KR20060025855A - Construction method of double composite plate girder railway bridge with precast concrete panels - Google Patents

Abstract

The present invention relates to a method for constructing a double composite railway plate-shaped bridge having a precast panel, comprising: a mold mounting process for arranging a pair of I-girders (10) having upper and lower flanges in parallel to an upper part of an alternating or pier; Precast panel mounting step of mounting the precast panel 30, the pre-fabricated panel 30 on the upper flange 11 of the I-girder 10, and the pre-precision panel to the inflection point due to dead weight A concrete bottom plate construction process for constructing the concrete bottom plate 40 on the upper part of the cast panel 30, and an upper bottom plate construction process for pouring the upper bottom plate 20 on the upper portion of the I-type girder 10; And a synthetic process in the constant moment region in which the connecting portion 60 made of concrete or non-contraction mortar is constructed on both ends of the precast panel 30 and the upper surface of the lower flange 11 in the constant moment region. According to this, the bottom plate is constructed as a precast panel and by adding concrete to the parent area, securing the rigidity, the cross section of the mold can be reduced and the reinforcement can be reduced.

Plate-shaped bridge, precast panel, parent cement, concrete, composite

Description

Construction method of double composite plate girder railway bridge with precast concrete panels

1 is a schematic configuration diagram showing an upper structure of a railroad plate-shaped bridge according to the prior art;

Figure 2 is an external view showing a railroad plate bridge according to the prior art as a whole;

Figure 3 is a view showing that the thickness of the flange of the I-girder of the railway plate-shaped bridge according to the prior art varies in the axial direction;

4 is a schematic structural diagram showing a superstructure of a double composite railroad plate bridge having a precast panel according to the present invention;

5 is a detailed view of the precast panel of the present invention;

Figure 6 is a view showing the thickness change of the concrete deck of the present invention;

7A to 7E are explanatory views showing, in process order, a method of constructing a double composite railroad plate bridge having a precast panel according to the present invention;

Fig. 8 is an external view of the double composite railway plate-shaped bridge having the precast panel according to the present invention as a whole.

※ Explanation of symbols about main part of drawing ※

10: I type girder 11: lower flange

12 stud 20 upper bottom plate

30: precast panel 32: rebar

34: projection 40: concrete deck

50: diaphragm 60: connection

The present invention relates to a method for constructing a double composite rail plate bridge, and more specifically, the bottom plate is constructed of a precast panel, and the cross section of the mold is reduced by adding concrete to the parent cement area to secure rigidity, thereby improving reinforcement. The present invention relates to a method for constructing a double composite railroad plate bridge having a precast panel that can be reduced.

In general, plate bridges widely used for supporting rails for rail transportation refer to bridge bridges that are formed by combining steel plates among girder bridges whose superstructures are designed according to Voyron.

It is known that the type of mold used in the plate-shaped bridge is of various structures, and it is more efficient to bend or shear the I-type girder as the mold.

1 is a schematic configuration diagram showing an upper structure of a railway plate-shaped bridge according to the prior art, showing a form of a two-wall plate-shaped bridge in which a pair of I-type girders 1 are installed at an upper part of an alternating or pier. 1) has a flange 1a formed at a predetermined width and thickness at the upper and lower ends, respectively.

In addition, an upper bottom plate 2, which is a portion directly receiving a traffic load of a train, is installed at an upper portion of the I-type girder 1, and is fixed to the rail 3 at an upper portion of the upper bottom plate 2.

In general, loads are a major cause of stress and deformation of each member constituting the bridge, and the loads used in the design of road bridges and railway bridges are considered as main loads and loads in terms of load frequency, operation method, and impact on structures. It is divided into medium and special loads.

The main load is a load that always or frequently acts when designing the main structural part of the bridge and has a decisive effect on the load capacity.The load, which does not always or frequently acts, can affect the load capacity. This is a load that must be considered in the combination of loads. In addition, special loads are loads that must be specially considered depending on the type of bridge, type of structure, and the situation of construction site.

In another aspect, the dead load, which is the continuous weight of the bridge itself and the additives (water pipe, gas pipe, etc.) added to the bridge, and the live load, which is a load that moves on the bridge like a vehicle or a crowd, acts as a future load. Considering the increase, proper load is assumed and used as standard live load in the design of bridges.

