JP2004225403A - Uplift preventing device for building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact uplift preventing device capable of positively preventing the lift of a base-isolated building from uplifting and having a small grounding area and few binding parts. <P>SOLUTION: A base plate 21A mounted with a first universal joint 22A is mounted to the lower part of an upper skeleton 11 of the base-isolated building 10, and a base plate 21B mounted with a second universal joint 22B is mounted to the upper part of a lower skeleton 12. The respective other end sides of arms 22a, 22b of the first and second universal joints 22A, 22B are mounted in a bent state to a third universal joint 22C provided with a pin of cruciform plane shape so that the extended direction of the arm 22a and the extended direction of the arm 22b form a dog legged shape. The uplift preventing device 20 of such constitution is mounted between laminated rubber 13 provided at the base-isolated building 10. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing a building from being lifted, and more particularly, to a seismic isolation device in which a plurality of laminated rubber bearings having a rubber elastic body are interposed between a lower structure and an upper structure. The present invention relates to a device for preventing a building from rising during an earthquake.
[0002]
[Prior art]
In general, laminated rubber, which is often used to support seismically isolated buildings, is strong in compression but weak in tension, so the seismic isolated building rises during an earthquake, causing a large pull-out force in the laminated rubber. Could not be adopted for seismic isolation buildings. For example, as shown in FIG. 7A, when the tower-like ratio (height / width) of the base-isolated building 50 using the laminated rubber 51 is about 4 or more, FIG. As described above, the overturning moment acts on the seismic isolation building 50 at the time of the earthquake, and the seismic isolation building 50 rises. Therefore, as a countermeasure, a structural plan is made so that the tower ratio of the seismic isolation building 50 is about 4 or less so that no pull-out force is generated, or as a seismic isolation device, a roller as shown in FIG. There is a method in which the natural force of the base-isolated building 50 is extended by using the bearing 52 (or the sliding bearing) to suppress the horizontal force at the time of the earthquake and prevent the pull-out force from being generated. However, there is a drawback that the degree of freedom of design is extremely small and the shape of the base-isolated building must be limited because of seismic isolation.
On the other hand, as shown in FIGS. 9A and 9B, on the condition that the base-isolated building 50 does not fall, instead of allowing a slight lifting, the laminated rubber 51 is provided with a dowel pin 51P and the laminated rubber 51 is provided. There is also a method in which the horizontal force / compression force is transmitted to the rubber 51 but the tension force is not transmitted. However, in this case, it is possible to cope with a slight lifting amount, but when a large lifting occurs, the dowel pin 51P may come off. That is, in this method, it is possible to prevent a pull-out force from being generated in the laminated rubber 51, but it is not possible to prevent the seismic isolation building 50 from falling down, and it is also necessary to set the seismic isolation There is no guarantee that the building 50 will return to its original shape.
[0003]
Therefore, conventionally, a mechanical lifting prevention device 60 as shown in FIGS. 10A to 10C is attached between the seismic isolation portions where the laminated rubber 51 is arranged, and a certain amount of the seismic isolation building 50 is provided. They try to bear the lifting power. More specifically, the mechanical lifting prevention device 60 is configured such that the upper member 61 and the lower member 62, which are made of a steel frame material assembled in a gate shape, are opened upward, and the lower member 62 is opened. Are arranged so as to open downward, and the horizontal pieces (hereinafter referred to as horizontal members) 61m and 62m of the upper member 61 and the lower member 62 are orthogonal to each other, and the horizontal member 62m of the lower member is provided. Are arranged above the horizontal member 61m of the upper member, and a vertical piece (hereinafter, referred to as a vertical member) 61n of the upper member 61 is provided on a lower surface of the upper body 71 and a vertical member 62n of the lower member 62. Are fixed to the upper surface of the lower frame 72 by binding materials such as anchor bolts.
[0004]
[Problems to be solved by the invention]
However, in the mechanical lifting prevention device 60, it is necessary to fix the four vertical members 61n and 62n constituting the device at two locations, that is, at a total of four locations, with a binding material corresponding to the maximum pulling force. The vertical members 61n and 62n need to be formed of members that resist the maximum pulling force. Further, when a horizontal force that generates the pulling force is applied, if the rigidity of the device is not designed to be large, the laminated rubber 51 In addition, the drawback force is generated, so that the size of the apparatus is increased and a large area is required for installation.
In addition, four members (vertical members) that resist pulling out are required, and there are four places that are tied to the frame, which is uneconomical.
