JP3814748B2 - High attenuation frame of building - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of building frames with high damping performance for reducing response vibrations of buildings due to large earthquakes and strong winds.
[0002]
[Prior art]
Conventionally, in order to reduce the response at the time of earthquake and strong wind of a building, the following means has been adopted based on the idea that the attenuation performance of the building should be increased.
(1) An interlayer damper that is installed so that a damping force is generated against an interlayer displacement that occurs when a building vibrates.
(2) A tuned mass damper (seismic control device) that absorbs the vibration energy of the building by installing an additional weight on the site where the vibration of the building is large (top, etc.) and synchronizing the period of the additional weight with the period of the building .
(3) A seismic isolation structure in which a building is supported by a member (seismic isolation device) having a large vertical rigidity and a small horizontal rigidity and absorbing vibration energy by a damper or the like.
[0003]
The three means (1) to (3) have different characteristics, but are finally common in that vibration energy is absorbed by a damper.
[0004]
By the way, when the same damper is used, the additional damping effect by the damper is almost inversely proportional to the square of the deformation amount between the two points where the damper is installed. Considering each of the means (1) to (3) from this point of view, the interlayer damper of (1) is mounted between the layers of the building where the amount of deformation is very small, so the efficiency is poor and it is necessary to mount a large number of dampers. is there. The tuned mass damper of the above (2) is configured such that the additional weight fluctuates greatly using a resonance phenomenon, and the damper is operated against the amplified deformation, so that the efficiency is high. The (3) seismic isolation structure uses a support member having a small horizontal rigidity and increases the deformation of the seismic isolation layer, so that the efficiency is still high.
[0005]
As described above, the interlayer damper (1) is not only less efficient than the other means (2) and (3) , but also has a drawback of being limited in the design of the layout inside the building.
[0006]
Further, even in the tuned mass damper of the above (2) , since the resonance phenomenon is used, the efficiency is drastically reduced when the period of the building deviates from the set period. In addition, there are disadvantages including negative factors in both the cost of using the additional weight and the space for installing the additional weight.
[0007]
Furthermore, even with the seismic isolation structure of (3), the seismic isolation layer shakes greatly when the building vibrates, so a large seismic isolation clearance with the surrounding area (adjacent buildings, roads, etc.) must be secured. There are great constraints on architectural planning. In addition, there is a drawback in that flexible joints must be used for pipes straddling the seismic isolation layer.
[0008]
Conventionally, as a technique for solving the above-described drawbacks, for example, the “high damping structure for axial deformation control” according to the invention A of Japanese Patent No. 2616334 is installed with a rod-shaped control member extending over a plurality of floors of a building, The top and bottom of this control member are connected to the building, a passive damper is interposed in the middle, and the amount of deformation between the damper installation points is increased to increase the additional damping effect. However, this patented invention A is implemented for a high-rise building where bending deformation is dominant, and a high damping effect cannot be expected for medium to low-rise buildings (for example, up to 15 stories) where shear deformation dominates. In addition, it is essential to install a high-rigidity additional shaft member (control member) as an “inner pillar” in the pillar while being structurally independent from the pillar across multiple floors. Is expected to be quite difficult.
[0009]
Next, the “seismic isolation structure for high-rise buildings” according to Invention B of Japanese Patent No. 2713096 is a seismic isolation structure for high-rise buildings where bending deformation is also predominant. Shear resistance members are placed on the legs of high-rise buildings to increase shear rigidity, stretch / compressible longitudinal vibration absorbing bearings are placed, and longitudinal damping dampers are placed to attenuate vibrations during earthquakes. Yes.
[0010]
[Problems to be solved by the present invention]
The technical idea of the present invention is quite similar to the “seismic isolation structure for a high-rise building” according to Invention B of the above-mentioned Patent No. 2713096, and will be referred to for comparison.
[0011]
First, patent invention B is a seismic isolation structure for a high-rise building in which bending deformation is dominant as described above (FIG. 1B). On the other hand, the building in which the present invention is implemented is rather a medium to low-rise building (for example, up to 15 floors) where shearing force and shear deformation are dominant (see FIG. 1A).
[0012]
Secondly, for the purpose described above, the patent invention B has “shear resistance member”, “extensible / compressible longitudinal vibration absorbing bearing” and “longitudinal damping damper” as constituent elements. On the other hand, the present invention does not require the “shear resistance member” and the “elongation / compressible longitudinal vibration absorption support”, and reduces the column rigidity at the outer periphery of the building (extremely makes it zero). It is characterized by facilitating rotational deformation in the building as elastic deformation.
[0013]
In short, an object of the present invention is to provide a high-damping structure of a building that is particularly effective when applied to a low-rise building where shear deformation is excellent and has a large additional damping effect.
