JP2021032033A - Roof structure - Google Patents

Abstract

To provide a roof structure capable of concealing a tension end of a PC steel material from public notice to improve building appearance, while applying tension in an eaves-ridge direction to a roof substrate using the PC steel material.SOLUTION: A roof structure comprises a roof substrate 1 constituted of prestressed concrete which is applied with tension by introducing tensioning force to a PC steel material 2 extending along an eaves-ridge direction X. A recessed portion 7 is provided in a place moved backward to a ridge side from an eaves edge of an upper face 1a of the roof substrate 1. A tensioned end 4 of the PC steel material 2 fixed to the roof substrate 1 in a state of introducing the tensioning force to the PC steel material 2 is disposed inside the recessed portion 7.SELECTED DRAWING: Figure 2

Description

The present invention relates to a roof structure of a building.

Patent Document 1 discloses, as a roof structure of a building, a roof structure provided with a roof base composed of prestressed concrete in which tension is applied by introducing tension to a PC steel material extending along the direction of the eaves. Has been done. By applying tension in the eaves direction to the roof base with PC steel, it is possible to construct a roof base having a large dimension in the eaves direction. In this roof structure, the tension end of the PC steel material fixed to the roof base in a state where the tension force is introduced into the PC steel material is arranged at the eaves of the roof base.

Japanese Patent No. 42666463

In the roof structure described in Patent Document 1, there is a problem that the tension end of the PC steel material arranged at the eaves of the roof base is easily noticeable from the ground around the building, under the eaves, etc., and the appearance of the building is not very good.
In view of this situation, the main subject of the present invention is a roof structure capable of improving the appearance of a building by hiding the tension end of the PC steel material from the eyes while applying tension to the roof base in the direction of the eaves by the PC steel material. Is in the point of providing.

The first characteristic configuration of the present invention is provided with a roof base composed of prestressed concrete in which tension is applied by introducing tension to a PC steel material extending along the direction of the eaves.
A recess is provided in the portion of the upper surface of the roof base that is recessed from the eaves to the ridge side.
The point is that the tension end of the PC steel material fixed to the roof base in a state where the tension force is introduced into the PC steel material is arranged inside the recess.

According to this configuration, by having the PC steel material extending along the eaves ridge direction, it is possible to construct a roof base having a large dimension in the eaves ridge direction, and it is possible to easily construct an eaves having a large allowance. Then, the tension end of the PC steel material is arranged inside a recess provided in a portion recessed from the eaves edge of the upper surface of the roof base, which is difficult to see from the ground around the building or under the eaves, to the eaves side. The tension edge of the steel material can be hidden from the public, and the appearance of the building can be improved.

The second characteristic configuration of the present invention is that the recess is composed of recesses extending in parallel in the direction in which the eaves are continuous, and the tension ends of the plurality of PC steel materials are arranged inside the recesses. is there.

According to this configuration, the tension ends of a plurality of PC steel materials can be collectively arranged in one concave groove extending in parallel in the continuous direction of the eaves, and a recess is formed for each tension end of one PC steel material. The roof structure can be simpler than that of.

The third characteristic configuration of the present invention is that the concave groove is configured as a rain gutter.

According to this configuration, it is possible to efficiently construct a structure that hides the tensioned ends of a plurality of PC steel materials from the eyes by utilizing the concave groove formed as a rain gutter. Moreover, compared to arranging the rain gutter at the eaves, the rain gutter can be hidden from the public, and the appearance of the building can be further improved.

In the fourth characteristic configuration of the present invention, the opening edge of the recess on the eaves side is arranged at a position lower than the opening edge of the recess on the ridge side.
The tension end of the PC steel material is located on a wall portion on the ridge side inside the recess.

According to this configuration, since the opening edge on the eaves side of the recess is lower than the opening edge on the ridge side of the recess, the tension jack of the tension end of the PC steel material arranged on the wall portion on the ridge side inside the recess is tensioned. When pulling and tensioning with, the pulling direction by the tension jack can be made as close as possible to the tension direction of the tension end, and the difficulty of introducing the tension force to the tension end inside the recess can be reduced.

Roof plan of the building Sectional view of the roof structure of the building Sectional view of the main part of the roof structure

An embodiment of a building to which the roof structure of the present invention is applied will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the roof structure of the building B is configured as a hipped roof having an eaves N and a ridge M, and is provided with a reinforced concrete roof base 1 on the roof base 1. It is constructed by laying roofing materials (not shown) on the floor.