In addition, the above-described device provides a gap between the horizontal members 61m and 62m of the upper member 61 and the lower member 62 so that there is no resistance to the pulling force until a certain amount of pulling occurs. Need to be kept. This is to prevent the horizontal displacement from being restrained until a certain degree of withdrawal occurs. If the gap is too small, a frictional force is generated between the upper member 61 and the lower member 62 to restrain the horizontal displacement. As a result, the seismic isolation effect of the laminated rubber 51 is limited. Conversely, if the gap is too large, there is a problem that the laminated rubber 51 rises.
[0005]
The present invention has been made in view of the conventional problems, and provides a compact floating prevention device that can surely prevent the floating of a seismic isolation building, has a small installation area, and has few binding points. With the goal.
[0006]
[Means for Solving the Problems]
The inventor of the present invention has made intensive studies, and as a result, (1) follows the horizontal displacement of the seismic isolation layer in any direction of up to about 60 cm generated between the upper structure and the lower structure, which is necessary as a device for preventing lifting. (2) Satisfies the function of effectively bearing the pull-out force at the time of maximum horizontal displacement when lifting occurs, and (3) Following the seismic isolation layer (laminated rubber) and the flat twisting of the upper and lower structures. Basically, it consists of three hinges, which are always in a bent state, and which form a straight line at the time of large deformation of the seismic isolation layer, where horizontal force occurs when an earthquake occurs. The present invention has been found to be able to reliably prevent the seismic isolation building from rising even with a compact structure having a small installation area and few binding points by adopting a configuration that bears Those were.
That is, the invention according to claim 1 of the present invention is a lifting prevention device inserted between a lower structure and an upper structure for preventing the building from rising, and is rotatable with respect to the upper structure. A first connecting member attached to the lower structure, a second connecting member rotatably attached to the lower structure, and a connecting member for rotatably connecting the first and second connecting members to each other. It is characterized by the following.
According to a second aspect of the present invention, there is provided a lift prevention device for preventing a base-isolated building having a plurality of laminated rubber bearings provided with rubber elastic bodies between a lower structure and an upper structure from rising. An apparatus, comprising: a first connecting member rotatably mounted on an upper structure; a second connecting member rotatably mounted on a lower structure; and the first and second connecting members. And a coupling member rotatably coupled.
[0007]
According to a third aspect of the present invention, the first and second connecting members and the connecting member are formed of a chain.
In addition, in the device for preventing a seismic isolation building from rising according to claim 4, the upper structure and the first connecting member, the lower structure and the second connecting member, and the connecting member are each formed by a ball bearing. It is a concatenation.
[0008]
The device for preventing a seismic isolation building from rising according to claim 5, wherein a base plate on which a pin constituting a universal joint is mounted is mounted on each of the upper structure and the lower structure, and one end is mounted on both ends of the pin. The other ends of the arms constituting the first and second connecting members are attached to the pins of a universal joint having pins having a cross-shaped planar shape.
According to a sixth aspect of the present invention, there is provided a device for preventing a seismic isolation building from being lifted, wherein the extending direction of the first connecting member and the second connecting member are connected in a bent state in a dogleg shape.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a plurality of flat rubber elastic bodies and a plurality of steel plates between an upper frame 11 and a lower frame 12 in the vertical direction. A seismic isolation building in which a plurality of laminated rubbers 13 (only one is shown in the figure) is alternately laminated, and 20 is a device for preventing the seismic isolated building 10 from being lifted between the laminated rubbers 13 The lifting prevention device 20 includes base plates 21A and 21B attached to a lower portion of the upper skeleton 11 and an upper portion of the lower skeleton 12, respectively, and first and second mounting devices mounted on the base plates 21A and 21B, respectively. Universal joints 22A and 22B and a third universal joint 22 having arms 22a and 22b of the first and second universal joints 22A and 22B as arms. Composed of a.
Specifically, as shown in FIG. 2, the base plate 21A includes a horizontal plate 21m and two mounting plates 21n, 21n projecting upward from the horizontal plate 21m. Are tightened by a plurality of anchor bolts 23. The base plate 21B has the same configuration as the base plate 21A, and the two base plates 21A and 21B are fastened to the lower part of the upper body 11 and the upper part of the lower body 12 so as to face each other. Cross-shaped pins 22P constituting universal joints 22A and 22B are mounted on surfaces of the base plates 21A and 21B facing each other.
