JPH01154971A - Variable rigidity device for building frame - Google Patents

Abstract

PURPOSE: To control the deformation of a building by using a rope member with a tension adjusting take up device as a brace in a plane of a structure and laying a buffer having a preset stroke at least one end of the brace. CONSTITUTION: Gusset plates 6 are provided at diagonal positions in a plane of a column/beam structure, one of which is mounted with a pulley 7 and the other with a buffer 4 and a take up device 5. A wire 3a is suspended over the pulley 7 and the buffer 4 to form a brace 3. Tension is previously given to the wire 3a so as to be pushed a half stroke of the buffer 4 inward. During earthquake, a strut material 5a is rotated by a device 5 for tensioning the wire 3a to cause a spring for the buffer 4 to be adhered thereto, so that high rigidity against tension is obtained and the damping buffer 4 is functioned as the brace/damper of low rigidity during tension and compression.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a variable rigidity device used in a building frame with a restraining structure, which adjusts the rigidity of the building frame according to external forces such as earthquakes and wind input to the building. This is to change the environment and deal 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 the seismic isolation construction method or microseismic construction method in which laminated rubber bearings or dampers are interposed between the building and the foundation, methods to consume earthquake energy by destroying non-main building components, walls or columns, etc. A slit is provided in the
There are methods to adjust the rigidity of a building to its optimum level.

By the way, confirmation of the safety of buildings designed using current seismic design methods in the event of an earthquake is based on the basic idea that the energy absorbed by the hysteresis characteristics associated with plasticization of the structure exceeds the seismic energy acting on the structure. However, this has the problem of reliability regarding 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 the rigidity of the building itself be changed based on the judgment of a response prediction system based on the detected seismic motion, instead of using the passive seismic resistance method described above. We are proposing an installation method that ensures the safety of the building, equipment inside the building, occupants, etc. by setting it outside the area or in a state with little resonance.

In the above installation method, a control device is installed in all or part of columns, beams, braces, walls, and their joints, or between the building and the foundation or adjacent building, so that the connection state can be changed according to computer commands. , The building is installed 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 micro-wires or telephone lines.

In addition, narrow-area earthquake sensing devices consist of seismometers installed around buildings or in the surrounding ground, and vibration sensors installed at the base of buildings or inside buildings.
Detect with "-".

■ For detected earthquakes, a computer is used to determine the scale of the earthquake, analyze its frequency characteristics, predict the amount of response, etc., and determine whether or not the vibration of the building should be controlled, and if so, the amount of control. The decision is made as to provide the optimum stiffness (natural frequency) that avoids resonance and reduces the amount of seismic response.

■ The computer's commands are transmitted to the control devices in each part of the building, and the control devices operate so that the building's stiffness 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 by applying tension or fixing at any position between the fixed state and uncoupled state using a hydraulic mechanism. Alternatively, it may be adjusted using a special alloy or the like.

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

[Purpose of the invention]

The variable rigidity device for a building frame of the present invention is used in the above-mentioned installation method within the column and beam structure, floor slab structure, etc., and by freely controlling the deformation of the structure during an earthquake, it can improve the structure of the building. The purpose of this is to reduce the response of earthquakes and prevent earthquake disasters in buildings, as well as protect people and machinery inside from discomfort caused by earthquakes, vibration disturbances, etc.

[Structure of the invention]

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

This invention uses wires such as steel cables, PCfi wires, and piano wires, or cable members 3a such as chains, ropes, and belts as braces 3 in the structural plane, and adjusts the tension of the cable members 3a by a tensioning device 5. This allows the deformation of the frame to be freely controlled during an earthquake.

A buffer 4 having a predetermined stroke is interposed at at least one end of the brace 3, and the damper function of the buffer 4 allows the brace 3 to work as a damper brace, or when the rigidity is suddenly changed, the buffer 4 can function as a natural buffer.

The buffer 4 can be of a spring type or a hydraulic type, but the type is not particularly limited.

The cable part '74' 3a constituting the brace 3 is a loop-shaped cable member, and if one end is hung on the buffer 4 and the other end is hung on the pulley 7, the frictional force acting on the cable member 3a can be reduced. etc. can be reduced.

