JP5053589B2 - How to build a bridge girder - Google Patents

Description

  The present invention relates to a construction method of a bridge girder used as a road bridge, a railway bridge, etc., in particular, a steel plate bent into a corrugated shape is used as a web, and upper and lower edges are joined to an upper floor plate and a lower floor plate made of concrete, and a cross-sectional shape is obtained. It relates to a box-shaped bridge girder construction method.

  A bridge girder is known in which the upper floor slab and lower floor slab are made of prestressed concrete and corrugated steel is used for the web part connecting the upper floor slab and lower floor slab. Yes. In this bridge girder, the upper floor slab is made of concrete to support the wheel load acting on a wide area of the road surface, and the weight of the bridge girder can be reduced by using steel for the web. Also, by using a so-called corrugated steel web that has a steel web bent into a corrugated shape along the longitudinal bend line, the lateral bending rigidity, that is, the rigidity against deformation of the girder cross section, is significantly increased, effectively preventing web buckling. can do.

For the construction of a bridge girder having such a structure, as with a box-shaped bridge girder made of prestressed concrete, it is constructed by projecting from a pier or abutment to each side or one side for each construction block of a predetermined length. Overhang construction method can be adopted.
As described in Patent Document 1, for example, this overhang construction method constructs a bridge girder for each construction block having a predetermined length from the head of the bridge pier raised on the ground. Is projected in a cantilevered manner. In many cases, each block is constructed while balancing the falling moment from the head of the pier to both sides. It is also possible to construct a bridge girder so that it protrudes from the abutment firmly fixed to the ground to one side, or constructs a girder in advance from the center of the pier to the one in the girder axis direction, on the other side, It can also be constructed so that the girders are cantilevered.

As shown in FIG. 11, each construction block divided into a predetermined length is formed by a moving erection device 102 that supports and supports a working scaffold 104 and a supporting work 103 at the tip of a bridge girder 101 that has already been constructed. Is installed. This mobile erection device 102 is generally called a mobile work vehicle or a wagen, and is supported so as to project from the tip of the already constructed bridge girder 101, and is connected to the tip of the bridge girder 101 for one construction. The work scaffold 104 and the supporting work 103 are suspended and supported so that a bridge girder for blocks can be constructed. And in the bridge girder which a web is comprised with a corrugated steel material, the corrugated steel member 105 of the length for one construction block is first suspended and supported, and it connects to the predetermined position in the front-end | tip part of the existing bridge girder 101. FIG. Thereafter, a form for forming the upper floor slab 101b and the lower floor slab 101a is assembled on the support 103 or suspended from the moving erection device 102, and uncured concrete is poured into the form. When the concrete is hardened and a bridge girder for one construction block is formed, the moving construction device 102 is moved forward and the same operation is repeated. Thereby, a bridge girder of a predetermined length is constructed by adding a bridge girder one construction block at the tip of the bridge girder 101 already constructed.
JP 2004-1106060 A

However, the conventional construction methods as described above have the following problems.
The above moving construction apparatus must support the weight of the working scaffold 104, the weight of the formwork and support for forming the upper floor slab 101b and the lower floor slab 101a, and the weight of uncured concrete and many weights. Don't be. Moreover, since the said load is supported in the position overhang | projected from the front-end | tip part of the already formed bridge girder 101, the moving construction apparatus 102 will enlarge and its own weight will also become large. For this reason, it is necessary to set the length of one construction block that can be constructed in one cycle to be small, which is an obstacle to improving the construction efficiency. Moreover, the operation | work of a movement may become difficult and the expense of a moving construction apparatus may become large.

  The present invention has been made in view of the circumstances as described above, and its purpose is to reduce the load acting on the mobile erection device in the cantilever erection method of the bridge girder, and can be constructed in one cycle. It is possible to improve the work efficiency and shorten the work process by making it possible to set the length of the work block, that is, the length of one construction block large.

