KR20090122608A - Prestressed concrete composite girder - Google Patents

Abstract

PURPOSE: A PSC composite beam for integrally manufacturing a bridge deck and a cross beam is provided to reduce the crack incidence by making the lower part of a beam at the compression stress state and to shorten the construction period by simplifying the process. CONSTITUTION: A PSC composite beam(100) for integrally manufacturing a bridge deck and a cross beam is composed of a bridge deck which is integrally formed in the upper part, cross beams which are integrally formed in both sides to be projected, and a horizontal tendon which is each inserted into a horizontal post-tensioning sheath pipe of a bridge deck and a cross beam to apply the horizontal prestress.

Description

PS composite girder which manufactures bridge deck and cross beam integrally {PRESTRESSED CONCRETE COMPOSITE GIRDER}

The present invention relates to a PSC composite girder, in particular, to form a composite girder by integrally fabricating the girder, bridge deck and crossbeam, and then mounted the composite girder on the bridge or alternating girder and transverse between the composite girder and the adjacent composite girder The present invention relates to a PSC composite girder that integrally fabricates a bridge deck and a crossbeam to introduce post-tensioning in a direction.

Pre-stressed concrete is called prestressed concrete (PSC) in order to offset the tensile stress that occurs in concrete.In this case, the prestress of concrete is applied to the concrete with tension of PC steel (PC steel wire, PC steel rod, etc.). It is introduced by fixing. The emergence of this PSC structure created an opportunity to overcome the shortcomings of RC concrete, which is vulnerable to tension. Currently, the use of PC steels is active and various construction methods are being developed.

In particular, synthetic girder bridges with PSC girders are more constructed than other types of bridges in the field of bridge construction in Korea, and the demand is expected to continue to increase in view of Korea, where most bridges between small and medium-sized sites are constructed.

In conventional bridge systems using PSC girders, PSC girders are manufactured at a site near a factory or a bridge construction site, transported to the site, mounted on the bridge, or mounted between bridges and bridges, and then concrete-floored by slaying concrete. And crossroads were constructed.

However, when the bridge deck is constructed with cast-in-place concrete, it requires a lot of construction costs because it requires work by manpower, such as installation of copper bars and formwork, and there is a problem in that a long construction period is required according to the curing period of concrete. .

In order to solve this problem, recently in the bridge system using the PSC girders, instead of the site-cast concrete bridge deck, the bridge deck is manufactured in advance at the factory or the site, and then transferred to the site to transfer the PSC girder. The method of constructing the bridge deck is proposed, which also requires a lot of construction costs due to the connection process between the girder and the bridge deck and separate cross beam placement, and a long construction period depending on the curing period of the concrete. There is a problem.

The present invention is to solve the problems as described above, after forming the girder and the bridge deck and cross beams integrally to form a composite girder and then mount the composite girder on the bridge or alternating bridge and the bridge deck and cross beams of the composite girder and neighbor By adopting post-tensioning in the transverse direction to bridge decks and crossbeams of composite girders, the construction process can be greatly shortened by the simplification of the process, and the long span of the PSC girder bridge can be made, The objective is to provide a PSC composite girder that can be made in a single state, so that the bridge deck and cross beams can be manufactured integrally to greatly reduce the possibility of cracking.

Features of the present invention for achieving the above object,

In the PSC girder, the bridge bottom plate is integrally formed on the upper surface, and at least one cross beam is integrally formed on both sides of the PSC girder.

Here, the bridge bottom plate and the cross beams are embedded with a sheath pipe for a number of transverse post-tension in the width direction.

Here, the PSC girder is arranged in the transverse direction by placing a plurality on the pier or alternating to insert the tendon in the transverse post-tension sheath pipe formed in each bridge deck and crossbeam, respectively to introduce the transverse prestress. .

