Floor slab connection hanging jig and floor slab erection method

Abstract

To provide a floor slab connection hanging jig and a floor slab erection method capable of installing a floor slab in a predetermined position in a short time even when there is no insert or hanging hole on the upper surface of the floor slab and joint width is small.SOLUTION: In a floor slab connection hanging jig 1 for lifting a precast floor slab C1 to erect and join in a predetermined position of a bridge girder (steel girder G1), the jig comprises multiple U-shaped members 2 formed into U-shape with one side in the horizontal direction opened to place the precast floor slab C1, and one or more hanging beams 3 that connect and support the U-shaped members 2, and a lifting place 32 having a lifting hole 34 that can be lifted by a lifting machine is attached to the hanging beam 3.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a formwork connection lifting jig used when erecting a formwork such as a bridge deck replacement work, and a formwork erection method using the same.

Background Art

[0002] In the erection work of precast formworks, generally, anchors and inserts are provided in advance at the top end of the formwork and used for lifting. In recent years, in the bridge deck replacement work of bridges, in order to improve the durability of the formwork to be replaced, there have been proposals to reduce the notch on the precast formwork such as stud holes and suspension holes opening on the upper surface of the formwork, and to minimize the joint width between precast formworks to reduce the on-site casting work as much as possible.

[0003] However, when there are no suspension holes on the upper surface of the precast formwork and the joint width is small, in order to install the formwork at a predetermined position, it is necessary to lift it with a nylon sling and pull it with a manual lifting device such as a chain block or a lever block (registered trademark) to horizontally move the formwork and narrow the joint width. There was a problem that the formwork erection work took a long time. In addition, there were problems such as shear deformation of the temporary wedges during pulling and inability to readjust after erection.

[0004] Further, Patent Document 1 discloses a precast formwork construction method and a C-shaped jig in which a precast formwork suspended by a lifting device is transferred from an open end surface on one side of the C-shaped jig to the inner surface of the C-shaped jig and placed thereon. Then, the upper suspension member is removed from the precast formwork and rotated by 90 degrees, and the longitudinal direction of the upper suspension member is arranged on the upper surface in the longitudinal direction of the C-shaped jig, and the suspension tool suspended from the upper suspension member is fixed to a fixing portion provided on the upper surface of the C-shaped jig. Further, the precast formwork placed on the C-shaped jig by a lifting device is set at a predetermined position of PC steel materials stretched between bridge abutments and suspended from the PC steel materials (see Claims 1 and 3 of the claims of Patent Document 1, paragraphs

[0009] to

[0018] of the specification, FIGS. 1 to 7 of the drawings, etc.).

[0005] However, as described in paragraph

[0003] of the specification of Patent Document 1, the precast floor slab construction method and the C-shaped jig described in Patent Document 1 are such that "it is necessary to temporarily place the precast floor slab in front of the abutment and install a large-scale shoring for lateral movement. Furthermore, equipment for laterally moving the precast floor slab to the lower surface of the PC steel material and for height adjustment is also required, which becomes a factor in increasing costs." Also, as shown in FIG. 5 of Patent Document 1, the installation of the C-shaped jig 9 on the precast floor slab 3 is to insert the precast floor slab 3 from the open end of the C-shape of the C-shaped jig 9 with the longitudinal direction of the C-shaped jig 9 and the longitudinal direction of the precast floor slab 3 (perpendicular to the bridge axis) aligned. Since the lower horizontal member 9c of the C-shaped jig 9 is perpendicular to the bridge girder, the precast floor slab 3 cannot be installed on the bridge girder while finely adjusting the C-shaped jig 9 in the bridge axis direction with the precast floor slab 3 placed thereon, and there is a problem that it cannot be used for a floor slab connection hanging jig for horizontally moving the floor slab to adjust the joint width between the floor slabs.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, the present invention has been devised in view of the above-described problems, and an object thereof is to provide a floor slab connection hanging jig and a floor slab erection method capable of installing a floor slab at a predetermined position in a short time even when there are no inserts or suspension holes on the upper surface of the floor slab and the joint width is small.

