JPH0716826A - Molding method for split-type box culvert and molding tool therefor - Google Patents

Abstract

PURPOSE:To facilitate an incorporating operation by a method wherein a PC rod steel with an anchor plate and a nut firmly fixed to the base end thereof is disposed in a lower block form, and a concrete is molded by disposing a coupler containing recess molding mold over the coupler on a bonding surface to an upper block. CONSTITUTION:A coupler containing recess molding tool 10 used for a lower block consists of a recess molding mold 11 and a bolt 12 to be fastened to a coupler. On the center of the recess molding mold 11, a recess 11b is formed, and a hole 11c is pierced. The recess molding tool 10 is placed and positioned on the bottom of a form 30. After the bolt is removed, a top of a PC rod steel 15 with an anchor plate and a nut firmly fixed is helically fitted into the coupler 13. A concrete is molded by disposing the recess molding mold 11 over the coupler 13 on a bonding surface to an upper block. In this manner, the lower block is molded with the coupler 13 set on the top of the PC rod steel 15. Thus, a block incorporating operation can be easily conducted without an effect on another operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a split box culvert and a molding tool therefor.

[0002]

2. Description of the Related Art Box culverts are used when constructing underdrains and the like. In particular, when constructing a large underdrain, a box culvert is formed by separately molding blocks having a shape obtained by horizontally dividing the box culvert into two or three parts and assembling them on site. ing. Such a box culvert is called a split type box culvert.

In the split type box culvert, as shown in FIG. 4, PC steel rods c and d are inserted into the side wall a of the upper block A and the side wall b of the lower block B, respectively. d is connected to each other by a coupler e at the junction of both blocks A and B, whereby the upper and lower blocks A and B are connected to each other, and
Tension is applied to the side walls a and b to increase the strength.

In such a split type box culvert, as shown in FIG. 5, a coupler accommodating recess f is formed on the upper surface of the side wall b of the lower block B, and the side wall b is formed.
A PC steel rod d is embedded in the PC steel rod d, and the upper end of the PC steel rod d is projected into the coupler housing recess f. The lower end of the PC steel rod d is fixed in the block B by an anchor plate g.

In such a split type box culvert, as shown in FIG. 5, when assembling the upper and lower blocks, the coupler e is first screwed into the tip of the PC steel rod d in the recess f. Next, the upper block A is placed on the lower block B, the PC steel rod c is inserted from the upper end of the sheath hole h of the upper block A, and the lower end of the PC steel rod c is screwed into the coupler e. Then, the above PC steel bar c
The upper end of the PC is pulled up with a jack, etc., and PC steel rods c, d
In the state of being tightened, the upper end of the PC steel rod c is fastened to the upper block A by the anchor plate i and the nut j.

[0006]

By the way, the lower block B is formed so that the joint portion is downward, as shown in FIG. 6 as an example. And PC steel rod d
Has one end supported by the mold 1 or the like via the holder k, the other end inserted into the hole n of the coupler accommodating recess mold m, and positioned on the mold o via the coupler accommodating recess mold m. To be done. Then, in this state, concrete is poured into the mold to mold the lower block B.

The block B molded in this manner is demolded after being cured. In this demolding work, block B
Is removed from the mold with the coupler m containing recess m attached, and then the coupler m containing recess m is removed from the block B.

Therefore, the hole n in the coupler accommodating recess mold m is formed in a tapered shape, as is apparent from FIG. 7, in order to facilitate the removal. Therefore, when pouring concrete, there is a possibility that concrete will flow into the hole n, and if it flows in, concrete will adhere to the tip of the PC steel rod d. In that case, when the coupler e is screwed, the mortar must be removed, and the work of attaching the coupler e becomes complicated.

Further, the work of attaching the coupler e must be carried out in the coupler accommodating recess f, which is not easy. Furthermore, it is necessary to form a coupler accommodating recess with sufficient space for the work,
Although the recess is later filled with grout, it is disadvantageous in terms of strength as a box culvert.

Therefore, an object of the present invention is to provide a split type box culvert which facilitates the work of assembling a PC steel rod and is advantageous in strength.