According to the PSC composite girders to integrally produce the bridge deck and cross beams of the present invention configured as described above, after forming the girder and bridge bottom plate and cross beams integrally to form a composite girder and then mount the composite girder on the piers or shifts The bridge bottom plate and cross beam of composite girder can be integrated into the bridge bottom plate and cross beam of neighboring composite girders to facilitate post-tensioning, greatly shorten the construction period, and make the bottom of the girder an appropriate size. It can be made in the compressive stress state of the has the advantage that can greatly reduce the possibility of cracking.

In addition, according to the present invention by constructing a cross beam integrally to the PSC composite girders there is an advantage that can be prevented from falling when transporting or mounted on the piers or shifts.

In addition, there is an advantage that the long span can be achieved by introducing longitudinal prestress into the PSC composite girders according to the present invention.

Hereinafter, with reference to the accompanying drawings, the configuration of the PSC composite girders to integrally produce the bridge deck and crossbeams according to the present invention will be described in detail.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

1 is a perspective view showing the configuration of a PSC composite girder for integrally manufacturing a bridge deck and a cross beam according to the present invention, Figure 2 is a cross-sectional view AA of Figure 1, Figure 3 is a cross-sectional view BB of Figure 1, Figure 4 PSC composite girder integrally manufacturing the bridge deck and crossbeams according to the present invention is a perspective view showing the state mounted on the piers.

1 and 4, the PSC composite girder 100 integrally manufacturing the cross beam and the bridge bottom plate according to the present invention, the bridge bottom plate 110 is integrally formed on the upper surface, the cross beam 120 on both sides Is integrally formed to protrude. In this case, the horizontal beam 120 may be formed as many as necessary according to the selection.

At this time, the PSC composite girder 100 embeds a plurality of longitudinal post tension sheath tubes 140 in the longitudinal direction at the lower end and the center thereof, and introduces longitudinal prestress by inserting the longitudinal tendons 130 therein.

In addition, the bridge bottom plate 110 and the cross beam 120 embed a plurality of sheath pipes 160 for post tension in the width direction.

In addition, the PSC composite girder 100 is arranged in the transverse direction and placed in the pier or alternating lateral after the transverse post tension sheath pipe 160 formed in each bridge bottom plate 110 and cross beam 120 Directional tendons 150 are inserted respectively to introduce transverse prestress.

On the other hand, the sheath tube 140 for the longitudinal post-tension and the sheath tube 160 for the lateral post-tension are preferably installed so as not to interfere with each other.

Hereinafter, with reference to the accompanying drawings manufacturing process and operation of the PSC composite girder to manufacture a bridge deck and cross beams in accordance with the present invention in detail as follows.

5a to 5c is a girder bridge by the PSC composite girder to integrally manufacture the bridge deck and crossbeams according to the present invention, and the stepped stress state of the existing technology I (conventional PSC girder bridge) and the existing technology II (multi-stage tensioned PSC girder bridge) The figure which shows.

First, the formwork is assembled by using a traditional panel using plywood or an improved panel such as Eurofoam, and the frame is assembled by binding the deformed steel bars in the formwork individually, or by using a separate work from the outside. Input. In this case, formwork is formed so that the bridge bottom plate 110 and the cross beam 120 are formed together.

Then, the sheath tube 140 for longitudinal post tension is arranged in multiple stages to introduce the longitudinal tendon 130. At this time, the sheath pipe for longitudinal post-tension 140 is preferably fixed to a separate fixing means so that the position at the time of concrete placement in the formwork.

In addition, in order to introduce the transverse tendon 150, the sheath pipe 160 for the transverse post tension is arranged at equal intervals on the bridge bottom plate 110, and arranged in multiple stages on the cross beam 120. At this time, it is preferable that the sheath pipe 160 for the post-post tension is fixed to a separate fixing means such that the position is fixed when the concrete is placed in the formwork. At this time, the sheath pipe for transverse post tension 160 is installed so that there is no mutual interference with the sheath pipe for longitudinal post tension 140.