Incidentally, the buffer 4 and the pulley 7 are installed at the column-beam joint, or in the case of a floor-slab structure, on the column plate 6 or the like provided at the column 1 position. The tensioning device 5 can also be attached to the gasket plate 6 or the like, or it can be separated and attached separately.

[For production]

■ By tensioning the cable member 3a of the brace 3 in advance so that the buffer 4 is pushed in by half of its throw (see Figure 1), the buffer 4
This means that a prestress equal to the amount of deformation of the spring or the like is introduced into the cable member 3a, and the brace 3 can bear that amount of compressive force. That is, the stiffness of the brace 3 is low in both compression and tension directions due to the spring of the buffer 4, etc., and the relationship between the load applied to the brace 3 and deformation becomes linear. In addition, the amount of compressive deformation and the amount of allowable tensile deformation of the buffer 4 as a frame of the lower bar brace 3 should be greater than or equal to the total.

(2) By tensioning the cable member 3a of the brace 3 using the tensioning device 5, the springs of the buffer 4 can be brought into close contact with each other (see FIG. 2).

At this time, the tensile rigidity of the brace 3 is
This makes the brace highly rigid against tension. On the other hand, the above-mentioned (2) remains unchanged for compression.

FIG. 7 shows the relationship between the load applied to the brace 3 and the deformation at this time.

■ Due to the damper function of the buffer 4, in the condition ■ mentioned above, it acts as a brace and damper with low rigidity in both tension and compression, and in the condition ■, it acts as a brace with high rigidity in tension and in compression. Acts as a brace and damper with low rigidity (.

■ The shock that occurs when the stiffness suddenly changes due to the tension device 5 (particularly the shock caused by the force released as soon as the force borne by the high stiffness is transferred to the low stiffness) is absorbed by the shock absorber, which is the original function of the sofa 4. It can be absorbed by acting as a vessel.

〔Example〕

Next, the illustrated embodiment will be described.

FIGS. 1 to 3 show examples in which the variable rigidity device of the present invention is applied to a column and beam structure.

In this embodiment, gusset plates 6 are provided at diagonal positions within the structural surface of the column and beam, a pulley 7 is attached to one side, a buffer 4 and a tension device 5 are attached to the other side, and a loop-shaped cable member is attached to the pulley 7 and buffer 4. The wire 3a is passed through the wire to form the brace 3.

The tension device 5 rotates the bundle material 5a by operating the motor 8, expands the gap between the loop-shaped wires 3a at both ends of the bundle material 5a, tensions the wire 3a, and returns the bundle material 5a. This allows the tension to be released.

The bundle material 5a rotates around the rotating shaft 9 attached to the gusset plate 6, and when the bundle material 5a and the brace 3 are in series as shown in FIG. 1, there is no tension from the tensioning device 5, and as shown in FIG. The maximum tension force is introduced when the bundle 5a is perpendicular to the brace 3.

The buffer 4 may be of a hydraulic type or of various other types, but for convenience of explanation, it will be described below as a spring as shown in the drawings. Note that other formats can be considered in the same way. As shown in FIG. 1, when there is no tension from the tension device 5, the spring of the buffer 4 is compressed in advance, and the wire 3a of the brace 3 is in a neutral state against the tension and compression forces, that is, a certain amount of tension is applied to the wire 3a of the brace 3. Leave it in a state where it is installed as Press I/Res.

At this time, the rigidity of the brace 3 is the same as that of the wire 3a and the buffer 4.
It has the stiffness of a series spring.

In the tensioned state as shown in FIG.
Although the rigidity of the series spring of the buffer 4 remains the same, only the wire 3a has the rigidity against tension, resulting in high rigidity. In addition, in the mechanism for pushing out or returning the distance between the loop-shaped wires 3a, even if the resistance to pushing out is large during tension and it is difficult to change the rigidity instantaneously, when the structure is vibrating, The force acting on the brace 3 then shifts to compression, facilitating the pushing and spreading action, resulting in the changed stiffness for the next tension. FIG. 6 shows this relationship.

