KR101384087B1 - Rahmen bridge construction method using support tendon apparatus and construction method therewith - Google Patents

Abstract

The present invention relates to a rigid-frame bridge which uses a structurally efficient and economical support tension device by reducing a bending negative moment of a support, which is upper ends of both bridge support units, and a manufacturing method for the same. The rigid-frame bridge includes a reverse U-shaped steel girder including a vertical unit fixed to the upper surface of both bridge support units and a girder horizontal unit extended between the upper ends of the vertical unit; a support tension device installed on both ends of the girder horizontal unit to reduce the bending negative moment generated in both supports (both upper ends of the bridge support units in a completed rigid-frame bridge); and a slab concrete formed on the upper part of the steel girder while integrating the steel girder and both bridge supports.

Description

Ramen bridge using branch tension device and its manufacturing method {RAHMEN BRIDGE CONSTRUCTION METHOD USING SUPPORT TENDON APPARATUS AND CONSTRUCTION METHOD THEREWITH}

The present invention relates to a ramen bridge using the point tension device, the production thereof. More specifically, the present invention relates to a ramen bridge using a point tension device which is more economical and structurally effective by reducing the bending moment between the upper and the second bending portions, that is, the bending parent moment between the branch portions and the branch portions.

Due to the recent changes in the Korean Peninsula due to the rise of the river flooding level, the reinforced concrete ramen bridge is installed as a bridge for conventional small rivers by mounting girders between the two shifts, and placing slab concrete integrally with the girder and both shifts. It is common to complete and construct.

In this case, the girder may use a PSC girder, but may also use a girder or a compound girder. At this time, the steel girder uses a steel plate (steel girder of type I or H type cross section), and the composite girder uses a preflex girder (PF girder), a leafless preflex girder (RPF girder), and the like.

The use of such a girder or a composite girder has the advantage that it is possible to construct a ramen bridge between Jangji has been recently constructed a lot.

At this time, even in the case of using the PSC girder, girder girder, and composite girder, the ramen bridge mounts the girder at both shifts, and the response of the structural system to the load at the stage of construction is almost the same.

In other words, the behavior of ramen bridge due to pavement load, vehicle load, earth pressure and temperature change may be somewhat different depending on the stiffness and strength of the material of the girder used in the construction and construction of each bridge. similar.

Therefore, in order to secure economic feasibility especially in the construction of long span synthetic ramen bridges, efficiency before the completion stage, that is, before the slab concrete formation stage, is more important.

As described above, the behavior of the two alternating portions and the girder (based on the bending moment due to the working load) before the slab concrete formation step can be largely divided into a short span structure system and a ramen structure system.

First of all, the behavior of the short span structure system is shown in FIG. 1A, in which the slab concrete is constructed by mounting the girder 20 between the upper surfaces of both shift portions, and then constructing the slab concrete. On the other hand, since the girder has short span behavior and the center of the girder generates a very large bending positive moment (+), the girder pre-stressed by the prestress is pre-introduced in the center of the girder as a way to solve this problem. To respond.

However, if the introduction of prestressTM in the middle of the girder, the size and range of prestresses to be introduced will increase, and there is a problem that there is a limit in that it is not easy to have economic feasibility in the girder manufacturing process and material required for the construction of the ramen bridge. .

Next, when looking at the behavior by the ramen structure system, as shown in Figure 1b, both the ramen bridge 10 to have a height smaller than the height of the completed shift, and the reverse U-shaped girder 30 is mounted on the upper surface of both shifts. In this case, the construction of slab concrete becomes more complicated in comparison with the behavior of the short span structure system, and the girder horizontal part and both vertical parts must be connected to each other to produce the girder. Because the bending moment acting on the reverse U-shaped girder 30 is transmitted to both of the alternating portions 10 by the bending parent moment (-) generated at the upper ends of both the alternating ramen bridges, the reverse U-shaped girder ( 30) can be optimized, and the U-shaped steel girders (30) made of steel resist the bending parent moments that occur largely at both points, thus having a very favorable behavior in the long span ramen bridge. It can be called.

In addition, the ramen bridge (reverse U type girder) based on the ramen structure system can exclude the process such as introducing prestress, but the amount of steel required for fabrication of girder increases, so the economical aspect is significantly different from the short span behavior. There was no limit to this.

