JP2006207116A - Method of joining bottom sheet steel in synthetic floor panel bridge or synthetic floor panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a structure for joining bottom sheet steels to each other capable of performing up to painting on the bottom sheet steels beforehand by preventing the painting from being damaged when nuts are tightened in installing a splice plate even if bolts are fitted to the bottom sheet steels and the painting is performed to eliminate the necessity of a scaffold facility. <P>SOLUTION: This method of joining the bottom sheet steels of the synthetic floor panel bridge or the synthetic floor panel to each other comprises a step for fixing high tension bolts 15 with primary bolts 19 by inserting the high tension bolts 15 into the bolt holes 17 of the bottom sheet steels 1 from the lower side, a step for installing the bottom sheet steels to which the high tension bolts 15 are fixed, a step for installing the splice plate 23 across the adjacent bottom sheet steels, and a step for tightening the splice plate 23 from the upper side with secondary nuts 25. The tightening of the primary nuts in the step for fixing the high tension bolts 15 is performed with at least an introduced torque of 3 kgfm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a steel-concrete composite floor slab and a method for joining bottom steel plates in a composite floor slab bridge and a joint structure used when building roads, bridges, and the like.

The construction method of steel-concrete composite deck is generally performed as follows. A plurality of steel plate panels are sequentially lifted from the ground on a hollow main girder and arranged in a direction perpendicular to the main girder. And the bottom steel plate in the arranged steel plate panel is mutually joined, and concrete is laid on these joined bottom steel plates.
The steel-concrete composite floor slab bridge construction method is such that a girder block formed by welding a T-shaped cross-section member on a bottom steel plate is disposed between abutments or between abutments and intermediate piers. The bottom steel plates are joined together, and concrete is placed on the joined bottom steel plates.

Thus, in the construction process of the steel-concrete composite floor slab and the composite floor slab bridge, an operation of joining the bottom steel plates to each other is required.
Conventionally, as shown in FIG. 4, the joining operation of the bottom steel plates is performed by arranging a contact plate 23 at the joint between the bottom steel plate 1 and the bottom steel plate 1 to be joined to each other. A worker on the work scaffold installed on the base plate inserts a high-strength bolt 15 from the bottom surface of the bottom steel plate, and another worker on the top of the bottom steel plate 1 projects above the attachment plate 23. This is done by attaching and tightening the nut 25 to the force bolt 15.
However, if the bottom steel plate lower surface is not coated, the work scaffold in this method is unnecessary except for the insertion of high-strength bolts, and the work scaffold needs to be removed and is high. Therefore, it is not desirable for safety.

Therefore, as a solution to such a problem, for example, a method for connecting bottom steel plates in a joint portion of a steel-steel composite floor slab steel plate filled with concrete in a hollow steel shell having a bottom steel plate, Bolt holes are provided at predetermined intervals in the connecting portion of the bottom steel plate, the bolts are passed through the bolt holes of the bottom steel plate so that their heads are down before the floor slab panel is installed, and the bolts do not fall Attached, after laying the floor slab panel, the attachment plate provided with bolt holes at predetermined intervals corresponding to the bolt holes of the bottom steel plate is bridged to the upper surface side between the bottom steel plates of adjacent floor slab panels, There is a bottom steel plate connection method for a composite floor slab panel, wherein the bolt is passed through a bolt hole of the attachment plate and nut-tightened from the upper surface side of the attachment plate (see Patent Document 1).
JP 11-324199 A (Claim 1)

Certainly, according to the above-mentioned Patent Document 1, since the bolt is attached to the bottom steel plate so that the bolt does not fall, there is no need to access the lower surface side of the bottom steel plate after the bottom steel plate is installed for bolt insertion. The force bolt can be tightened on only one side.
However, when the rust prevention specification on the lower surface side of the bottom steel plate is painting, the method of Patent Document 1 has the following problems.
Even if bolts are attached to the bottom steel plate so as not to drop, if the bottom surface of the bottom steel plate is coated after the nuts are tightened, a scaffolding facility for performing the painting work is required.
However, it is possible to coat the lower surface side of the bottom steel plate when the bolt is attached to the bottom steel plate. However, after painting the bottom steel plate, if the bottom steel plate is installed and tightened with nuts, there is a problem that if the bolt is not firmly fixed, the coating will crack due to the joint rotation of the bolt .
In this respect, in Patent Document 1, since the purpose is to prevent the bolt from dropping, there is a high possibility that the coating is cracked by the joint rotation of the bolt in the nut tightening after the coating.