Means for Solving the Problems

[0008] The floor slab connection hanging jig according to claim 1 is a floor slab connection hanging jig for lifting a precast floor slab and installing and joining it at a predetermined position on a bridge girder, comprising a plurality of U-shaped members with one horizontal side open for placing the precast floor slab, and one or more hanging beams connecting and supporting the U-shaped members, wherein a hanging fitting that can be lifted by a hoist is attached to the hanging beam.

[0009] The floor slab connection hanging jig according to claim 2 is the floor slab connection hanging jig according to claim 1, wherein a buffer material for buffering so that the concrete part does not chip when contacting the precast floor slab is adhered to the bottom surface and side surface of the U-shaped member.

[0010] The floor slab erection method according to claim 3 is a floor slab erection method for lifting a precast floor slab using the floor slab connection hanging jig according to claim 1 or 2 and installing it at a predetermined position on a bridge girder, characterized in that the precast floor slab is placed on the plurality of U-shaped members and lifted by a hoist via the lifting plate and installed at the predetermined position on the bridge girder.

Advantages of the Invention

[0011] According to the invention according to claims 1 to 3, even when there are no inserts or hanging holes on the upper surface of the floor slab and the joint width is small, the floor slab can be installed at a predetermined position in a short time.

[0012] In particular, according to the invention according to claim 2, since the buffer material is adhered, it is possible to prevent the precast floor slab from being damaged when the precast floor slab and the hanging jig come into contact, such as when placing the precast floor slab on the hanging jig.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0014] Hereinafter, an embodiment of the post-construction method for misalignment prevention welding according to the present invention will be described in detail with reference to the drawings.

[0015] <Hanging jig for floor slab connection> First, with reference to FIGS. 1 to 3, the hanging jig 1 for floor slab connection according to the embodiment of the present invention will be described. FIG. 1 is a front view showing the hanging jig 1 for floor slab connection according to the embodiment of the present invention, and FIG. 2 is a side view showing the hanging jig 1 for floor slab connection. Further, FIG. 3 is a plan view showing the hanging jig 1 for floor slab connection.

[0016] The hanging jig 1 for slab connection according to an embodiment of the present invention includes a plurality (four in the illustrated form) of U-shaped members 2, ···, 2 with one horizontal side open for placing a precast slab (C1: see FIG. 5, the same applies hereinafter), and one or a plurality (a pair in the illustrated form) of hanging beams 3, 3 that connect and support these U-shaped members 2. It is used when lifting the precast slab C1 and installing and joining it at a predetermined position on a bridge girder (steel girder G1: see FIG. 5 etc.).

[0017] (U-shaped member) As shown in FIG. 2 etc., the U-shaped member 2 is a member formed in a U-shape in side view by combining a plurality of steel materials joined by welding etc. with a section steel such as an H-shaped steel as a base. As shown in FIG. 2, this U-shaped member 2 includes an upper member 20 made of a straight H-shaped steel, a lower member 21 also made of a straight H-shaped steel, and a connecting member 22 that connects them, and has a U-shape with one horizontal side (the right side in the figure) open. This connecting member 22 has steel plates welded to both end faces of its flange with an H-shaped steel as a base.

[0018] Also, as will be described later, in the illustrated embodiment, when the thickness t1 of the precast slab (C1) is 220 mm (see also FIG. 7), the interval h1 between the upper member 20 and the lower member 21, which is the space for placing the precast slab (C1), is set to 335 mm, which is slightly wider than the thickness of the precast slab (C1) so that the precast slab (C1) can be inserted or withdrawn freely into this interval h1.

[0019] And on the upper surface of the lower member 21 that abuts against the precast floor slab (C1), a buffer material 23 is adhered to buffer the impact during abutment and prevent the concrete portion of the precast floor slab (C1) from chipping. In this embodiment, the buffer material 23 is hard rubber. Since the buffer material 23 is made of hard rubber, it also has the function of anti-slip for the precast floor slab (C1). And as described above, since the thickness t1 of the precast floor slab (C1) and the height interval of the U-shaped member 2 are set to be approximately the same height, no special measures for preventing falling are required. However, for the purpose of preventing falling, the precast floor slab (C1) and the floor slab connection hanging jig 1 may be fastened with a wire, a jig, or the like.