Therefore, the present invention provides a ramen bridge that can be behaved by the ramen structural system as the behavior before the slab concrete formation in the ramen bridge, but to minimize the cross section of the girder and the cross section of both shifts to secure economical points together It is a task to solve the provision of the ramen bridge and its manufacturing method using the secondary tension device.

In addition, in the construction of a ramen bridge as a four-row bridge, there is no interference between the two shift parts and the girder, so that the girder can be easily installed at both shifts, and the tensile stress due to the bending parent in the construction of both the shift parts. It is a task to solve the provision of a ramen bridge and its manufacturing method using a structurally very efficient point tension device by enabling to resist effectively.

In order to achieve the above object,

Firstly, in the ramen structure system before the slab concrete formation, the girder uses a girder so that the girder installed at both shifts can perform the ramen behavior, but the girder is an inverted U-shaped steel in which the girder horizontal part and both vertical parts are integrated. Girder is used.

When using the reverse U-shaped girder, bending parent moments are generated at both points, but the radial moment generated at the center of the girder can be reduced relatively compared to the short span structure system. It is very advantageous for construction.

Second, when using the reverse U-shaped girder as described above, it is possible to construct a long span ramen bridge, but it is disadvantageous in terms of materials, thereby reducing economic efficiency. Therefore, the present invention is to introduce a pre-stress for offsetting the bending parents generated in the two point portion, the point portion that can specifically cancel the bending parent moment generated largely in both points using the point tension device Prestress is introduced.

This minimizes the prestress introduction area by the branch tension device and secures the work and economics to install the branch tension device and introduces the tension force, while reducing the member force of the reverse U-shaped steel girders to secure the economic feasibility of the production. As a result, the self-weight of the inverted U-shaped girder is reduced, which is very advantageous for transportation and construction.

Third, the reverse U-shaped girder is composed of a girder horizontal part and both vertical parts. In this case, the inverted U-shaped steel girders use steel materials of various cross sections. However, both vertical parts should be fixedly connected to the alternating part in the vertical installation on the upper surface of both alternating parts. The large area of the upper surface of both alternating parts does not matter much, but especially in the case of four bridges, it is relatively limited to the upper surface area of both alternating parts. Therefore, there was a problem (interference in construction) that it is not easy to secure the working space in the installation of the internal reinforcing bars, connecting plates or connecting brackets of both shifts in the installation of both vertical parts.

Accordingly, the present invention is to minimize the interference caused by the area of the upper surface of the two alternating portion of the vertical U-girder girder, especially in the reverse U-shaped girder, and furthermore, the tension, such as T-shaped steel that acts as a reinforcing bar in the circular steel pipe By installing additional reinforcement materials, while minimizing on-site work, it is possible to make more efficient construction by minimizing the work such as reinforcing bars required for the construction of both shifts.

According to the present invention, it is possible to provide a ramen bridge between the Jangji, and to secure the aesthetic space of the bridge according to the use of a slimmer girder and to enhance the aesthetics.

In addition, since the ramen bridge of the present invention uses a steel girder, it may be referred to as a synthetic ramen bridge, and the bending parent moments at both points and the bending moments at the center may be used while using an inverted U-shaped steel girder that performs ramen behavior at the stage before slab concrete is formed. Can be effectively offset by using a tension device in the branch portion can be economically reduced (optimization of the cross-section) of the amount of steel required for the production of inverted U-shaped girder.

In addition, in the construction of four-bridge ramen bridge, both vertical parts of the inverted U-shaped steel girders are made of circular steel pipes so that the inverted U-shaped steel girders are installed on the upper surfaces of both alternating parts so that the workability and workability are low. In addition, it is possible to secure enough, and if additional tensile stiffeners are installed on both vertical parts, which are circular steel pipes, it can effectively resist the tensile stresses generated in the concrete at the point due to the bending parent moment occurring at both points. The used girder can be used more effectively.

