JP3799199B2 - Seismic building structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a building excellent in earthquake resistance.
[0002]
[Prior art]
As is well known, the structure for improving the earthquake resistance of buildings includes a load-bearing structure that increases rigidity and strength, and a seismic isolation device that extends the natural period of buildings to reduce earthquake input. There are seismic structures and vibration control structures that install vibration control devices such as various dampers at key points of buildings to control vibrations and absorb energy, and various types have been proposed and put into practical use. In particular, seismic isolation structures in which the entire building is supported by a seismic isolation device such as laminated rubber for a long period are effective.
[0003]
[Problems to be solved by the invention]
If a conventional seismic isolation device is used to increase the period of a building of a certain size or more for a period of 4 to 5 seconds or more, there is a problem that the design is difficult or the cost is increased. Although it is conceivable to use a slip-type seismic isolation device instead of the laminated rubber, this case is not preferable because a device for returning the building to the original position at the end of the earthquake is required.
[0004]
[Means for Solving the Problems]
In view of the above circumstances, the present invention makes it possible to sufficiently lengthen the natural period of a building, and the invention of claim 1 is a highly rigid core shaft provided in the center of a building, and the core shaft. A main structure that is swingably supported around the core shaft with the top of the core shaft as a fulcrum, and the main structure is supported on the top of the core shaft via a swing support device. A building main body of a multi-story floor is suspended and supported around the core shaft from the structure, and the main structure is made to respond as a pendulum swingable around the core shaft while being supported by the core shaft during an earthquake, and the natural period of the pendulum of the main structure, and set to a sufficiently long period than ground motion cycle envisaged, as the rocking support device, said main are installed respectively in an inclined state toward the center of the virtual An assembly of a plurality of seismic isolation devices that support the structure so as to be swingable about the center is employed, and a swing support structure is interposed between the top of the core shaft and the top structure, A set of seismic isolation devices as the swing support devices are respectively arranged above and below the swing support structure.
[0008]
In the invention of claim 2 , between the building main body and the core shaft or the ground, they are connected in a normal state to restrain the swinging of the main structure, and are released in the event of an earthquake. A fuse mechanism that allows rocking is interposed.
[0009]
According to a third aspect of the present invention, a damper that absorbs vibration energy is interposed between the building body and the core shaft or the ground.
[0010]
According to a fourth aspect of the present invention, the slab of each layer is suspended and supported by using the pillar of the building main body as a suspension material, and each layer of the building main body is provided with a stiffening means for restraining interlayer displacement.
[0011]
According to a fifth aspect of the present invention, a support column protruding upward is provided at the center of the top structure, and the peripheral portion of the top structure is suspended and supported from the support by a tensile material.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 7 to 8. Prior to that, reference examples related to the present invention will be described with reference to FIGS. In the following description, the reference examples shown in FIGS. 1 to 6 are also referred to as “embodiments of the present invention” for convenience.
1 and 2 show an outline of an earthquake-resistant building according to an embodiment of the present invention. FIG. 1 is an elevational sectional view, and FIG. 2 is a reference floor plan view. As shown in FIG. 1, the earthquake-resistant building of this embodiment is supported so as to be swingable in all directions around the high-rigidity core shaft 1 provided at the center of the building and the top of the core shaft 1 as a fulcrum. The main structure 2 is formed. The main structure 2 includes a high-rigidity top structure 4 supported on the top of the core shaft 1 via a single ball seat 3 serving as a swing support device, and a multilayer supported by the top structure 4. It consists of the building body part 5 on the floor.
[0013]
The core shaft 1 is a reinforced concrete structure having high axial rigidity and high bending rigidity capable of supporting the total vertical load (self-weight) of the entire building and the total horizontal load in the event of an earthquake. In this embodiment, the core shaft 1 is shown in FIG. Thus, the horizontal cross-sectional shape is almost square, and the inside is used as a common space such as an elevator or a staircase, that is, as the center core of the entire building. A cast steel ball seat 3 is provided at the central position of the top of the core shaft 1, and the main seat 2 is supported by the ball seat 3 in a state where it can swing in all directions.
[0014]
The top structure 4 constituting the main structure 2 is a high-rigidity structure capable of supporting the entire weight of the building main body 5 in a suspended manner. In this embodiment, a large-scale truss (so-called hat truss) made of a steel frame is used. It is configured. The top structure 4 is formed in a square shape in plan view with a size projecting to the outer peripheral side of the core shaft 1, and the center of the top structure 4 is swung in all directions at only one point by the core shaft 1 through the spherical seat 3. Supported as possible. In addition, the support | pillar 6 which protrudes upwards is provided in the center part of the top structure 4, and the tension | tensile_strength material 7 for suspending and supporting the peripheral part of the top structure 4 from the support | pillar 6 is constructed by this, and top structure The structure can be simplified while securing the rigidity of 4, and the building body 5 can be stably supported.