[0011]

In the method for forming a split type box culvert according to the present invention, an unbonded PC steel rod having an anchor plate and a nut fixed to the base end is arranged at a predetermined position in the lower block form, and A coupler is screwed onto the tip of the PC steel rod, and the coupler accommodating recess mold is arranged on the joint surface with the upper block so as to cover the coupler, and concrete molding is performed.

[0012]

In the method of forming the split type box culvert of the present invention, since the coupler is screwed to the tip of the PC steel rod, the molding is performed, so that there is no possibility that concrete will adhere to the tip of the PC steel rod. Even if concrete flows between the tip of the PC steel rod and the coupler, it does not affect the work because the coupler is already attached.

[0013]

1 to 3 show a split type box culvert according to the present invention. The split type box culvert is divided into an upper block 1 and a lower block 2.

In molding the lower block 2, a coupler-accommodating recess molding tool 10 made of steel as shown in FIG. 1 is used. The coupler housing recess forming tool 10 is composed of a coupler housing recess mold 11 for forming the coupler housing recess 3 and a bolt 12 for fastening the coupler housing recess mold 11 to the coupler. The coupler housing recess mold 11 has a truncated cone shape. The flange 1 is attached to the large-diameter side end.
1a is formed. Further, a recess 11b is formed in the center of the small-diameter side end surface of the coupler housing recess mold 11, and a hole 1 reaching the recess 11b is formed in the center of the large-diameter side end surface.
1c is pierced.

On the other hand, the coupler 13 has a screw hole 13 in the shaft core.
a, and a taper 13b is formed in the screw hole opening portion of the end surface. Further, a pin 14 is planted in the middle portion of the peripheral surface of the coupler 13.

When the lower block 2 is molded, the coupler 13 is screwed onto the tip 15a of the PC steel rod 15 until the tip 15a of the unbonded PC steel rod 15 comes into contact with the pin 14, and then the coupler housing recess mold 11 is formed. The concave portion 11b of the bolt is fitted into the coupler 13, and then the bolt 12 is inserted into the hole 11c.
And insert the tip 12a of the bolt 12 into the coupler 1
It is screwed into the screw hole 13a of No. 3 so that the tip end portion 15a of the PC steel rod 15 supports the coupler housing recess mold 11.

In this PC steel rod 15, similarly to the conventional example shown in FIG. 6, the coupler accommodating recess forming tool 10 is placed on the bottom portion of the mold 30 and positioned there, and the anchor plate 16 is provided.
The end portion 15b on the side is fixed to the upper portion of the mold 30 by a holder or the like. Then, in this state, concrete is poured into the mold 30.

The lower block 2 molded and cured in this way, together with the coupler accommodating recess molding tool 10,
It is taken out of the mold 30. Then, the bolt 12 is removed from the coupler 13, and then the coupler housing recess mold 11 is taken out from the lower block 2.

FIG. 2 shows the lower block 2 molded in this way. In this lower block 2, a coupler accommodating concave portion 3 is formed in the upper portion, and an annular notch 4 for accommodating a gasket is formed in the peripheral edge of the opening end of the concave portion 3.
Are formed. And, in the coupler storing concave portion 3,
A coupler 13 is arranged and holds the upper end of an unbonded PC steel rod 15. This PC steel rod 1
The lower end of 5 is held by an embedded anchor plate 16. In addition, the side wall upper surface 2a of the lower block 2
Is formed with two grooves 5 extending over both ends of the lower block 2, and a pin hole 6 is formed between the recesses 3 and 3.

In the lower block 2 formed in this way, as shown in FIGS. 2 and 3, an annular gasket 17 is mounted in the notch 4 of the coupler accommodating recess 3 and a rod-shaped gasket 18 is inserted in the groove 5. And pin hole 6
The pin 19 is inserted into. Then, the upper block 1 is superposed on the lower block 2, and the pin 19 is fitted into a pin hole (not shown) of the upper block 1 to position the upper block 1. Next, the sheath hole 1a of the upper block 1
Insert the PC steel rod 20 from the recess 1b into the
A is screwed into the screw hole 13a of the coupler 13.

Next, one end 20b of the PC steel rod 20 is pulled up with a jack or the like, and the PC steel rod 20 and the PC steel rod 15 of the lower block 2 are tensioned. Then, as shown in FIG. 3, after the anchor plate 21 is positioned on the bottom surface of the recess 1b, the anchor plate 21 is fixed by the nut 22.
Fix it there.