1a and 1b is a front view and a bending moment diagram showing the behavior before the slab concrete formation in the conventional ramen bridge,
Figure 1c is a connection configuration of the girder and the alternating portion in the conventional social mating,
Figure 2a, 2b, 2c and 2d is a perspective view and excerpt perspective views of the ramen bridge using the point tension device according to the present invention,
Figure 3a, Figure 3b and Figure 3c is a construction sequence diagram of the ramen bridge using the point tension device according to the present invention,
4a, 4b and 4c is a bending moment diagram according to the construction step of the ramen bridge using the point tension device according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. 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 order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless otherwise stated. Also, the term "part" or the like, as described in the specification, means a unit for processing at least one function or operation, and may be implemented by hardware, software, or a combination of hardware and software.

[Ramen action of the present invention]

Figure 2a shows a perspective view of the configuration of the ramen bridge 100 using the point tension device according to the present invention.

First, the ramen bridge 100 using the point tension device includes both alternating parts 110, inverted U-shaped girder 120 and the point tension device 130.

First, the two alternating parts 110 are constructed as a reinforced concrete structure on the ground before the ramen bridge is constructed as a wall structure to be constructed in the construction of the ramen bridge.

Normally, a wall portion extending perpendicular to the foundation installed on the ground is formed to install an alternating portion, and the reverse U-shaped girder 120 is mounted to be installed in the axial direction between the alternating upper surfaces.

At this time, the two shift parts to secure the final construction height (H) to secure the height (H2 = H-H1) except for the height (H1) of both vertical portions 121 of the reverse U-shaped girder 120 which will be described later In addition, the lower portions of both vertical portions 121 of the reverse U-shaped girder 120 are installed to be connected and fixed to the upper surfaces of both shift portions 110 having the height H2.

Both vertical parts 121 of the reverse U-shaped girder 120, which will be described later, so that the connecting bracket 123 is separately installed as shown in FIG. 2C on the upper surfaces of both shift parts 110, the anchor bolts are connected to the connecting bracket 123. In a simple fastened manner by the reverse U-shaped girder 120 can be easily connected to both shifts.

In addition, as shown in FIG. 2B, the inner reinforcing bars 111 and the reinforcing bars are extended upward, so that the alternating parts are poured together with the slab concrete around both vertical parts of the reverse U-shaped girder 120. The internal reinforcing bar is buried so that the synthetic capacity can be secured (integrated).

As a result, the slab concrete, which will be described later, allows the internal reinforcing bars extending from both shift portions to be integrally formed with the two shift portions by the placed slab concrete.

The reverse U-shaped girder 120 of the present invention is installed on the upper surfaces of both of the alternating portions 110, and the reverse U-shaped girder 120 includes a vertical portion 121 and a girder horizontal portion 122. .

The reverse U-type girder 120 may use a girder having various cross sections, such as an I-type or H-type steel, and a plurality of girders may be spaced apart from each other in the transverse direction.

The reverse U-shaped girder 120 may be manufactured integrally, but may also be manufactured by connecting a plurality of steel materials to each other.

It can be seen that the inverted U-shaped girder 120 is formed in an inverted U shape as a whole. When both vertical portions 121 are fixed to both shifts, both shift portions and the girder behave in a ramen structure system in the construction process. Therefore, the bending parent moment (M-) is generated at the portion (both points) connected to both vertical portions and the girder horizontal portion, and the bending constant moment (M +) is generated at the girder horizontal portion 122,

The bending constant moment of the girder horizontal portion 122 can be reduced in size compared with the girder generated at both ends of the simple supporting state, thereby optimizing the inverse U-shaped girder cross section.

However, this optimization is inevitably increased the amount of steel for girder fabrication compared to the girder consisting only of the girder horizontal portion by using both vertical portions 121.

That is, since the amount of steel used increases as the two vertical portions 121 are further formed as opposed to the simple support at both ends, the effect of material saving is not large.

In the present invention, if the inverse U-shaped girder 120 can further reduce the size of the bending parent moment occurring in both points in the ramen structure system by using the reverse U-shaped girder 120 It is possible to minimize the amount of steel (120).

To this end, the present invention introduces compression prestress only to both end portions of the girder horizontal portion 122 of the point portion, as shown in FIG. 2B.

This is because it is only to reduce the size of the bending parent occurs in the two point portion is easy to install, and also easy to work on the girder horizontal portion 122, including the tension member 131 and the fixing member 132 only on the upper end of both sides The point tension device 130 is to be installed.

