which is a standard I-shaped steel; And a lower member 130 which is a standardized T-shaped steel welded to the bottom surface of the lower flange of the upper member 110, wherein the upper member 110 and the lower member 130 are integrated with each other. As a girder of the state
The lower member 130 is made of a steel material having a greater strength than the upper member 110 is used, and the upper and lower portions of the synthesized girder are formed so that residual stresses, which are compressive stresses, are introduced in advance based on the neutral axis. And
The residual stress is a non-synthetic girder by integrating the upper member and the lower member with each other in a state in which the upper member and the lower member to be bent by applying a load to the girder of the non-synthetic state that the upper member and the lower member is welded to each other to convert the girder of the synthetic state into a synthetic girder Forming and removing the load to release the girder in the synthetic state by using the upper and lower members, characterized in that the residual stress is introduced by the elastic restoring force of the girder. delete The method of claim 1,
The girder of the non-synthetic state welded welded is installed so that both ends are supported on the lower support in the upside down state,
Both ends of the girder are fixed to the lower support by anchor fixing device,
The upper member and the lower member are completely welded to each other in a state in which a vertical load is applied upward to the upper member of the girder fixed and fixed to the lower support,
Girder using the upper and lower members, characterized in that the residual stress is introduced by the elastic restoring force of the synthesized upper and lower members by removing the vertical load. The girder of claim 1 is fabricated and placed in a branch part,
Connect the standard I-shaped steel between the girder and the girder disposed in the point portion,
Bridge construction and construction method using the girder using the upper and lower members provided with the perforated plate 40 on the upper surface of the girder and the standardized I-shaped steel.

Images