JPH09242232A - Installation structure of precast concrete curtain wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide installation structure capable of preventing damage of a PC curtain wall of a building as much as possible at the time of an earthquake disaster. SOLUTION: A fastener 22 is fastened on the side of a building structural body 6 free to connect and disconnect, and a bolt integrally erected on a back surface of a PC curtain wall 2 in fastened and fixed on this fastener 22. A stress absorbing part to yield and deform before this PC curtain wall 2 comes to be broken at the time when force transmitted to the PC curtain wall 2 through the fastener 22 in accordance with deformation of the building structural body 6 becomes excessive is provided on this fastener 22, for example, as a section defective part in shapes of grooves 30, 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of a precast concrete curtain wall (hereinafter abbreviated as PC curtain wall), and in particular, a PC curtain wall designed to facilitate repair work after an earthquake. Related to the improvement of the mounting structure.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, a PC curtain wall 2 which is attached to a building as an exterior material has anchor bolts 4 which are erected and erected at four corners of the upper and lower sides of the back surface thereof. Lower floor building structure 6
(For example, a slab, a beam or the like) is fastened and attached to a fastener 8 made of an L-shaped metal fitting or the like. Here, the fasteners 8 are usually attached to the building structure 6 by welding or the like.

Further, the load of the curtain wall 2 is supported by the upper or lower structure 6 side via the load receiving bolts 10 at the upper or lower two places.

By the way, a building vibrates and deforms due to wind or an earthquake, and when the deformation is large, the interlayer displacement between the upper floor and the lower floor of the building structure 6 due to the deformation is directly applied to the curtain wall 2. The curtain wall 2
Excessive force acts on and destroys it. Therefore, the curtain wall 2 needs to be attached to the building structure 6 so as to absorb the interlayer displacement between the upper floor and the lower floor to some extent. For this reason, as a mounting method that absorbs such interlayer displacement, it can be roughly divided into horizontal movements (sway).
Two methods, a method and a rotation (rocking) method, are adopted.

In the horizontal movement system, for example, as shown in FIG. 4 (a), the upper anchor bolt 4a of the curtain wall 2 is rigidly connected to the fastener fixed to the building structure side of the upper floor, and While the curtain wall 2 is displaced integrally with the building structure on the upper floor, the anchor bolts 4b on the lower side can be slid horizontally relative to the fastener fixed to the building structure on the lower floor. The one shown in FIG. 3 corresponds to this horizontal movement type. That is, as shown in FIGS. 3A and 3B, the upper anchor bolt 4a is rigidly fastened and coupled to the fastener 8a welded to the beam 12 (building structure 6) on the upper floor, while The anchor bolt 4b on the lower side is fastened and fixed to a fastener 8b that is provided integrally with the mounting pedestal 16 (building structure 6) of the slab 14 on the lower floor so as to allow relative movement in the horizontal direction. Anchor bolt 4 formed on this fastener 8b as shown in (c)
The insertion hole 9 of b is a horizontally long loose hole.

Further, in the above-mentioned rotation system, for example, as shown in FIG. 4B, four anchor bolts 4 are fastened and coupled so as to be relatively rotatable with respect to respective fasteners.
When interlayer displacement occurs, the curtain wall 2 is moved (rotated) around the load receiving bolt 10 as a fulcrum so as to absorb the interlayer displacement. In this case, the anchor bolt 4 and the fastener are Since the relative displacement of is small in the horizontal direction and large in the vertical direction, the fastener is formed with a vertically long insertion hole.

[0007]

However, in such a conventional mounting structure, when the building structure 6 is deformed more than originally assumed due to a large earthquake or the like, the interlayer displacement due to the deformation is prolonged. The anchor bolt 4 cannot be completely absorbed by only the insertion hole 9 formed as a loose hole.
And the fastener 8 interfere with each other, thereby applying an excessive force to the PC curtain wall 2 and
There was a problem that was damaged.

The damage in such a case is a crack generated in the concrete plate 2a of the PC curtain wall 2 or a fracture of the welded portion of the fastener 8,
Alternatively, the anchor bolts 4 may be fractured, resulting in a wide variety of fracture modes and randomly occurring at various locations. Therefore, in order to grasp the situation of the fracture modes and fracture locations, the curtain wall 2 and its I had to fully investigate the surrounding area.