In the embodiment shown in FIGS. 4 and 5, a hydraulic or pneumatic cylinder 10, 11 is used as the tensioning device instead of the tensioning device 5 for rotating the bundle material 5a in the above-described embodiment. Further, in the above embodiment, by expanding the interval between the loop-shaped wires 3a, the wires 3a
However, the wire may be tensioned by simply pulling one end of the wire instead of using a looped wire. In that case, compress the spring of buffer 4 in advance,
In order to achieve a neutral state with respect to both tension and compression forces, a tension equal to the prestress is applied by a tension device, and tension is introduced and released based on this tension.

Furthermore, although the above is a case of one-sided braces, by providing two braces 3 that intersect within the structural plane (see FIG. 10), the rigidity change pattern of the frame becomes as shown in FIG. 8. That is, in a state where there is no tension from the tension device 5, the load and displacement have a linear relationship in the form of adding the rigidity of the frame and the above-mentioned spring rigidity, and when tension is applied and the spring rigidity stops moving by 1, Wire 3 of brace 3
It is the sum of the high rigidity of a itself and the rigidity of the frame.

Also, if the distance between the loop-shaped wires 33 is expanded,
A force equal to the tensile force of the brace is applied to the bundle member 5a or the cylinders 10, 11, etc., but since the angle of the brace 3 due to these is gentle, the force component is sufficiently small, and it is sufficient that the force is strong enough to resist it. In the embodiment shown in FIG. 9, a pulley or pin 12 is provided on the gusset plate 6 so that the angle θ on both sides of the bundle material 5a due to the spreading of the wire 3a is made equal. Further, in this embodiment, the tensioning device 5 is provided not on the buffer 4 side but on the pulley 7 side.

The above has been explained in relation to the structural surface surrounded by a pair of columns 1 and beams 2, but when applied to a multi-story building as shown in Figure 10, a large number of this device is arranged to increase the rigidity of the entire building. It can be changed.

〔Effect of the invention〕

- By combining a brace made up of rope-like members and a tension device, it is possible to control the deformation of the frame during an earthquake.

■ When tension force is not introduced or increased, the damper function of the buffer acts as a brace and damper with low rigidity in both tension and compression; when tension force is introduced or increased, it acts as a brace and damper in tension. As a high-rigidity brace, it acts as a low-rigidity brace and damper during compression.

■ The shock that occurs when the stiffness suddenly changes due to the tensioning device, especially
The shock caused by the force released as soon as the force borne by the high rigidity is transferred to the low rigidity can be absorbed by the buffer's original function as a shock absorber.

■ Using a tensioning device controlled by a computer, etc., the stiffness of the braces can be changed and the deformation of the entire building can be controlled according 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]

1 and 2 are front views showing one embodiment of the present invention, FIG. 3 is a side view of the tensioning device portion, FIGS. 4 and 5 are front views showing a modification of the tensioning device, and FIG. The figures are graphs for explaining the action of the device of this invention, Figures 7 and 8.
The figure is a graph showing the relationship between the load acting on the brace and the deformation of the brace, Figure 9 is a front view showing another embodiment of the invention, and Figure 10 is a front view showing an example of application to a multi-story building. be. 1...Column, 2...Beam, 3...Brace, 3a...
・Wire, 4...Buffer, 5...Tension device, 6
...Gusset plate, 7...Pulley, 8...
Motor, 9...Rotating shaft, 10...Cylinder, 1
1...Cylinder, 12...Pin Figure 9 Figure 10 (1) Goze Co-destruction 1

Claims (6)

[Claims] (1) A building frame characterized in that a rope-like member equipped with a tensioning device for tension adjustment is used as a brace within the structure, and a buffer having a predetermined stroke is interposed at at least one end of the brace. Variable stiffness device. (2) The variable rigidity device for a building frame according to claim 1, wherein the stroke of the buffer is greater than or equal to the sum of an allowable compressive deformation amount and an allowable tensile deformation amount for the brace frame. (3) The variable rigidity device for a building frame according to claim 1 or 2, wherein the cable member is a steel cable. (4) The variable rigidity device for a building frame according to claim 1 or 2, wherein the cable member is a chain. (5) The variable rigidity device for a building frame according to claim 1 or 2, wherein the cable member is a rope. (6) The variable rigidity device for a building frame according to claim 1 or 2, wherein the cable member is a belt.