In the example shown in FIG. 1, the protruding dimension L1 of the eaves N on the short side side (left side in the drawing) of the building B (the dimension from the outer wall surface W of the outer peripheral portion 5 of the building to the eaves tip) is the long side side of the building B (the dimension from the eaves tip). It is set to be larger than the protruding dimension L2 of the eaves N (upper and lower sides in the figure). Then, the roof base 1 on the short side having a large protrusion of the eaves N introduces tension into a plurality of PC steel materials 2 extending in parallel along the eaves ridge direction X, and tension is applied to the prestressed concrete. Consists of concrete. By having a plurality of PC steel materials 2 extending in parallel along the eaves ridge direction X, the strength of the roof base 1 having a large protrusion dimension of the eaves N can be secured, and the eaves N having a large protrusion can be appropriately configured. ..

Hereinafter, the details of the roof base 1 will be described with reference to FIGS. 2 and 3. In addition, in FIGS. 2 and 3, various reinforcing bars arranged in the reinforced concrete portion such as the roof base 1, the beam 5A, and the wall body 5B are omitted.

As shown in FIG. 2, the roof base 1 is integrally formed on a reinforced concrete beam 5A, a wall body 5B, and a column (not shown) on the outer peripheral portion 5 of the building. For example, the roof base 1 has a substantially right-angled triangular cross section in which the portion 1A on the eaves side outside the outer peripheral portion 5 of the building becomes thinner toward the eaves side, and the portion on the ridge side inside the outer peripheral portion 5 of the building. 1B is formed in a plate-like cross section in an inclined posture extending toward the ridge side with the same thickness continuously above the portion 1A on the eaves side.

The upper surface 1a of the eaves-side portion 1A and the ridge-side portion 1B of the roof base 1 is formed of a substantially series of inclined surfaces that are lower toward the eaves side. In the illustrated example, on the upper surface 1a, the eaves side of the roof base 1 on the eaves side of the portion 1A is slightly steeper than the other.
The lower surface 1b of the portion 1A on the eaves side of the roof base 1 is formed on a horizontal plane at a height equivalent to the lower surface of the beam 5A, and constitutes an eaves ceiling.
The lower surface 1c of the ridge-side portion 1B of the roof base 1 is formed on an inclined surface having the same inclination as the upper surface 1a of the roof base 1.

Then, the fixed end 3 of the PC steel material 2 is arranged at the ridge side portion 1B of the roof base 1, and the tension end 4 of the PC steel material 2 is arranged at the eaves side portion 1A of the roof base 1. In the present embodiment, the PC steel material 2 is provided on the roof base 1 by a post-tension method that introduces a tension force after placing concrete. Post-tensioning methods include a bond method in which the PC steel material 2 is inserted into the sheath pipe 6 buried in the roof base 1 after concrete is placed, and a PC steel material in which the outside is covered with the sheath pipe 6 with grease or the like interposed between them. An unbonded construction method or the like in which 2 is buried in the roof base 1 can be used. The PC steel material 2 is fixed to the roof base 1 in a state where tension force is applied from the tension end 4 in the sheath pipe 6 embedded in the roof base 1 over the tension end 4 and the fixed end 3.

The fixed end 3 of the PC steel material 2 is configured by, for example, attaching a commercially available fixed end fixing body 3A having a diameter larger than that of the PC steel material 2 and the sheath pipe 6 to the end portion of the PC steel material 2. The tension end 4 of the PC steel material 2 is configured by, for example, attaching a commercially available tension end fixing body 4A having a diameter larger than that of the PC steel material 2 and the sheath pipe 6 to the end portion of the PC steel material 2. The tension end fixing body 4A is configured so that the PC steel material 2 can be moved in the length direction through the concave opening 1d that faces the outside, and the end portion of the PC steel material 2 can be tightened and fixed in the introduced state. To.

Then, in this roof structure, the tension end 4 of the PC steel material 2 is arranged inside the concave groove 7 (an example of the concave portion) of the upper opening provided in the portion 1A on the eaves side of the roof base 1. The concave groove 7 is provided at a portion of the upper surface 1a of the portion 1A on the eaves side of the roof base 1 that is slightly retracted from the eaves to the ridge side. As shown in FIG. 1, the concave groove 7 extends parallel to the direction in which the eaves N are continuous (the direction of the outer periphery of the building along the outer wall surface W), and serves as a rain gutter that receives and drains rainwater flowing down the roof surface. It is composed. By doing so, it is possible to hide the tension ends 4 of the plurality of PC steel materials 2 from the public by utilizing the concave groove 7 configured as a rain gutter, and the appearance of the building B can be efficiently improved. ..

