JPH03103556A - Framing of structure - Google Patents

Abstract

PURPOSE:To properly absorb the vibration of earthquake and wind by a method in which the core wall of a reinforced concrete is connected by sliding bearing with beams and also by pin bearing only for a given stair as needed. CONSTITUTION:A reinforced concrete core wall 1 is constructed, and brackets 3 with slide plates 4 such as stainless steel plate are projectionally provided on the periphery of the wall 1. A frame consisting of columns 17 and beams 5 is provided on the side of the wall 1, and the ends of the beams 5 are supported slidably through sliding bearing 6 bonded with fluororesin plate, etc., on the brackets 3. In cases where water proofing is needed, the uppermost floor 14 and the wall 1 are integrally constructed, or the beams 5 and the wall 1 are connected by pin-bearing. Also, as needed, the beams 5 and the wall 1 are connected by pin-bearing for each given stair and the floor 14 is connected with the wall 1. The earthquake input can thus be reduced, and when using pin-bearing, overmuch sliding can be prevented.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a building frame.

(Prior art) A reinforced concrete core wall (a) is constructed in advance using the slip form construction method, etc. This is followed by the construction of outer columns (b) and beams (0), and this is followed by the construction of the floor (d). A building construction method that involves pouring concrete and finishing work is widely used in the United States and other countries.

(See Figures 7 and 8) At this time, steel frames or precast concrete members are usually used for the columns and beams. Further, the joint between the beam and the core wall has a pin structure (e).

The weight of buildings and cargo is borne by the beams, columns, and walls, but the horizontal forces caused by wind and earthquakes are borne only by the walls.

According to the above construction method, slipform is used for wall construction, columns and beams only need to be joined on site with steel frames, precast concrete members, etc., and the joint between the core wall and beam is a pin structure. It has the advantage of being simpler than rigid joints, and requires a shorter construction period than reinforced concrete buildings.

They also have the advantage of being cheaper than steel-framed buildings and less susceptible to lateral sway due to wind and other factors.

(Problems to be Solved by the Invention) However, in regions such as Japan where seismic activity is more active than in the United States, it is unreasonable to apply the conventional construction method as is.

That is, since the horizontal rigidity of the reinforced concrete core wall is large, the natural period of the building is shortened, and the seismic force acting on the building is usually larger than that of a building with a flexible structure such as a steel frame.

If the walls are made thicker to resist this seismic force, the natural period of the building becomes even shorter, which also increases the weight of the building, creating a vicious cycle in which the seismic force increases.

The present invention has been proposed in view of the problems of the prior art described above, and its purpose is to develop reinforced concrete that can withstand earthquakes and other winds expected in regions with active seismic activity such as Japan. The object of the present invention is to provide a composite frame building structure having a core wall made of concrete or steel-framed reinforced concrete.

(Means for Solving the Problems) In order to achieve the above-mentioned object, in the building frame according to the present invention, the core wall and the beam connected to the wall are joined by a sliding joint.

According to a second aspect of the invention, the core wall and the beam are connected with pins for each required floor in the frame of the building.

The invention of claim 3 provides a straight joint between the core wall and the floor beam on the standard floor, a structural edge cut between the core wall and the floor outside the core wall, and a joint between the core wall and the floor beam on the top floor. This is a pin connection or rigid connection between the core wall and the core wall.

(Function) Since the frame structure of the building according to the present invention is constructed as described above, when the ground surface vibrates horizontally during an earthquake, the columns will be more stable than the core walls of the reinforced concrete structure or steel-framed reinforced concrete structure. Since the core has low rigidity, vibrations are transmitted to the upper part through the core wall.

Since the core wall and the beam connected to the core wall are connected through a sliding joint, if the vibration of the core wall is to be transmitted to the beam, floor, column, etc., the vibration will exceed a certain limit. When force is to be transmitted, a slip occurs between the core wall and the beam at the sliding joint, making it difficult for the vibration of the core wall caused by an earthquake to be transmitted to the surrounding areas of the beam, floor, columns, etc., reducing earthquake input. be done.

In addition, if an earthquake occurs that includes vibrations close to the natural period of the building, the seismic input to parts other than the core wall will reach a ceiling at a constant value regardless of the natural period, so there is no risk that the building will resonate. .

The invention according to claim 2 provides resistance against wind loads by pin-joining the core wall and the beam for each required floor without making a sliding joint between the core wall and the beam on all floors. ,
The beam pin-bonded to the core wall can be used as a fulcrum, and the pillars on the outer periphery can oppose it. At this time, even if slipping occurs at the sliding joint between the core wall and beam due to wind load,
Since the columns have lateral rigidity, excessive slipping will not occur. In addition, due to slipping occurring at the sliding joint,
t1! ．． The effect of frictional damping produces the effect of reducing wind-induced vibrations.

