JP2008297706A - Sealing diaphragm of u-shaped rib of steel plate deck, its installation method, and method for repairing existing steel plate deck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an installation method for a sealing diaphragm of a U-shaped rib of a steel plate deck which does not strongly resist a vertical force and which facilitates construction. <P>SOLUTION: At least a part of the sealing diaphragm 22 is composed of at least either of a thermosetting resin and a photo-curing resin. When the sealing diaphragm 22 is mounted in an installtion position inside the U-shaped rib 20, the resin is not cured. The resin is cured by performing at least either of heating and light irradiation after the sealing diaphragm 22 is mounted in the installation position inside the U-shaped rib 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steel diaphragm slab U-rib sealed diaphragm, its installation method, and a repair method for an existing steel deck slab, and in particular, a U-rib sealed diaphragm suitable for use in a steel deck of a bridge structure, The present invention relates to an installation method and a repair method of an existing steel slab.

  Conventionally, there are RC slabs, composite slabs, steel slabs, etc., as the floor slab structure in bridges, but steel slabs are light weight or manufactured to a certain size in the factory and installed on site Since it has features such as being able to shorten the construction period, it has many achievements. However, since the steel slab is a welded structure of a relatively thin steel plate, it is easy to be directly affected by the wheel load of the vehicle, and there are cases where fatigue cracks are generated. In particular, there are many cases in which cracks propagate from crossing portions of horizontal ribs and vertical ribs, scallops, or the like.

  In the steel floor slab structure used in the bridge structure, as shown in FIG. 1, the U-shaped closed cross-section vertical rib (hereinafter referred to as U-rib) structure is relatively rigid and easy to construct. Employment has become mainstream. When using the U rib 20, it is common to install the horizontal rib 30 at intervals of about 1 to 3 m. For reasons of production and transportation, the steel slab 10 is manufactured with a length of a lateral rib interval (span) of about 10 m and joined on site. In FIG. 1, 14 is a deck plate and 16 is a main girder. The position of the field bolt joint portion 12 shown in FIG. 2 is generally provided at a position where the bending force is relatively small (1/4 of the lateral rib span L).

  In the case of the steel deck 10 using the U rib 20 in the vertical rib structure as described above, basically, the inside of the U-rib having high airtightness is not subjected to painting or rust prevention treatment. However, an opening (hand hole 20H, scallop 32, bolt joint 12 or the like) is provided in the vicinity of the site bolt joint portion 12, and outside air enters the U-rib from the opening. Therefore, as shown in FIG. 2, steel diaphragms (hereinafter referred to as sealed diaphragms) 22 welded at the periphery are provided at both ends of the on-site bolt joint portion 12 to maintain the airtightness inside the U rib 20. Usually, this sealed diaphragm 22 is installed in the U-rib 20 by welding the outer periphery in the factory. Since the installation position is about 200 to 500 mm from the joint portion 12, the distance from the lateral rib 30 of the sealed diaphragm 22 on the side close to the lateral rib 30 is about 0 to 425 mm. Further, the plate thickness is generally about 6 to 8 mm, which is equivalent to the plate thickness of the U-rib 20, but a steel plate of about 12 to 19 mm may be used when also used as a backing material.

  As shown in FIG. 3, when a vertical downward force F eccentric from the center of the U rib cross section acts on the U rib 20 near the position where the sealed diaphragm 22 is disposed by the wheel 8 or the like passing over the deck plate 14, At the position where the hermetic diaphragm 22 is disposed, the U-rib 20 rotates rigidly while maintaining the cross-sectional shape, and the stress of the structural details such as the weld toe at the intersection of the lateral rib 30 and the U-rib 20 Has been reported in Non-Patent Document 1. In FIG. 3, 32 is a scallop.

  As a cause of this, as shown in FIG. 4, the torsional force due to the rigid rotation R of the steel sealed diaphragm 22S causes the oil canning deformation (distortion of the U rib side wall) of the web of the U rib 20 on the lateral rib 30. The stress concentration may occur in the scallop 32 turning welding or the like due to induction and local bending of the U-rib web. Due to this stress concentration, there is a possibility that fatigue cracks may occur from structural details that can be fatigue weak points, such as scallop 32 weld toes at the intersections of the lateral ribs 30 and the U ribs 20.