Then, grout is injected from the recess 1b of the upper block 1 through the injection hole 21a of the anchor plate 21 to fill the coupler housing recess 3 and the sheath hole 1a. At that time, the annular gasket 17 prevents the grout from flowing out between the upper and lower blocks 1 and 2. After that, the concave portion 1b is closed with mortar or the like. The rod-shaped gasket 18 is composed of the upper and lower blocks 1,
A seal is made between the two to prevent water, etc. in the box culvert from leaking to the outside after construction, and prevent water, etc. from entering from the outside.

[0023]

As described above, in the block molding method of the split type box culvert according to the present invention, since the lower block is molded while the coupler is attached to the tip of the PC steel rod, the concrete is molded into PC. There is no possibility of sticking to the tip of the steel rod, and even if concrete flows between the tip of the PC steel rod and the coupler, the coupler is already attached, so there is no effect on the work. . Therefore, the work of assembling the blocks becomes easy.

Further, it is not necessary to make the coupler accommodating recess too large since it is not necessary to perform the work of attaching the coupler in the coupler accommodating recess. Therefore, the strength of the box culvert can be increased.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a coupler accommodating recess forming tool for carrying out a block forming method for a split type box culvert according to the present invention.

FIG. 2 is a partial perspective view showing a cross section of a molded lower block.

FIG. 3 is a cross-sectional view showing a state in which a split box culvert is assembled.

FIG. 4 is a perspective view showing a split box culvert.

FIG. 5 is an exploded sectional view for explaining an assembling work of a conventional split type box culvert.

FIG. 6 is a cross-sectional view for explaining a forming operation of the lower block.

FIG. 7 is a cross-sectional view showing a coupler accommodating recess forming tool used in block molding of a conventional split type box culvert.

[Explanation of symbols]

 1 Upper Block 2 Lower Block 3 Coupler Recessed Recess 4 Annular Notch 10 Coupler Recessed Recess Molding Tool 11 Coupler Recess Recessed Mold 11a Flange 11b Recess 11c Hole 12 Bolt 13 Coupler 13a Screw Hole 13b Taper 14 Pin 15 Unbonded PC Steel Rod 15a Tip 16 Anchor plate 17 Gasket 20 PC steel rod 21 Anchor plate 22 Nut 30 Formwork

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhisa Shimizu 3-5-6 Hoshin, Higashiyodogawa-ku, Osaka-shi, Osaka (72) Inventor Kojiro Yuki 2-10-22 Misono-cho, Kodaira-shi, Tokyo (72) Invention Hideki Mishima 1-36-1-1830, Togane-cho, Katsushika-ku, Tokyo (72) Inventor Akira Honma 4814-1, Obari, Ina-cho, Tsukuba-gun, Ibaraki

Claims (3)

[Claims] 1. A box culvert is divided into a plurality of blocks in a horizontal direction, each block is molded, and PC steel rods inserted into their side walls are connected to each other by a coupler, and by the connected PC steel rods. ,
In a method for forming a split-type box culvert in which tension is applied to a side wall, an unbonded PC steel rod having an anchor plate and a nut fixed to a base end is arranged at a predetermined position in a lower block mold, and the PC steel rod is attached. A method for forming a split-type box culvert, characterized in that the coupler is screwed onto the tip of the coupler, and the coupler housing concave portion mold is placed on the joint surface with the upper block so as to cover the coupler and concrete molding is performed. . 2. A coupler accommodating recess mold having a peripheral surface forming the inner peripheral surface of the coupler accommodating recess, a recess accommodating the coupler in the center of the lower end, and a bolt insertion hole penetrating from the upper surface to the recess. The bolt for inserting the coupler housing recess mold into the bolt insertion hole and screwing the tip of the coupler housing recess into the coupler to fasten the coupler housing recess mold to the coupler. A coupler storage recess molding tool used in the block molding method of the split type box culvert of. 3. The coupler used in the block molding method of a split type box culvert according to claim 1, wherein a pin for regulating the insertion amount of the PC steel rod is planted in the middle.