[0014]
[Means for Solving the Problems]
As a means for solving the above-described problem, a high-damping frame of a building according to the invention according to claim 1 is:
Some or all of the pillars of the damping layer S in definitive building outer peripheral portion formed in-low-rise building 1 of base part 2 or the intermediate floor section 4 shear deformation is dominant is removed, the building is left in the inner peripheral portion The building portion 1 or 1 ′ above the damping layer S of the base portion 2 or the intermediate floor portion 4 is likely to be rotationally deformed by reducing the rotational rigidity of the column 3 and the deformation generated in the building by the rotation of the damping layer S Is constructed to be approximately equal to the shear deformation x of the building itself ,
Wherein the damper 5 to exert a damping force to the rotational deformation of the building 1 is installed on a building outer peripheral portion of the rotational deformation is concentrated in the attenuation layer S.
[0015]
The high-damping frame of a building according to the invention of claim 2 is:
Some or all of the pillars of the damping layer S in definitive building outer peripheral portion formed in-low-rise building 1 of base part 2 or the intermediate floor section 4 shear deformation is dominant is removed, the building is left in the inner peripheral portion The building portion 1 or 1 ′ above the damping layer S of the base portion 2 or the intermediate floor portion 4 is likely to be rotationally deformed by reducing the rotational rigidity of the column 3 and the deformation generated in the building by the rotation of the damping layer S Is constructed to be approximately equal to the shear deformation x of the building itself ,
The damping layer S in which the building 1 is rotationally deformed supports the vertical load of the building, but a brace-type column 7 having a small resistance is installed in the direction of the rotational deformation, “the rotational deformation of the building 1 The damper 5 that exhibits a damping force is installed on the outer periphery of the building where rotational deformation concentrates in the damping layer S.
[0016]
The invention according to claim 3 is the high attenuation frame of the building according to claim 1 or 2,
The magnitude of rotational rigidity in the damping layer of the foundation part or intermediate floor part that is likely to cause rotational deformation is expressed by the following equation so that the deformation amount generated in the building by rotation is in the same order as the deformation amount x of the building itself. ;
Σ (Fi × Hi) / Kr × H = x
To design the rotational rigidity Kr ( however, when the foundation is fixed, assuming that deformation x occurs at the top of the building due to the external force Fi, Hi is the height at which the external force Fi acts and H is the height of the top of the building) .
[0017]
The capacity of the damper is expressed by the following equation when the damping coefficient Cr in the rotational direction is Ω as the overall primary circular frequency:
Cr = 1.6Kr / Ω
A numerical value obtained by the maximum value by, characterized by installing a damper 5 in the required number in the design range.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
2A to 2C conceptually show an embodiment of a building damping frame according to the first and second aspects of the present invention.
[0019]
FIG. 2B shows an embodiment in which some or all of the pillars in the outer periphery of the building 1 in the foundation part 2 of the building 1 are removed, and the building 1 is constructed by the remaining pillars 3 to easily cause rotational deformation in the foundation part 2. ing. Further, FIG. 2C shows that a part or all of the pillars in the outer peripheral part of the building 1 ′ in the intermediate floor part 4 are removed, and the building 1 ′ is constructed by the remaining pillars 3 so as to easily cause rotational deformation in the foundation part 2. Embodiments are shown.
[0020]
In short, rotational deformation is locally generated in the foundation portion 2 or the intermediate floor portion 4 of the building, and the rotational deformation is coupled to the primary mode of the building. The damper 5 is made to work against this rotational deformation, and the damping performance as a whole building is drastically improved. Therefore, the damper 5 is installed in an outer peripheral portion where rotational deformation is concentrated (or the largest). Even if the original building does not cause bending deformation and only shear deformation, the above-described damping frame shown in FIGS. 2B and 2C can be used to couple “ rotation ” and “shear”. It is possible to dramatically increase the attenuation of the next mode, resulting in a small response. 2B and 2C, the pin portion indicated by reference numeral 6 has rotational rigidity.
[0021]
Incidentally, in the design method of the high attenuation frame, as described above, the magnitude of the rotational rigidity at the concentrated position of the rotational deformation in the foundation part 2 or the intermediate layer part 4 configured to easily generate rotational deformation is changed to the deformation generated in the building by the rotation. So that the amount is in the same order as the amount of deformation of the building itself;
Σ (Fi × Hi) / Kr × H = x
By designing the rotation rigidity Kr. However, when the foundation is fixed as shown in FIG. 2A, assuming that the external force Fi causes deformation of x at the top of the building, Hi is the height at which the external force Fi acts and H is the height of the building top.
[0022]
The capacity of the damper 5 is calculated by the following equation when the damping coefficient Cr in the rotation direction is Ω as the overall primary circular frequency:
Cr = 1.6Kr / Ω
The required number of dampers 5 is installed within a designable range using the numerical value obtained by the above as a guideline for the maximum value (the invention according to claim 3).
[0023]
3 to 5 show a more specific embodiment of the present invention.
3 and 4 show an embodiment in which the base portion 2 is likely to be rotated (or bent). FIG. 5 shows an embodiment in which it is easy to cause rotational (or bending) deformation in the building middle floor portion 4. By removing some or all of the pillars on the outer periphery of the building in the attenuation layer indicated by the symbol S in the figure, the vertical rigidity is reduced, and the vertical rigidity of the pillar 3 remaining on the inner periphery of the building is increased. While maintaining the vertical rigidity of the same as that of a normal building, the rotational rigidity is made smaller than that of a normal building to make it easy to cause rotational deformation.