In order to solve the above-mentioned problems, the invention described in claim 1 is characterized in that a bridge girder that forms a box-shaped cross section with an upper floor slab and a lower floor slab made of concrete and a plurality of corrugated steel webs that connect them vertically. , A method of erection by overhang construction for each construction block of a predetermined length, wherein a bridge girder of a part already formed by hardening the concrete of the upper floor slab and the lower floor slab integrally with the corrugated steel web A corrugated steel sheet web that is supported by the bridge girder and supports a part of the weight of the scaffold and the construction block to be formed next by projecting from the tip of the bridge girder, and corresponds to one construction block length by the movable construction apparatus. In this state, the corrugated steel web is joined to the tip of the bridge girder already formed, and concrete for forming an upper floor slab on the corrugated steel web is placed. A formwork for assembling concrete forming the lower floor slab was already formed immediately below the position where the formwork of the upper floor slab was provided, and the mold was supported by the moving erection device. The corrugated steel sheet web projecting from the tip of the bridge girder of the part is assembled and supported, and the concrete of the upper floor slab and the concrete of the lower floor slab are placed in the mold, and the upper floor slab and the lower floor slab are assembled. The step of assembling a mold for placing the concrete that forms the lower floor slab is joined along the lower edge of the corrugated steel web. The lower corrugated steel web is locked on the part where the two corrugated steel webs protrude on the opposite side of the surface facing each other, and the outer support beam is bridged between the two corrugated steel webs on the lower side of the lower flange. The bridge girder One end of the longitudinal beam spanning in the line direction is supported on the outer support beam, and the other end is already supported by a bridge girder in which the concrete of the lower floor slab and the corrugated steel web are integrated, and a mold is formed on the longitudinal beam. The construction method of the bridge girder that supports the frame is provided.

The invention according to claim 2 is a construction in which a bridge girder that forms a box-shaped cross section with an upper floor slab and a lower floor slab made of concrete and a plurality of corrugated steel webs connecting the upper and lower slabs up and down for each construction block of a predetermined length It is a method of erection by construction, and the concrete of the upper floor slab and the lower floor slab is supported by the bridge girder already formed by hardening together with the corrugated steel web, and from the tip of the bridge girder A moving erection device is provided to support a part of the weight of the scaffolding and the construction block to be formed next, and the corrugated steel sheet web corresponding to one construction block length is suspended and supported by the moving erection device. A steel plate web is joined to the tip of the bridge girder that has already been formed, and a formwork for placing concrete forming an upper floor slab on the corrugated steel plate web is supported by the movable laying apparatus. The formwork for placing the concrete that forms the lower floor slab is projected from the tip of the bridge girder in the already formed part immediately below the position where the formwork of the upper floor slab is provided. The corrugated steel web is supported and assembled, and the upper floor slab concrete and the lower floor slab concrete are placed in the formwork so that the upper floor slab and the lower floor slab are continuously integrated with the corrugated steel web. The step of assembling a formwork for placing the concrete that forms the lower floor slab comprises two corrugations of a lower flange made of steel joined along the lower edge of the corrugated steel web The steel plate webs are locked on the portions projecting to the sides facing each other and the inner support beam is bridged between the two corrugated steel plate webs, and arranged substantially parallel from the inner support beam to the lower side of the inner support beam. Outer support beam One end of the longitudinal beam spanning in the axial direction of the bridge girder is supported on the outer support beam, and the other end is already supported by the bridge girder in which the concrete of the lower floor slab and the corrugated steel web are integrated. A method for constructing a bridge girder that supports a formwork on the longitudinal beam is provided.

In these methods, the formwork for forming the lower floor slab and the weight of the unhardened concrete poured into the formwork are supported by the corrugated steel web, and the corrugated steel web is further formed at the tip of the bridge girder already formed. Supported by the department. Therefore, all or part of the formwork and the uncured concrete weight for forming the lower floor slab is supported without burdening the mobile laying apparatus, and the load on the mobile laying apparatus is reduced. Thereby, if the length of one construction block is made the same, the weight of a mobile erection device can be reduced, and work, such as a movement and installation of this mobile erection device, becomes easy, and work efficiency is improved. Moreover, if the weight of a mobile erection apparatus is made substantially the same, the length of one construction block can be set large and the number of cycles for constructing the whole bridge girder will be reduced. Therefore, the efficiency of forming the bridge girder is improved.