[0020] Also, on the inner surface of the connecting member 22 that abuts against the precast floor slab (C1) (the surface on the open end side of the U-shape), a buffer material 24 having the same shape as the convex portion (C1a) of the shear key that fits into the concave portion (C1b) of the shear key of the precast floor slab (C1) is adhered (see also Fig. 7). In this embodiment, this buffer material 24 is also hard rubber. However, the buffer material 24 may be provided with flat rubber in the height of the connecting member 22, which is not the same shape as the convex portion (C1a) of the shear key but is flat. This is because even if it is flat rubber, it has the function as a buffer material.

[0021] Adjacent U-shaped members 2, 2 are joined by a pair of staggered bars 4, 4 with adjustable length, where steel bars are joined by a turnbuckle or the like, and are configured such that the distance between the U-shaped members 2, 2 is constant and parallel.

[0022] Also, the depth D1, which is the length from the inside of the connecting member 22 of the lower member 21 to the protruding end of the lower member 21, is set to a length corresponding to the depth of the precast floor slab (C1) along the bridge axis direction when the precast floor slab (C1) is placed on the bridge girder so that the precast floor slab (C1) can be stably placed (see also Fig. 7).

[0023] (Hanging beam) The suspension beam 3 is a beam member having a beam body 30 made of a steel material such as an H-shaped steel as a base, and has a function of connecting and supporting the plurality of U-shaped members 2, ···, 2 described above. A plurality of reinforcing members 31 are joined to the beam body 30 to reinforce the rigidity between the upper and lower flanges.

[0024] Further, a lifting plate 32 for lifting by a hoisting machine such as a crane is welded and attached to the upper surface of the upper flange of the beam body 30. This lifting plate 32 is reinforced with a reinforcing plate 33 so as not to rotate around the welding line during lifting and is attached to the upper flange of the beam body 30. Further, the lifting plate 32 is formed with a lifting hole 34 for lifting a wire rope or the like for lifting through a shackle or the like.

[0025] Note that the reference numeral 5 in FIG. 1 is a chain block which is a manual hoisting device, and this chain block 5 is provided for adjusting the length so that the floor slab connecting suspension jig 1 and the precast floor slab (C1) placed on the floor slab connecting suspension jig 1 become horizontal. Of course, the chain block 5 may be other hoisting devices capable of adjusting the length regardless of whether it is manual or electric, such as a lever block (registered trademark).

[0026] <Floor slab erection method> Next, with reference to FIGS. 4 to 8, a floor slab erection method according to an embodiment of the present invention will be described. A case where the precast floor slab C1 is lifted using the above-described floor slab connecting suspension jig 1 and erected at a predetermined position of the steel girder G1 which is a bridge girder will be described while comparing with a conventional floor slab erection method.

[0027] FIG. 4 is a schematic side view showing each step of a conventional floor slab erection method as viewed in a direction perpendicular to the bridge axis. (a) shows the state when the floor slab is lifted, (b) shows the state when the floor slab is placed, and (c) shows the state after the floor slab is pulled and connected. FIG. 5 is a schematic side view showing each step of the floor slab erection method according to the present embodiment as viewed in a direction perpendicular to the bridge axis. (a) shows the state when the floor slab is lifted, and (b) shows the state when the floor slab is placed. Note that the symbol BP indicates the pier BP, which is the substructure of the bridge. In the figure, X indicates the bridge axis direction X, Y indicates the direction perpendicular to the bridge axis, and Z indicates the vertical direction Z.

[0028] FIG. 6 is a front view showing a state in which the precast floor slab C1 is lifted by the floor slab connection lifting jig 1 according to the present embodiment, and FIG. 7 is a side view showing a state in which the precast floor slab C1 is lifted by the floor slab connection lifting jig 1. FIG. 8 is a plan view showing a state in which the precast floor slab C1 is lifted by the floor slab connection lifting jig 1. In the figure, X indicates the bridge axis direction X, Y indicates the direction perpendicular to the bridge axis, and Z indicates the vertical direction Z.

[0029] [Conventional Floor Slab Erection Method] (Floor Slab Lifting and Transporting Step) First, the conventional floor slab erection method will be briefly described. In the conventional floor slab erection method, as shown in FIG. 4, in the case of a structure in which no notches are provided in the precast floor slab C1, such as stud holes or suspension holes that open on the upper surface of the floor slab of the precast floor slab C1, that is, when the stud hole Sh of the precast floor slab C1 is a recess that opens on the lower surface and no inserts for connecting suspension fittings are provided on the upper surface of the precast floor slab C1, since the precast floor slab C1 cannot be normally lifted with a wire rope, it is necessary to perform a floor slab lifting and transporting step of lifting the precast floor slab C1 using a nylon sling and transporting it to a predetermined position on the steel truss G1.