  The present invention has been made to solve such a problem, and even when a bolt is attached to the bottom steel plate and further painted, the coating is not damaged when the nut is tightened during the subsequent attachment plate installation. Thus, an object of the present invention is to provide a joining method and a joining structure for a bottom steel plate that can be applied to the bottom steel plate in advance and can eliminate the need for scaffolding equipment.

(1) A method for joining bottom steel plates according to the present invention is a method for joining bottom steel plates of girder blocks constituting a composite floor slab bridge or bottom steel plates of steel plate panels constituting a composite floor slab, wherein a high strength bolt is used. Inserting into the bolt hole of the bottom steel plate from the lower surface side and fixing the high strength bolt with a primary nut, laying a girder block or steel plate panel to which the high strength bolt is fixed, and between adjacent bottom steel plates And a step of tightening with a secondary nut from the upper surface side of the attachment plate, and tightening the primary nut in the step of fixing the high strength bolt with an introduction torque of at least 3 kgf · m. It is characterized by this.

The reason why the introduction torque at the time of tightening the primary nut is at least 3 kgf · m is that it is necessary to tighten at the introduction torque of at least 3 kgf · m in order to completely prevent the high-strength bolt from rotating together when the secondary nut is tightened. It is. In addition, as an introduction torque at the time of tightening of a primary nut, 3-5 kgf * m is preferable.
Although it is necessary to avoid interference between the primary nut and the attachment plate, as a means for that purpose, for example, a countersink may be provided on the interference side of the attachment plate with the primary nut.

In addition, the girder block in a composite floor slab bridge means the structure formed by welding a T-shaped cross-section member (for example, a member formed by welding a steel plate to a T-shaped steel) to a bottom steel plate. Moreover, the steel plate panel in a synthetic floor slab means the structure formed by welding shape steel, such as a T-shaped steel with a low protrusion, to a bottom steel plate.
As the high-strength bolt used in the present invention, it is preferable to use F8T (plating) with a long threaded portion. The reason for using F8T (plating) is that, in the method of the present invention, the final fastening is often not performed immediately after opening the bolt, but even in such a case, by using F8T (plating), a high strength bolt is used. It is because it can prevent rusting.

(2) Further, in the above-described item (1), after the high-strength bolt is fixed by the primary nut, before the girder block or the steel plate panel is installed, the surface on the lower side when the bottom steel plate is installed is coated. It is characterized by this.

(3) In addition, in the above-described (1) or (2), after installing the girder block or the steel plate panel, a step of installing a filler plate having a thickness larger than the thickness of the primary nut on the bottom steel plate is provided. It is characterized by that.

(4) Moreover, the thing in any one of said (1)-(3) WHEREIN: The thickness of the primary nut was set to 3 mm-4 mm, It is characterized by the above-mentioned.
By setting the thickness of the primary nut to 3 mm or more, the primary nut can be tightened with a mechanical drive tool such as an impact wrench, and work efficiency can be improved.
Further, by setting the thickness of the primary nut to 4 mm or less, the thickness of the filler plate when installing the filler plate can be reduced, and the cost can be reduced.
That is, by setting the thickness of the primary nut to 3 mm to 4 mm, both improvement in work efficiency and cost reduction can be realized.
The primary nut is preferably made of the same material and the same planar shape as the ordinary nut. The reason is that a mechanical drive tool such as a general-purpose impact wrench can be used.

(5) Moreover, as for the joining structure of the bottom steel plates in the composite floor slab bridge or the composite floor slab according to the present invention, the bottom steel plates are joined by the bottom steel plate joining method described in any one of (1) to (5) above. It is characterized by that.

  In the present invention, the high strength bolt is fixed by tightening the primary nut with an introduction torque of at least 3 kgf · m, so that the high strength bolt can be completely prevented from rotating when the secondary nut is tightened. Thus, it is possible to complete the coating of the bottom steel plate lower surface (bolt head side) up to the top coating in advance. For this reason, even when the rust-proof specification of the bottom steel plate lower surface is paint, the joint construction after on-site installation is only the nut tightening work on the bottom steel plate upper surface side, and the scaffolding equipment etc. can be dispensed with.

FIG. 1 is an explanatory diagram of a bottom steel plate joining structure according to the present embodiment, FIG. 2 is an explanatory diagram of a road bridge using a composite floor slab to which the bottom steel plate joining structure is applied, and FIG. 3 is a present embodiment. It is explanatory drawing of the joining method of the bottom steel plate concerning.
In addition, in FIG. 1, the arrow AA sectional view taken on the line in FIG. 1 (a) is shown as FIG.1 (b). Moreover, in FIG. 2, the junction part of the baseplate is expanded and shown. Further, in FIG. 3, the main steps of the bonding method are shown in three views of FIGS. 3 (a), (b), and (c), and each drawing also includes a partial plan view in addition to a side view. is doing.