Moreover, since the peripheral portion of the fastener 8 is usually covered with a refractory material or the like, it takes a lot of time, labor, and time only to find the damaged portion, and further various destruction modes are required. There is a problem that it is necessary to perform various repair work depending on the situation, and it takes a lot of cost and time to restore it.

The present invention has been made in view of the above conventional problems, and an object thereof is to prevent damage to a PC curtain wall of a building at the time of an earthquake disaster as much as possible, and to destroy a damaged portion. Not only can be concentrated on a predetermined part, but also its destruction mode can be assumed in advance,
Therefore, it is an object to provide a mounting structure for a PC curtain wall that can restore the building and accelerate reuse.

[0011]

In order to achieve such an object, in the invention according to claim 1, a bolt integrally erected on the back surface of the precast concrete curtain wall is fastened to a fastener provided on the building structure side. In the mounting structure of the precast concrete curtain wall to be fixed by fixing the fastener is detachably fixed to the building structure, the fastener,
When the force transmitted to the precast concrete curtain wall via the fastener becomes excessive due to the deformation of the building structure, a stress absorbing portion that yields and deforms prior to the damage of the curtain wall is provided. Is characterized by.

According to the PC curtain wall mounting structure of the present invention having the above structure, even if the building structure is largely deformed due to an earthquake or the like, the stress of the fastener is first absorbed before each part of the PC curtain wall is damaged. Since the part yields and deforms and absorbs the force transmitted to the curtain wall, it is possible to prevent damage to the PC curtain wall as much as possible.

[0013] Further, not only can fasteners be concentrated on the breakage points due to the deformation of the building structure, and the breakage pattern can be assumed in advance, but if the PC curtain wall is also damaged, the fasteners must be installed. Since it has undergone yield deformation, the damage status of the PC curtain wall can be predicted by first examining the damage status of the fastener.
If damage is limited to the deformation of the fastener, it can be easily repaired by removing it and replacing it.

Therefore, the damage condition can be easily investigated, and the repair work of the building can be performed efficiently and easily, and the restoration and reuse of the building can be achieved as soon as possible.

Here, as described in claim 2, the fastener is an L-shaped metal fitting having a plate piece portion connected to the building structure side and a plate piece portion connected to the curtain wall side, and the stress is applied. The absorbing portion can be formed as a cross-section defective portion formed on the metal fitting.

Further, as described in claim 3, it is preferable that the cross-section defective portion is formed in a groove shape extending along the wall surface direction of the curtain wall on the two plate pieces of the L-shaped metal fitting.

Further, as described in claim 4, claim 2,
In 3, when the plate piece portion of the fastener coupled to the building structure side is arranged in the vertical direction, it is particularly excellent in absorbing the displacement in the horizontal direction and is suitable for use in the horizontal movement system.

On the other hand, as described in claim 5, claim 2,
In 3, when the plate piece portion of the fastener coupled to the building structure side is arranged in the horizontal direction, it is particularly excellent in absorbing the displacement in the vertical direction, and is suitable for use in the rotation system.

[0019]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a main portion of a mounting structure for a PC curtain wall according to an embodiment of the present invention, showing a mounting portion corresponding to a lower right corner portion of the PC curtain wall when viewed from the inside of the building. It is a thing. Here, in the present embodiment as well, the PC curtain wall is generally installed such that four bolts that are integrally erected at the four corners of the back surface of the PC curtain wall are fastened and attached to the fasteners provided on the building structure side. The basic structure is almost the same as the conventional one shown in FIG. 3 described above. In this example, anchor bolts are used for the bolts, and the upper anchor bolts are provided on the beams (building structure) on the upper floors. The fasteners are rigidly fastened and coupled to move integrally. In the following description, the same members as those of the above-described conventional device will be designated by the same reference numerals and detailed description thereof will be omitted.

In FIG. 1, 2 is a PC curtain wall, 4 is an anchor bolt (lower anchor bolt 4
Reference numerals b) and 16 denote mounting pedestals (building structure 6) integrally formed with the floor slab 14. As shown in the figure, the lower anchor bolts 4b are erected by being embedded in a raised block portion 2b which is formed in a box-like protruding manner integrally on the back surface of the concrete plate 2a of the PC curtain wall 2. A load receiving bolt 10 is arranged on the lower surface of the raised block portion 2b.
The load of the PC curtain wall 2 through the floor slab 14
It is supposed to be supported by the side.