  As a method for reinforcing a steel floor slab, Patent Document 1 describes that a lightweight foamed concrete as a filler is injected into the internal space of a longitudinal rib to improve the fatigue strength of a welded joint. It is described that a reinforcing cross beam is fastened and fixed between the steel main girders, a support metal fitting is provided at a position corresponding to the vertical rib of the reinforcement cross beam, and the vertical rib is supported by the support metal fitting.

  In Non-Patent Document 1 and the like, it is pointed out that the rigidity of the sealed diaphragm has an effect.

JP 2001-248114 A JP 2002-173912 A Iguchi et al. "Static loading test before SFRC pavement construction of steel floor slab" The 60th Annual Scientific Lecture Meeting (September 2005) CS10-017, pp. 333-334

  When the U rib is externally restrained by a lateral rib at regular intervals, and when it is restrained by a sealed diaphragm from the inside, when a torsional force due to a vertically downward force eccentric from the center of the U rib cross section acts on the U rib, If the U-rib is deformed while maintaining the cross-sectional shape at the position where the hermetic diaphragm is disposed, troubles such as cracks occur at the lateral rib restraining position. However, in the past, there has been little research on how to deal with this, and in a previous application (Japanese Patent Application No. 2005-349824) not known by one of the present inventors, as a countermeasure, a sealed diaphragm is used as a vertical force. A steel diaphragm slab U-rib closed diaphragm structure and a steel slab are proposed only as a structure that does not resist the above.

  In the present invention, regarding the sealed diaphragm structure of the steel plate slab U-rib according to the previous application (Japanese Patent Application No. 2005-349824), further studies are made on the material and construction aspects of the sealed diaphragm and the application to repair. A steel diaphragm slab U-rib sealed diaphragm that does not strongly resist vertical force and is easy to construct, its installation method, and a repair method for an existing steel deck using the installation method The issue is to provide.

  The sealed diaphragm according to the present invention includes a deck plate, a U-rib disposed on the lower surface of the deck plate, a sealed diaphragm installed inside the U-rib, and a lateral rib that restrains the side surface of the U-rib from the outside. And a steel diaphragm slab diaphragm structure, wherein a vertical downward force acts on the U rib in a position eccentric from the center of the U rib cross section in the vicinity of the position where the sealed diaphragm is installed. In addition, at least a part of the sealed diaphragm is irradiated with a thermosetting resin and light of 900 nm or less exceeding a wavelength of 350 nm so that the U-rib in the vicinity of the installation position of the sealed diaphragm does not torsionally deform while maintaining the cross-sectional shape. It is characterized in that it is constituted by at least one of a photocurable resin that cures.

  A first aspect of an installation method of a sealed diaphragm according to the present invention includes a deck plate, a U rib disposed on a lower surface of the deck plate, and a lateral rib that restrains the side surface of the U rib from the outside. A method of installing a sealed diaphragm installed inside a U-rib in a steel floor slab, wherein at least a part of the sealed diaphragm is composed of at least one of a thermosetting resin and a photocurable resin. When the sealing diaphragm is attached to the installation position inside the U-rib, the resin is not cured, and after the sealing diaphragm is attached to the installation position inside the U-rib, at least one of heating and light irradiation The resin is cured by performing the steps.

  A second aspect of the method for installing a hermetic diaphragm according to the present invention includes a deck plate, a U rib disposed on the lower surface of the deck plate, and a lateral rib for restraining the U rib side surface from the outside. A method of installing a sealed diaphragm installed inside a U-rib in a steel floor slab, wherein at least a part of the sealed diaphragm is composed of at least one of a thermosetting resin and a photocurable resin. When the sealing diaphragm is attached to the installation position inside the U-rib, the resin is not cured, and after the sealing diaphragm is attached to the installation position inside the U-rib, The resin is cured by receiving either one of them.

  A third aspect of the method for installing a hermetic diaphragm according to the present invention includes a deck plate, a U rib disposed on the lower surface of the deck plate, and a lateral rib for restraining the side surface of the U rib from the outside. An installation method of a sealed diaphragm installed inside a U-rib in a steel floor slab, wherein at least a part of the sealed diaphragm is made of a thermosetting resin, and is located at an installation position inside the U-rib. Then, after attaching the hermetic diaphragm without curing the thermosetting resin, the U-rib is attached to the bottom surface of the deck plate to form the steel floor slab, and the heat during asphalt construction on the top surface of the steel floor slab A thermosetting resin is cured.