[0010]
FIG. 3 is a view showing the details of the lifting prevention device 20. Arms 22a, 22a of a first universal joint 22A are provided at both ends of one pin 22k of a cross-shaped pin mounted on the base plate 21A. Of the cross-shaped pin attached to the base plate 21B and extending to a direction orthogonal to the direction in which the pin 22k extends, is attached to the arm 22b of the second universal joint 22B. One end side is attached respectively. The other ends of the arms 22a, 22a and the arms 22b, 22b are respectively attached to pins 22K, 22T of the cross-shaped pins of the third universal joint 22C corresponding to the pins 22k, 22t, respectively. Can be
Thus, the arms 22a, 22a, which are first connecting members rotatably attached to the lower part of the upper skeleton 11, and the arms, which are second connecting members rotatably mounted to the upper part of the lower skeleton 12. 22b, 22b are rotatably connected to each other by the third universal joint 22C.
Alternatively, the other ends of the arms 22a and 22a and the arms 22b and 22b rotatably connected to each other by the third universal joint 22C are connected to the lower part of the upper body 11 and the upper part of the lower body 12 respectively. Respectively, so that they are rotatable.
[0011]
At this time, the arms 22a, 22a and the arms 22b, 22b are shaped like a letter so that they form a straight line at the time of horizontal deformation in which a pre-calculated lifting is considered to occur (hereinafter referred to as “lifting horizontal deformation”). Connect and install in a state of being bent into a mold. Thereby, the upper skeleton 11 can also follow a slight vertical displacement (shrinkage due to creep or expansion and contraction due to temperature change) with respect to the lower skeleton 12.
When the upper frame 11 is displaced in the horizontal direction with respect to the lower frame 12, as shown in FIG. 4, the end 221 of the arm 22a on the upper frame 11 side is connected to the lower frame 12 of the arm 22b. The arm 22a and the arm 22b move on the bottom surface Vs of the cone V having the side end 222 as the apex without any resistance, and when reaching the horizontal deformation (for example, up to about 60 cm) at which the floating occurs, the arms 22a and 22b are linear. . As a result, the lifting prevention device 20 of the present example follows the horizontal displacement of the laminated rubber 13 as the seismic isolation layer, for example, up to about 60 cm, and resists the lifting force at that time, and acts on the laminated rubber 13. To effectively bear the pulling force.
[0012]
Therefore, as shown in FIG. 3, the lifting prevention device 20 is connected in a state where the arms 22a, 22a and the arms 22b, 22b are bent in a U-shape, so that the device can be used in a horizontal direction during an earthquake. As shown in FIG. 5, the arm 22a and the arm 22b are aligned with each other and act on the laminated rubber 13 against a large lifting force generated at the maximum horizontal displacement. It can bear the pull-out force. Furthermore, by adopting the above-described configuration, even when a slight twist occurs in the plane between the laminated rubber 13 and the upper skeleton 11 and the lower skeleton 12, it can be followed.
[0013]
As described above, according to the present embodiment, the base plate 21A to which the pin 22k of the first universal joint 22A is attached is attached to the lower part of the upper body 11 of the base-isolated building 10, and the second universal The base plate 21B to which the pin 22t of the joint 22B is attached is attached, and one end of each of the arms 22a and 22b of the first and second universal joints 22A and 22B having one end attached to both ends of the pins 22k and 22t. The end side is connected to the extension direction of the arm 22a of the first universal joint 22A with the extension direction of the arm 22a of the first universal joint 22A with the pins 22K and 22T of the third universal joint 22C having the pins 22K and 22T having a cross-shaped planar shape. Arm 22b of the universal joint 22B A lifting prevention device 20 having a structure mounted in a state of being attached is attached between laminated rubbers 13 provided in the seismic isolation building 10, and in the event of an earthquake, the arms 22 a and 22 b extend completely and pull out acting on the laminated rubber 13. Since the force is borne, the floating of the seismic isolation building 10 can be reliably prevented even in a compact structure having a small installation area and few binding points.
[0014]
In addition, the lifting prevention device 20 according to the present invention stops lifting when the laminated rubber 13 which is the seismic isolation layer undergoes large deformation, and simultaneously restrains the horizontal force. However, in general, the occurrence of the lifting is allowed in the seismic isolation layer. Since the maximum deformation time is close, the deformation speed is extremely low. Therefore, since the impact force due to restraining the horizontal deformation is extremely small, no structural damage is given to the upper structure.
