JPH0718271B2 - Seismic isolation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a seismic isolation device that exerts a seismic isolation effect against a wide range of disturbances ranging from large earthquakes to micro-tremors, and specifically, a superstructure. A base seismic isolation structure that consists of a seismic isolation isolator that places a building that is a substructure on a foundation that has weak horizontal spring rigidity, and a fixing member that fixes the building until a horizontal earthquake of a specified value or more is applied. In addition, a vibration isolation mechanism is provided to prevent vibration even when the seismic isolation isolator does not provide seismic isolation, and to further reduce vibration when the seismic isolation isolator is performing seismic isolation. From the vibration caused by passage to the small, medium and large earthquakes, the vibration transmitted to the entire building or the part to be protected should be reduced to the required level (for example, when a precision instrument such as an electron microscope is placed). The reduction can be seismic isolation structure,
It is provided at low cost.

(Prior Art) In the seismic design of structures such as buildings, it has been a conventional idea to consider the building as a hard and non-deformable object and to increase the strength of the object itself. On the other hand, due to the need for measurement due to the increase in the height of buildings, it is considered that the building has a soft structure, and the natural vibration period of the building is deviated from the period of the seismic motion, and a damping mechanism is incorporated to damp the vibration of the building. The seismic isolation system of is developing.

As a method of shifting the natural vibration period, for example, an eccentric flywheel having a natural vibration period different from that of the building is rotatably mounted in the building (turned mass method), or the building is constructed by combining different materials to improve the rigidity of the building. There is something to adjust. As a method of incorporating a damping mechanism, there is a method of incorporating an energy consuming mechanism using a viscous body in the building itself.

However, all of these methods are intended to perform seismic isolation after fixing the building to the ground, and the building moves integrally with the ground and receives the input acceleration of the earthquake directly. Therefore, although it is effective against vibrations caused by the passage of vehicles or small earthquakes, it is impossible to protect the building from the large input acceleration of medium and large earthquakes, and it is possible to cope with earthquakes of a level exceeding a small earthquake. In order to improve the seismic isolation performance of these seismic isolation facilities, the building itself is structurally structured (as a framework) even if the scale is increased.
Not only does it not reduce the seismic strength that it should have, but its weight and installation volume occupy a large part of the building, making it completely impractical.

Therefore, the applicant has a fundamentally different idea from these,
That is, as shown in FIG. 12, the building (2) is mounted on the foundation (3) so as to be swingable by using the seismic isolation isolator (1).
A basic seismic isolation system is proposed in which the seismic isolation isolator (1) is supported and regulated horizontally by the weak spring rigidity of the isolator (1).

In this method, the ground is the resonant frequency of the building (2), for example 5H.
Even if it sways in the cycle of z, the building moves slower than that, for example, in the cycle of 1 to 0.5 Hz, so that the response acceleration of the building to the seismic input is greatly reduced, and a large seismic isolation effect can be mentioned.

Here, the seismic isolation isolator (1) is shown in Figs.
As shown in the figure, rigid plates (5) (5) ... such as steel plates and thin elastic plates (6) (6) ... such as natural rubber and synthetic rubber are alternately laminated and fixed. This seismic isolation isolator (1)
Has a large vertical loading capacity and a small horizontal spring because the elastic plates (6) (6) ... Which are sandwiched between the rigid plates (5) (5) ... It has rigidity.

The seismic isolation system using this seismic isolation isolator (1) prevents the building from shaking due to vibrations caused by large vehicles running near the building, and prevents unidirectional displacement of the building due to horizontal wind loads such as typhoons. To prevent this, a fixing member is required to fix the building so that it will not move under a small horizontal load. Therefore, in the basic seismic isolation structure (8) proposed by the applicant, the fixing member (7) is juxtaposed with the seismic isolation isolator (1) as shown in FIG. The fixing member (7) developed by the applicant of the present invention has a steel strip (7a) partially having a weak portion as shown in FIG. 15 (JP-A-57-71965) and a bullet shown in FIG. Plastic rod (steel rod) (7b) (JP-A-59-217877), No. 1
There is lead lump (7c) (Japanese Patent Application No. 60-102175) shown in Fig. 7.