[0015]
The building body 5 is of the same form as a normal multi-layer building consisting of columns 8, beams 9, and slabs 10, but it is suspended from the top structure 4 and floats from the ground surface. It is installed around the shaft 1. And clearances 11 and 12 are ensured between the inner periphery of the building main body 5 and the core shaft 1 and between the lower end of the building main body 5 and the ground surface, so that the building main body 5 has the top structure 4. And can be swung in all directions. In addition, although the channel | path 13 is provided in each layer between the building main-body part 5 and the core shaft 1, these passages 13 are provided via the expansion joint so that the rocking | fluctuation of the building main-body part 5 may not be restrained.
[0016]
As shown in a model in FIG. 3, the seismic building having the above structure is a pendulum capable of swinging in all directions like a jiabero while the main structure 2 is supported by the ball seat 3 at the top of the core shaft 1. It will be a response. Therefore, by setting the natural period as the pendulum of the main structure 2 to be sufficiently longer than the assumed earthquake motion period, resonance of the main structure 2 with respect to the earthquake input can be almost completely prevented. According to the simulation, the natural period of the main structure 2 is about 13 seconds or more in a 20-story building having the above structure, which is much longer than a long-period seismic vibration period.
[0017]
As described above, according to the above structure, it is possible to realize a long period or an ultra-long period of the building main body part 5 which is a living space, and therefore the building main body part 5 hardly vibrates even during an earthquake. Even if it is a building installed in any region or ground against any earthquake motion, it is possible to sufficiently ensure the safety and comfort of the earthquake.
[0018]
And according to the said structure, since the building main-body part 5 is suspended and supported from the top structure 4, and is installed in the state which floated from the ground surface, the compression strength is not required for the pillar 8, and it is a simple suspension material. I just need it. Therefore, the structure of the building main body 5 may be any structure as long as the slab 10 of each layer is suspended and supported by the pillars 8 as the suspension members as shown in FIG. It is possible to employ a steel material having the smallest possible cross section, or to adopt a parallel strand cable as the pillar 8. Also, for the same reason, the required number of pillars 8 can be reduced, so the interior space of the building body 5 can be made free of pillars, and the building body 5 is floating above the ground surface, so the site is widely open. There is also an advantage that effective use can be achieved. However, it is preferable that the building body 5 swings as an integrated pendulum as a whole. Therefore, for example, each layer is provided with a stiffening means 14 such as a brace as shown in FIG. It is preferable.
[0019]
In addition, since the core shaft 1 always receives the total weight of the entire building as a vertical load, the tensile stress generated in the core shaft 1 can be almost ignored even if the stress fluctuation at the time of the earthquake is taken into consideration. The shaft 1 and the foundation are structurally simple and clear and easy to design, and can be sufficiently handled by a normal reinforced concrete structure. However, since the natural period of the core shaft 1 itself is naturally short, it is assumed that the core shaft 1 resonates during a short period type earthquake. Therefore, when there is a concern that the vibration of the core shaft 1 is transmitted to the main structure 2 via the ball seat 3, the core shaft 1 is provided by interposing a seismic isolation device or a vibration control device in the support portion. Vibration transmission from the main structure 2 to the main structure 2 can be controlled.
[0020]
In the above structure, it is assumed that the main structure 2 is caused to swing by the wind load. Therefore, when it is feared that the habitability is impaired by the wind load, this is prevented. Therefore, for example, as shown in FIG. 4, between the building body 5 and the core shaft 1 or the ground, the main structure 2 is restrained from swinging in a normal state and opened in an earthquake to allow the swinging. It is preferable to provide a caulking fuse mechanism 15. However, if there is concern about damage to the building due to a storm, such as a huge typhoon that occurs once every few decades, the fuse structure 15 is opened as in the case of an earthquake, and the main structure is opened. In some cases, it is better to allow the swinging of 2. As the fuse mechanism 15, a mechanism that mechanically operates in response to an earthquake force or a mechanism that is forced to operate by detecting an earthquake with a sensor can be suitably employed. Then, it is effective to install the fuse mechanism 15 at the lowermost part of the building body 5.
[0021]
Similarly, between the lower end of the building body 5 and the core shaft 1 or the ground, by providing various dampers 16 that act when the main structure 2 swings during an earthquake and absorb the vibration energy. The swinging of the main structure 2 can be suppressed and quickly attenuated. It is conceivable that the damper 16 is incorporated in the fuse mechanism 15 as shown in FIG. 4 or the fuse mechanism 15 itself has a function as the damper 16. Further, by providing a large number of such dampers 16 between the core shaft 1 and the building body 5, the vibrations of the core shaft 1 during the earthquake described above can be suppressed and attenuated by these dampers 16. .