After the fixing utensils 132 are installed on the upper surfaces of both sides of the girder horizontal portion 122 of the inverted U-shaped girder 120 so as to be horizontally spaced from each other, and the tension member 131 is installed between the fixing utensils 132, the tension member. After tensioning the 131 using a hydraulic jack (not shown), both ends are fixed to the fixing unit 132.

Accordingly, the compressive prestress due to tension and fixation of the tension member is transmitted to the girder horizontal portion 122 and both vertical portions 121 connected thereto, and acts as a reaction force resisting the bending moment in the ramen structure system, thereby inverting U of the present invention. In the ramen structure system of the mold girder 120 and the two alternating portions 110, the bending parent moments of the two alternating portions (the branch portions) can be more effectively reduced.

Furthermore, the bending pre-moment acting on the reverse U-shaped girder 120 between the two points by the compression prestress can also be reduced, thereby making the reverse U-shaped steel girder 120 of the optimum cross section.

Accordingly, the present invention can reduce the amount of steel used even by using the point tension device 130 even if the inverse U-type inverted U-shaped girder 120 by both vertical portions 121, the ramen of the present invention In the structural system, it is possible to secure sufficient structural and material advantages.

2C and 2D, in particular, it can be seen that both vertical portions 121 of the steel girders of the present invention use circular steel pipes as steel materials.

When the circular steel pipe is used, even when the Ramen bridge is constructed as a four-row bridge, regardless of the cross-sectional shape of the girder horizontal section on the upper surface of both alternating sections, load transfer, interference with internal reinforcing bars and two alternating sections, and space-time interference such as anchor bolts, etc. It will not affect the work of the back.

That is, in the case of the four-row bridge as shown in FIG. 1c, when both vertical portions 31, which are I-type or H-type steels, are used, the interference of construction occurs in the installation of anchor bolts for fixing the position of the internal reinforcement and the vertical portion to the alternating portion. In this case, the vertical portion 31 may be disposed to deviate from the girder horizontal portion 32, or the vertical portion 31 may be manufactured by a parallelogram, etc. In this case, there is a disadvantage in that it is disadvantageous due to distortion.

However, in the case of the present invention, if the girder horizontal portion 122 uses I-type or H-type steel (as well as circular section, square section, U-shaped section (opening type), etc.) as shown in FIGS. 2C and 2D, Since the vertical portion 121 is a circular steel pipe is used to integrate the connecting plate of the horizontal plate form on the upper surface of the vertical portion 121 of the circular steel pipe, and also integrated the bottom of the end portion of both horizontal girders to the connecting plate (anchor bolt, etc.). By using it, you can simply integrate the circular steel pipe and I- or H-shaped steel.

At this time, it is obvious that the round steel pipe may include an elliptical steel pipe and a closed pipe type pipe.

Of course, in order to connect to the upper surface of both of the alternating portion 110 by using the connection plate of the horizontal plate form as it is to be able to fix the connecting plate to the upper surface of the two alternating portion by the anchor bolt, as shown in Figure 2c separate connection bracket ( 123) does not matter.

The connection bracket 123 can be said to be simply connected to each other using an anchor bolt and a fixing nut when mounting the reverse U-shaped girder 120 of the present invention to both shifts.

Furthermore, both point portions of the present invention will generate a large cross-sectional force due to the generation of the bending parent moment before, during the construction of the slab concrete 141.

This cross section force can be resisted by the slab concrete and steel girders coated by concrete casting, but in order to effectively resist such cross section force,

The present invention basically uses a method of integrating the internal reinforcement and the inverted U-shaped girder extending to the upper surface of the two alternating parts and then integrating each other by pouring slab concrete.

However, according to the present invention, both vertical portions connected to both alternating portions are used to reinforce the internal reinforcing bars by further integrating additional reinforcing bars or steel sheets or angles in the vertical direction on the outer circumferential surface of the circular steel pipes. Done.

The reinforcing bar or steel sheet or angle is to be formed on both sides of the alternating portion in particular in the outer peripheral surface of both vertical portions 121 to act as a tensile reinforcement 125 that can resist the tensile stress caused by the bending parent.

The reason is that concrete is vulnerable to tensile stress, so if the resistance can be effectively resisted, both vertical parts, which are circular steel pipes, can be used more efficiently, and the reinforcement effect can be maximized at both shifts with large cross-sectional forces.