Here, the steel strip (7a) is fixed to the building foundation when the horizontal load is small, and when the horizontal load more than a predetermined value is applied due to the arrival of a large earthquake, it is cut at the weak part to open the seismic isolation isolator. It is to be freely displaced. In addition to the fixed effect, the elasto-plastic rod (7b) and lead lump (7c) absorb the vibration energy by hysteresis damping due to plasticity when the building (2) undergoes a large period vibration when a large earthquake occurs,
The effect is to reduce the amplitude of vibration and at the same time to converge the shaking quickly.

(Problems to be Solved by the Invention) The above-described conventional basic seismic isolation structure (8) exerts a great effect against a large earthquake. However, for small earthquakes, because of the fixed effect of fixing the building to the foundation with rigidity, the vibration of 5Hz to 20Hz that is easily felt by the human body is transmitted to the building in a relatively short period. A component that coincides with the natural vibration period of the building, for example, a component of 5 Hz resonates the building, and the amplification effect causes the building to shake more than the ground vibration.

In this case, especially in a high-rise building, the amplitude becomes higher toward the upper floor, so that the occupants are likely to feel anxiety due to shaking of furniture, which is a serious problem. Even though the basic seismic isolation structure completely prevented the destruction of the building itself, there still remained a problem in terms of habitability.

(Means for Solving Problems) The present invention has been made in view of the problems of the above-mentioned conventional techniques, and this means for solving problems is applied to the superstructure during the vibration and seismic isolation operation caused by the fixed effect. To suppress the transmitted vibration,
There are two structures, one for the entire superstructure and one for a part of the superstructure.

These two are mounted and supported so that the upper structure can swing horizontally in the horizontal direction by a seismic isolation isolator formed by alternately stacking elastic plates and rigid plates, and shear stress below a predetermined value. The basic seismic isolation structure, in which the upper structure is connected to the lower structure by a fixing member that exhibits rigidity, has a common structure.

The structure for suppressing the vibration of the entire upper structure, which is the first aspect of the present invention, is provided in a state in which the upper structure is rigidly coupled to the lower structure and in a state in which the upper structure swings horizontally with respect to the lower structure. A vibration suppression mechanism is provided in the upper structure that is coupled between the parts that are displaced relative to each other due to strain in the vibrating upper structure, and that follows this displacement while giving resistance to it. Includes an inertial pump damper that performs viscous damping as shown in FIG.
As shown in Fig. 3, a seismic damper using the inertial force of the weight,
Alternatively, there is a brace damper as shown in FIG.

According to a second aspect of the present invention, a structure for suppressing vibration of a part of an upper structure is such that a part of the upper structure is an independent floor structure supported by another part of the upper structure, and By providing a vibration suppression mechanism that supports in a floating state that can move in the vibration suppression direction, the upper structure is rigidly coupled to the lower structure, and the upper structure is horizontal to the lower structure. FIG. 7 is a view in which vibration transmission to the floor structure is suppressed from the other portion that vibrates while swinging, and a specific example of this vibration suppressing mechanism is shown in FIG. 7 for the purpose of suppressing horizontal vibration. Floor seismic isolation structure,
There is a floor seismic isolation structure shown in FIGS. 8 and 9 for suppressing horizontal and vertical vibrations.

(Operation) In the above configuration, particularly in earthquakes (medium and large earthquakes and small earthquakes) in which the seismic isolation isolators work, the seismic isolation isolators reduce the input acceleration in the horizontal direction to provide effective seismic isolation.
This horizontal vibration is reduced to such an extent that it does not cause a problem as the destructive force of the building, and is transmitted to the superstructure.

In addition, vertical vibration (since the building is originally subjected to a large gravitational acceleration, this itself does not pose a problem as a destructive force against the building in an earthquake) is mitigated by the seismic isolation isolator, which is a laminate of elastic plates. Transmitted to the superstructure.

As a living space or a space for arranging precision equipment, the above-mentioned reduced horizontal vibrations and moderated vertical vibrations are also problems, but these vibrations have a damping function according to the purpose in the superstructure. It is damped to the required level by the vibration suppression mechanism installed with the.

This vibration suppression mechanism targets the vibration damped or mitigated by the seismic isolation isolator, so it is a much smaller device than the case without a seismic isolation isolator.
The vibration can be reduced to the required level.

