JP2972738B1 - Construction method of precast concrete slab using variable section stud - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a variable-section stud and a method for constructing a precast concrete slab using the variable-section stud. SOLUTION: A stud base member 1 having a diameter larger than that of a bolt member 2 and having an internal thread is welded to a position of a hole H for preventing slippage formed in a precast concrete floor slab C laid on a load supporting member B. A precast concrete floor slab C in which a groove-shaped notch G is formed in a portion corresponding to the stud base member 1 after the load supporting member B is erected at a predetermined position.
Is laid on the load supporting member B to which the stud base member 1 is welded, and is horizontally fed out from the end of the load supporting member B on the load supporting member B, and the position where the stud base member 1 is welded and the precast concrete floor The bolt member 2 is screwed to the stud base member 1 in a state where the position of the hole H for slip prevention formed in the plate C is matched with the position of the hole H for slip prevention. Filler F
Fill.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of constructing a precast concrete slab composite girder or composite beam using studs having variable cross-sections (hereinafter referred to simply as "construction method of precast concrete slab"). ), In particular, to improve the rigidity of displacement of studs with respect to load supporting members such as composite beams of bridges using precast concrete floor slabs and composite beams of building structures, and, at the time of construction, welding protrusion lengths of studs to load supporting members. The present invention relates to a method of constructing a precast concrete slab using a stud with a variable cross section , in which workability during construction of the precast concrete slab is improved by shortening the length.

[0002]

2. Description of the Related Art Conventionally, for example, in a method of constructing a precast concrete slab by laying and integrating a precast concrete slab on a steel girder of a bridge or an elevated road, a heavy construction machine such as a crane is used. Position of holes for preventing slippage formed in precast concrete floor slab laid in
Align the stud welding position of the steel girder, lower the precast concrete floor slab from above the steel girder, and place the stud in the hole for slip prevention, no shrinkage in the hole for slip prevention Fillers such as concrete, mortar and the like are used.

[0003]

By the way, in the method of constructing this precast concrete slab, the stud used to be welded to the upper surface of the upper flange of the steel girder conventionally has a required length and diameter (constant cross-sectional shape). Use a rod-shaped stud with a head and weld the stud to the upper surface of the upper flange of the steel girder at the factory or construction site in accordance with the position of the slip prevention hole formed in the precast concrete slab laid on the steel girder. I was

[0004] When the precast concrete floor slab is laid on a steel girder, the rod-shaped stud with a head having a cross section such as a shaft protrudes greatly from the upper surface of the upper flange when it is welded. It is not possible to adopt a construction method that sends the steel girder horizontally to the predetermined position of the steel girder with the stud welded in the set state, and usually lifts the precast concrete slab using a crane etc. The construction method of laying it by hanging it on top was adopted.

[0005] However, the construction method in which a precast concrete slab is lifted by using a crane or the like and laid by hanging it on a steel girder requires a heavy construction machine such as a crane. When moving, the precast concrete slab oscillates, and its supporting state is not stable. For this reason, the precast concrete slab is suspended by aligning the studs with the slip prevention holes formed in the precast concrete slab. There was a problem that the work required time and trouble.

[0006] The magnitude of the shear rigidity of the stud attached to the upper surface of the upper flange of the steel girder by the stud welding depends on the cross-sectional area of the welded portion at the root of the stud. It is necessary to use a large diameter stud, but by using this required length and a large diameter rod-shaped stud, the stud welding machine is increased in size in addition to the cost increase of the stud itself, and the overall cost is reduced. There was a problem of rising.

[0007] In addition, since the rod-shaped stud with a head projects greatly from the upper surface of the upper flange of the steel girder when welded, there is a problem that the stud may be bent during transportation or construction. In other words, when stud welding is performed at the factory, compared to the case where stud welding is performed at the construction site, the work efficiency and work accuracy of the welding work can be improved, but the steel girder is transported, At the time of erection or hanging of precast concrete floor slabs, it was necessary to pay attention so that the studs would not bend by hitting objects.

Further, the studs which protrude from the upper surface of the upper flange of the steel girder obstruct the work performed on the steel girder.
This also has the problem that the working efficiency of the construction surface is reduced.

