JPH0336989B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a seismic isolation system for structures and equipment that utilizes an earthquake observation network and a communication network.

[Conventional technology]

Currently being researched and partially implemented as a seismic isolation structure for buildings and equipment, the seismic isolation target is insulated by the foundation or installation floor, laminated rubber bearings are used as flexible support devices, and other methods are used. Basic seismic isolation combined with some kind of energy absorption device has become mainstream. This is a passive control that deterministically sets the characteristics of the seismic isolation device in advance so that the vibration characteristics of the seismic isolation system optimize the response of the seismically isolated object during an earthquake.

[Problem to be solved by the invention]

These conventional passive control type basic insulation structures for the purpose of seismic isolation and vibration damping have the following problems.

That is, in the seismic isolation construction method for buildings that lowers the horizontal rigidity of the insulating layer, some kind of trigger mechanism is required in order to obtain stability of the building during normal times, such as suppressing shaking caused by wind. A plastic damper is used for this,
It is common to add a trigger function to its elastic rigidity, or to use a mechanical fuse that ruptures in the event of a major earthquake. However, in this case, the seismic isolation effect cannot be obtained against small and medium-sized earthquakes that occur frequently.

Furthermore, in vibration-proof structures that support buildings and equipment using laminated rubber or rubber blocks, the vertical rigidity of the insulating layer is considerably reduced. In this case, there is a risk that large rocking vibrations (see Figure 7b) may occur in structures supported by flexible support devices, such as buildings, during an earthquake. It is difficult to implement this in our country. For the same reason, it is extremely difficult to achieve vertical seismic isolation, which requires further lowering the vertical rigidity of the space (seismic isolation layer) in which the flexible support device is installed, that is, seismic isolation against vibrations in the vertical direction.

Therefore, the present invention improves the disadvantages of the conventional passive control type seismic isolation and vibration isolation systems as described above, and uses a group of actuators and an automatic control system to ensure that the seismically isolated object is always stable. The purpose of the present invention is to provide an active seismic isolation system for a structure that can actively control a seismically isolated or vibration-isolated object so as to maintain its properties or prevent the object from being affected by seismic motion.

[Means to solve the problem]

The active seismic isolation system for structures according to the present invention supports the building and the ground-side foundation with a flexible support device, and also provides a trigger device that can connect or release the building and the ground-side foundation,
Earthquake observation devices are installed at a plurality of observation points around the building, and a control device is provided that uses data from these earthquake observation devices to grasp the occurrence of an earthquake, its nature, etc., and releases or connects the trigger device. It was established.

The control device includes an earthquake analysis means for processing observation data obtained by the earthquake observation device, and controls the release or connection state of the trigger device according to the nature of the earthquake determined by the earthquake analysis means. and trigger device control means for sending out control signals. More specifically, for example, a computer analyzes signals from the acceleration sensor of an earthquake observation device, determines the level of seismic motion, the impact on structures, etc., and drives the trigger device between the released and connected states. A device that emits a signal can be used.

〔Example〕

The illustrated embodiment will be described below.

FIG. 1 shows a schematic diagram of the entire system according to an embodiment of the present invention, in which a wide area warning system A and a narrow area warning system B are configured around a building 1 to be seismically isolated. Of these, regarding the wide area warning system A, earthquake observation devices 7 consisting of acceleration sensors, amplifiers, etc. are installed at multiple earthquake observation points relatively far from the building 1, and the observation data of these earthquake observation devices 7 is The information is transmitted to the building 1 via a micro line 8 or a telephone line 9 such as INS or VAN.

Further, the narrow area warning system B is one in which the earthquake observation device 7 having the above configuration is installed at an earthquake observation point set relatively near the building 1, and is connected to the building 1 by a dedicated cable.

The building 1 is equipped with a control device 6 incorporating a computer for seismic data analysis that processes data from these wide-area and short-area warning systems A and B.

Here, as shown in FIG. 2, the building 1 is supported on a foundation 3 by a plurality of flexible support devices 4 made of laminated rubber, and furthermore, according to instructions from the control device 6, the lower end of the building 1 is A trigger device 5 is installed to control the connection or release from the foundation 3.

