JPH0786270B2 - Arrangement method of PC steel material of tubular structure - Google Patents

Description

[Detailed Description of the Invention] <Industrial field of application> The present invention relates to a tubular structure for introducing prestress by tensioning a PC steel material when constructing a tubular structure.
PC steel material placement method.

<Prior art> Generally, for a tubular structure or the like, in order to apply prestress, a sheath for inserting a PC steel material is first embedded in the wall body formwork before the concrete is poured into the wall body. The PC steel material is inserted into the sheath and tensioned, thereby introducing prestress in a predetermined direction of the wall body, that is, the tubular structure.

However, in such a case, the sheath to be embedded in the wall body form is configured to have a predetermined length, and since the sheath is added in accordance with the length of the wall body, the sheath embedding work is unexpectedly complicated. In addition, when the sheath is embedded, it is necessary to sufficiently stop the water in the sheath body and the joint portion so that concrete slag does not enter the sheath, resulting in poor workability.

Therefore, as shown in FIG. 5, the PC steel material 2 is replaced by the tubular structure 1
After the wall body 10 is constructed without being embedded in the wall body 10,
PC steel material 2 is stretched over both sides of 10 along with the PC
A method has been proposed in which the fixing tools 3 at both ends of the steel material 2 are fixed to the wall body 10 and the foundation portion 11 to tension the PC steel material, whereby the PC steel material 2 is erected in an exposed state on both sides of the wall body 10 in the vertical direction. Because of the tension, the work of placing concrete on the wall 10 can be simplified and the workability can be improved.

<< Problems to be Solved by the Invention >> However, FIG. 6 is an enlarged sectional view showing a portion corresponding to an arrow VI portion (top portion of the wall body 10) of FIG.
As shown in the figure, when the PC steel material 2 is arranged only on one side of the wall body 10 to introduce prestress, the tension of the PC steel material 2 causes the PC steel material 2 of the wall body 10 to There is a difference in tension between the erected tension side and the non-erected tension side, and the bending moment F acts in the radial direction at the top of the PC steel material 2 at right angles to the erection tension direction. Because of this, the wall
No. 10 had a problem that harmful tensile stress such as being deformed to the tension side of the PC steel material 2 might be generated.

The present invention has been made in view of the above background, and can reduce the influence of harmful bending moment acting on the top of the structure when the PC steel material is disposed only on one wall surface of the cylindrical structure. An object of the present invention is to provide a method for arranging a PC steel material in a tubular structure.

<< Means for Solving the Problem >> In order to achieve the above object, the present invention, when the PC steel material is longitudinally arranged on one side of the wall of the tubular structure, in advance in the wall of the wall body end portion. PC steel partially buried vertically and
Characterized by tensioning PC steel.

In addition, a compression ring made of reinforced concrete is provided in advance on the peripheral wall at the end of the PC body on which the PC steel material is arranged, and the PC steel material is arranged by penetrating the compression ring.
Alternatively, the PC steel material is tensioned. Alternatively, a compression ring made of reinforced concrete is provided in advance on the peripheral wall at the end of the wall body on which the PC steel material is arranged, and the PC steel material is arranged by penetrating the compression ring. PC in the circumferential direction on the wall of the part
It is characterized by arranging steel materials and tensioning those PC steel materials.

Furthermore, while preliminarily partially embedding the PC steel material in the wall at the end of the wall body in the longitudinal direction, a compression ring made of reinforced concrete is provided on the wall peripheral wall of the PC steel material embedding site, and the PC steel material is penetrated through the compression ring. It is characterized by arranging and tensioning those PC steel materials.

<< Working >> According to the above method, the PC steel material is partially embedded in the wall of the tubular structure and is tense, so the above-mentioned difference in tension between the front and back sides of the wall is reduced. can do. That is, by partially embedding the PC steel material, it is possible to reinforce the end portion of the wall body, thereby reducing the influence of harmful bending moment.