In general, when looking at the structural characteristics of the bending moment generated when dead and live loads are applied, the bending moment of the parent moment section acts relatively larger than the bending moment of the constant moment section. Segments predominantly govern bridge structure specifications.

That is, the bridge is designed in consideration of the above loads, in the case of a two-bar plate-shaped bridge, in order to maintain a constant height, the thickness of the steel plate must be used in the direction of the bridge (see Fig. 3), many stiffeners to prevent buckling Is fixed by welding or the like, and in order to increase the torsion resistance, a large number of bracings 4 are provided at the bottom (see FIG. 2). In addition, due to such design constraints, the steel amount of the entire bridge is increased and the workability is poor.

In particular, railway bridges, unlike road bridges, are the dominant stiffness of the cross-section and dominate the design due to large live loads.

And, in the case of a general steel box bridge, the bottom plate can be poured without formwork after the mold is mounted, but in the case of plate bridge, there is a lot of air to install the formwork and remove it after the bottom plate is completed, as well as concrete curing. There is a problem.

Accordingly, the present invention is to solve the above-described problems, the construction of a double composite structure in which the lower bottom plate to the general plate-shaped bridge bridge as a precast panel and additionally cast concrete in the parent cement area to efficiently increase the rigidity It is an object of the present invention to provide a method for constructing a double composite railroad plate bridge having a precast panel which can reduce the mold cross section and reduce the reinforcement by increasing the buckling strength.

As a technical configuration for achieving the above object, the present invention provides a mold mounting process for arranging a pair of I-type girders having upper and lower flanges in parallel to an upper part of an alternating or pier, and a pre-fabricated free Precast panel mounting process for placing cast panels on the upper flange of the I-girder, and concrete floorboards for installing concrete floorboards on top of the precast panels from the point where the parent moment acts to the inflection point due to dead load A construction process, an upper bottom plate construction process for placing an upper bottom plate on top of the I-girder, and a connection of concrete or non-shrink mortar on both sides of the precast panel and the upper surface of the lower flange in a constant moment region Construction of Double Composite Railroad Bridges with Precast Panels including Synthesis Process in the Constant Moment Region The law is due to maryeonham.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a schematic configuration diagram showing a superstructure of a double composite railway plate-shaped bridge having a precast panel constructed by a construction method according to the present invention, in which a pair of I-type girders 10 are installed on an upper portion of an alternating or pier. .

The I-girder 10 has a flange formed in a predetermined width and thickness at the upper and lower ends, respectively, and the upper bottom plate 20, which is a portion directly receiving the traffic load of the train, is installed on the upper portion of the I-girder 10. do. Of course, the I-girder 10 is a commonly used steel material and structure is adopted.

In addition, a precast panel 30 is positioned between the I-type girder 10, and both ends of the pre-cast panel 30 in the width direction of the pre-cast panel 30 have a lower flange of the I-type girder 10 ( 11) It will be placed on the top.

As shown in more detail in FIG. 5, the precast panel 30 has a plurality of reinforcing bars 32 protruding from both ends, and the upper surface of the precast panel 30 is roughly formed or has a plurality of protrusions 34. ) Is formed to increase the bonding strength with the concrete. Preferably, the reinforcing bar 32 may be prepared in a form surrounding the upper part of the precast panel 30.

The precast panel 30 is used as a formwork in the parent area, the concrete floor plate 40 is constructed on the upper part of the precast panel 30. Of course, for the construction of the concrete bottom plate 40, it is preferable that several studs 12 are fixedly fixed by welding on the lower portion of the I-type girder 10 and the upper portion of the lower flange 11.

As shown in FIG. 6, the concrete floor plate 40 is formed to have a maximum thickness over a predetermined length along the length direction, including a portion where the parent moment acts as a maximum, and then a portion having a smaller thickness than that is a predetermined length. Is continuous throughout. In addition, the concrete bottom plate 40 is not constructed in the constant moment region.

In addition, the lower portion of each of the I-type girder 10 and the central portion of the upper bottom plate 20 are connected by the truss diaphragm 50, which diaphragm 50 is ubiquitous and lateral in design. The review can be installed if necessary.

Hereinafter, a method for constructing a double composite railway plate-shaped bridge having a precast panel according to the present invention will be described in the order of steps.

[Mould Mounting Process]

As shown in Fig. 7A, a pair of steel cast I-girders 10 are provided on top of alternating or pier not shown at appropriate intervals parallel to each other.