The invention according to claim 3 provides structural insulation between the core wall and the floor outside thereof by a sliding joint between the floor beam of the standard floor and the core wall, and the beam of the top floor and the core wall. The stress of the core wall is transmitted to the pillars on the outside of the core wall by pin-joining or rigidly joining, thereby increasing the rigidity of the entire frame.

(Example) The present invention will be described below with reference to the illustrated embodiments.

(1) is a core wall made of reinforced concrete or steel reinforced concrete, and (2) is a floor within the core wall (1).

A bracket (3) is provided protruding from the outer peripheral surface of the core wall (1), and a sliding plate (4) made of a stainless steel plate or the like is attached to the upper surface of the bracket (3).

(5) is a beam connected to the outer peripheral surface of the core wall (1),
A notch (5a) is provided at the bottom of the connecting end of the beam (5) to the core wall (1), and a sliding support (6) is attached to the lower surface of the notch (5a).

As shown in Figure 4, the sliding bearing (6) is connected to the upper and lower bearing pieces (8) (
9), the steel plate 00) attached to the upper end surface of the upper support piece (8) is joined to the lower end of the beam (5), and the fluororesin support plate OD is attached to the lower end surface of the lower support piece (9). As shown in Fig. 5, the rubber bearing 021
It is constructed by pasting two fluororesin support plates on the lower end surface of the
A beam (5) is constructed on the bracket (3) via a sliding plate (4) and a sliding support (6).

Concrete with a floor of 0/D is placed on the beam (5), and a gap corresponding to the sliding margin i is provided between the floor (+41 and beam (5)) and the core wall (1). Then, 0 sliding boards are provided protruding from the core wall (1) on the same gap, and a tread of 0ω is installed between the sliding board 05) and the floor 04). In this way, normally the floors are continuous, but in the event of an earthquake, the stepping 0ω jumps up, so that the floor 04) and the core wall (1) do not collide with the sliding board 0, and the floor 04) and the core wall (1) Structurally insulated. In Figure 2, X is the same floor 041 and the core wall (
1) Structural insulation part, y in FIGS. 1 and 2 is the beam 0
The sliding joint between the brown and core walls is shown.

In addition, in the figure, 0 is a pillar, and 00 is a beam on the outer periphery.

Since the illustrated embodiment is configured as described above, when the ground surface vibrates horizontally during an earthquake, the column OD is moved from the core wall (
Since the rigidity is lower than that of core wall (1), vibrations are transmitted upward through the core wall (1).

In the prior art, the core wall and the beam are joined by pins, so the core wall and the beam vibrate in the same way, and the floors, columns, and finishing materials connected to the beam also vibrate in the same way as the core wall.

Suppose that for a certain floor, the acceleration of the core wall is α of the gravitational acceleration.
Double, the weight of the core part is W, the total of the floor, beams, and the finishing materials and live loads supported by these is W2, and the total of the columns and outer beams, and the finishing materials and live loads supported by these is W3.
Then, the seismic force on this floor is FI=αx (W, +Wz+Wi).

On the other hand, according to the present invention, the vibration of the core wall (1) is caused by the vibration of the beam (5).
When the force is transmitted to the beam (5), the column (04), etc., a slip occurs between the sliding plate (4) and the sliding bearing (6), and the vibration of the core wall (1) due to the earthquake is transmitted to the beam (5), floor (04), etc. Column 0'
A type of seismic isolation effect is exerted that is difficult to transmit to surrounding members such as I).

Next, this seismic isolation effect is roughly shown numerically.

Let μ be the coefficient of friction between the sliding bearing (6) and the sliding plate (4). The surface pressure acting on this sliding surface is 0.0. 5 Wt.

Therefore, the horizontal force exchange between the core wall (1) and the surrounding area is μ
X 0. It reaches a ceiling at the upper limit of 5 W t.

If the acceleration of the core wall (1) is α times the weight acceleration, the seismic force on this floor is F. =α×W, +μX0.5W2.

Normally, 0.2 is often used as α, and μ is a value of about 0.1 between fluororesin and stainless steel plates, so if these values are used, the difference between the above-mentioned conventional technology and the frame according to the present invention is The difference in seismic force on this floor between the two floors is as follows.

F. -F. =α(W!+WX)-μx 0. 5W
z=0.15Wz+0.20V/3 That is, according to the frame of the present invention, it is possible to reduce seismic force in this way. Therefore, even buildings such as those shown in FIGS. 7 and 8 can be designed to be sufficiently seismically resistant even in earthquake areas such as Japan.