Further, since the compression ring reinforces the wall structure itself, the influence of the bending moment can be reduced also by this. Then, by arranging the PC steel material in the circumferential direction on the wall body at the compression ring portion, it is possible to apply tension force in the radial direction to the wall body, thereby reducing the influence of the bending moment acting on the compression ring portion.

<< Examples >> Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a portion similar to FIG. 6 in a tubular structure showing an application of the first embodiment of the present invention.

This invention is basically provided on one side of the wall 10 of the tubular structure 1.
When arranging the PC steel materials 2 in the longitudinal direction, the PC steel materials 4 are partially buried in the longitudinal direction in the wall at the end portion of the wall body 10 in advance, and the PC steel materials 2 and 4 are tensioned.

That is, the PC steel material 4 is partially stretched in advance along the PC steel material 2 in the top wall of the wall body 10, and both ends of the PC steel material 4 are fixed.
Then, the PC steel material 2 is stretched vertically to one side of the wall body 10 and both ends thereof are fixed to the fixing tool 3 and tensioned.

As a result, the PC steel material 2 is erected and tensioned in the vertical direction on one side of the wall body 10 in an exposed state, and prestress is introduced in the vertical direction of the wall body 10, that is, the tubular structure 1, and at the same time, The PC steel material 4 is partially embedded in the top wall and tensioned by erection, and a partial prestress is introduced at the top of the wall body 10 in the longitudinal direction of the non-installed side of the PC steel material 2.

Therefore, according to such a method, the PC steel material is
Although the tension force will be different between the front and back sides of the wall body 10 due to the tension being applied to one side, at the top of the wall body 10, the PC steel material 4 is partially embedded in the wall and the tension is applied. Therefore, the above-mentioned difference in tension can be alleviated by the prestress introduced by the PC steel material 4. That is, the top portion of the wall body 10 can be reinforced by partially embedding the PC steel material 4, whereby the influence of the bending moment acting on the portion can be reduced.

FIG. 2 is a sectional view of a portion similar to FIG. 1 showing the application of the second embodiment of the present invention.

That is, the present invention is basically the wall body 10 of the tubular structure 1.
When arranging the PC steel material 2 vertically on one side of the
10 is provided with a compression ring 10a made of reinforced concrete on the peripheral wall at the end of the PC steel material 2 on the side where the PC steel material 2 is disposed, and the PC steel material 2 is disposed by penetrating the compression ring 10a and tensioning the PC steel material 2.

Therefore, according to such a method, since the compression ring 10a reinforces the top structure itself of the wall body 10, it is possible to reduce the influence of the bending moment acting on the site also by this. In this case, when the PC steel material 2 is tensioned, a radial force S acts on the lower portion of the compression ring 10a, and a strong load is applied to the relevant portion. Therefore, the thickness W1 of the compression ring 10a is reduced. It must be set thicker than a certain amount.

FIG. 3 is a sectional view of a portion similar to FIG. 1 showing the application of the third embodiment of the present invention.

This invention is basically provided on one side of the wall 10 of the tubular structure 1.
When arranging the PC steel material 2 in the longitudinal direction, a compression ring 10a made of reinforced concrete is provided in advance on the peripheral wall of the end portion of the wall body 10 on which the PC steel material 2 is arranged.
The PC steel material 2 is arranged so as to penetrate through 0a, and the PC steel material 6 is also arranged in the circumferential direction on the wall body 10 at the compression ring 10a portion to tension the PC steel materials 2 and 6.

That is, as in the case of the embodiment shown in FIG. 2, the compression ring 10a and the PC steel material 2 are arranged, and the wall 10 at the lower portion of the compression ring 10a is arranged.
Then, the PC steel material 6 is wound in the circumferential direction to make it tense. As a result, the prestress P is introduced into the tensioned portion of the PC steel material 6 in the radial direction.

Here, in the present embodiment, the PC steel material 6 is wound around the outside of the wall body 10 so as to be tensioned. However, as shown by the broken line in FIG. 3, the PC steel material 6 is arranged inside the wall body 10. You may set it up and make it tense.