The present invention has been made in view of the problems of the above-mentioned conventional method of constructing a precast concrete slab using a rod-shaped stud with a head, and a steel girder for a bridge or an elevated road supporting the precast concrete slab and a building structure. Not only can improve the rigidity of the studs against the load supporting members such as steel beams, but also improve the workability during precast concrete slab construction by shortening the protruding length of the studs against the load supporting members during construction. It is an object of the present invention to provide a method for constructing a precast concrete slab using studs having a variable cross section .

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, a precast controller using a stud of variable cross section according to the present invention.
The construction method of the cleat floor slab is the precast concrete floor slab laying on the load supporting member in the precast concrete slab laying method in which the precast concrete slab is integrated on the load supporting member such as steel girder or steel beam. in accordance with the position of the displacement prevention holes formed in the plate, the bolt member
Body and bolts with internal threads for screw joining
A stud with a weld formed larger than the diameter of the
After mounting the load supporting member welded to the stud base member at a predetermined position, a precast concrete slab having a groove-shaped notch formed in a portion corresponding to the stud base member is laid on the load supporting member welded to the stud base member. To do this, from the end of the load support member, send it horizontally over the load support member,
With the stud base member welded to the position of the slip prevention hole formed in the precast concrete slab, the bolt member is screwed to the stud base member, and there is no shrinkage in the slip prevention hole. It is characterized by being filled with filler such as concrete, mortar or the like.

[0011] The construction of the precast concrete slab
The studs used in the method are divided into a stud base member that is directly welded to the base material and a bolt member that is screwed to the stud base member. The projecting length of the stud base member to be directly welded with respect to the base material can be shortened, and the overall length of the stud can be arbitrarily and easily set by appropriately selecting a bolt member to be screwed to the stud base member. Can be.

[0012] Further , the welded portion of the stud base member is bolted.
The stud can be formed to have a larger diameter than the diameter of the material, and the displacement rigidity of the stud, which depends on the cross-sectional area of the welded portion at the root of the stud, can be increased without increasing the diameter of the stud over its entire length.

[0013] Then, the variable cross-section in construction methods of precast concrete slab with studs in accordance with the positional displacement prevention holes formed in the precast concrete slab to be laid on a load bearing member, the screw joint bolt member You
Of main body and bolt member with female screw
By welding a stud base member with a welded part formed to a larger diameter , a precast concrete slab is
In order to lay the stud base member on the welded load support member, send out the load support member horizontally from the end of the load support member, and prevent the position where the stud base member was welded and the slip formed on the precast concrete slab The bolt member can be screwed to the stud base member with the position of the hole being matched.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for constructing a precast concrete floor slab using studs having variable cross sections according to the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show a precast condenser according to the present invention.
1 shows an embodiment of a variable cross section stud used for a method of constructing a cleat floor slab . The stud A with the variable cross section is made of a base material B, for example,
A stud base member 1 that is directly welded to a load supporting member such as a steel girder of a bridge or an elevated road or a steel beam of a building structure, and a bolt member 2 that is screwed to the stud base member 1 to be divided and configured. I am trying to do it.

As shown in FIGS. 1 and 4, the stud base member 1 has a diameter D21 of the bolt member 2 shown in FIG.
It is configured to include a welded portion 11 formed to have a diameter D11 larger than the diameter D11 and a main body portion 12 formed with a female screw 13 for screwing the bolt member 2 together.

In this case, the length L1 of the stud base member 1 is such that the required length of the female screw 13 for supporting the welded portion 11 and the bolt member 2 by screwing is secured, and the stud welded to the base material B is secured. The projection length of the base member 1 with respect to the base material B is set to a length that can be minimized.

In this embodiment, the diameter D11 of the welded portion 11 is formed to be larger than the diameter D12 of the main body portion 12, so that the rigidity of the stud A can be reduced. Although the diameter can be further increased without increasing the diameter, as shown in FIG. 2, as in a modified example of the stud base member 1, the diameter D11 of the welded portion 11 and the diameter D12 of the main body 12 are the same. In this case as well, a higher rigidity can be obtained as compared with a conventional rod-shaped stud having a head or the like having a cross section such as a shaft.