Buildings have a natural period, and if an earthquake that happens to include a vibration M frequency close to the natural period of the building occurs, there is a risk that the building will resonate and cause unexpected damage. According to such a structure, regardless of the natural period of the building, the seismic force due to parts other than the core wall peaks out at a constant value as described above.

Next, wind load will be explained.

Wind loads first act on the outer periphery of the building. This load is transferred to the core wall if the joint between the beam and the core wall does not slip. The rigidity of the core wall is considerably higher than that of ordinary steel frames, so it is possible to create buildings that are more resistant to shaking in the wind than steel frames.

In Japan, unless it is a very high-rise building, the earthquake force is usually much larger than the wind load, so the core wall (1
) and the beam (5) slips, which has the aforementioned seismic force reduction effect, and it is quite possible that the joint does not slip against wind loads.

Also, by selecting the material for the edge surface, it is possible to obtain a sliding joint with a friction coefficient that provides both the above-mentioned seismic isolation effect and the effect of being less likely to sway in the wind.

In addition, if it is necessary for waterproofing, please use the floor 04 on the top floor.
) are integrally cast with the core wall (1), or the beam (5) and the core wall (1) are connected with pins. 2 in FIG. 1 shows this pin joint.

In addition, the beam on the top floor is connected to the core wall (1) as a highly rigid hat beam to increase the rigidity of the entire structure by transmitting the rotation of the core wall (1) to the column Q7). You can.

FIG. 6 shows another embodiment of the invention, in which beams (
5) Instead of making a sliding connection between the floor 07I) and the core wall (1), a pin connection is made between the beam (5) and the core wall (1) for each predetermined floor, and the floor 04) is also connected to the core wall. Continue to (1).

According to this embodiment, the wind load can be counteracted by the column θ force on the outer periphery, using the beam (5) pin-bonded to the core wall (1) as a fulcrum.

At this time, even if a slip occurs in the sliding joint y due to wind load, the column 0'7) has lateral rigidity, so that no excessive slip occurs. Furthermore, the occurrence of slippage at the veri joint also produces the effect of reducing wind-induced vibrations due to the hysteresis damping effect due to frictional resistance.

In the figure, parts equivalent to those of the above embodiment are given the same reference numerals.

(Effects of the Invention) According to the present invention, as described above, in a frame having a core wall made of reinforced concrete or steel-framed reinforced concrete, earthquake input is reduced by making the connection with the beam connected to the core wall a sliding joint. It also prevents resonance of the building in the event of an earthquake that includes a vibration component close to the natural period of the building.

Further, according to the present invention, the advantages of the prior art such that the construction period is shorter than the reinforced concrete structure and the cost is lower than the steel frame structure are maintained.

The invention according to claim 2 is characterized in that the core wall and the beam are connected with pins for each predetermined floor without making a sliding connection between the core wall and the beam on all floors, so that the beam can withstand wind loads. The pillars on the outer periphery are used as fulcrums to counteract each other, and even if sag occurs at the sliding joint between the core wall and the beam, the company's lateral rigidity prevents excessive sag from occurring. The friction damping effect caused by slippage at the sliding joint reduces vibrations caused by wind.

The invention according to claim 3 provides a sliding connection between the floor beam of the standard floor and the core wall, and a structural connection between the core wall and the floor outside the core wall! ! ! The rigidity of the entire structure was increased by using a pin or rigid connection between the top floor beam and the core wall.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of a building frame according to the present invention, a view taken from the arrow 1-1 in Fig. 2, a plan view thereof, and Fig. 3 a diagram showing the structure of a core wall and a beam. 4 and 5 are front views showing each embodiment of the sliding bearing, FIG. 6 is a front view showing another embodiment of the present invention, and FIG. A front view showing the conventional frame, Fig. 8 is the arrow direction in Fig. 7 -
■It is a diagram. (1) Core wall, (3) Bracket, (4) Horizontal plate, (5) Beam, (6) Horizontal support, 04)... floor, X
...Structural insulation of floors and core walls, y...Sliding joints, 2...Pin joints.

Claims (1)

[Scope of Claims] 1. A building frame having a core wall made of reinforced concrete or steel-framed reinforced concrete, characterized in that the joint with a beam connected to the core wall is a sliding joint. 2. The building structure according to claim 1, wherein the core wall and the beam are connected with pins for each required floor. 3. A sliding connection is made between the beam of the standard floor and the core wall,
2. The building structure according to claim 1, wherein the core wall and the beam on the top floor are connected by a pin connection or a rigid connection.