Hereinafter, the present embodiment will be described with reference to FIGS.
As shown in FIG. 2, the composite floor slab to which the bottom steel plate joining structure of the present embodiment is applied includes a steel plate panel 4 formed by welding a T-shaped steel 3 with projections on the bottom steel plate 1, and a T-shaped steel. 3, a main reinforcing bar 5 arranged in parallel with the main reinforcing bar 5, a distribution reinforcing bar 7 arranged perpendicular to the main reinforcing bar 5, and an expanded concrete 9 placed on the bottom steel plate 1. Yes.
Hereinafter, the joining method of the bottom steel plate 1 in the synthetic floor slab comprised in this way is demonstrated.

The method of joining the bottom steel plates according to the present embodiment is a step of inserting the high strength bolts 15 into the bolt holes 17 of the bottom steel plate 1 in the steel plate panel 4 from the lower surface side and fixing the high strength bolts 15 with the primary nuts 19 (high Force bolt fixing step), a step of painting the lower surface side of the bottom steel plate 1 to which the high strength bolt 15 is fixed (painting step), and a step of laying the steel plate panel 4 to which the high strength bolt 15 is fixed (steel plate panel). Erection step), a step of installing the filler plate 21 on the bottom steel plate 1 (filler plate installation step), a step of arranging the attachment plate 23 between the adjacent bottom steel plates (attachment plate arrangement step), A step of tightening with a secondary nut 25 from the upper surface side of the attachment plate 23 (secondary nut tightening step).
Hereinafter, each process will be described in detail.

(1) High-strength bolt fixing process (see Fig. 3 (a))
At the stage where the bottom steel plate 1 is on the ground, the high strength bolt 15 is inserted into each bottom steel plate 1 provided with the bolt holes 17 for inserting the high strength bolts 15. The high-strength bolt 15 is fixed to the bottom steel plate 1 by tightening the primary nut 19 on the upper surface side (in this specification, the upper surface when the bottom steel plate 1 is installed is called the upper surface).
At this time, even when painting is performed on the lower surface side of the bottom steel plate 1, the high-strength bolts 15 need to be rotated together when the secondary nut 25 is tightened so that the coating is not damaged. .
Therefore, in the present embodiment, the primary nut 19 is tightened with an introduction torque of at least 3 kgf · m. If tightening is performed with an introduction torque of 3 kgf · m, even when the secondary nut 25 is tightened, the high-strength bolt 15 does not rotate together, and therefore the coating is not damaged.

In the present embodiment, the thickness of the primary nut 19 is set to 4 mm in order to efficiently tighten the primary nut 19.
By setting the thickness of the primary nut 19 to 4 mm, the primary nut 19 can be tightened with a mechanical drive tool such as an impact wrench, and work efficiency can be improved.
Further, the filler plate 21 needs to be set slightly thicker than the primary nut 19, but by setting the thickness of the primary nut 19 to about 4 mm, the thickness of the filler plate 21 can be made relatively thin and the cost can be reduced. The relationship between the filler plate 21 and the thickness of the primary nut 19 will be described in detail in the description of the filler plate installation step described later.

  In this example, the thickness of the primary nut 19 is 4 mm. However, in the present invention, the thickness of the primary nut 19 is not limited to 4 mm. However, it is preferable to set the thickness of the primary nut 19 to 3 to 4 mm because the same effect as described above can be obtained.

In this embodiment, the high-strength bolt 15 is made of M22, F8T (plating) and having a long threaded portion.
The material and shape of the primary nut 19 are not particularly limited, but are preferably the same material and the same planar shape as the normal nut. The reason is that a mechanical drive tool such as a general-purpose impact wrench can be used.

(2) Painting process In the painting process, the bottom surface of the bottom steel plate 1 is coated for rust prevention. In the present embodiment, since the high strength bolt 15 is fastened with the primary nut 19 with an introduction torque of 3 kgf · m or more in the high strength bolt fixing step, the high strength bolt rotates together when the secondary nut 25 is tightened. And will not damage the previously applied coating.

(3) Steel plate panel erection step The steel plate panel erection step is a step in which the steel plate panel 4 is erected on the main girder laid hollow. In addition, after installing the steel plate panel 4, the position shift between the bottom steel plates in the steel plate panel 4 is adjusted.