When the curing is completed by putting concrete into the formwork, the longitudinal tendon 130 is installed in the sheath tube 140 for the longitudinal post-tension, and the post-tensioning is performed to introduce a predetermined compressive stress and a camber. .

Then, the PSC composite girders 100 introduced with longitudinal post-tensioning are mounted between alternations and shifts, alternations and piers, or between piers and piers. At this time, overturning is prevented by the horizontal beams 120 protruding from both sides of the PSC composite girder 100.

On the other hand, during mounting, the side of the bridge bottom plate 110 of the PSC composite girder 100 and the side of the bridge bottom plate of the neighboring PSC composite girder are in contact with each other, formed on the bridge bottom plate 110 and crossbeam 120 The sheath pipe 160 for lateral post tension is positioned on the same line.

In this state, the transverse tendon 150 is inserted into the transverse post tension sheath tube 160 to introduce the transverse prestress to integrate the PSC composite girder 100 and the neighboring PSC composite girders.

Then, the PSC girder bridge is completed by paving, barriers and median.

On the other hand, the girder bridge manufactured by the PSC composite girder to integrally produce the bridge bottom plate and the cross beam according to the present invention manufactured as described above can be a long span, as shown in Table 1 below, the construction period by simplifying the process It can be seen that this is very fast, the longitudinal prestressing amount can have a theoretical maximum, the stepwise stress state is very efficient, and the stress calculation process is simpler than conventional techniques.

TABLE 1

Item The present invention (bottom plate integrated PSC girder bridge) Existing Technology I (Prior PSC Girder Bridge) Existing Technology II (Multilevel Tensioned PSC Girder Bridge) Maximum possible span More than 50m (road bridge) More than 30m (railroad bridge) 25 ~ 35m (road bridge) 20 ~ 25m (railway bridge) 45 ~ 50m (road bridge) 30m (railway bridge) Construction period Fast usually usually Possible longitudinal prestressing amount Very large (theoretical maximum) usually greatness Step stress state Very efficient (Figure 5a) Usually (Figure 5b) Efficient (Figure 5c)

As those skilled in the art would realize, the described embodiments may be modified in various ways, all without departing from the spirit or scope of the present invention. It is to be understood, however, that the present invention is not limited to the specific forms referred to in the description, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. Should be.

1 is a perspective view showing the configuration of a PSC composite girder for integrally manufacturing a bridge deck and a cross beam according to the present invention;

2 is a cross-sectional view taken along line A-A of FIG.

3 is a cross-sectional view taken along line B-B of FIG.

4 is a perspective view showing a state in which a PSC composite girder integrally manufacturing a bridge deck and a cross beam according to the present invention is mounted on a pier;

5a to 5c is a girder bridge by the PSC composite girder to integrally manufacture the bridge deck and crossbeams according to the present invention, and the stepped stress state of the existing technology I (conventional PSC girder bridge) and the existing technology II (multi-stage tensioned PSC girder bridge) The figure which shows.

<Explanation of symbols on main parts of the drawings>

100: PSC composite girder 110: bridge deck

120: cross beam 130: longitudinal tendon

140: sheath pipe for longitudinal post tension 150: transverse tendon

160: sheath pipe for lateral post tension

Claims (3)

In the PSC girder, The PSC girder is A bridge bottom plate is integrally formed on an upper surface, and at least one cross beam is integrally protruded from both sides, and the PSC composite girder integrally manufacturing the bridge bottom plate and the cross beam. The method of claim 1, The bridge deck and transverse, A PSC composite girder which integrally manufactures a bridge deck and a cross beam, wherein a sheath pipe for transverse post tension is embedded in the width direction. The method of claim 2, The PSC girder is After placing a plurality in the pier or alternating in a lateral direction, the bridge bottom plate, characterized in that the transverse pre-stress is introduced by inserting the tendon respectively in the transverse post tension sheath pipe formed in each bridge bottom plate and cross beams PSC composite girders to produce crossbeams and crossbeams integrally.

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