Accordingly, the tensile reinforcement 125 is embedded in the alternating portion concrete which is poured together with the slab concrete,

The tensile reinforcement 125 is a T-shaped steel using the upper surface of the T-type steel to be connected to the lower flange bottom surface of the steel girder horizontal portion, the integral behavior of the tensile reinforcement 125 in the inverted U-shaped girder 120 It will be possible.

After all, the steel composite ramen bridge (steel girder and reinforced concrete alternating parts) by the ramen structure system is used for the construction of the final steel composite ramen bridge depending on how to effectively manage the cross-sectional force of the members largely generated at both points. Since the member usage can be minimized, it is possible to secure enough economics accordingly.

Therefore, the present invention is the use of the reverse U-shaped girder to minimize the cross section of the girder horizontal portion of the girder, the point portion for efficiently reducing the bending moment of the two alternating portions in the use of the reverse U-shaped girder 120 The use of the tension device 130, in the use of both vertical parts of the reverse U-shaped girder, the use of round bridges, etc., the use of round steel pipes to ensure work and construction, the cross-sectional force of both alternating parts in the use of both vertical parts of the circular steel pipes It can be seen that the tensile reinforcing material 125 is used to effectively resist the resistance.

When both of the alternating portion 110, the reverse U-shaped girder 120 is formed, the tension reinforcement 125 is formed, the point tension device 130 is completed using the final die not shown, both the upper and the slab The slab reinforcement for the formation and slab and alternating concrete is placed so that the slab concrete 141 can be constructed while integrating the final two shift portions and the girder.

In this case, the concrete may be divided into slab concrete for slab formation and alternating concrete for covering both vertical portions, and such concrete is poured in one piece.

When the traffic load is generated in the slab concrete 141, the load to the bridge of the ramen structure is to be transmitted to both of the alternating portion 110 and the ground.

[Ramen construction method of the present invention]

Figures 3a, 3b and 3c shows a flow chart of the ramen bridge construction method of the present invention.

First, as shown in FIG. 3a, the ramen bridge must be constructed so that both shift portions 110 are constructed on the ground of the position.

The alternating portion 110 is to be constructed as a reinforced concrete structure, but it is common to manufacture the cast-in-place concrete using the formwork, but it is not to exclude the construction as a precast structure.

The height H1 of the final shift portion 110 is formed to have a height H2 of approximately half at the final construction height H of the shift portion, and internal reinforcement 111 is formed on the upper surfaces of the shift portions 110. The slab concrete 141 and the two alternating parts 110 may be integrated by the concrete that is poured during the construction of the slab concrete 141.

The internal reinforcement 111 may be bent to the upper surface of the girder horizontal portion 122 of the reverse U-shaped girder 120, or may be connected to the slab concrete reinforcement with a coupler.

In addition to proceeding with the construction of both of the alternating portion 110 to prepare a reverse U-shaped girder 120 of the present invention.

Since the reverse U-shaped girder 120 includes both vertical portions 121 and girder horizontal portions 122 as inverted U-shaped as shown in FIG. 3B, the fabrication of the reverse U-shaped girder 120 is completed in advance in the factory. ,

In particular, in the present invention, using the point fixing unit 130 installed above the upper end of both ends of the girder horizontal portion,

The girder horizontal portion 122 uses H-type or I-type steel, but both vertical portions 121, which are circular steel pipes, are formed on both bottom surfaces thereof.

It can be seen that the tensile reinforcing material 125, which is, for example, T-shaped steel, is formed on the outer circumferential surface of both vertical portions 121, which are the circular steel pipes.

Accordingly, as shown in FIG. 3B, the reverse U-type girder 120 is mounted on the upper surfaces of the two shift portions 110, and then connected and fixed to be integrated with each other.

The inverted U-shaped girder 120 is installed so as to be bound to each other by using at least one or more in accordance with the transverse width of the ramen bridge along the transverse extension length of the two alternating portion.

The ramen bridge has advantages in being used in bridges with an extension length of 20 to 30m in length, but the control (reduction) of bending moments occurring at both shifts is most important.

The present invention can effectively control such a U-shaped steel girders 120 in order to optimize the end is provided with a point tension device 130 is possible to provide a more economical bridge of the ramen structure.