As shown in FIG. 3, the concave groove 7 on the upper surface 1a of the eaves side portion 1A of the roof base 1 is substantially vertical to the eaves side wall portion 7A and the substantially vertical posture to the ridge side wall portion 7B. It has a bottom portion 7C in a horizontal posture, and the opening edge 7a on the eaves side corresponding to the upper end of the wall portion 7A on the eaves side is larger than the opening edge 7b on the ridge side corresponding to the upper end of the wall portion 7B on the ridge side. It is placed in a low position. Further, the concave groove 7 is configured to have a groove width larger than the groove depth. Then, the tension end 4 of the PC steel material 2 is arranged on the wall portion 7B on the ridge side inside the concave groove 7.

Therefore, as shown in FIG. 3, when the tension end 4 of the PC steel material 2 arranged in the wall portion 7B on the ridge side inside the concave groove 7 is pulled by the tension jack 8 to introduce the tension force into the PC steel material 2. Using the difference in height between the opening edge 7a on the eaves side and the opening edge 7b on the ridge side in the concave groove 7, the tensioning direction (pulling posture) of the tension jack 8 is set to the tensioning direction (approximately horizontal direction) of the tension end 4. It is possible to lay it in an oblique direction as close to as possible, and it is possible to reduce the difficulty of the tension force introduction work for the tension end 4 inside the concave groove 7.

In the illustrated example, a tubular tension guide 9 in a curved posture having a handle 9a is provided on the tip end side of the tension jack 8. With this tension guide 9, the pulling force of the tension jack 8 can be converted into the pulling direction (substantially horizontal direction) of the tension end 4, and the tension force can be efficiently introduced to the tension end 4. The extra length portion of the PC steel material 2 is cut and removed after introducing a tension force.

As shown in FIG. 2, a plurality of hollow portions 10 and the like for reducing the weight of the eaves N having a large allowance can be provided on the lower side of the portion 1A on the eaves side of the roof base 1.

[Another Embodiment]
Other embodiments of the present invention will be described. It should be noted that the configurations of the respective embodiments described below are not limited to being applied independently, but can also be applied in combination with the configurations of other embodiments.

(1) In the above embodiment, the concave portion of the upper surface 1a of the roof base 1 is formed by a concave groove 7 extending in parallel in the direction in which the eaves N are continuous, and the tension of a plurality of PC steel materials 2 is formed inside the concave groove 7. Although the case where the end 4 is arranged is shown as an example, it may be composed of a plurality of recesses such as a quadrangle in a plan view, and the tension end 4 of one PC steel material 2 may be arranged in each recess.

(2) In the above embodiment, the case where the concave groove 7 is configured as a rain gutter is shown as an example, but it may be configured as a dedicated one for arranging the tension end 4 of the PC steel material 2.

(3) In the above embodiment, the case where the tension end 4 of the PC steel material 2 is arranged on the wall portion 7B on the ridge side of the concave groove 7 is shown as an example, but the tension end 4 is arranged in another portion inside the concave groove 7. May be done.

(4) In the present embodiment, the case where the PC steel material 2 is provided on the roof base 1 by the post-tension method in which the tension force is introduced after the concrete is placed is shown as an example, but the concrete is provided in the state where the tension force is introduced. It may be provided in the roof base 1 by the pretension method of placing.

(5) The roof structure of the present invention is preferably applied not only to the hipped roof shown in the above embodiment but also to various roof types such as a gable roof and a one-sided roof when the eaves N having a large allowance are provided. be able to.

1 Roof base 1a Top surface 2 PC steel 4 Tension end 7 Concave groove (recess)
7A Eaves side wall 7B Building side wall 7C Bottom 7a Eaves side opening edge 7b Building side opening edge N Eaves M Building X Eaves direction

Claims (4)

A roof base made of prestressed concrete that is tensioned by introducing tension into the PC steel that extends along the direction of the eaves is provided.
A recess is provided in the portion of the upper surface of the roof base that is recessed from the eaves to the ridge side.
A roof structure in which a tension end of the PC steel material fixed to the roof base in a state where a tension force is introduced into the PC steel material is arranged inside the recess. The roof structure according to claim 1, wherein the recess is formed of a groove extending parallel to the eaves in a continuous direction, and a plurality of tension ends of the PC steel material are arranged inside the recess. The roof structure according to claim 2, wherein the concave groove is formed as a rain gutter. The opening edge on the eaves side of the recess is arranged at a position lower than the opening edge on the ridge side of the recess.
The roof structure according to any one of claims 1 to 3, wherein the tension end of the PC steel material is arranged on a wall portion on the ridge side inside the recess.

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