Further, a lower flange is attached along the lower edge of the corrugated steel sheet, and projects from both sides of the corrugated steel sheet substantially horizontally or at a small inclination angle. Therefore, the formwork for forming the lower floor slab can be easily supported by the member locked on the lower flange.

  As described above, in the bridge girder construction method according to the present invention, the weight when forming the upper floor slab or the weight when forming the lower floor slab is loaded on the corrugated steel web, It is possible to reduce the load applied to the mobile laying apparatus supported so as to overhang. Therefore, it is possible to reduce the weight of the mobile erection device or to set the length of one construction block to be large, and to improve the construction efficiency.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic side view and cross-sectional view showing an example of a bridge girder that can be installed by the method according to the present invention.
The bridge girder 1 is supported by an abutment 2 and a pier 3 and constitutes a continuous ramen bridge with the pier 3, and is supported on the abutment 2 via a support 4, and the horizontal direction in the axial direction of the bridge girder. Directional movement is possible. The cross section of the bridge girder 1 has a box-shaped cross section in which an upper floor slab 10 made of concrete is connected to an upper part of a pair of left and right corrugated steel webs 30 and a lower floor slab 20 is connected to a lower part.

  The corrugated steel sheet web 30 is formed of a corrugated steel sheet 31 having a corrugated cross section formed by bending a structural steel sheet along a vertical folding line, and is made of a steel sheet along the upper and lower edges of the corrugated steel sheet 31. The upper flange 32 and the lower flange 33 are joined by welding.

  The upper floor slab 10 and the lower floor slab 20 are made of reinforced concrete formed by pouring unhardened concrete into a formwork at the construction site. The upper floor slab 10 is an upper flange 32 welded to the corrugated steel web 30. The lower floor slab 20 is formed so as to be in close contact with the lower surface of the lower flange 33. The upper surface of the upper flange 32 and the lower surface of the lower flange 33 are joined to each other by an anti-slip member such as an angle diver or a stud diver (not shown), and the concrete embeds these members into the flange 32, 33 is in close contact. Therefore, the concrete upper floor slab 10 and the lower floor slab 20 are firmly integrated with each of the two corrugated steel sheet webs 30.

Next, a method for constructing the bridge girder 1, which is an embodiment of the present invention, will be described.
In this construction method, as shown in FIG. 2, a support 41 is formed on the upper portion of the pier 2 raised from the foundation ground, and the corrugated steel web 30 is installed on the upper slab 10 and the lower floor slab 20 and A part of the bridge girder, that is, the column head 1a is formed by placing concrete. Then, as shown in FIG. 3, two mobile erection devices 50 are installed on the pillar head 1a, and the construction blocks divided into predetermined lengths on both sides are sequentially constructed. . In the movable laying apparatus 50, frame bodies 51 are provided on the upper floor slab 10 above the position where the corrugated steel web 30 is provided, and the rear end portion 51a of the frame body 51 is fixed to the already formed bridge girder 1b. At the same time, the tip 51b is installed so as to protrude from the tip of the bridge girder 1b being constructed. And from the overhang | projection part, the supporting work (not shown in FIG. 3) and the work scaffold 52 of the range of the length of one construction block can be suspended and supported. In addition, the length of one construction block can be set to about 5 m, for example.

Each construction block is constructed as follows.
First, as shown in FIG. 3, the steel member 34 corresponding to the length of one construction block is suspended and supported from the moving construction device 50, and two corrugated steel webs are formed from the tip of the bridge girder 1b already formed. Support to overhang each. As shown in FIG. 4, the steel member 34 is obtained by previously welding an upper flange 32 and a lower flange 33 to the upper and lower ends of the corrugated steel plate 31 that becomes the corrugated steel web 30, respectively. The steel member 34 can be manufactured in a work yard provided in the vicinity of the factory or the construction site.

