KR20080020755A - End cutoff type prestressed composition bridge which stairs type strain equipment possesses, and its construction method - Google Patents

Abstract

A stair shaped end prestressed composition beam with fixing devices and a bridge construction method using the same are provided to disperse tensile force of the beam and to prevent local fracture of casing concrete by connecting steel wires with ends of the fixing devices. A stair shaped end prestressed composition beam comprises prestressed synthetic beams, and fixing devices(20). The prestressed synthetic beams are introduced by pouring concrete, installing lower casing concrete, and removing load to surround steel beams and lower flanges with predetermined thickness. The fixing devices includes fixing tools(22) fixed at upper and lower parts of the stair shaped ends, and steel wires(24) crossing the fixed areas. A cut part(18) is shaped like a stair. A width(‘±) of the cut part is a value of adding a width from an end of the steel beam to a rear end of the bridge device with a width from the rear end of the bridge device to the rear end of the abutment and of adding the length with 10 to 20cm more.

Description

End cutoff type prestressed composition bridge which stairs type strain equipment possesses, and its construction method

1 is an exemplary view showing a bridge using a stepped end prestress composite beam equipped with a fixing device according to the present invention,

2 is an enlarged detail view of an end of a stepped end prestress composite beam including a fixing device according to the present invention;

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

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

5 is a cross-sectional view taken along the line C-C in FIG.

Explanation of symbols on the main parts of the drawing

10: prestressed composite beam 12: steel beam

14: lower flange 16: casing concrete

18: cutout 20: fixing device

22: anchorage 24: steel wire

30: shift 32: top

34: chair

B: Stepped endless prestressed beam bridge with fixing device

G: stepped end prestress composite beam with fixing device

ℓ: cutting width ℓ1: podium distance

ℓ2: width of the steel beam to the end of the pedestal

The present invention relates to a stepped end prestressed composite beam having a fixing device and a bridge construction method using the same. Particularly, a fixing device having a stepped end formed at an end of the prestressed composite beam and a fixing device provided at each of the stepped ends is provided. And a stepped end prestress composite beam and a bridge construction method using the same.

In general, simple bridges have been constructed to secure the geometry of simple bridges, but most of the plate girder bridges, which are not found in concrete bridges, are mostly precast beam bridges with short spans.

The reason is that the cross section becomes smaller in the maximum shear force generation section of the bridge, so in the case of the plate girder bridge, it can be applied by increasing the thickness of the steel sheet. Because.

In addition, the plate girder bridge as described above is concerned about the buckling, which is a disadvantage of the bridge itself, even in the increase of the thickness of the abdominal plate, and in the plate girder bridge crossing the river, maintenance costs and environmental problems due to painting and repainting due to the fear of corrosion of the bridge. Is seriously emerging.

Meanwhile, the general prestressed composite bridge is the same as the PSC bridge (Prestressed Concrete Beam Bridge), but the structure is different from the plate girder bridge.

In other words, the plate girder bridge constructs a segment by segmenting the mold, and constructs the bridge by connecting bracing and crossbeam between each mold, but the prestressed composite bridge produces a mold corresponding to one span, After the mold is installed on the alternating and pier, the concrete is poured in the absence of bracing or cross beams, and the bottom plate is synthesized.

In the prestress composite bridge construction hypothesis type, when the concrete corresponding to the bottom plate is cast due to the length of the cantilever bottom plate and the length of the center bottom plate, torsional phenomenon occurs in the bottom plate concrete, which causes severe deformation of the seating device. If the load is loaded in the same state, there is a possibility that the deviation of the bridge device may occur, such a deviation of the bridge device is a problem that appears larger as the bridge or the more severe the bridge.

Accordingly, the present invention has been made to solve the problems described above, by forming the end of the pre-stressed composite beam in a stepped manner, by providing a fixing device connecting the steel wire to each of the stepped end, dispersing the tension force Stepped end prestress with fixing device to prevent local destruction of casing concrete, to eliminate unnecessary dead load at the end, to re-tension during use of the bridge as needed, and to lower the vertical curve by the height of the stepped end Its purpose is to provide a composite beam and a bridge construction method using the same.

