JPH0572490B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a variable rigidity brace whose rigidity can be changed by the operation of a control device, and which can be used to control external forces such as earthquakes and wind that are input to a building with a damping structure. The rigidity of the building frame is changed according to the earthquake, etc., in order to cope with earthquakes, etc.

[Conventional technology]

Conventionally, in the seismic design of high-rise buildings and important structures, dynamic design has been performed to check safety by calculating the ground movement and building response during an earthquake.

Earthquake resistance methods include seismic isolation or attenuation construction methods in which laminated rubber bearings or dampers are interposed between the building and the foundation, methods that consume earthquake energy by destroying non-main building components, walls or columns. There is a method to adjust the rigidity of the building to the optimum level by creating slits in the building.

By the way, the basic idea of confirming the safety of buildings designed using current seismic design methods during earthquakes is that the energy absorbed by the hysteresis characteristics associated with plasticization of the structure exceeds the seismic energy acting on the structure. This has the problem of trust in the history loop characteristics.

In addition, all conventional methods provide a passive seismic structure against natural external forces such as earthquakes and wind, and because buildings have a specific natural frequency, they do not allow resonance phenomena to occur against uncertain inputs such as earthquakes. You can't avoid it.

In contrast, in Japanese Patent Application No. 61-112026, the applicant proposed that instead of using the above-mentioned passive seismic resistance method, the rigidity of the building itself was changed based on the judgment of a response prediction system based on the detected seismic motion, and the We are proposing a vibration damping method that ensures the safety of the building, its equipment, residents, etc. by setting it outside the area or in a state with little resonance.

In the above seismic control method, a control device is installed in all or part of columns, beams, braces, walls, and their joints, or between a building and the foundation or an adjacent building, so that the connection state can be changed according to computer commands. , Damping the building is done as follows.

The occurrence of an earthquake is detected by earthquake sensing devices placed in both narrow and wide areas around buildings, and the observation data is transmitted to a computer via wired and wireless communication networks. Wide-area earthquake sensing equipment connects seismometers at existing earthquake observation points or specially installed equipment using microcircuits or telephone lines.
In addition, narrow-area earthquake sensing devices consist of seismometers installed around buildings or in the surrounding ground, and vibration sensors placed at the base of buildings or inside buildings, and the effects of wind force etc. are detected by vibration sensors inside buildings.

For detected earthquakes, a computer determines the scale of the earthquake, analyzes frequency characteristics, predicts the amount of response, etc., and determines whether or not to control the vibration of the building, and if so, the amount of control to avoid resonance. The judgment is made based on the one that provides the optimum stiffness (natural frequency) with a small amount of seismic response.

The commands from the computer are transmitted to the control devices in each part of the building, and the control devices are operated so that the stiffness of the building reaches the optimal stiffness based on the computer's predictions. The connection state can be adjusted by turning the fixed state and uncoupled state on and off using hydraulic mechanisms, electromagnets, etc., or hydraulically adjust the fixed state and uncoupled state by applying tension or fixing at any position. Possible options include those that are adjusted using a mechanism or a special alloy.

In addition, vibration sensors placed inside the building can detect the amount of response in each part of the building as well as the actual vibration when control is performed, and this can be fed back to correct the amount of control.

[Purpose of the invention]

The variable rigidity brace of the present invention is used in the above-mentioned vibration control method within the column and beam structure, floor slab structure, etc., and reduces the response of the building by controlling the deformation of the frame due to earthquakes, etc. The purpose is to prevent earthquake disasters in buildings, as well as to protect the people and machinery and equipment living inside from the discomfort and vibration disturbances caused by earthquakes.

[Structure of the invention]

Hereinafter, an overview of the present invention will be explained using reference numerals in the drawings corresponding to the embodiments.

The variable rigidity brace 3 of the present invention consists of a first brace 4 and a second brace 5 arranged parallel to the first brace 4. The first brace 4 and the second brace 5 are integrated by operating a connecting device 6. be separated or separated.

The first brace 4 is connected at both ends to a building frame composed of columns 1, beams 2, etc., and functions alone as a low-rigidity brace. On the other hand, the second brace 5 is integrated with the first brace 4 by operating the coupling device 6, thereby increasing the rigidity of the variable rigidity brace 3 as a whole. Further, by operating the coupling device 6 in the direction of releasing the restraint, the original rigidity can be restored.

By providing a plurality of coupling devices 6 in the longitudinal direction of the first brace 4, the rigidity of the second brace is added between the restraining positions of the first brace 4 and the second brace 5, so that the variable rigidity brace 3 can be provided with various stiffnesses. When there is only one connecting device 6, the first brace 4 and the second brace 5 are connected in advance at at least one location, and the second brace 5 is restrained to the first brace 4 side by the operation of the connecting device 6. The rigidity can be varied between low and high rigidity by adjusting the rigidity or releasing the restraint.

In this way, by changing the stiffness of the variable stiffness brace 3, the stiffness of the frame can be changed depending on the seismic characteristics between a state of high stiffness, that is, a large natural frequency, and a state of low stiffness, that is, a state that has a small natural frequency. You can change it freely. Therefore, the rigidity of the building as a whole can be controlled by performing a switching operation using the coupling device 6 in accordance with a command from a computer.