In the vicinity of the height corresponding to the upper portion of the steel member 34 that is supported in a projecting manner in parallel, between the two steel members 34 and on the outside of the steel member 34, the axis of the bridge girder formed as shown in FIGS. The suspension beam 53 supports the front portion 53a by the suspension material 55 from the lateral beam 54 laid over the two frames 51 of the movable laying device 50, and supports the rear portion 53a. 53b is suspended and supported from the upper floor slab 10 of the already formed bridge girder 1b. Then, the formwork 56 is supported on the plurality of suspension beams 53 and the reinforcing bars are assembled thereon, and then the uncured concrete is poured to form the upper floor slab 10 of the reinforced concrete. At this time, the weight of the uncured concrete forming the suspension beam 53, the formwork 56, and the upper floor slab 10 acts on the moving erection device 50 from the front portion 53a of the suspension beam 53, and the already formed upper floor from the rear portion 53b. Acts on plate 10.
On the other hand, the work scaffold 52 is provided in a range wider than the range corresponding to the length of at least one construction block, and is necessary for forming the upper floor slab 10 and the lower floor slab 20 by suspending and supporting from the moving erection device 50. It makes work possible.

  As shown in FIG. 5 or FIG. 6, the lower flange of the steel member 34 supported so as to be overhanged is substantially perpendicular to the axial direction of the bridge girder between the two steel members 34 and 34 arranged in parallel. The outer support beam 61 and the inner support beam 62 are bridged between the two. The outer support beam 61 is locked to a portion protruding to the outside of the lower flange, and supports a beam member 61a made of shape steel on the lower side of the range where the lower floor slab 20 is formed. Further, the inner support beam 62 is bridged between portions projecting to the inner side of the lower flange 33 and is connected by the beam member 61 a and the suspension member 63. The beam member 61a supports a front portion 64a of a plurality of vertical beams 64 arranged in the axial direction of the bridge girder, and a rear portion 64b is supported by a horizontal beam 65 suspended from the already formed bridge girder 1b. A mold 66 for forming the lower floor slab 20 is assembled on the plurality of vertical beams 64. Then, concrete is poured into the frame to form the lower floor slab 20 in close contact with the lower flange 33 of the steel member 34.

  By supporting the load at the time of erection as described above, the weight of the upper floor slab during erection, that is, the weight of uncured concrete, the weight of the formwork 56 and the suspension beam 53 functioning as a support work, etc. are partially moved Acting on the device 50, the work scaffold 52 is also suspended and supported by the moving erection device 50. However, the weight of the uncured concrete forming the lower floor slab 20 and the weight of the formwork 66 are supported by the longitudinal beam 64 which functions as a support, and the weight acting on the longitudinal beam 64 is outside at the front portion 64a. It is supported by the steel member 34 via the support beam 61 and the inner support beam 62, and is supported by the lower floor slab 20 of the bridge girder 1b already formed via the cross beam 65 at the rear part 64b. Therefore, the load of the lower floor slab 20 does not act on the mobile erection device 50, and the load of the mobile erection device 50 is reduced.

FIG. 7 is a schematic side view showing, as a reference, another example of a method capable of reducing the load on the mobile erection device, similarly to the method for constructing a bridge girder according to the present invention.
In this method, a bracket 71 is attached in advance as a temporary receiving member to the tip of the steel member 34 supported by the already formed bridge girder 1b. The brackets 71 are respectively attached to two parallel steel members 34 serving as two webs, and support the cross beam 72 so as to be bridged between them. The lower horizontal beam 73 is suspended and supported from the horizontal beam 72, and the front portion 64a of the vertical beam 64 is supported. The rear part 64b is supported by the cross beam 65 suspended and supported on the lower floor slab 20 of the already formed bridge girder 1b as in the embodiment shown in FIGS.
The vertical beam 64 and the formwork 66 supported in this manner have the same configuration as that of the embodiment shown in FIGS. 5 and 6, and the configuration of the means for forming the upper floor slab 10 and the work scaffold 52 is also shown in FIGS. 5 and 6. It is the same as the embodiment.

  Even in such a construction method, the weight of the mold 64 and the uncured concrete for forming the lower floor slab 20 is not applied to the moving erection device 50, and the load acting on the moving erection device 50 can be reduced. It becomes possible.