On the other hand, due to the action of the fixing member, the vibration suppressing mechanism functions to suppress minute vibrations against vibration or a small earthquake in which the seismic isolation isolator does not deform in the horizontal direction. Even at this time, the seismic isolation isolators alleviate the vertical vibrations (especially the impact when the ground descends is alleviated), and the total vibration suppression effect is higher than that of the vibration suppression mechanism alone. .

As a result of the above actions, a wide range of seismic isolation and vibration control is possible from large earthquakes to small earthquakes and vibrations due to the passage of vehicles.

(Embodiment) The present invention is the basic seismic isolation structure (8) described above additionally provided with a vibration suppressing mechanism.

This vibration suppressing mechanism prevents resonance by changing (mainly extending) the vibration period of the upper structure or a part thereof with respect to the period of seismic motion, and absorbs vibration energy to enhance damping. All publicly known technologies for seismic isolation with the building fixed to the foundation correspond to this and can be used as they are.

Next, a structural example of the first invention for suppressing the vibration of the entire upper structure will be described with reference to FIGS. 1 to 5 as first to third embodiments, and suppressing a part of the vibration of the upper structure. A sixth example of the structure of the above-mentioned second invention is described as the fourth and fifth examples.
FIG. 11 to FIG. 11 will be described.

The behavior of the basic seismic isolation structure (8) consisting of buildings, foundations and seismic isolation isolators in the event of a large earthquake has already been explained, so in the following explanation, the same symbols as those used in the previous explanation are attached. And the description is omitted.

The seismic isolation device (10) according to the first embodiment shown in FIG. 1 uses an inertial pump damper (11) as a vibration suppressing mechanism.

As shown in FIG. 2, the inertia pump damper (11) divides the center of a bellows-shaped expandable container (12) into two parts by a movable plate (13) and connects both ends thereof with a thin connecting pipe (14). , These are filled with a viscous body (15). Both ends of the expandable container (12) are fixed to the floor (16) of the building, and the movable plate (13)
By fixing the to the ceiling (17) of the building, when the building vibrates and is distorted, the movable plate (13) moves due to the relative movement of the floor (16) and ceiling (17) at this time, and the viscous The body (15) moves through the thin connecting pipe (14). By viscous resistance at this time, the natural vibration period of the building (2) can be adjusted so as to deviate from the period of the earthquake, and the vibration energy can be absorbed to increase the damping rate. As a result, a sufficient seismic isolation effect can be given to the vibration transmitted to the superstructure through the seismic isolation isolator.

The inertia pump damper (11) may be attached so that the movable plate (13) moves due to the distortion of the building during vibration, and the attachment position can be set arbitrarily. The second embodiment shown in FIG. 3 is a seismic isolation device (20) using a vibration suppressor (18) utilizing a pendulum and lever action as a vibration suppressing mechanism.

This seismic damper (18) is a metal rod (21) that is liable to the top of a tripod-shaped support (19) assembled on the floor (16) of the building.
The rotatably holding the support portion (22) of the, the weight (23) is fixed to one end of the metal rod (21), and at the same time, the other end (24) is planted in the ceiling (17) of the building (25). And link (26).

In this structure, when the seismic acceleration acts on the building (2), the weight (23) tends to swing in the same direction as the direction in which the ceiling (17) is distorted with respect to the floor (16). This force is magnified by the lever action, and the direction is reversed, and the ceiling (17)
Be transmitted to. This gives a large additional mass to the building (2). Since the reaction of the weight (23) works in proportion to the lever ratio λ, it functions as an effective dynamic vibration suppressor even with a small weight. This seismic damper (18) is also effective against the vibration or small earthquake caused by the passage of a vehicle or the like in which the seismic isolation isolator (1) does not move, and the vibration transmitted to the upper structure when the seismic isolation isolator acts. Vibration control.

The third embodiment shown in FIGS. 4 and 5 is a seismic isolation device (30) using a vibration suppressing mechanism called a brace damper (31).

This brace damper (31) is a quadrilateral combination 4
Two rotating plates (33) between book links (32) (32)
Pins (35) (35) that incorporate (33) and link-connect
... is connected to the four corners of the building with diagonal members (36) (36). When the building (2) is deformed as shown in FIG. 5, this device converts a slight linear movement acting on the link portion into a conventional relative rotational movement of the rotating plate. Rigidity and damping coefficient can be set arbitrarily by mounting a rubber elastic body or super-adhesive material between the two rotating plates (33) (33), which is effective for vibration or small earthquakes. Seismic isolation is possible. Therefore, by combining with the basic seismic isolation structure (8),
It becomes an ideal seismic isolation device.