  The repair method of the existing steel floor slab according to the present invention includes a deck plate, a U-rib arranged on the lower surface of the deck plate, a steel sealed diaphragm installed inside the U-rib, and the U-plate. A method of repairing an existing steel floor slab comprising a lateral rib for restraining a side surface of the rib from the outside, wherein the steel sealed diaphragm is removed, at least a part of which is a thermosetting resin and photocuring A sealed diaphragm constituted by at least one of the mold resins is newly installed.

  At least a part of the sealed diaphragm according to the present invention is composed of at least one of a thermosetting resin and a photocurable resin that is cured with light having a wavelength exceeding 350 nm and not more than 900 nm. Since it can harden | cure without irradiating a 350 nm or less light beam, irradiation equipment can be reduced in size comparatively cheaply.

  According to the method for installing a sealed diaphragm according to the present invention and the method for repairing an existing steel deck using the installation method, the sealed diaphragm to be installed is at least one of a thermosetting resin and a photocurable resin. Because it is composed of, it does not strongly resist the vertical force. For this reason, the oil canning deformation (distortion of the U rib side wall) of the web of the U rib 20 on the lateral rib 30 is suppressed, and stress concentration occurs in the turn welding of the scallop 32 due to the local bending of the U rib web. Suppresses the occurrence.

  Further, according to the installation method of the sealed diaphragm and the repair method of the existing steel deck using the installation method according to the present invention, when the sealed diaphragm is attached to the installation position inside the U-rib, the sealed diaphragm Since the resin of the sealed diaphragm is cured by performing at least one of heating and light irradiation after being attached to the installation position inside the U rib, the resin of the sealed diaphragm is installed. Easy. Further, it can be installed without performing welding, deformation due to welding heat does not occur, and there is no weak point on fatigue.

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

[Embodiment related to sealed diaphragm structure]
The sealed diaphragm in the present embodiment is configured at least in part by at least one of a thermosetting resin and a photocurable resin that is cured with light having a wavelength exceeding 350 nm and not more than 900 nm.

  As photo-curing resins, UV-curing resins that cure when irradiated with ultraviolet light with a wavelength of 350 nm or less are used in various fields (clear coating of building materials and furniture, anti-corrosion paints for metals, dry films, semiconductors, and liquid crystals. It is widely used in display resist materials, plastic and paper coatings, printing inks, plate making materials, adhesives, etc.), but the photocurable resin used in the sealed diaphragm of this embodiment has a wavelength exceeding 350 nm. In order to cure with light having a high safety to the human body (light having a wavelength of more than 350 nm and not more than 800 nm) and near infrared light (light having a wavelength of more than 800 nm and having a wavelength of 900 nm or less), Inexpensive and easy to handle.

[Embodiment related to installation method of sealed diaphragm]
(First embodiment)
The hermetic diaphragm used in the installation method according to the first embodiment is a plate-like body, at least a part of which is composed of at least one of a thermosetting resin and a photocurable resin, a deck plate, and the deck It is installed inside a U-rib in a steel slab having a U-rib disposed on the lower surface of the plate and a lateral rib that restrains the side surface of the U-rib from the outside.

  As the thermosetting resin, for example, phenol resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, polyurethane, polyimide and the like can be used. The state before curing of the photocurable resin is at least one of a photocurable monomer and a photocurable oligomer, and examples of the photocurable monomer include acrylate, methacrylate, and cationic polymerization polymer. For example, urethane acrylate, polyester acrylate, epoxy acrylate and the like.

  The thermosetting resin and the photocurable resin are impregnated in a nonwoven fabric, glass cloth, roving cloth, glass mat, etc., and the sealed diaphragm can maintain a certain shape even before the resin is cured. Yes.

After the nonwoven fabric, glass cloth, roving cloth, glass mat, etc. impregnated with at least one of the thermosetting resin and the photocurable resin are cured, at least one of short fibers and long fibers in the resin. It becomes the fiber reinforced resin containing. If the Young's modulus of the fiber reinforced resin is about half or less of the Young's modulus (200,000 N / mm ² ) of the steel material, the stress generated by the presence of the sealed diaphragm is halved when a vertical force is applied. Therefore, the generated stress is considered to be equivalent to a structure without a sealed diaphragm.

  Thus, the sealed diaphragm used for the installation method according to the first embodiment does not strongly resist the vertical force. For this reason, the oil canning deformation (distortion of the U rib side wall) of the web of the U rib 20 on the lateral rib 30 is suppressed, and stress concentration occurs in the turn welding of the scallop 32 due to the local bending of the U rib web. Suppresses the occurrence.