The stud base member 1 shown in FIG.
Is to weld the stud base member 1 to the base material B by submerged arc welding (as described above,
The method of constructing a precast concrete slab using studs having variable cross sections includes a case where a welding method other than arc stud welding is used to weld the stud base member 1 to the base material B. ) Of course, the stud base member 1 can be welded to the base material B by arc stud welding,
In this case, as shown in a modified example of the stud base member 1 in FIGS. 2 and 5, the lower part of the welded portion 11 of the stud base member 1 is formed into a tapered surface, or the flux 14 is formed at the center of the weld surface (lower surface). Can be appropriately adopted.
By welding the stud base member 1 to the base material B by arc stud welding, workability and work efficiency can be improved.

On the other hand, the bolt member 2 screwed to the female screw 13 formed on the stud base member 1 is a known bolt member such as a headed / threaded stud, a high-strength bolt, and more specifically, shown in FIG. As described above, a bolt member having the male screw 22 and the head 23 formed at the end of the main body 21 (diameter D21) can be used.

In this case, the length L of the bolt member 2
2 can be of any length depending on the purpose of use and the like, and the total length of the stud A can be set arbitrarily and easily by appropriately selecting a bolt member 2 having a different length L2. Can be done.

Next, using the above-mentioned stud A having a variable cross section,
One embodiment of a method for constructing a precast concrete slab of the present invention, in which a precast concrete slab C is laid and integrated on a load supporting member B constituting a composite girder of a bridge or a composite beam of a building structure, FIG. This will be described using the composite girder of the bridge shown in FIGS.

First, a steel girder B as a load supporting member manufactured to a required strength and size is prepared, and is placed at a position of a slip prevention hole H formed in a precast concrete floor slab C laid on the steel girder B. In addition, the diameter is larger than the bolt member 2,
The stud base member 1 having the female screw is attached by welding (see FIG. 6A). In this case, the stud base member 1
Welding can be performed in the factory,
Compared to the case where welding is performed at a construction site, the working efficiency and working accuracy of welding work can be improved. Further, since the stud base member 1 directly welded to the upper surface of the upper flange of the steel girder B can protrude shorter than the steel girder B, when the steel girder B is transported or installed, the stud base member 1 has an object. Does not bend, so that the steel girder B can be easily handled and the stud base member 1 does not hinder the work performed on the steel girder B, thereby improving the work efficiency of the construction surface. Can be done.

As described above, the steel girder B obtained by welding the stud base member 1 to a predetermined position on the upper surface of the upper flange of the steel girder B is erected on the supporting frame E such as a pier or abutment via the bearings E1 and E2.
By supporting, it is erected at a predetermined position (FIG. 6
(B)).

Then, a precast concrete floor slab C in which a groove-shaped notch G is formed in a portion corresponding to the stud base member 1 is laid on the steel girder B to which the stud base member 1 is welded. Then, the stud base member 1 is horizontally fed out on the upper surface of the upper flange of the steel girder B, and the position where the stud base member 1 is welded and the position of the slip prevention hole H formed in the precast concrete floor slab C coincide with each other. A bolt member 2 is screwed to the member 1 and a filler F such as non-shrinkable concrete or mortar, for example, a non-shrink mortar is provided in a slip prevention hole H and a groove-shaped notch G formed in a precast concrete floor slab C. , The precast concrete floor slab C is integrated with the steel girder B (see FIGS. 6B and 6C and FIG. 7).

In this case, the length of the bolt member 2 is selected so that the head 23 of the bolt member 2 of the stud A does not protrude from the hole H for preventing slippage formed in the precast concrete slab C.

FIG. 8 shows an embodiment in which a prestress is introduced into a precast concrete slab C by using a PC steel wire P. In this case, after introducing the prestress, the non-shrinkable concrete is inserted into the slip prevention holes H formed in the precast concrete slab C.
Filler F such as mortar is filled.

As described above, the method of constructing a precast concrete slab using the studs having variable cross sections according to the present invention will be described with reference to an embodiment in which a precast concrete slab C is laid on a steel girder B constituting a composite girder of a bridge and integrated. Although described based on, the object of the present invention is not limited to this, the present invention is, for example, when laying a precast concrete slab on a steel beam constituting a composite beam of a building structure and integrating them Is also widely applicable.