[0024]
In the figure, what is indicated by reference numeral 7 supports the vertical load of the building 1 'on the damping layer S in which the building 1' above the damping layer S is rotationally deformed. It is a brace-type support column installed in a configuration in which the resistance is reduced, and the stability of the building 1 ′ is ensured (the invention according to claim 2).
[0025]
The damper 5 that exhibits a damping force in the rotational deformation of the building is installed at the concentrated position of the rotational deformation. For this damper 5, an oil damper, a viscous body damper, an extreme bottom yield point steel damper, a friction damper, and the like can be applied. The installation part of the damper 5 is assumed to make the damping layer S susceptible to rotational deformation as described above, and yields at an early stage even if there is a rigid oil damper or a viscous damper or a rigid body. Extreme bottom yield point steel dampers or friction dampers that do not contribute to bending stiffness are applied.
[0026]
FIG. 6 shows the effect of implementing the high-damping frame of the present invention on a 15-story building by simulation analysis. Rotational ( shear ) deformation was applied to the foundation (types of FIG. 2B, FIG. 3 and FIG. 4). The rotational rigidity was set such that the amount of displacement of the building due to rotation (x in FIG. 2A) was equivalent to the amount of shear deformation of the building itself. The result of the analysis is shown in the form of a transfer function. According to FIG. 6, it can be seen that the peak of the transfer function is significantly lower than that of a normal building, and that there is a very large additional attenuation effect.
[0027]
[Effects of the present invention]
According to the high-damping frame of a building according to the first to third aspects of the present invention, it is particularly effective when applied to a middle- and low-rise building where shear deformation is excellent, and a building having a large additional damping effect can be provided.
[Brief description of the drawings]
FIG. 1A is an elevation view conceptually showing deformation characteristics of a building in which the present invention is implemented, and B is conceptually showing deformation characteristics of a building in which a known invention B is implemented.
FIG. 2A is an explanatory diagram quantifying and showing deformation properties of a building in which the present invention is implemented, and B and C are elevation views conceptually illustrating different embodiments of the present invention.
FIGS. 3A and 3B are elevation views showing an embodiment of the present invention before and after deformation. FIGS.
4A and 4B are elevational views showing different embodiments of the present invention before and after modification.
FIGS. 5A and 5B are elevational views showing still another embodiment of the present invention before and after modification. FIGS.
FIG. 6 is a diagram showing the effect of implementing the present invention on a 15-story building by simulation analysis.
[Explanation of symbols]
1, 1 'building 2 foundation part 3 pillar remaining in inner circumference part 4 middle part 5 damper 7 brace type pillar

Claims (3)

Some or all of the pillars of the base portion or the intermediate floor portions are formed definitive damping layer building outer peripheral portion of the low-rise buildings and in the shear deformation is dominant is removed, of the building was left in the inner peripheral portion pillars The rotational rigidity is reduced so that the building part above the damping layer of the foundation part or the intermediate floor part is likely to be subjected to rotational deformation , and the deformation generated in the building by the rotation of the damping layer is substantially equal to the shear deformation of the building itself. That it is built,
A high-damping structure for a building, wherein a damper that exhibits a damping force for the rotational deformation of the building is installed on an outer peripheral portion of the building where the rotational deformation is concentrated in the damping layer . Some or all of the pillars of the base portion or the intermediate floor portions are formed definitive damping layer building outer peripheral portion of the low-rise buildings and in the shear deformation is dominant is removed, of the building was left in the inner peripheral portion pillars The rotational rigidity is reduced so that the building part above the damping layer of the foundation part or the intermediate floor part is likely to be subjected to rotational deformation , and the deformation generated in the building by the rotation of the damping layer is substantially equal to the shear deformation of the building itself. That it is built,
The building supports a vertical load on the damping layer in which the building is rotationally deformed, but brace-type support columns with low resistance are installed in the direction of the rotational deformation.
A high-damping structure for a building, wherein a damper that exhibits a damping force for the rotational deformation of the building is installed on an outer peripheral portion of the building where the rotational deformation is concentrated in the damping layer . The magnitude of rotational rigidity in the damping layer of the foundation part or intermediate floor part that is likely to cause rotational deformation is expressed by the following equation so that the deformation amount generated in the building by rotation is in the same order as the deformation amount x of the building itself. ;
Σ (Fi × Hi) / Kr × H = x
Designing the rotational stiffness Kr by (provided that when the basal portion fixed, as the deformation in the building top x is caused by an external force Fi, height of the action of external force Fi to the Hi, the H height of the building top) ,
The capacity of the damper is expressed by the following equation when the damping coefficient Cr in the rotational direction is Ω as the overall primary circular frequency:
Cr = 1.6Kr / Ω
As the maximum value a numerical value obtained by, characterized by installing the required number of dampers in designable range, high attenuation Frame building according to claim 1 or 2.

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