  In this embodiment, when the sealing diaphragm is attached to the installation position inside the U rib, the resin of the sealing diaphragm is not cured, and after being attached to the installation position inside the U rib, at least heating and light irradiation are performed. By carrying out either one of them, the resin of the sealed diaphragm is cured. For this reason, it is easy to install a sealed diaphragm. Moreover, since it can be installed without performing welding, deformation due to welding heat does not occur, and there is no fatigue weak point.

  The actual attachment work is performed as follows, as shown in FIGS.

(1) Check the mounting position. Then, the attachment position is wiped with a cloth impregnated with acetone, and degreased and washed.

(2) The hermetic diaphragm 22 before curing matched to the cross-sectional shape of the U-rib 20 is installed at an attachment position (see FIG. 5A). When installing, temporarily fix it with tape.

(3) A non-woven fabric, glass cloth, roving cloth, glass mat or the like impregnated with at least one of the thermosetting resin and the photocurable resin is cut into a tape shape of about 5 to 10 cm to obtain a resin-impregnated tape. 24 is produced. While removing the temporarily fixing tape, the produced resin-impregnated tape 24 is stuck around the installed sealing diaphragm 22 (see FIG. 5B). At this time, it is pasted so that air does not enter as much as possible. If there is a gap, the produced resin-impregnated tape 24 is stacked and pasted to fill the gap.

(4) After confirming that there is no gap, the curing operation is performed by the heating device or the light irradiation device 26 (see FIG. 5C). For example, when the curing operation is performed by the light irradiation device, the distance from the light source to the sealed diaphragm 22 is set to about 10 cm, and the light irradiation time is set to about 40 minutes. However, this value varies depending on the device and is an approximate guide.

(5) After curing, check whether there is a gap, and if a gap is found, fill the gap with a caulking material or the like.

(Second Embodiment)
In the first embodiment, the resin is cured by the heating device or the light irradiation device 26. However, in the second embodiment, as shown in FIG. Specifically, the sealed diaphragm 22 before the resin is cured is attached to a U-rib steel slab before being welded on site, and is temporarily placed outdoors where sunlight and the heat accompanying it hit. At this time, as shown in FIG. 6, it is preferable that the lower surface of the U-rib 20 is directed to the sunlight side so that the sealed diaphragm 22 is easily irradiated with sunlight and the heat accompanying it.

  Alternatively, the resin may be cured by temporarily placing it in a yard having a light source instead of sunlight. In this case, the resin can be cured even at night.

  In the case of curing with sunlight and the accompanying heat, there is no need to use a heating device and a light irradiation device for curing, which is advantageous in terms of cost. However, the time for curing becomes longer.

(Third embodiment)
In the third embodiment, the resin is cured by radiant heat when the asphalt pavement 27 is constructed as shown in FIG. Since the resin is cured by radiant heat when constructing the asphalt pavement 27, the resin included in the sealed diaphragm 22 used in the third embodiment is a thermosetting resin.

  Specifically, before the asphalt pavement 27 is constructed, the sealed diaphragm 22 before the resin is cured at a predetermined position in the U rib 20 in the same manner as the steps (1) to (3) in the first embodiment. Install. Thereafter, asphalt pavement 27 is applied, and the resin is cured by radiant heat at that time. This eliminates the need for step (4) in the first embodiment, which is advantageous in terms of cost and shortens the construction period. However, when the asphalt pavement 27 after construction reaches a normal temperature, it is necessary to confirm the cured state of the resin that the sealed diaphragm 22 has. If the curing is insufficient, additional heating is performed by a heating device.

[Embodiment related to repair method of sealed diaphragm]
In the present embodiment, the existing steel sealed diaphragm 22S is removed, and instead, at least a part of a plate-like body constituted by at least one of a thermosetting resin and a photocurable resin is used. A sealed diaphragm 22 is installed.

  Actual repair work is performed as follows, as shown in FIGS.

(1) In an existing steel floor slab structure (see FIG. 8A) in which a steel sealed diaphragm 22S is installed, a steel material cutting device such as a gas cutting device 28 is inserted into the U rib 20 from a hand hole 20H or the like. Then, the existing steel sealed diaphragm 22S is removed (see FIG. 8B). Although complete removal is desirable, if it seems difficult, the peripheral part may be left and only the central part may be removed.