A mounting base 16 is integrally provided on the floor slab 14, and a primary fastener 20 is integrally mounted on the mounting base 16. The primary fastener 20 is an L-shaped metal fitting, and the vertical side plate piece 20a standing upright in the vertical direction has its plate surface oriented in a direction orthogonal to the wall surface of the curtain wall 2.

A secondary fastener 22 is attached to the vertical side plate piece 20a of the primary fastener 20. The secondary fastener 22 is also connected to the building structure 6 (here, the vertical side plate piece 20a) side, and the structure side plate piece portion 22a.
And an L-shaped metal piece having a curtain side plate piece portion 22b connected to the PC curtain wall 2 side. The structure side plate piece portion 22a is sandwiched between the attachment plate 24 and the vertical side plate piece 20a and is attached / detached with the bolt 26. Fixed as possible.

The structure side plate piece portion 22a extends toward the PC curtain wall 2, and the extending end thereof is bent at a right angle to be integrally formed as an L-shaped curtain side plate piece portion 22b. An insertion hole 9 for inserting the lower anchor bolt 4a standing on the raised block portion 2b of the PC curtain wall 2 is formed in the curtain side plate piece portion 22b so as to be long in the lateral direction. Bolt 4b
Is inserted and fastened and fixed with a nut so as to be relatively movable in the horizontal direction. A spacer 28 is engaged between the raised block 2b and the curtain side plate piece 22b, and a predetermined space is provided between the raised block 2b and a portion near the base of the curtain side plate piece 22b on the bent side. Part is formed.

By the way, the secondary fastener 22 has the secondary fastener 2 as the building structure 6 is deformed by an earthquake or the like.
When the force transmitted to the PC curtain wall 2 via 2 becomes excessive, a stress absorbing portion that yield-deforms in advance is provided before the PC curtain wall 2 is damaged. The stress absorbing portion is formed by a groove-shaped cross-section missing portion formed in the secondary fastener 22, and specifically, two plate pieces of the L-shaped metal fitting forming the secondary fastener 22, that is, a structure side plate piece. 22a and the curtain side plate piece 22b are formed as grooves 30 and 32 extending vertically along the wall surface direction of the PC curtain wall 2, respectively. The groove 30 of the structure side plate piece is located at a position close to the primary fastener 20. The groove 30 of the curtain side plate piece portion 22b is formed at a position close to the root of the bent portion.

Although not shown, the lower anchor bolt on the left side of the PC curtain wall 2 is also connected to the building structure side via a primary fastener and a secondary fastener having the same structure as in FIG. In addition, the upper side anchor bolt also has the same structure as that shown in FIG.
Although it is connected to the building structure side via the next fastener, in the case of this embodiment, the PC curtain wall 2 is horizontally moved integrally with the building structure on the upper floor side.
The insertion hole of the secondary fastener through which the upper anchor bolt is inserted is not formed as a loose hole in an elongated hole, but is formed as a tight hole in a perfect circle shape corresponding to the bolt diameter.

Therefore, in the PC curtain wall mounting structure as described above, when the interlayer displacement of the building vibration due to an earthquake falls within the range originally assumed, the PC curtain wall 2 is used as in the conventional case. Moves horizontally along with the beams 12 of the upper-floor building structure 6, while the lower anchor bolt 4b horizontally slides in the horizontally long insertion hole 9 of the secondary fastener 22 to move to the lower-floor building structure. It is displaced relative to the body 6. Therefore, the interlayer displacement is not absorbed and an excessive force that destroys the PC curtain wall 2 is not transmitted.

On the other hand, when a large earthquake occurs in which the interlayer displacement of building vibration exceeds the originally assumed range, the interlayer displacement cannot be absorbed by the insertion hole 9 of the horizontally long loose hole, and The side anchor bolt 4b interferes with the secondary fastener 22 in the insertion hole 9. However, even if a large force resulting from the interlayer displacement is transmitted to the PC curtain wall 2 via the primary and secondary fasteners 20 and 22 as described above,
Since the secondary fastener 22 is formed with a groove-shaped cross-section lacking portion as a stress absorbing portion, the secondary fastener 22 precedes before the PC curtain wall 2 is damaged and is yield-deformed in the groove portions 30, 32. It bends, and this causes the interlayer displacement to be absorbed.

For this reason, it is possible to prevent as much as possible a force that would damage the PC curtain wall 2 from being transmitted through the secondary fastener 22, and the PC curtain wall 2 is cracked in the concrete slab 2a. It is prevented as much as possible that a breakage such as the entry of the anchor bolt 4 or the anchor bolt 4 is broken.