Stepped end prestressed composite beam with a fixing device according to the present invention for achieving the above object is to form a stepped end on both side ends of the member to be installed on both sides without introducing a camber, The steel beams are integrally connected to each of the beams in which the pre-induction is introduced, and the concrete is poured to cover the lower flange to a certain thickness while applying a load to the steel beams. A prestress composite beam into which prestress is introduced; While placing concrete on the upper flange and the abdomen of the prestressed composite beam, the concrete is also placed on the stepped ends of both ends, and the stepped ends are installed, respectively. It consists of a fixing device made of steel wire fixedly installed.

In addition, the bridge construction method using a stepped end prestress composite beam with a fixing device according to the present invention for achieving the above object does not introduce a camber while forming a stepped end on both side ends of the member installed on both sides, In the center member, a camber, i.e., a steel beam integrally connected to each beam into which the preflection is introduced, and cast concrete to cover the lower flange to a certain thickness while applying a load to the steel beam, cured lower casing concrete A prestressed composite beam provided with prestressed by removing the load; While placing concrete on the upper flange and the abdomen of the prestressed composite beam, the concrete is also placed on the stepped ends of both ends, and the stepped ends are installed, and the fixing ports are fixedly installed above and below the stepped ends of the both ends, and across the fixing section. Manufacturing a prestressed composite beam comprising a fixing device in which steel wires are fixedly installed (I); Tensioning the wire of the stepped end prestress composite beam with the fixing device (II); Installing a teaching device on the shift (III); Mounting (IV) a stepped end prestress composite beam comprising a fixing device on the stabilization device; Step (V) is formed by placing and curing concrete on top of the stepped prestressed composite beam provided with the fixing device to form a bottom plate.

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

1 is an exemplary view showing the construction of a bridge using a stepped end prestress composite beam with a fixing device according to the present invention, Figure 2 is installed on the alternating side of a stepped end prestress composite beam with a fixing device 3 is a cross-sectional view taken along line AA of FIG. 2, FIG. 4 is a cross-sectional view taken along line BB of FIG. 2, and FIG. 5 is a cross-sectional view taken along line CC of FIG. 2.

As shown in these figures, the stepped end prestressed composite beam G equipped with the fixing device according to the present invention forms a stepped end at both end portions of a member provided at both sides, and does not introduce a camber, but has a central member. There is a camber, that is, the steel beam 12 is integrally connected to each beam introduced pre-flection, and the concrete is poured to wrap the lower flange 14 to a certain thickness while applying a load to the steel beam 12, A prestressed composite beam 10 in which cured lower casing concrete is installed and prestress is introduced by removing a load; Fixing means 22 are installed in the upper flange and the abdomen of the pre-stressed composite beam 10 while the concrete is also placed on the stepped end of both ends to install a stepped end, and fixed to the top and bottom of the stepped end of the both ends, respectively; It consists of a fixing device 20 that the steel wire 24 is fixed across the fixing section.

That is, the prestressed composite beam G provided with the fixing device 20 at the stepped end according to the present invention has a structure in which the prestressed composite beam 10 and the fixing device 20 are organically combined.

Here, the prestressed composite beam 10 is composed of a steel beam 12 and the casing concrete 16, the steel beam 12 is a stepped by forming a cutout portion 18 in a stepped portion of both ends Although formed at the end, the shape of the cutout 18 is a stepped structure.

That is, the steel beam 12 is cut to cut the abdominal cross-section of both ends of the steel beam 12 to be arranged in the same plane with the lower surface of the lower flange 14 and the inner upper surface 32 of the alternating 30. The part 18 is formed, and the cross-sectional shape of this cutout part 18 is formed stepwise.

In particular, the width l of the cutout 18 is the length l2 of the steel beam 12 and the end of the alternating device 34 and the length l2 of the cutting beam 18 from the end of the alternating device to the end of the alternating 30. It consists of length value which added margin width 10-20cm to length which put (l1) together.