In addition, since the lifting prevention device 20 is a device that prevents lifting when the seismic isolation building 10 undergoes large deformation, an error of about 10 mm in the tensile direction of the laminated rubber can be tolerated. An error of about several mm is acceptable. Therefore, there is an advantage that it is not necessary to use expensive parts for the rotating part and the like.
A large tensile force acts on the arms 22a and 22b and the universal joints 22A and 22B when the arms 22a and 22b are fully extended, and the movement of the universal joints 22A, 22B and 22C is caused by lifting. This is a point in time when the prevention device 20 expands and contracts. At that time, the arms 22a and 22b do not exert much force other than the own weight of the device, so that the durability is excellent.
[0015]
In the above embodiment, a case has been described in which three hinges (universal joints 22A, 22B, 22C) in which the arms 22a, 22b are always bent are used, but the present invention is not limited to this. For example, as shown in FIG. 6A, the first arm 31 and the second arm 32 are connected using three ball bearings 33, 34, 35 to form a hinge. It may be.
Alternatively, as shown in FIG. 6B, one end of the thick chain 41 is passed through a ring member 42 fixed to the lower part of the upper frame 11 so as to be rotatable. One end may be rotatable through a ring member 44 fixed to the upper part of the lower frame 12, and the other ends of the chain members 41 and 43 may be rotatably coupled to each other.
Further, in the above example, the case where the lifting prevention device 20 is applied to the seismic isolation building having the laminated rubber bearing is described. However, the present invention is not limited to this. The device can be used as a pull-out prevention device.
[0016]
【The invention's effect】
As described above, according to the present invention, the first connecting member is rotatably attached to the upper structure, and the second connecting member is rotatably mounted to the lower structure. Since the lifting of the seismically isolated building is prevented by using a lifting prevention device having a structure in which the member and the second connecting member are rotatably connected to each other, the installation area is small, and a compact portion with few binding points is used. With such a configuration, it is possible to reliably prevent the seismic isolation building from being lifted.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a base plate according to the present embodiment.
FIG. 3 is a diagram showing details of a lifting prevention device according to the present embodiment.
FIG. 4 is a diagram showing the operation of the lifting prevention device according to the present embodiment.
FIG. 5 is a diagram showing a lifting prevention device at a maximum horizontal displacement point.
FIG. 6 is a diagram showing another configuration of the lifting prevention device according to the present invention.
FIG. 7 is a diagram showing a conventional seismic isolation building.
FIG. 8 is a diagram showing another example of a conventional base-isolated building.
FIG. 9 is a diagram showing another example of a conventional base-isolated building.
FIG. 10 is a view showing a configuration of a conventional mechanical lifting prevention device.
[Explanation of symbols]
10 seismic isolation building, 11 upper frame, 12 lower frame, 13 laminated rubber,
20 Lift prevention device, 21A, 21B base plate, 21m horizontal plate, 21n mounting plate, 22A, 22B, 22C universal joint,
22a, 22b arm, 22P cross-shaped pin,
22k, 22K, 22t, 22T pins, 23 anchor bolts.

Claims (6)

What is claimed is: 1. A lifting prevention device interposed between a lower structure and an upper structure for preventing a building from floating, comprising: a first connecting member rotatably attached to the upper structure; and a lower structure. And a connecting member rotatably connecting the first and second connecting members to each other. 2. An apparatus for preventing lifting of a building, comprising: An anti-lift device for preventing a seismic isolated building from having a plurality of laminated rubber bearings with rubber elastic bodies interposed between the lower structure and the upper structure, which is rotatable with the upper structure. A first connecting member attached to the lower structure, a second connecting member rotatably attached to the lower structure, and a connecting member for rotatably connecting the first and second connecting members to each other. A device for preventing a building from being lifted. 3. The device according to claim 1, wherein the first and second connecting members and the connecting member are formed of a chain. The upper structure and the first connecting member, the lower structure and the second connecting member, and the connecting member are connected to each other by a ball bearing, respectively. Prevention device for building lift. A base plate on which a pin constituting a universal joint is mounted is attached to each of the upper structure and the lower structure, and one end of each of arms forming first and second connecting members attached to both ends of the pin. 3. The device according to claim 1, wherein the other end is attached to each of the pins of a universal joint having a pin having a cross-shaped planar shape. 4. The rising of the building according to any one of claims 1 to 5, wherein the extension direction of the first connection member and the second connection member are connected in a state of being bent in a dogleg shape. Prevention device.

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