The fourth embodiment shown in FIGS. 6 and 7 is a seismic isolation device (40) using a floor seismic isolation structure (41) for suppressing horizontal vibration as a vibration suppressing mechanism.

This floor seismic isolation structure (41) was designed to protect the equipment installed on the floor of the building from an earthquake. As shown in FIG. 7, a movable floor on which the seismic isolation target (42) is placed. The horizontal support member (45) is provided to support the (43) by the slide bearing (44) and at the same time to give a restoring force to the movable floor (43).

Here, the sliding bearing (44) is an element that supports the vertical load of the seismic isolated object (42) and the movable floor (43) and hardly resists horizontal force. For example, Teflon (trademark) or ball bearing is used. To use. A horizontal resistance member (45), a reinforcing bar or an iron plate is used.

This seismic isolation device (40) allows the movable floor (45) to operate even when the seismic isolation isolator (1) does not operate due to a small earthquake.
Swings in the direction opposite to the vibration direction of the building to reduce the vibration of the seismic isolation target (42) on the movable floor. Furthermore, the natural period is adjusted by the horizontal resistance member (45) and energy is consumed by plasticizing the member, and effective seismic isolation is performed against vibrations or small earthquakes.

The seismic isolation device (40) that uses the floor seismic isolation structure (41) tries to isolate the seismic isolation of a specific part of the building up to the level of slight vibration, and when precision equipment is installed on the upper floor of a high-rise building. Suitable for etc.

The fifth embodiment shown in FIG. 8 and FIG. 9 uses the floor seismic isolation structure (51a) (51b) as a vibration suppressing mechanism for the purpose of suppressing the vibration in the vertical direction in addition to the vibration in the horizontal direction. It is a seismic device (50).

This floor seismic isolation structure (51a) (51b) has two types of devices structurally for the purpose of absorbing three-dimensional vibration in order to protect precision equipment such as computers from small earthquakes and slight vibrations.

The floor seismic isolation structure (51a) shown in FIG. 8 is a combination of a slide bearing (52) and a coil spring (53), and the floor seismic isolation structure (51b) shown in FIG. 9 is an air spring (54) and oil. It is also used with the damper (55). In FIGS. 8 and 9, (56) is a fixed floor in the building, (57) is a movable floor,
(58) is a large beam and (59) is a pedestal.

FIGS. 10 and 11 show what is used in combination with the floor seismic isolation structure of the fourth embodiment shown in FIGS. 6 and 7 or the fifth embodiment shown in FIGS. 8 and 9. Show.

In FIG. 10, the floor slab (61) and the beam (63) are insulated from the building by an insulating material (62a) such as rubber to suppress microvibration. Fig. 11 shows the case where the floor is relatively small and the floor slab (6
Only 4) is insulated from the building (2) by the insulating material (62b). The insulating material (62a) (62b) is used for the purpose of blocking the vibration transmitted through the building, and may be a material having a vibration absorbing performance such as a rubber elastic body.

Since this structure is accompanied by a reduction in the proof stress of the structural body, a high effect can be obtained by using it together with the basic seismic isolation structure (8) in which the energy of a large earthquake is blocked by the seismic isolation isolator (1).

(Effects of the Invention) The present invention provides a basic seismic isolation structure in which an upper structure mounted and supported on a seismic isolation isolator is also provided with a fixing member so as not to move due to vibration due to passage of a large vehicle or wind load of a typhoon. In contrast, vibration that is transmitted when the upper structure (building) is fixed to the lower structure (foundation) and that is transmitted while the upper structure is horizontally swinging with respect to the lower structure is suppressed. Therefore, a vibration suppression mechanism that suppresses the vibration distortion of the entire superstructure or suppresses the vibration transmission to the seismic isolation floor independently installed in the superstructure was installed, so Wide-area seismic isolation becomes possible.

In particular, the present invention achieves the following effects, which cannot be obtained when each is used alone, by combining the seismic isolation isolator and the vibration suppressing mechanism.