(4) Filler plate installation process (see FIG. 3B)
In this step, a filler plate 21 for preventing interference between the primary nut 19 and the attachment plate 23 is installed on the bottom steel plate 1. The filler plate 21 of the present embodiment has an opening 22 in which the primary nut 19 is accommodated, and the primary nut 19 is accommodated in the opening 22 when the filler plate 21 is installed.
The thickness of the filler plate 21 is set to 4.5 mm. Since the thickness of the primary nut 19 is 4 mm, it is set 0.5 mm thicker than this thickness. By setting the thickness 0.5 mm thick, interference between the primary nut 19 and the attachment plate 23 can be prevented.

(5) Attachment plate arrangement step This is a step of arranging the attachment plate 23 between adjacent bottom steel plates. A bolt hole 24 is provided in the attachment plate 23, and the hole diameter is φ26.5 mm.
The bolt hole diameter of the bottom steel plate 1 is φ22.5 mm, whereas the hole diameter of the attachment plate 23 is set large in order to absorb the deviation of the bottom steel plate 1 when the steel plate panel 4 is arranged.
The plate thickness of the attachment plate 23 is not particularly limited, but generally a steel material of about 8 to 16 mm is used.

(4) Secondary nut tightening step After the attachment plate 23 is installed, the secondary nut 25 is tightened to the high strength bolt 15. The tightening of the secondary nut 25 is completed by performing a primary tightening using a dedicated wrench, marking, and then performing a final tightening by a nut rotation method. At this time, since the high-strength bolt 15 is securely fixed by the primary nut 19, the high-strength bolt 15 does not rotate together, and the coating of the lower surface of the bottom steel plate 1 already performed is not damaged. .

As described above, in the present embodiment, the high strength bolt 15 is fixed to the bottom steel plate 1 on the ground with the primary nut 19 and the rust-proof coating is performed in this state. There is no work from the bottom surface, and no scaffolding equipment is required, improving work costs and efficiency.
Further, since the high-strength bolt 15 is fastened with at least 3 kgf · m when the primary nut is fixed, the high-strength bolt 15 does not rotate together when the secondary nut 25 is tightened, and the bottom steel plate is coated on the lower surface. Will not damage.

In the above-described embodiment, the case where the lower surface of the bottom steel plate 1 is painted on the ground is shown. However, even when the lower surface side of the bottom steel plate 1 is not painted, the present embodiment shows the case. If the primary nut is tightened with the introduced torque, it is possible to reliably prevent the high-strength bolt from co-rotating and improve the working efficiency.
Further, in the above embodiment, the case where the joining method of the bottom steel plate is applied to the composite floor slab is shown, but the same effect can be obtained even when applied to the composite floor slab bridge.

It is explanatory drawing of the joining structure of the bottom steel plate which concerns on one Embodiment of this invention. It is explanatory drawing of the composite floor slab to which the joining structure of the bottom steel plate which is one Embodiment of this invention was applied. It is explanatory drawing of the joining method of the bottom steel plate in one Embodiment of this invention. It is explanatory drawing of the joining method of the conventional bottom steel plate.

Explanation of symbols

1 bottom steel plate 15 high strength bolt 19 primary nut 21 filler plate 23 splice plate 25 secondary nut

Claims (5)

A method of joining bottom steel plates of girder blocks constituting a composite floor slab bridge or bottom steel plates of a steel plate panel constituting a composite floor slab, in which a high-strength bolt is inserted into the bolt hole of the bottom steel plate from the lower surface side and a primary nut Fixing the high-strength bolt by the step, laying a girder block or a steel plate panel to which the high-strength bolt is fixed, a step of disposing an attachment plate between adjacent bottom steel plates, and an attachment plate And a step of tightening with a secondary nut from the upper surface side, and performing the tightening of the primary nut in the step of fixing the high strength bolt with an introduction torque of at least 3 kgf · m. 2. The method for joining bottom steel plates according to claim 1, wherein after the high-strength bolts are fixed with primary nuts, the surface which is on the lower side during construction is applied before the girder block or the steel plate panel is constructed. The method for joining bottom steel plates according to claim 1 or 2, further comprising a step of installing a filler plate having a thickness larger than that of the primary nut on the bottom steel plate after the girder block or the steel plate panel is installed. . The joining method of the bottom steel plates according to any one of claims 1 to 3, wherein the thickness of the primary nut is set to 3 mm to 4 mm. The joining structure of the bottom steel plates in the synthetic floor slab bridge or the synthetic floor slab, wherein the bottom steel plates are joined by the joining method of the bottom steel plates according to any one of claims 1 to 4.

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