  On the other hand, the longitudinal beam 64 that supports the formwork 66 for forming the lower floor slab 20 can also suspend and support the front portion from above the steel member. That is, as shown in FIG. 8, the temporary support beam 81 is bridged in a direction perpendicular to the axis of the bridge girder on the steel member 34 overhanging and fixed, and the front portion 64 a of the vertical beam 64 is extended from the horizontal beam 81 to the suspension member 82 and It is suspended and supported by the lower lateral beam 73. The rear portion 64b of the vertical beam 64 is supported by the lower floor slab 20 of the already formed bridge girder 1b in the same manner as the method shown in FIG. Even with this method, the load acting on the mobile erection device 50 can be reduced.

9 and 10 show another example of a method for constructing a bridge girder that can reduce the load of the mobile laying apparatus as a reference, and the load when forming the upper floor slab 10 is the tip of the bridge girder 1b. It is the schematic side view and schematic front view which show the example supported by the steel member 34 fixed to.
In this method, the formwork 66 for forming the lower floor slab 20 is supported by the longitudinal beam 64, and the front portion of the longitudinal beam 64 is supported by the lateral beam 91 that is suspended and supported by the suspension member 92 from the movable laying device 50. Let The rear portion is supported by the lower floor slab 20 of the already formed bridge girder 1b as in the method shown in FIG. However, the upper floor slab is formed in a state where it is supported by the steel member 34 supported so as to protrude from the bridge girder 1b that has already been formed as follows.

  First, a plurality of rib members 93 made of precast concrete, shaped steel or the like are bridged on the steel member 34 in a direction perpendicular to the axis of the bridge beam 1b. And thin precast concrete board 94 is bridged between these rib materials 93, and unhardened concrete 95 is poured on rib material 93 and precast concrete board 94 by using these precast concrete boards 94 as a part of a formwork. . The uncured concrete 95 is cured integrally with the rib member 93 and the precast concrete plate 94 to form the upper floor slab 10.

  Thus, when the upper floor slab 10 is formed, the rib member 93 and the precast concrete plate 94 are supported by the steel member 34, and the weight of the uncured concrete 95 is also reduced by the steel member 34 via the precast concrete plate 94 and the rib member 93. Supported. Therefore, the load during the formation of the upper floor slab 10 is not applied to the mobile erection device 50, and the load on the mobile erection device 50 can be reduced.

  In the above example, the upper floor slab 10 is formed by using the rib member 92 and the precast concrete plate 93. However, the mold member is supported by the steel member 34, and uncured concrete is poured into the mold frame to form the upper floor slab. It may be formed. In this case, as in the method shown in FIGS. 5 and 6, the formwork for forming the upper floor slab is supported by the suspension beam 53, and the front portion of the suspension beam is supported by the steel member 34. Good. The structure for supporting the front portion of the suspension beam may be supported by linking a horizontal beam on a steel member, or a bracket or the like for supporting a formwork may be attached to the steel member 34 in advance. .

It is the schematic side view and sectional drawing which show an example of the bridge girder which can be constructed | assembled by the method which concerns on this invention. FIG. 2 is a schematic side view showing a step of the bridge girder construction method shown in FIG. 1 and showing one step of the bridge girder construction method according to an embodiment of the present invention. FIG. 3 is a schematic side view showing a step that follows the step shown in FIG. 2. It is a schematic perspective view of the steel member used as the web of the bridge girder shown in FIG. It is a schematic side view which is a main process in the construction method of the bridge girder which is one embodiment of this invention, and shows the process of forming a bridge girder so as to project every construction block. It is a schematic front view of the state which supported the support work and the work scaffold as shown in FIG. It is a schematic side view which shows the other example of the construction method of the bridge girder which can reduce the load of a mobile construction apparatus for reference. It is a schematic side view which shows the other example of the method of supporting a support work. It is a schematic side view which shows the main process in the other example of the bridge girder construction method which can reduce the load | burden of a mobile erection apparatus, Comprising: The process of forming a bridge girder so that it may project over every construction block. It is a schematic front view of the state which supported the support work and the work scaffold as shown in FIG. It is the schematic for demonstrating the conventional construction method.