〔Example〕

Next, the illustrated embodiment will be described.

FIG. 1 shows an outline of the case where the variable rigidity brace of the present invention is applied within the structural surface of a column and beam.

The first brace 4 is connected at both ends to a gusset plate 7 at the column-beam joint with bolts 8. The second brace 5 is arranged so as to sandwich the first brace 4 from both sides, and in this embodiment, it is connected to the first brace at the upper part of the diagonal brace 3, and connected to the first brace at the lower part via a connecting device 6. ing. At the connecting position using the lower connecting device 6, a friction plate 11 is provided between the first brace 4 and the second brace 5 sandwiching it, and these are tightened by the operation of the connecting device 6 (temporarily turned on). , the first brace 4 and the second brace 5 can be connected by frictional force. Furthermore, when the coupling device 6 is operated in the direction of releasing the restraint (temporarily turned off), the second brace 5 becomes free.

In the off state mentioned above, the rigidity of the variable rigidity brace 3 is only that of the first brace 4, and in the on state, the stiffness of the variable rigidity brace 3 is that of the first brace 4 only, and in the on state, the stiffness of the variable rigidity brace 3 is the same as that of the first brace 4.
The stiffness of the second brace 5 is added as the stiffness of the variable stiffness brace 3 between the two positions. In addition, as shown by the two-dot chain line in the figure, by providing the coupling device 6 at the middle of the variable rigidity brace 3 in the longitudinal direction,
The rigidity of the variable rigidity brace 3 can be controlled by varying the connection position by the connection device 6.

In this embodiment, the joint portion of the beam 2 to the column 1 is formed by a pin joint so that the rigidity of the place 3 becomes dominant in the frame. That is, by changing the rigidity of the variable rigidity brace 3, it is possible to greatly change the rigidity of the frame. In the figure, 9 is a splice plate and 10 is a bolt.

FIG. 2 shows an example of the structure of the coupling device 6, in which a bolt 13 passes through the first brace 4 and the second brace 5. A motor 12 is attached to one end of the bolt 13, and a motor 12 is attached to the other end of the bolt 13. comes with nut 14. By rotating the motor 12, tension is applied to the bolt 13, and frictional force is generated on the friction plate 11 located between the first brace 4 and the second brace 5. This frictional force allows the first brace 4 and the second brace 5 to be connected, and when the motor 12 is rotated in the opposite direction, the frictional force is released.

FIG. 3 shows another example of the structure of the connecting device 6, in which a steel rod 16 passes through the first brace 4 and the second brace 5, and a jack 15 is attached to one end of the steel rod 16. However, an anchor plate 17 is attached to the other end. The jack 15 applies tension to the steel rod 16 to generate a frictional force on the friction plate 11 between the first brace 4 and the second brace 5. This frictional force allows the first brace 4 and the second brace 5 to be connected, and when the tension is released, the frictional force disappears and the second brace 5 becomes free.

In addition, in the above embodiment, the coupling device 6 utilizes the frictional force of the friction plate 11;
It also functions as a friction damper.

In addition, in the embodiment shown in FIG. 1, a pair of pillars 1 and beams 2
Although the explanation has been made in relation to the structural surface surrounded by the structure, when applied to a multi-story building, a large number of variable stiffness braces can be arranged to change the stiffness of the building as a whole.

[Effects of the invention] By operating the connecting device, the stiffness of the second brace can be added to or removed from the stiffness of the entire variable rigidity brace, and if multiple connecting devices are provided, the stiffness can be changed in stages. becomes.

The mechanism as a device is simple, and design and maintenance are also easy.

It is also possible to make the coupling device that connects the first brace and the second brace also serve as a friction damper.

By increasing the difference between the rigidity of the first brace and the rigidity of the second brace, the width of the rigidity change can be increased, and the range of application can be widened.

The operation of the coupling device is controlled by a computer,
By varying the stiffness of the braces and frame, the deformation of the entire building can be controlled in response to individual seismic characteristics. This increases the safety of the building and creates a comfortable living space with less shaking.

[Brief explanation of the drawing]

FIG. 1 is a front view of the frame showing the outline of this invention;
FIGS. 2 and 3 are front views showing the structure of the connecting device portion, respectively. 1... Column, 2... Beam, 3... Variable rigidity brace, 4... First brace, 5... Second brace,
6... Connection device, 7... Gusset plate, 8...
...Bolt, 9... Splice plate, 10...
Bolt, 11...Friction plate, 12...Motor, 1
3... Bolt, 14... Nut, 15... Jacket, 16... Steel bar, 17... Anchor plate.

Claims (1)

[Claims] 1. A first brace whose both ends are connected to a building frame;
a second brace arranged parallel to the first brace with a connecting device interposed therebetween;
A variable rigidity brace, characterized in that the brace is configured to be integrated with or separated from the first brace by actuation by an electrical switching operation of the connecting device. 2. The variable rigidity brace according to claim 1, wherein a plurality of coupling devices are provided in the longitudinal direction of the first brace.