A horizontal trigger device using an electromagnet is illustrated as a specific example of the trigger device 5 in FIGS. 3a to 3d.
This trigger device 5 has cylinders 10, 10 facing each other on the building 1 side and the foundation 3 side, and has pistons 11, 11 that can be projected from the cylinders 10, 10 by an electromagnet.

In this trigger device 5, the flexible support device 4 stops functioning in the triggered state shown in FIG. 3b, and the building 1 is seismically isolated supported by the flexible support device 4 in the triggered released state shown in FIG.

Further, FIGS. 4a to 4d show an example of the configuration of a horizontal trigger device using a hydraulic cylinder. This trigger device 5 is equipped with an electric hydraulic pump 12 controlled by a control device 6, and a piston 14 controlled by this hydraulic pump 12 to protrude freely toward the building 1 side from a hydraulic cylinder 13 attached to the foundation 3 side. This enables flexible support by horizontal connection and release between the building 1 and the foundation 3.

Further, FIGS. 5a to 5d show an example of the configuration of the trigger device 5 which is fixed in three dimensions horizontally and vertically. In this trigger device, a concave portion 16 is formed in the foundation 3, and a convex portion 15 is formed protruding from the lower end of the building 1 to fit into the concave portion 16 with considerable clearance, and this convex portion 15 is inserted into the concave portion 16. It is fixed or released by a hydraulic cylinder 13 and a piston 14.

With this horizontal and vertical trigger device, the first two
For example, a vertical fixation can also be obtained.

These trigger devices 5 are actuated by the control device 6, which analyzes alarm data including acceleration data from the wide-area or narrow-area warning systems A and B to determine the intensity of the earthquake, and If the value exceeds the allowable value, a command is issued to the mechanical system such as the trigger device 5, and necessary measures are taken immediately.

To give a numerical example, in wide-area warning system A, if the epicenter a, the earthquake observation device 7 at the earthquake observation point, and the building 1 as a seismically isolated object are in a straight line, and there is a distance of 50 km between each, then P S after wave detection
It takes about 18.5 seconds to complete the wave operation, and it is sufficient to complete the control in 12 seconds after the S-wave is detected.

Also, even in the case of narrow-area warning system B, the epicenter a
If the distance is 100 km, there is a time of approximately 12 seconds from P wave detection to S wave operation, and control should be completed within this time.

In such a system configuration, the following response patterns can be broadly classified depending on the structure of the building 1 to be seismically isolated or vibration-proofed and the type of equipment housed therein.

1. For stability during normal times, the foundation 3 and the building 1 are fixed with a trigger device 5, and in the event of an earthquake, the trigger device 5 is released to create a seismically isolated support state.

(1) It is supported by a flexible support device 4 that has low horizontal rigidity and high vertical rigidity, and provides horizontal two-dimensional seismic isolation with the trigger device 5 released. As for the structure of the trigger device 5, in addition to the structure illustrated in FIGS. 3, 4, and 5, a mechanism that is driven by an electric motor or a detonator to release the fixed state can be adopted. Also, after an earthquake, the trigger device 5 is used to fix the trigger device 5 again.

This method is used for buildings, equipment, plants, etc.
Generally applicable.

(2) Air springs with low horizontal and vertical stiffness,
Using a flexible support device 4 such as a coil spring, the seventh
As shown in Figure a, the building 1 is supported at the height of its center of gravity, and with the trigger device 5 released, horizontal and vertical three-dimensional seismic isolation is achieved. Since the object is supported at the height of the center of gravity, rocking vibrations due to the seismic horizontal motion shown in FIG. 7b are not induced, even though the vertical rigidity of the support part is low. This is suitable for application to equipment, plant equipment, etc.

For both (1) and (2) above, if an energy absorbing device such as an oil damper, plastic damper, or viscous damper is used between the building 1 and the foundation 3, the seismic isolation effect will be further enhanced, especially during an earthquake. Objects and basics 3
The relative displacement between the two can be suppressed.

2. For objects that are supported with anti-vibration support under normal conditions, but which are expected to generate harmful locking vibrations during an earthquake, the trigger device 5 should be fixed in the event of an earthquake, and the action of the flexible support device 4 should be disabled in the locked state. This will prevent rocking during earthquakes. In this method, after an earthquake, the trigger device 5 is released to return to the original vibration-proof support state. This can be applied to buildings, facilities, equipment, and in general, but does not reduce earthquake loads.