Therefore, according to such a method, as in the case of the embodiment shown in FIG. 1, the influence of the bending moment acting on the relevant portion can be reduced and the compression ring can be reduced.
Prestress P is introduced by the tension of the PC steel material 6 in the lower wall portion 10a of the 10a, and the prestress P is opposed to the above-mentioned force S, so that both can be offset and the portion is reinforced. it can. Therefore, the thickness W2 of the compression ring can be reduced, and can be set thinner than the above-mentioned thickness W1.

FIG. 4 is a sectional view of a portion similar to FIG. 1 showing the application of the fourth embodiment of the present invention.

This invention is basically provided on one side of the wall 10 of the tubular structure 1.
When arranging the PC steel material 2 in the vertical direction, the PC steel material 4 is partially embedded in the vertical direction in the wall at the end of the wall body 10 in advance, and the reinforced concrete is applied to the wall 10 surrounding the PC steel material 4 embedded portion. The compression ring 10a is provided, and the PC steel material 2 is arranged through the compression ring 10a.
It is to make C steel materials 2 and 4 tense.

That is, this embodiment is the same as the PC steel material 4 described in FIG.
And the compression ring described earlier in Figure 2.
In combination with the arrangement of 10a, the synergistic effect of these two cases can be expected.

<< Effects of the Invention >> As described above in detail in the embodiments, according to the method for arranging the PC steel material of the tubular structure according to the present invention, the PC steel material is partially included in the wall of the tubular structure. Since it is buried and strained,
It is possible to reduce the difference in tension between the front and back sides of the wall body due to the PC steel material being exposed on one side of the wall body, and to reinforce the end portion of the wall body. As a result, it is possible to reduce the influence of the bending moment acting on the part.

Further, since the compression ring reinforces the wall structure itself, the influence of the bending moment can be reduced also by this. Then, by arranging the PC steel material in the circumferential direction on the outside of the wall of the compression ring portion, it is possible to apply a tension force in the radial direction to the wall body, thereby reducing the force acting on the compression ring portion. It can be further reinforced.

[Brief description of drawings]

1 to 4 are partial sectional views of a tubular structure showing application of each embodiment of the present invention, FIG. 5 is a sectional view of a tubular structure for explaining a conventional method, and FIG. 6 is a part thereof. FIG. 1 …… Cylindrical structure 2,4,6 …… PC steel 10 …… Wall 10a …… Compression ring

Claims (4)

[Claims] 1. When vertically arranging a PC steel material on one side of a wall of a tubular structure, the PC steel material is partially buried in the wall at the end portion of the wall body in advance in the longitudinal direction, and the PC steel materials are A method for arranging PC steel in a tubular structure, which is characterized by tensioning steel. 2. When a PC steel material is longitudinally arranged on one side of a wall body of a tubular structure, a compression ring made of reinforced concrete is provided in advance on the peripheral wall of the end portion of the wall body on which the PC steel material is arranged, and the compression ring is provided. A method for arranging a PC steel material in a tubular structure, which comprises arranging a PC steel material through a ring and tensioning the PC steel material. 3. When a PC steel material is longitudinally arranged on one side of a wall body of a tubular structure, a compression ring made of reinforced concrete is provided in advance on the peripheral wall of the end portion of the wall body on which the PC steel material is arranged, and the compression ring is provided. A PC steel material of a tubular structure characterized by arranging a PC steel material through the ring and also arranging a PC steel material in the circumferential direction also on the wall body of the compression ring part and tensioning the PC steel material. How to place. 4. When vertically arranging the PC steel material on one side of the wall of the tubular structure, the PC steel material is partially embedded in the wall at the end of the wall body in the vertical direction in advance, and A compression ring made of reinforced concrete is provided on the peripheral wall of the wall where the PC steel material is embedded, and the compression ring penetrates the PC.
A method for arranging PC steel materials in a tubular structure, which comprises arranging steel materials and tensioning the PC steel materials.