The reason why the width of the cutout 18 is formed is to be used as a work space for smoothing the tension of the fixing device 20 installed in the cutout 18.

In addition, the casing concrete 16 uses the high-strength steel beam 12 to separate the steel beam 12 having a camber and cutouts formed at both ends thereof, and to a partially divided steel beam up to 80% of the elastic limit. After the pre-stress by the pre-flection load is applied to fasten the high-strength concrete to a certain thickness to the lower side flange 14 to be fixed to be integrally combined with the steel beam (12).

On the other hand, the fixing device 20 is composed of a fixing unit 22 and a steel wire 24, the fixing unit 22 is the upper and lower portions of the casing concrete 16, that is, the prestress composite beam at both ends of the prestress composite beam 10 It is fixed to each of the upper and lower cutouts 18 of both ends of the (10), the steel wire 24 is installed across the anchorage (22).

Such a fixing device 20 is a technique widely used in prestressed concrete beam bridges, and this technology is introduced into a bridge using a prestressed composite beam according to the present invention, whereby the steel wire 24 of the fixing device 20 is needed. This is to prevent the local breakdown of the casing concrete 16 by dispersing the tension between both ends of the prestressed composite beam G by tension.

Bridge (B) construction method using a stepped end prestress composite beam (G) having a fixing device 20 according to the present invention having the configuration as described above forms a stepped end on both side ends of the member installed on both sides While not introducing a camber, a steel beam 12 having integrally connected cambers, i.e., respective beams into which preflection has been introduced, is applied to the central member, and a lower flange 14 while applying a load to the steel beam 12. Pre-stressed composite beam 10 in which pre-stress is introduced by installing concrete to pour concrete to squeeze it to a predetermined thickness and removing cured lower casing concrete; Fixing means 22 are installed in the upper flange and the abdomen of the pre-stressed composite beam 10 while the concrete is also placed on the stepped end of both ends to install a stepped end, and fixed to the top and bottom of the stepped end of the both ends, respectively; Manufacturing a prestressed composite beam (G) comprising a fixing device (20) in which the steel wire (24) is fixedly installed across the fixing section (I); Tensioning the steel wire (24) of the stepped end prestress composite beam (G) with the fixing device (20); Installing a teaching device 34 on a subject (III); Mounting (IV) a stepped end prestress composite beam (G) provided with a fixing device (20) on the chair device (34); Step (V) is formed by placing and curing concrete on top of the stepped end prestress composite beam G provided with the fixing device 20 to form a bottom plate.

That is, the bridge B construction method using the stepped end prestress composite beam G provided with the fixing device 20 according to the present invention does not introduce a camber while forming stepped ends at both end portions of the members installed at both sides. Instead, the central member wraps the camber, i.e., the steel beam 12 integrally connecting the respective beams into which the preflection is introduced, and the lower flange 14 while applying a load to the steel beam 12 with a predetermined thickness. A prestressed composite beam 10 in which prestress is introduced by installing a lower casing concrete to which concrete is poured and cured; Fixing means 22 are installed in the upper flange and the abdomen of the pre-stressed composite beam 10 while the concrete is also placed on the stepped end of both ends to install a stepped end, and fixed to the top and bottom of the stepped end of the both ends, respectively; Manufacturing a prestressed composite beam (G) comprising a fixing device (20) in which the steel wire (24) is fixedly installed across the fixing section (I); Tensioning the steel wire (24) of the stepped end prestress composite beam (G) with the fixing device (20); Installing a teaching apparatus on a subject (III); Mounting (IV) a stepped end prestress composite beam (G) provided with a fixing device (20) on the chair device (34); By placing and curing concrete on top of the stepped end prestress composite beam G provided with the fixing device 20 to form a bottom plate, by dispersing the tension force to prevent local destruction of the casing concrete 16, Eliminating unnecessary dead weight, re-tension of the steel wire 24 during the use of the bridge, if necessary, there is an effect that can lower the vertical curve by the height of the cutout (18).

As described above, the stepped end prestress composite beam with a fixing device according to the present invention and a bridge construction method using the same have the following effects.

