JPH0830398B2 - Shield segment manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a shield segment of an arc-shaped body for performing a primary shoe in a space formed in a tail portion of a shield machine in a shield construction method.

[Prior Art] This type of segment is called a prefabricated reinforced concrete (so-called RC) shield segment manufactured in a factory, and its production is a space for connecting bolts from the end face of a formwork, so-called bolt. Bolts forming a box Insert a taper pin with a circular cross section into the formwork to cast concrete into the box, remove the pins and formwork after the concrete has hardened, and remove the bolt holes formed by the demolded pins. I was going to put the bolts in the bolt box. At this time, the taper pin had to have a demolding gradient of at least 1/100 in order to facilitate demolding.

[Problems to be Solved by the Invention] In the above conventional direction, when the bolt holes are long, it is not possible to directly see the condition of the outer ends of the bolts during assembly, and therefore the alignment of the bolt holes is troublesome. , It was difficult to assemble.

In addition, if the demolding gradient is set to 1/100 or more in order to facilitate the demolding of the taper pin, the bolt hole diameter becomes too large on the end surface side of the segment, and the large radial direction on the segment during the primary lining A difference occurs, which is not preferable.

It is an object of the present invention to provide a method of manufacturing a shield segment that facilitates demolding of a pin, facilitates segment assembly, and prevents misalignment.

[Means for Solving the Problems] According to the present invention, the cross-sectional shape is reduced from the end surface of the segment mold toward the bolt box portion toward the tip portion in which the radial direction of the segment is short and the direction orthogonal to the direction is long. It is characterized in that a pin is inserted, concrete is poured into the mold, the pin and the mold are removed after the concrete hardens, and the bolt is housed in a bolt hole formed by the pin.

The cross-sectional shape of the pin is an ellipse with the minor axis in the radial direction of the segment and the major axes in the directions orthogonal to the radial direction, that is, the width direction and the circumferential direction, and gradually shrinks toward the inner end. It is preferable that the end portion is formed in a circular shape having a diameter slightly larger than the outer diameter of the bolt and the gradient of the pin in the minor axis direction is 1/100 or less.

Further, it is preferable that the length of the pin is substantially equal to the length of the bolt.

[Operation] In the method of manufacturing the shield segment configured as described above, the segment width and the gradient in the circumferential direction of the pin are significantly larger than the conventional demolding gradient of at least 1/100. Demolding is extremely easy.

Moreover, the gap between the bolt hole and the direction of the bolt is much larger than in the past, so that when the segment is assembled, it is extremely easy to insert the other segment of the bolt into the bolt hole, and therefore the assembly is facilitated.

In addition, the gap between the bolt and the radial direction of the bolt hole is very small, so that misalignment of the segments is prevented.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a segment manufactured according to the present invention. An end face 2 in the width direction W of the segment indicated by reference numeral 1 for the entire arcuate planar body (the other end face is not shown)
And a plurality of end faces 3 (the other end face is not shown) in the circumferential direction C (two end faces 2 and four end faces 3 in the illustrated example).
Bolt holes 5 are formed and the inner peripheral surface 4 of the segment 1 is formed.
Has a bolt box 6 communicating with the middle of the bolt hole 5.
(FIG. 2) is formed. Then, as shown in FIG. 2, the bolt holes 5 and the bolt box 6 have bolts 7
Is stored.

In FIG. 3, for example, the inner peripheral surface 4 of the segment 1 of the mold 10 shown in FIG.
A bolt box portion 13 forming a bolt box 6 is provided in the vicinity of the peripheral surface 12 facing the end surface 11 and the end surface 11 facing the end surface 2 of the segment 1. Through holes 11a, 14a and 15a are formed in the end surface 11 and the outer wall 14 and the inner wall 15 of the bolt box portion 13, respectively.

FIG. 4 shows a trumpet-shaped pin 16 inserted into the through holes 11a, 14a and 15a. The shape of the outer end portion 16a of the pin 16 is such that the radial direction R of the segment 1 is the short axis b.
Then, a / b having a major axis a in the direction orthogonal to the radial direction R, that is, the width direction W (circumferential direction C on the end face 3) is formed in an oval shape of, for example, 1.3, and is directed toward the inner end portion 16b. Next, the inner end 16b is formed into a circular shape having a diameter larger than the outer diameter of the bolt 7 by about 1 mm, and the gradient in the direction of the short axis b is set to 1/100 or less.

When manufacturing the segment 1, pin from the end face 11 of the mold 10
16 toward the bolt box portion 13, through holes 11a, 14a and 15
Insert into a (Fig. 3).

Next, concrete A is cast on the mold 10, and when the concrete A hardens, the pins 16 are demolded and the mold 10 is demolded. At this time, since the pin 16 has a gradient in the direction of the major axis a much larger than the conventional demolding gradient of at least 1/100, it can be easily demolded.

Finally, the bolt 7 is housed in the bolt hole 5 and the bolt box 6 to complete (FIG. 2).

When assembling the segments, as shown in FIG. 5, the segments 1 and 1A are joined, and the bolt box 6 is inserted from the segment 1 side into the bolt hole 5A of the segment 1A by using the bolt box 6 to form the bolt boxes 6, 6A. The nuts 8 and 8A are screwed onto both ends of the bolt 7 by using the above, and the nuts 8 and 8A are tightened to connect both segments 1 and 1A.

At this time, as shown in FIG.
Even if 5A and 5A are deviated, the inclination in the direction of the major axis a is large, so that the bolt 7 has a large margin to move, and the bolt 7 can be easily inserted and assembled. Also,
At this time, since the clearance between the bolt 7 and the bolt holes 5 and 5A in the direction of the short axis b is small, the misalignment between the segments 1 and 1A can be eliminated.

EFFECT OF THE INVENTION Since the present invention is configured as described above,
The demolding gradient in the width direction or the circumferential direction of the pin segment can be increased to facilitate demolding.

Therefore, the width between the bolt and the bolt hole and the clearance between the bolt hole and the circumferential direction are increased to facilitate the assembling of the segment. Further, the clearance between the bolt and the radial direction of the bolt hole is reduced to prevent the misalignment of the segments. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view showing a segment manufactured according to the present invention, FIG. 2 is a sectional view in the circumferential direction of the main part of FIG. 1, and FIG. 3 is an embodiment of the present invention during concrete pouring. Sectional view of the mold in the circumferential direction, FIG. 4 is a perspective view showing a pin, and FIGS. 5 and 6 are sectional views in the direction orthogonal to FIG. It is a figure. 1,1A …… Segment, 5,5A …… Bolt hole, 7 …… Bolt, 8 …… Nut, 10 …… Form, 11 …… End face, 13 ……
Bolt box part, 16 …… pin

Claims (1)

[Claims] Claims: 1. From the end face of the segment formwork to the bolt box part, insert a pin whose cross-sectional shape is short in the radial direction of the segment and long in the direction orthogonal to the direction and shrinks toward the tip part, and concrete is inserted in the formwork. A method for manufacturing a shield segment, which comprises placing a mold, removing the pin and the form from the mold after hardening the concrete, and storing the bolt in a bolt hole formed by the pin.