Additionally, this response pattern can also be used as a system for buildings and plant facilities that are normally supported with flexible support devices and horizontally two-dimensional seismically isolated, to be fixed only during strong winds, in order to prevent wind sway during strong winds. .

3. Bring the object that is normally supported with anti-vibration support into a flexible support state.

It is supported by a flexible support device 4 that has a low vertical rigidity that provides vibration isolation function and a horizontal rigidity that is sufficiently low (approximately 1/100 or less) compared to that, and has a rigidity that does not impair the vibration isolation function in the horizontal direction under normal conditions. This is an object to which a soft trigger is attached, and in the event of an earthquake, the trigger is removed and the object is placed in a horizontal two-dimensional seismic isolation state. After the earthquake, the trigger device 5 restores the fixed vibration-proof support state. The trigger device for the soft trigger here is the piston 1 as shown in Figure 6a.
By forming a rubber layer 17 on the outer periphery of the cylinder 4, or by constructing the cylinder 13 with rubber as shown in Fig. 6b, the vibration isolation function in the horizontal direction is not impaired when the trigger is applied. Use a rigid one.

In this method, the horizontal stiffness of the object is sufficiently lower than the vertical stiffness in a two-dimensional seismic isolation state, so the vibration type during an earthquake becomes sway mode, and harmful rocking does not occur, significantly reducing the earthquake load. Effects can be obtained. However, since a large relative horizontal displacement occurs in the supporting portion during an earthquake, it is suitable for use in equipment that can tolerate large horizontal displacement.

In this way, the most suitable pattern is selected from among the above patterns according to the characteristics of the seismically isolated object, and the trigger device is changed from the normal connected state to the released state during an earthquake (for objects that are fixed to maintain stability). (for objects that are supported by vibration isolation and are in a disadvantageous state against earthquakes, are placed in a fixed state only during an earthquake), or from an open state in normal times to a connected state (objects that are supported by vibration isolation and are in a disadvantageous state against earthquakes are placed in a fixed state only during an earthquake) ) by controlling
The effects of earthquakes can be minimized.

[Effects of the Invention] According to the active seismic isolation system for structures of the present invention, the trigger device installed between the building and the ground foundation can be actively controlled according to the nature of the earthquake, etc. This makes it possible to maintain the stability of objects against external disturbances such as wind during normal times, and to make them seismically isolated during earthquakes, thereby minimizing the effects of earthquakes.
Furthermore, it is possible to make anti-vibration objects earthquake resistant only in the event of an earthquake.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the entire system in one embodiment of the present invention, Fig. 2 is a sectional view showing the connection structure between the building and the foundation, Figs. Figures a to d are configuration diagrams of the trigger device, No. 6
Figures a and b are block diagrams of a trigger device for soft triggers, and Figures 7a and b are schematic design diagrams of rolling and overturning movements. 1... Building, 2... Ground, 3... Foundation, 4...
Flexible support device, 5...Trigger device, 6...Control device, 7...Earthquake observation device, 8...Micro line, 9...Telephone line, 10...Cylinder, 11
...Piston, 12...Electric hydraulic pump, 13...
...Hydraulic cylinder, 14...Piston, 15...
Convex portion, 16...Concave portion, 17...Rubber layer, A...Wide area warning system, B...Narrow area warning system, a...
…epicenter.

Claims (1)

[Scope of Claims] 1. A flexible support device interposed between a building and a foundation on the ground side; a trigger device that can be connected or released; an earthquake observation device installed at a plurality of observation points in a narrow or wide area centered on the building; and a device for processing observation data obtained by the earthquake observation device. a control device comprising an earthquake analysis means, and a trigger device control means for sending a signal for controlling the release or connection state of the trigger device according to the nature of the earthquake determined by the earthquake analysis means; An active seismic isolation seismic system for structures. 2. The structure according to claim 1, wherein the earthquake observation device has an acceleration sensor and an amplifier, and a line for transmitting the observation data is provided between the earthquake observation device and the building. Active seismic isolation system.