(2) Thereafter, the sealing diaphragm 22 is installed at a predetermined position (for example, a position on the handhole side of about 10 cm from the existing steel sealing diaphragm) as in the embodiment according to the above-described installation method (see FIG. 8 (C)), the repair is completed (see FIG. 8D). At this time, it is not always necessary to install in an existing position. Rather, it is advantageous when investigating the soundness of the sealed diaphragm 22 by installing it as close as possible to the work hole such as the hand hole 20H.

Perspective view showing the shape of part of the steel deck The perspective view which similarly shows the arrangement | positioning state of a sealing diaphragm The perspective view which shows the eccentric bending which acts on the sealing diaphragm for demonstrating the conventional problem Sectional view showing oil canning deformation The perspective view which shows typically the procedure of 1st Embodiment of the installation method which concerns on this invention. The perspective view which shows typically the condition which is hardening the resin in 2nd Embodiment of the installation method which concerns on this invention. The perspective view which shows typically the condition which is performing resin hardening in 3rd Embodiment of the installation method which concerns on this invention. The perspective view which shows typically the procedure of embodiment of the repair method which concerns on this invention

Explanation of symbols

10 ... Steel slab 12 ... Joint part 14 ... Deck plate 20 ... U rib (vertical rib)
20H ... Hand hole 22 ... Sealed diaphragm 22S ... Steel sealed diaphragm 24 ... Resin impregnated tape 26 ... Heating device or light irradiation device 27 ... Asphalt pavement 28 ... Gas cutting device 30 ... Horizontal rib 32 ... Scallop

Claims (5)

Steel having a deck plate, a U-rib disposed on the lower surface of the deck plate, a sealed diaphragm installed inside the U-rib, and a lateral rib for restraining the side surface of the U-rib from the outside It is a sealed diaphragm structure of floor slab,
In the vicinity of the position where the sealed diaphragm is installed, when a vertical downward force is applied to the U rib at a position eccentric from the center of the U rib cross section, the U rib near the position where the sealed diaphragm is installed maintains the cross-sectional shape. In order to prevent torsional deformation, at least a part of the sealed diaphragm is composed of at least one of a thermosetting resin and a photocurable resin that is cured with light having a wavelength exceeding 350 nm and not more than 900 nm. Sealed diaphragm structure. A sealed diaphragm installed inside a U-rib in a steel deck comprising a deck plate, a U-rib disposed on the lower surface of the deck plate, and a lateral rib for restraining the side surface of the U-rib from the outside. The installation method of
At least a part of the sealed diaphragm is composed of at least one of a thermosetting resin and a photocurable resin,
When the sealing diaphragm is attached to the installation position inside the U-rib, the resin is not cured, and at least one of heating and light irradiation is performed after the sealing diaphragm is attached to the installation position inside the U-rib. Thus, the resin is cured to provide a sealed diaphragm installation method. A sealed diaphragm installed inside a U-rib in a steel deck comprising a deck plate, a U-rib disposed on the lower surface of the deck plate, and a lateral rib for restraining the side surface of the U-rib from the outside. The installation method of
At least a part of the sealed diaphragm is composed of at least one of a thermosetting resin and a photocurable resin,
When the sealing diaphragm is attached to the installation position inside the U-rib, the resin is not cured, and after the sealing diaphragm is attached to the installation position inside the U-rib, at least one of sunlight and accompanying heat A method for installing a sealed diaphragm, wherein the resin is cured by receiving one of the two. A sealed diaphragm installed inside a U-rib in a steel deck comprising a deck plate, a U-rib disposed on the lower surface of the deck plate, and a lateral rib for restraining the side surface of the U-rib from the outside. The installation method of
At least a part of the sealed diaphragm is made of a thermosetting resin,
After mounting the sealed diaphragm without curing the thermosetting resin at the installation position inside the U rib, the U rib is attached to the bottom surface of the deck plate to form the steel floor slab, A method for installing a sealed diaphragm, wherein the thermosetting resin is cured by heat during asphalt construction. A deck plate, a U-rib disposed on the lower surface of the deck plate, a steel sealed diaphragm installed inside the U-rib, and a lateral rib for restraining the side surface of the U-rib from the outside. A repair method for an existing steel slab,
The existing steel floor, wherein the steel sealed diaphragm is removed and a sealed diaphragm at least partly composed of at least one of a thermosetting resin and a photocurable resin is newly installed. How to repair the plate.