1: bridge girder, 2: abutment, 3: pier, 4: support,
10: Upper floor slab, 20: Lower floor slab, 30: Corrugated steel web,
31: Corrugated steel sheet, 32: Upper flange, 33: Lower flange, 34: Steel member including corrugated steel web, 41: Supporting work, 50: Mobile construction device, 51: Frame body of mobile construction device, 52: Work Scaffolding, 53: suspension beam, 54: lateral beam, 55: suspension material, 56: formwork,
61: Outer support beam, 62: Inner support beam, 63: Suspension material, 64: Vertical beam, 65: Horizontal beam, 66: Formwork,
71: Bracket, 72: Cross beam, 73: Lower cross beam, 81: Temporary receiving beam, 82: Suspension material, 91: Cross beam, 92: Suspension material, 93: Rib material, 94: Precast concrete board, 95: Uncured concrete concrete

Claims (2)

A bridge girder that forms a box-shaped cross-section with concrete upper and lower floor slabs and a plurality of corrugated steel webs connecting them up and down is constructed by overhang construction for each construction block of a predetermined length. ,
Construction in which the concrete of the upper floor slab and the lower floor slab is supported by the bridge girder of the part already formed by hardening together with the corrugated steel sheet web, and is projected from the tip of the bridge girder and then formed A mobile installation device that supports a part of the weight of the block is provided.
In this state, the corrugated steel web corresponding to one construction block length is suspended and supported by the moving construction device, and in this state, the corrugated steel web is joined to the tip of the bridge girder already formed,
Assembling the formwork for placing the concrete that forms the upper floor slab on the corrugated steel web, supported by the moving erection device,
The corrugated steel sheet web in which the formwork for placing the concrete forming the lower floor slab is projected from the tip part of the bridge girder in the already formed part immediately below the position where the formwork of the upper floor slab is provided Assemble and support
The upper floor slab concrete and the lower floor slab concrete are placed in the mold, and the upper floor slab and the lower floor slab are formed so as to be continuous with the corrugated steel web ,
The step of assembling a formwork for placing the concrete that forms the lower floor slab is made up of two corrugated steel webs facing each other, of the lower flange made of steel joined along the lower edge of the corrugated steel web. The outer support beam is bridged between two corrugated steel webs below the lower flange, and one end of the vertical beam spanned in the axial direction of the bridge girder is connected to the outer side. It is supported on a supporting beam, and the other end is already supported by a bridge girder in which the concrete of the lower floor slab and the corrugated steel web are integrated, and the formwork is supported on the vertical beam. How to build bridge girders. A bridge girder that forms a box-shaped cross-section with concrete upper and lower floor slabs and a plurality of corrugated steel webs connecting them up and down is constructed by overhang construction for each construction block of a predetermined length. ,
Construction in which the concrete of the upper floor slab and the lower floor slab is supported by the bridge girder of the part already formed by hardening together with the corrugated steel sheet web, and is projected from the tip of the bridge girder and then formed A mobile installation device that supports a part of the weight of the block is provided.
In this state, the corrugated steel web corresponding to one construction block length is suspended and supported by the moving construction device, and in this state, the corrugated steel web is joined to the tip of the bridge girder already formed,
Assembling the formwork for placing the concrete that forms the upper floor slab on the corrugated steel web, supported by the moving erection device,
The corrugated steel sheet web in which the formwork for placing the concrete forming the lower floor slab is projected from the tip part of the bridge girder in the already formed part immediately below the position where the formwork of the upper floor slab is provided Assemble and support
The upper floor slab concrete and the lower floor slab concrete are placed in the mold, and the upper floor slab and the lower floor slab are formed so as to be continuous with the corrugated steel web ,
The step of assembling a formwork for placing the concrete that forms the lower floor slab is made up of two corrugated steel webs facing each other, of the lower flange made of steel joined along the lower edge of the corrugated steel web. The inner support beam is bridged between the two corrugated steel webs by locking on the part protruding to the side, and the outer support beam arranged substantially parallel to the lower side of the inner support beam is suspended from the inner support beam. And supporting one end of the longitudinal beam spanning in the axial direction of the bridge girder on the outer support beam, and supporting the other end with a bridge girder in which the concrete of the lower floor slab and the corrugated steel web are already integrated. A method for constructing a bridge girder characterized by supporting a formwork on a vertical beam .

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