[0022]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and appropriate design changes can be freely made.
[0023]
For example, in the above-described embodiment, the single ball seat 3 is employed as the swing support device for swingably supporting the main structure 2, but instead, as shown in FIG. An assembly of a plurality of seismic isolation devices 20 which are installed in an inclined state so as to face O and support the main structure 2 so as to be swingable around the center O are adopted as swing support devices. It is also possible to configure 20 to operate along the tangential direction of a virtual curved surface S having a virtual radius R. As the seismic isolation device 20, not only laminated rubber as shown in the figure but also a bearing support and a sliding support can be adopted. As the virtual curved surface S, it is conceivable to set a spherical surface or a cylindrical surface according to the form of the building and the like. In the case of the spherical surface, the omnidirectional swing is possible. Can be swung in the circumferential direction. Further, in this case, it is only necessary that the seismic isolation devices 20 have a common center O and can rotate around the center O. To that extent, a single virtual curved surface S is set as shown in (a). However, as schematically shown in (b) or (c), the desired turning radius for each seismic isolation device 20 or for each group by dividing the seismic isolation device 20 into an arbitrary group. The virtual curved surface S (S1, S2) of R (R1, R2) may be set.
[0024]
When such a swing support device using a plurality of seismic isolation devices 20 is employed, the swing of the main structure 2 with respect to the core shaft 1 causes both translational motion and rotational motion at the same time. The ratio of the translational motion and the rotational motion changes according to the radius R of the. That is, theoretically, if the virtual radius R is infinite, each seismic isolation device 20 operates only in the horizontal direction, and the main structure 2 only performs translational movement. If the virtual radius R is zero, the above-described operation is performed. As in the case where such a single ball seat 3 is used, the main structure 2 has only rotational motion. Therefore, by setting the radius R to an arbitrary finite value, the ratio of translational motion and rotational motion can be set freely and optimally, thereby obtaining a desired natural period and seismic isolation effect. As shown in FIG. 6, the inclination of each seismic isolation device 20 is reversed from that in FIG. 5, and the virtual rotation center O is set below each seismic isolation device 20 so that the virtual curved surface S is convex upward. In this case, it is difficult to transmit the shaking of the top of the core shaft 1 to the main structure 2.
[0025]
The reference example related to the present invention has been described above, but the original embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, swing support devices composed of aggregates of seismic isolation devices 20 shown in FIGS. 5 and 6 are installed above and below the swing support structure 21. That is, in the present embodiment, as shown in FIG. 7, a rocking support structure 21 made of an annular high-rigidity frame as shown in FIG. 7B is interposed between the top of the core shaft 1 and the top structure 4. The seismic isolation device 20 as the swing support device is disposed above and below the virtual rotation center O ₁ of the assembly of the upper side seismic isolation device 20 above them ( Virtual rotation radius R ₁ ), and the virtual rotation center O ₂ of the assembly of the lower-stage seismic isolation devices 20 is set below them (virtual rotation radius R ₂ ). According to this, although it is stable in the state shown in FIG. 8 (a) at the normal time, in the vibration mode as shown in FIG. 8 (b), the assembly of the seismic isolation device 20 on the upper side mainly operates and FIG. In the vibration mode in which the main structure 2 behaves as a pendulum with certainty as shown, and the entire core shaft 1 bends and deforms as shown in (c), the assembly of the seismic isolation devices 20 on the lower side mainly. In the vibration mode in which the main structure 2 moves in translation as shown in (d), the assembly of both seismic isolation devices 20 is simultaneously operated. Operates in the opposite direction, and in any case, excellent seismic isolation effect is obtained. Contrary to the example shown in FIG. 7, the virtual rotation center O ₁ of the assembly of the upper seismic isolation device 20 is set downward, and the virtual rotation of the assembly of the lower seismic isolation device 20 is set downward. The same applies even if the center O ₂ is set upward.
[0026]
Further, in the above embodiment, the inside of the core shaft 1 is used as a center core, and although it is preferable and practical to do so, it is not limited thereto, and the core shaft 1 employs a simple core column. It is also possible to do. The top structure 4 is also practically constructed so that the truss is suspended and supported by the tension member 7 as described above, but the building body 5 can be stably suspended and oscillated by the oscillating support device. As long as it is possible, the form and structure are arbitrary.
[0027]
【The invention's effect】
According to the first aspect of the present invention, there is provided a main structure having a structure in which the main structure is made to respond as a pendulum such as a yajirobe in the event of an earthquake by supporting the main structure on the top of the core shaft so as to be swingable via a swing support device. It is possible to make the natural period of the earthquake sufficiently longer than the seismic motion period, so that the main structure hardly vibrates even during an earthquake, ensuring excellent seismic safety and comfort. it can. In addition, since the core shaft only receives compressive force, it is possible to design a simple and clear structure including the foundation, and the main structure is a structure that supports the main body of the building from the top structure. It is possible to sufficiently reduce the required cross section and the number of columns of the main body. Furthermore, since it is possible to make the building main body part float on the ground surface, it is also possible to open the site and make effective use.