[0030] However, the nylon sling is fixed only by friction to the precast floor slab C1, so it is unstable, making it difficult to level the precast floor slab C1. In the floor slab lifting and transporting process of the conventional floor slab erection method shown in Fig. 4(a), there is a problem that it takes time and effort to transport the floor slab from a transport vehicle such as a trailer to a predetermined position on the steel girder G1 (bridge girder) when lifting the floor slab.

[0031] (Floor slab erection process) Next, in the conventional floor slab erection method, as shown in Fig. 4(b), a floor slab erection process is performed to erect the precast floor slab C1 at a predetermined position on the steel girder G1. Specifically, in this process, the precast floor slab C1 is lifted with a nylon sling and placed so that the stud jib S1, which is a stud with a head protruding from the steel girder G1, is accommodated in the stud hole Sh that opens on the lower surface. Also, a temporary soleplate TB is installed on the steel girder G1, and the precast floor slab C1 is placed thereon.

[0032] However, in the floor slab erection process of the conventional floor slab erection method, as described above, since the precast floor slab C1 is lifted using a nylon sling, it is unstable because it is fixed only by friction, and it is difficult to level the precast floor slab C1. Also, in this process, it is very difficult and time-consuming to place the precast floor slab C1 on the steel girder G1 while accommodating the stud jib S1 in the stud hole Sh that cannot be seen from above.

[0033] (Floor slab installation (slide) process) After that, in the conventional floor slab erection method, as shown in Figs. 4(b) and 4(c), the precast floor slab C1 erected on the steel girder G1 in the previous process is horizontally slid to connect the floor slabs by fitting the shear key (protrusion C1a) into the shear key (recess C1b) of another adjacent precast floor slab C1. A floor slab installation process (slide process) is performed (see also Fig. 7).

[0034] Specifically, a newly installed precast floor slab C1 is horizontally pulled towards an existing structure side such as an already placed precast floor slab C1 or a steel girder G1 using a manual hoisting device such as a chain block or a lever block (registered trademark), and the floor slabs are separated to a predetermined joint width and connected to each other.

[0035] However, in the conventional floor slab erection method, there was a problem that the temporary soleplate TB would undergo shear deformation when the precast floor slab C1 was pulled and displaced horizontally. Moreover, in the conventional floor slab erection method, after the precast floor slab C1 was once placed on the steel girder G1, it was very difficult to lift the precast floor slab C1 using a nylon sling, and there was also a problem that readjustment could not be performed. Therefore, there was no choice but to pull and displace the precast floor slab C1 horizontally, and the problem of the shear deformation of the temporary soleplate TB became significant.

[0036] [Floor slab erection method according to the embodiment] (Floor slab lifting and transportation process) In contrast, in the floor slab erection method according to the embodiment of the present invention, as shown in FIGS. 5 to 8, with the above-described floor slab connection lifting jig 1, the precast floor slab C1 is placed on a plurality of U-shaped members 2 and lifted by a hoisting machine via a lifting plate 32 and erected at a predetermined position of the steel girder G1.

[0037] At this time, in the floor slab erection method according to the present embodiment, as shown in FIG. 6, the length can be freely adjusted using a chain block 5 through the suspension hole 34 of the lifting plate 32, and it is easy to level the precast floor slab C1. Also, as described above, since the buffer material 23 made of hard rubber is adhered to the upper surface of the lower member 21, it is possible to prevent the precast floor slab C1 from shifting.

[0038] Therefore, in the floor slab erection method according to the present embodiment, as shown in Fig. 5(a), the floor slab lifting and transporting step of lifting the precast floor slab C1 using the floor slab connection hanging jig 1 and transporting it to a predetermined position on the steel girder G1 can be accurately performed in a short time, and the working efficiency of the floor slab lifting and transporting step can be improved. Moreover, in the floor slab erection method according to the present embodiment, since the impact when the precast floor slab C1 abuts against the floor slab connection hanging jig 1 can be buffered by the buffer material 23, it is also possible to prevent the concrete portion of the precast floor slab C1 from chipping.