When such a large earthquake occurs, before the PC curtain wall 2 is damaged, it is always 2
Since the secondary fastener 22 is first yield-deformed and the fractured portions are concentrated on the secondary fastener 22, it is possible to check the destruction state of the secondary fastener 22 to find out whether the PC curtain wall 2 is damaged or not. It becomes possible to predict the situation such as the form to some extent. If the damage is limited to the yield deformation of the secondary fastener 22, it can be easily repaired by removing and replacing it.

Therefore, the damage situation can be easily investigated, and the repair work of the building can be performed efficiently and easily, and the restoration and reuse of the building can be achieved as soon as possible.

The embodiment of FIG. 1 described so far is
Although it is useful for application to the horizontal movement method, when applied to the rotation method, the secondary fastener 22 shown in FIG. 1 is oriented 90 degrees laterally as shown in FIG. Orient the portion 22a in the horizontal direction so that the primary fastener 20
And the PC curtain wall 2 may be combined. In this case, H type steel or I type steel may be used for the primary fastener 20.

[0033]

As described in detail above, according to the PC curtain wall mounting structure of the present invention, even if the building structure is largely deformed due to an earthquake or the like, each part of the PC curtain wall is damaged. First, since the stress absorbing portion of the fastener yields and deforms to absorb the force transmitted to the curtain wall, damage to the PC curtain wall can be prevented as much as possible.

Further, not only can the damage points due to the deformation of the building structure be concentrated on the fastener, and the damage pattern can be assumed in advance, but the fastener must be installed when the PC curtain wall is damaged. Since it has undergone yield deformation, the damage status of the PC curtain wall can be predicted by first examining the damage status of the fastener. If damage is limited to the deformation of the fastener, it can be easily repaired by removing it and replacing it.

Therefore, the damage situation can be easily investigated, and the repair work of the building can be carried out efficiently and easily, and the restoration and reuse of the building can be achieved as soon as possible.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a main part of an embodiment of a mounting structure for a PC curtain wall according to the present invention.

FIG. 2 is a partial perspective view showing a main part of another embodiment of the PC curtain wall mounting structure according to the present invention.

FIG. 3 is a cross-sectional view showing a conventional PC curtain wall mounting structure.

FIG. 4 is a diagram schematically illustrating two methods that are conventionally adopted, a horizontal movement (sway) method and a rotation (rocking) method, as an attachment method that absorbs interlayer displacement.

[Explanation of symbols]

2 PC curtain wall 4 Anchor bolt 4a Upper side anchor bolt 4b Lower side anchor bolt 6 Building structure 8 Fastener 9 Insertion hole 10 Load receiving bolt 12 Beam 14 Slab 16 Mounting base 20 Primary fastener 22 Secondary fastener 22a Structural side plate piece Part 22b Curtain side plate piece part 24 Supplementary plate 28 Spacer 30, 32 Groove as cross-section missing part (stress absorbing part)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masataka Sekine Inventor Masataka Sekine 2-3 Kandaji-cho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office

Claims (5)

[Claims] 1. A mounting structure of a precast concrete curtain wall in which a bolt integrally erected on the back surface of the precast concrete curtain wall is fastened and fixed to a fastener provided on the building structure side, wherein the fastener is attached to the building structure. On the other hand, the fastener is detachably fixed, and the curtain wall is damaged when the force transmitted to the precast concrete curtain wall through the fastener becomes excessive due to the deformation of the building structure. An attachment structure for a precast concrete curtain wall, characterized in that a stress absorbing portion for yielding deformation is provided in advance. 2. The fastener is an L-shaped metal fitting having a plate piece portion connected to the building structure side and a plate piece portion connected to the curtain wall side, and the stress absorbing portion is formed on the metal fitting. The mounting structure for a precast concrete curtain wall according to claim 1, wherein the mounting structure has a cross-section missing portion. 3. The cross-section defective portion is formed in a groove shape extending along the wall surface direction of the curtain wall on each of the two plate piece portions of the L-shaped metal fitting.
Precast concrete curtain wall mounting structure described. 4. The mounting structure for a precast concrete curtain wall according to claim 2, wherein a plate piece portion connected to the building structure side of the fastener is arranged in a vertical direction. 5. The mounting structure for a precast concrete curtain wall according to claim 2 or 3, wherein a plate piece portion connected to the building structure side of the fastener is arranged in a horizontal direction.