[0029]
In particular, the invention of claim 1 is a set of a plurality of seismic isolation devices which are installed in an inclined state so as to face the virtual center, and support the main structure so as to be swingable around the center. Since the main structure is oscillated, both the rotational motion and the translational motion occur simultaneously, and by adjusting the ratio of the two motions by setting the rotational curvature of the main structure, the optimal natural period and immunity can be reduced. It is possible to obtain a seismic effect.
[0030]
In addition, in the invention of claim 1 , a swing support structure is interposed between the top of the core shaft and the top structure, and a set of seismic isolation devices as swing support devices are respectively arranged above and below the swing support structure. Since it is provided, the swing support device at each stage appropriately operates for various vibration modes, and a more excellent seismic isolation effect can be obtained.
[0031]
In the invention of claim 2 , since a fuse mechanism that is opened in the event of an earthquake is interposed between the lower end portion of the building main body and the core shaft or the ground, the main structure is prevented from swinging due to a normal wind load. can do.
[0032]
According to the invention of claim 3 , since the damper is interposed between the building main body and the core shaft or the ground, the swinging of the main structure can be suppressed and attenuated. In particular, by providing a damper between the building body and the core shaft, a vibration suppressing effect and a vibration damping effect for the core shaft can also be obtained.
[0033]
In the invention of claim 4 , since the pillar of the building main body is used as a suspension material and the slabs of each layer are suspended and supported, and each layer is provided with a stiffening means for restraining the inter-layer displacement, so the steel or cable with the smallest cross section is adopted as the column. In addition, the building main body can be swung as a whole integrated pendulum by the stiffening means.
[0034]
In the fifth aspect of the present invention, since a support column projecting upward is provided at the center of the top structure and the peripheral portion of the top structure is suspended and supported by the tension member from the support column, the rigidity of the top structure is ensured. The structure can be simplified and the building body can be stably supported.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view showing an outline of a seismic building as a reference example related to the present invention.
FIG. 2 is a plan view of the reference floor.
FIG. 3 is a diagram modeling the seismic building.
FIG. 4 is a diagram showing the seismic building as another model.
FIG. 5 is a diagram showing a seismic building which is another reference example related to the present invention as a model.
FIG. 6 is a diagram showing a modification example.
FIG. 7 is a main part schematic diagram of an earthquake-resistant building according to an embodiment of the present invention.
FIG. 8 is a diagram showing a model of behavior during an earthquake.
[Explanation of symbols]
1 Core shaft 2 Main structure 3 Ball seat (swing support device)
4 Top Structure 5 Building Main Body 6 Column 7 Tensile Material 8 Column 10 Slab 14 Stiffening Means 15 Fuse Mechanism 16 Damper 20 Seismic Isolation Device (Swinging Support Device)
21 Oscillating support structure O Virtual center

Claims (5)

A high-rigidity core shaft provided in the center of the building, and a main structure that is swingably supported around the core shaft, with the top of the core shaft serving as a fulcrum. The high-rigid top structure supported on the top by a swing support device suspends and supports a multi-story building body around the core shaft, and supports the main structure on the core shaft during an earthquake. The natural period as the pendulum of the main structure is set to a period sufficiently longer than the assumed earthquake motion period .
The swing support device is an aggregate of a plurality of seismic isolation devices that are installed in an inclined state so as to face each virtual center and support the main structure so as to be swingable around the center .
A rocking support structure is interposed between the top of the core shaft and the top structure, and a set of seismic isolation devices as the rocking support devices are respectively disposed above and below the rocking support structure. The structure of a seismic building characterized by A fuse mechanism that connects the building main body and the core shaft or the ground in a normal state to restrain the main structure from swinging and is opened in an earthquake to allow the main structure to swing. The structure of the earthquake-resistant building according to claim 1 , wherein the structure is interposed. The structure of the earthquake-resistant building according to claim 1 or 2 , wherein a damper that absorbs vibration energy is interposed between the building body and the core shaft or the ground. The hanging support to the layers of the slab as a building body portion hanging member pillars, and該建comprises the layers of the main body or claim 2, characterized by comprising providing a stiffening means for restraining the interlayer displacement Structure of earthquake-resistant building according to 3 . Struts projecting upwardly in the center of the top structure is provided, according to claim 1, 2, 3 or 4, wherein by comprising supporting hanging by a peripheral portion tension member of said top structure than strut Earthquake-resistant building structure.

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