[0039] Furthermore, in the floor slab erection method according to the present embodiment, compared with the lifting using a nylon sling in the conventional floor slab erection method, it is easy to level the precast floor slab C1. Therefore, it is easy to accurately transport and lower the precast floor slab C1 to a predetermined position on the steel girder G1.

[0040] Also, in the floor slab erection method according to the present embodiment, since the self-weight of the precast floor slab C1 can be supported by a hoisting machine via the floor slab connection hanging jig 1 during transportation, it is easy to re-hoist the precast floor slab C1 and finely adjust the position of the precast floor slab C1. Even when the joint width between the precast floor slabs C1 is narrow, the precast floor slab C1 can be accurately placed at a predetermined position on the steel girder G1. For this reason, the slide step of horizontally sliding the precast floor slab C1 erected on the steel girder G1 in the conventional floor slab erection method can be omitted.

[0041] Moreover, in the floor slab erection method according to the present embodiment, since the slide step can be omitted, there is no need to enlarge the stud hole Sh in the slide direction, and the durability of the precast floor slab C1 can also be improved.

[0042] (Floor slab erection and installation step) Therefore, in the floor slab erection method according to the present embodiment, next, a floor slab erection and installation step of accurately erecting and installing the precast floor slab C1 at a predetermined position on the steel girder G1 is performed.

[0043] Specifically, while supporting the self-weight of the precast floor slab C1 with a hoisting machine using the floor slab connection hoisting jig 1, it is hoisted and lowered, and while biting a block, wedge, etc. with a predetermined width so that the joints between the precast floor slabs C1 have a predetermined width, it is finely adjusted and the precast floor slab C1 is accurately installed and fixed at a predetermined position on the steel girder G1.

[0044] With the completion of this process, the floor slab erection work of the precast floor slab C1 according to the floor slab erection method of the present embodiment is completed by installing the precast floor slab C1 at a predetermined position on the steel girder G1.

[0045] According to the floor slab erection method according to the present embodiment described above, even when there are no inserts or hanging holes on the upper surface of the floor slab and the joint width is small, the precast floor slab C1 can be accurately installed and fixed at a predetermined position on the steel girder G1 in a short time.

[0046] As described above in detail, the floor slab connection hoisting jig 1 according to the embodiment of the present invention and the floor slab erection method using the same have been described. However, any of the above-described or illustrated embodiments merely show one embodiment embodied in practicing the present invention. Therefore, the technical scope of the present invention should not be construed in a limited manner by these.

Explanation of Reference Numerals

[0047] 1: Floor slab connection hoisting jig 2: U-shaped member 20: Upper member 21: Lower member 22: Connecting member 23, 24: Buffer material 3: Suspension beam 30: Beam body 31: Supplemental stiffening member 32: Hoisting plate 33: Reinforcing plate 34: Hoisting hole 4: Lattice 5: Chain block (manual hoisting equipment) C1: Precast floor slab (floor slab) C1a: Protrusion (shear key) C1b: Recess (Shearing Key) Sh: Stud Hole G1: Steel Truss (Bridge Truss) S1: Stud Gib (Alignment) TB: Temporary Scaffold BP: Bridge Pier

Claims

1. A suspension jig for slab connection for lifting a precast slab and installing and joining it at a predetermined position on a bridge girder, comprising: a plurality of U-shaped members with one horizontal side open for placing the precast slab, and one or more suspension beams connecting and supporting the U-shaped members; a lifting plate with a lifting hole formed therein that can be lifted by a hoist is attached to the suspension beam. The suspension jig for slab connection is characterized by the above.

2. A buffer material for buffering so that the concrete part does not chip when contacting the precast slab is adhered to the bottom surface and side surface of the U-shaped member. The suspension jig for slab connection according to Claim 1, characterized by the above.

3. A slab erection method for lifting a precast slab using the suspension jig for slab connection according to Claim 1 or 2 and installing it at a predetermined position on a bridge girder, comprising: lifting the precast slab with a hoist through the lifting plate with the precast slab placed on the plurality of U-shaped members and installing it at a predetermined position on the bridge girder. The slab erection method is characterized by the above.

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