[0029]

According to the present invention, a pre-press using a stud having a variable cross section according to the present invention is provided.
According to the construction method of the cast concrete slab, the stud is divided into a stud base member directly welded to the base material and a bolt member screwed to the stud base member. , The protrusion length of the stud base member directly welded to the base material with respect to the base material can be shortened,
Further, by appropriately selecting a bolt member to be screwed to the stud base member, the entire length of the stud can be arbitrarily and easily set. Further, soluble stud base member
The contact portion can be formed to have a diameter larger than the diameter of the bolt member, and the stud displacement rigidity, which depends on the cross-sectional area of the weld at the base of the stud, is increased without increasing the diameter of the stud over its entire length. be able to. Furthermore, in addition to reducing the cost of the stud itself, there is no need to use a large-sized welding machine for welding the stud base member, and the overall cost can be reduced.

The female screw for screwing the bolt member is aligned with the position of the slip prevention hole formed in the precast concrete slab laid on the load supporting member.
The diameter of the formed main body and bolt member should be larger than
In order to lay the precast concrete slab on the load supporting member to which the stud base member is welded by welding the stud base member having the welded portion , the precast concrete slab is horizontally placed on the load supporting member from the end of the load supporting member. The bolt member can be screwed to the stud base member in a state where the position where the stud base member is welded and the position of the slip prevention hole formed in the precast concrete slab coincide with each other. Because the precast concrete slabs are always supported at the time of precast concrete slab construction, workability and construction accuracy can be improved, and heavy construction equipment such as cranes can be used for laying precast concrete slabs. Since it is not required, the operation can be performed easily.

[Brief description of the drawings]

FIG. 1 Construction of a precast concrete slab of the present invention
1A and 1B show an embodiment of a stud base member of a stud having a variable cross section used in a method, wherein FIG. 1A is a partially cutaway front view, and FIG. 1B is a bottom view.

2A and 2B show the same modified example, wherein FIG. 2A is a partially cutaway front view, and FIG. 2B is a bottom view.

FIG. 3 Construction of the precast concrete slab of the present invention
1A and 1B show an embodiment of a bolt member of a stud having a variable cross section used in a method, wherein FIG. 1A is a plan view and FIG. 1B is a front view.

FIG. 4 is a front view showing a state where a stud having a variable cross section is welded to a base material when the stud base member shown in FIG. 1 is used.

FIG. 5 is a front view showing a state where a stud having a variable cross section is welded to a base material when the stud base member shown in FIG. 2 is used.

FIG. 6 is a process explanatory diagram showing one embodiment of a method for constructing a precast concrete slab using the studs with variable cross-sections of the present invention.

FIGS. 7A and 7B are process explanatory views of FIG. 6B, wherein FIG.
(B) is a front sectional view, (C) is a sectional view taken along line II of (B), and (D) is a sectional view taken along line II-II of (B).

FIG. 8 is an external perspective view showing one step of an example of introducing a prestress in the construction method.

[Explanation of symbols]

 A Studs with variable cross section 1 Stud base member 13 Female screw 2 Bolt member 22 Male screw B Steel girder (load supporting member) C Precast concrete floor slab G Notch H Hole for preventing misalignment F Filler

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoichi Ikeo 474 Obata, Gokaso-cho, Kanzaki-gun, Shiga Prefecture Inside the Shiga Works of Japan Stud Welding Co., Ltd. (72) Inventor Yasuhide Maeda 3rd Dejima Nishimachi, Sakai City, Osaka Prefecture (1) Inside Sakai Iron Works, Ltd. (56) References: Japanese Utility Model Application Sho 61-91901 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) E04B 5/02 E01D 19/12

Claims (1)

(57) [Claims] 1. A method of constructing a precast concrete slab in which a precast concrete slab is laid on a load supporting member such as a steel girder or a steel beam and integrated therewith, wherein the precast concrete slab is formed on a load supporting member. Screw the bolt member to the position of the misalignment prevention hole.
Of the body and the bolt member with female threads
After mounting a load supporting member welded to a stud base member having a welded portion formed with a diameter larger than the diameter at a predetermined position, a precast concrete floor slab in which a groove-shaped notch is formed in a portion corresponding to the stud base member, In order to lay the stud base member on the welded load support member, send out the load support member horizontally from the end of the load support member, and prevent the position where the stud base member was welded and the slip formed on the precast concrete slab In a state in which the holes are aligned with each other, a bolt member is screw-connected to the stud base member, and a non-shrinkable filler such as concrete or mortar is filled in the hole for preventing slippage. Construction method of precast concrete slab using cross section stud.