Fixing of the reverse U-shaped girder 120 will be a task for fixing both vertical parts on the upper surface of both shifts, and the fixing plate, the connection brackets may be fixed by using anchor bolts on the upper surfaces of both shifts.

Next, as shown in FIG. 3c, the slab concrete 141 is constructed, but the upper portions of both shift portions are exposed to both vertical portions, so that the molds are coated to form slab concrete so that the girder is embedded. First, after installing the necessary slab concrete reinforcement, and then to install both the vertical portion of the inverted U-shaped girder 120 and the concrete for slab concrete construction to construct the ramen bridge of the present invention.

Along with the slab concrete 141, the alternating portion concrete 142 is also formed so that both vertical portions are embedded.

Finally, according to FIG. 4a, when the inverted U-shaped girder 120 of the present invention is connected and fixed to both shift portions 110, the bending parent moment between the two shift portions, both the point portions, and the both point portions before the slab concrete construction is performed. It can be seen that (-) and 휭 positive moments (+) are respectively generated.

When the compression prestress (P) is introduced between the two shifts and the two points and both points, as shown in Figure 4b through the point tension device 130 of the present invention,

As shown in FIG. 4c, when the final slab concrete and the alternating concrete are constructed, it can be seen that both the bending parent moment (−) and the positive moment (+) are reduced.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

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 their equivalents are to be construed as being included within the scope of the present invention do.

100: ramen bridge using the branch tension device
110: shift
120: reverse U type girder
121: vertical part
122: girder horizontal
123: connecting bracket
111: internal rebar
125: tensile reinforcement
130: branch tension device
131: tension
132: anchorage
141: slab concrete 142: alternating concrete

Claims (5)

An inverted U-shaped girder 120 including a vertical portion 121 fixedly connected to upper surfaces of both shift portions 110 and a girder horizontal portion 122 extending between upper ends of the vertical portions;
Branch tension device 130 is installed only at both ends of the girder horizontal portion to reduce the bending parent moment generated in both point portions and the bending constant moment generated in the reverse U-shaped girder 120; And
The slab concrete 141 is formed on the top of the girder while the alternating girders and the two alternating portions are integrated; The vertical portion 121 of the inverted U-shaped girder 120, both ends of the girder horizontal portion 122 Use the round steel pipe formed on the bottom,
Ramen bridge using the point tension device, characterized in that the tensile reinforcing member (125) is formed on the outer peripheral surface of the vertical section of the circular steel pipe and the tensile reinforcing member is connected to the lower flange of the girder horizontal portion. delete The method according to claim 1,
The vertical portion 121 of the reverse U-shaped girder 120 is connected to each other with a connection bracket 123 formed on the upper surface of the upper and lower portions of the reverse U-shaped girder 120 to be connected and fixed to both alternating portions.
The slab concrete is a ramen using a point tension device, characterized in that the internal reinforcement 111 extending from both shifts to be formed integrally with both shifts by the slab concrete 141 is extended toward the slab concrete. Kyo. Girder horizontal portion 122, the branch portion tension device 130 is installed only at both ends; And inverted U-shaped steel girders 120 including both vertical portions 121 formed of circular steel pipes formed on both bottom surfaces of the girder horizontal portions.
By connecting and fixing the two vertical portions 121 to the upper surface of the two alternating portion 110 previously constructed, the U-shaped girder 120 is mounted on both of the alternating portions 110, and then fixed to be connected.
Compression prestress is introduced to both points using the point tension device 130 in order to reduce the bending parent moment occurring in both point portions and the bending constant moment occurring in the reverse U-shaped steel girders 120,
And forming slab concrete 141 on the girder while the girder and the two shift portions are integrated.
The tensile reinforcing member 125, which is a T-shaped steel, is formed on the outer circumferential surface of the vertical portion of the circular steel pipe so that the tensile reinforcing member is connected to the lower flange of the girder horizontal part, which is a steel of I-type or H-shaped cross section, and the vertical portion of the reverse U-shaped girder. (121) is connected to each other and the connection bracket formed in advance on the upper surface of the two alternating portion so that the reverse U-shaped girder is connected to the two alternating portion, the slab concrete is an internal reinforcement extending from the two alternating portion is extended toward the slab concrete Method of producing a ramen bridge using the point tension device, characterized in that to be formed integrally with both alternating parts by the cast slab concrete. delete

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