In other words, since the seismic energy is blocked by the seismic isolation isolator for an earthquake of a size such that the superstructure is released from the restraint of the fixing member, the vibration of the superstructure at this time is compared with the case where there is no seismic isolation isolator. Becomes extremely small. In addition, the seismic isolation isolator absorbs the vibrations and transmits them to the superstructure even when the seismic isolation isolators do not deform horizontally or a small earthquake occurs. Therefore, the vibration suppression mechanism installed in the superstructure may be a small one that reduces the vibration transmitted to the superstructure through the seismic isolation isolators to the required level. It can be made much smaller than when the mechanism is used alone.

Therefore, the present invention in which the seismic isolation isolator with a fixing member is combined with the above vibration suppressing mechanism includes a room in which a required level (electron microscope or precision mechanical device is arranged) from a vibration due to a vehicle or the like to a large, medium or small earthquake. ), It is possible to provide a seismic isolation device that can perform seismic isolation or vibration control at a low space and cost.

[Brief description of drawings]

1 is a front view showing a first embodiment of a seismic isolation device of the present invention using an elastic pump damper as a vibration suppressing mechanism, and FIG.
The figure is an enlarged cross-sectional view of the elastic pump damper. FIG. 3 is a front view showing a second embodiment of the present invention in which a vibration suppressor in which a pendulum and a lever are combined is used as a vibration suppressing mechanism. 4 and 5 are front views showing a third embodiment of the present invention using a brace damper as a vibration suppressing mechanism.
The figure shows normal conditions and Fig. 5 shows the condition at the time of earthquake. FIG. 6 is a front view showing a fourth embodiment of the present invention using a floor base isolation structure for suppressing horizontal vibration as a vibration suppressing mechanism, and FIG. 7 is a partially enlarged front view of the vibration suppressing mechanism of FIG. It is a figure. 8 and 9 are sectional views showing a fifth embodiment of the present invention in which a floor seismic isolation structure for suppressing three-dimensional vibration is used as a vibration suppressing mechanism, and FIG. 8 shows one using a sliding floor, FIG. 9 shows one using an air spring. 10 and 11 are used in combination with the floor seismic isolation structure of the fourth and fifth embodiments, and FIG. 10 is a cross section showing a structure in which the floor slab and the beam are insulated with rubber or the like. Figure, Figure 11
FIG. 11 is a cross-sectional view showing a modified example of FIG. 10 when the floor is light. FIG. 12 is a front view showing a basic seismic isolation structure which is a premise of the present invention, FIGS. 13 and 14 are front and plan views of a seismic isolation isolator, and FIGS. 15 to 17 are steels as fixing members, respectively. band,
It is a front view showing an elastic body and a lead mass. (1) ... Seismic Isolator, (2) ... Superstructure, (3)
... foundation, (5) ... rigid plate, (6) ... elastic plate, (7) (7
a) (7b) (7c) ... Fixing member, (8) ... Basic seismic isolation structure,
(10) (20) (30) (40) (50)… seismic isolation device, (11)
(18) (31) (41) (51a) (51b) ... Vibration control mechanism.

Claims (2)

[Claims] 1. A seismic isolation isolator formed by alternately laminating elastic plates and rigid plates mounts and supports the upper structure on the lower structure so that the upper structure can swing horizontally, and shear stress of a predetermined value or less. In the basic seismic isolation structure in which the upper structure is connected to the lower structure by a fixing member that exhibits rigidity, the upper structure is rigidly connected to the lower structure, and the upper structure shakes horizontally with respect to the lower structure. A vibration suppression mechanism that suppresses the vibration is coupled in the upper structure by being coupled between the parts that are displaced relative to each other by strain in the upper structure that vibrates while moving, and by following this displacement while giving resistance. A seismic isolation device characterized by being installed. 2. A seismic isolation isolator formed by alternately laminating elastic plates and rigid plates mounts and supports the upper structure on the lower structure so that the upper structure can swing horizontally, and shear stress of a predetermined value or less. In the basic seismic isolation structure in which the upper structure is connected to the lower structure by a fixing member that has rigidity to, a part of the upper structure is an independent floor structure supported by other parts of the upper structure and By providing a vibration suppression mechanism that supports the structure in a floating state capable of moving in the vibration suppression direction with respect to the above-mentioned other parts, the upper structure is rigidly coupled to the lower structure, and the upper structure is lower than the lower structure. The seismic isolation device is characterized in that vibration transmission from the other portion that vibrates in a state of horizontally swinging to the floor structure is suppressed.