First, the present invention has the advantage of preventing the local destruction of the casing concrete by dispersing the tension of both ends of the pre-stressed composite beam.

Second, the present invention has the advantage that by removing the undesired dead weight of the composite beam itself generated at both ends by forming a cutout at both ends of the prestressed composite beam, as well as lowering the vertical curve by the step difference.

Third, since the present invention is provided with a fixing device, it can be re-tensioned during use of the bridge if necessary, there is an advantage that the durability of the bridge is improved.

Claims (6)

The steel beam 12 which integrally connects the camber, ie, each beam into which the preflection was introduced, is formed in the center member without forming a camber while forming stepped ends at both end portions of the members provided on both sides, and the steel materials. A prestressed composite beam 10 in which concrete is laid to cover the lower flange 14 to a predetermined thickness while applying a load to the beam 12, and a cured lower casing concrete is installed, and a prestress is introduced by removing the load; Fixing means 22 are installed in the upper flange and the abdomen of the pre-stressed composite beam 10 while the concrete is also placed on the stepped end of both ends to install a stepped end, and fixed to the top and bottom of the stepped end of the both ends, respectively; Stepped end prestress composite beam comprising a fixing device characterized in that the steel wire 24 is fixed to the fixing section 20 is installed across the fixing section. The method of claim 1, The steel beam 12 has a cutout portion in which both abdominal cross-sections of the steel beam 12 are cut in a predetermined shape so that the lower flange 14 is disposed coplanar with the inner upper surface 32 of the alternating surface 30. A stepped end prestress composite beam with a fixing device, characterized in that 18) is formed in a stepped shape. The method of claim 2, The width ℓ of the cutout 18 is the width ℓ2 to the end of the steel beam 12 and the end of the throttle device 34 and the ℓ2 to the end of the alternate device 30 at the end of the throttle device 34. Stepped end prestress composite beam comprising a fixing device, characterized in that the length of the combined length (l1) plus the margin width 10 ~ 20cm. While forming the stepped ends at both end portions of the members provided on both sides, the camber is not introduced, and the steel member beams are integrally connected to each beam to which the preflection is introduced, and the load is applied to the steel beams. A prestressed composite beam manufactured by placing concrete to cover the lower flange with a predetermined thickness, installing cured lower casing concrete, and removing a load; While placing concrete on the upper flange and the abdomen of the prestressed composite beam, the concrete is also placed on the stepped ends of both ends, and the stepped ends are installed, respectively. Manufacturing a prestressed composite beam comprising a fixing device in which steel wires are fixedly installed (I); Tensioning the wire of the stepped end prestress composite beam with the fixing device (II); Installing a teaching apparatus on a subject (III); Mounting (IV) a stepped end prestress composite beam comprising a fixing device on the stabilization device; Bridge construction method using a stepped end prestressed composite beam with a fixing device, characterized in that the step (V) is formed by placing and curing concrete on top of the stepped end prestressed composite beam equipped with the fixing device (V). . The method of claim 4, wherein Stepped end prestressed composite beam (G) equipped with the fixing device is a steel beam 12, both ends are formed in a step-like cross-sectional shape and the preflection is introduced, and the lower flange 14 of the steel beam 12 A prestressed composite beam (10) made of casing concrete (16) in which concrete is poured to wrap in a constant thickness; A fixing device 20 comprising a fixing tool 22 fixedly installed at upper and lower ends of the lower flanges 14 at both ends of the prestressed composite beam 10, and a steel wire 24 fixedly installed across the fixing tool 22. Bridge construction method using a stepped end prestress composite beam with a fixing device characterized in that consisting of. The method of claim 5, The width ℓ of the cutout 18 is the width ℓ2 to the end of the steel beam 12 and the end of the throttle device 34 and the ℓ2 to the end of the alternate device 30 at the end of the throttle device 34. Bridge construction method using a stepped end prestress composite beam with a fixing device, characterized in that consisting of a length value plus the margin width 10 ~ 20cm to the combined length (l1).

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