Of course, the I-type girder 10 is provided with a flange having a predetermined width and thickness at the top and bottom.

[Precast Panel Mounting Process]

As shown in Fig. 7B, a precast panel 30 made in advance is mounted between the I-girder 10 by a crane.

At this time, both ends of the precast panel 30 are respectively mounted on the upper end of the lower flange 11 of the I-type girder 10, the lower flange 11 of the portion where the precast panel 30 is not mounted The stud 12 and the lower abdomen is formed to protrude upward.

[Concrete Deck Construction Process]

As shown in FIG. 7C, a concrete floor plate 40 is constructed on the upper part of the precast panel 30, and the concrete floor plate 40 is formed from an inflection point due to dead weight at the point where the parent moment works at the maximum. According to the size of the moment, the thickness of the concrete deck 40 may be changed. Of course, the concrete base plate 40 is constructed to include the site where the stud 12 is formed is made with the mold, such a stud 12 is sufficient to transfer all the axial force of the concrete base plate 40 The strength must be secured and, if necessary, can be installed by welding on the upper surface of the lower flange 11 as well as the lower part of the abdomen.

[Top Bottom Plate Construction Process]

Subsequently, the upper bottom plate 20 is poured on the upper portion of the I-type girder 10 to complete the upper structure of the railway plate-shaped bridge.

Of course, if necessary through the ubiquitous and lateral load examination, each lower portion of the I-type girder 10, and the central portion of the upper bottom plate 20 may be connected by the truss diaphragm (50).

[Synthesis process in the constant moment region]

In the constant moment region, as shown in FIG. 7E, the concrete floor plate 40 is not constructed over the entire area of the precast panel 30, except that both end portions and the lower flange 11 of the precast panel 30 are constructed. In some areas, including the upper surface of), a connection 60 made of concrete or non-contraction mortar is constructed for synthesis.

According to the synthesizing process in the constant moment, the I-type girder 10 is formed with the precast panel 30 and the mold, i.e., in the region of the constant moment, after the upper base plate 20 has been cast and all the secondary dead weights have risen. Since the type girders 10 are connected to the lower precast panel only for live loads, it is possible to prevent excessive cracking and to increase the torsional strength not as a composite section in the constant moment section. Consider it in the design. At this time, since there is no connection between the precast panels, it is possible to reduce the cracking of the panel by acting as a crack-induced joint at the joint portion by the tensile deformation caused by the live load.

Also, as shown in Fig. 8, the precast panels are arranged at regular intervals in the lower part, so that they are aesthetically superior.

As described above, according to the double-synthetic railway plate-shaped bridge construction method having a precast panel according to the present invention, by placing the precast panel between the I-girder and the concrete floor plate on the top of the precast panel due to buckling The problem is solved, whereby the thickness of the lower flange and the abdomen is reduced.

In addition, it is possible to minimize the thickness change of the lower flange by the construction of the concrete deck, and the lower bracing for strength reinforcement has an unnecessary effect.

In addition, since the formwork supporting structure is unnecessary, the long span can be achieved.

In addition, the work space is secured at the top of the precast panel or concrete floorboard and has an effect of easy maintenance.

In addition, when calculating the cross section with the same bridge bridge, it is possible to reduce the mold height to a considerable extent.

In addition, the dynamic behavior is excellent, as well as the corrosion protection environment of the steel inside the box has a good effect.

Claims (2)

A mold mounting process for arranging a pair of I-girders 10 having upper and lower flanges in parallel to the upper part of an alternating or pier, A precast panel mounting process in which a precast panel 30 prepared in advance is placed on an upper portion of the lower flange 11 of the I-type girder 10, Concrete floor plate construction process for constructing the concrete floor plate 40 on the top of the precast panel 30 to the inflection point due to dead load at the point where the parent moment is the maximum action, An upper bottom plate construction process of pouring the upper bottom plate 20 on the upper portion of the I-type girder 10; Precast panel comprising a synthesis process in the constant moment region in which the connecting portion 60 of concrete or non-contraction mortar is constructed on both ends of the precast panel 30 and the upper surface of the lower flange 11 in the constant moment region. Construction method of double composite rail plate-shaped bridge having a. 2. The method of claim 1, wherein the lower flange (11) has a plurality of studs (12) protruding from the upper portion of the lower flange (11).

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