JP6090840B2 - Preload holding device - Google Patents

Description

  The present invention relates to a preload holding device that holds a preload introduced into a seismic isolation device.

  Conventionally, as a seismic isolation device, a seismic isolation structure that supports a building main body through a laminated rubber is known. Specifically, this seismic isolation device is installed at the position of each pillar. For example, a lower flange plate for fixing to the foundation and a building body are fixed above and below the laminated rubber of each seismic isolation device. And an upper flange plate for carrying out the operation.

  The procedure for installing this seismic isolation device in a new building is as follows, for example. First, a foundation is constructed, and a plurality of seismic isolation devices are installed on this foundation. Subsequently, the building body is constructed on the seismic isolation devices in order from the bottom to the top.

  When the building is constructed in order from the lowest layer to the upper side in this way, the load applied to the laminated rubber of the seismic isolation device gradually increases with the progress of the construction and reaches the design load. In this case, even if the installation time differs depending on the seismic isolation device, the laminated rubber of each seismic isolation device is gradually compressed, so there is a problem that the building body sinks, but the building due to the difference in shrinkage for each laminated rubber The uneven settlement of the body is often not so large.

However, when a seismic isolation retrofit structure is used in the renovation of an existing building, the installation time differs depending on the seismic isolation device, and the design load is applied to the laminated rubber of each seismic isolation device. There was a risk that only the pillars with rubber would shrink and the building itself would sink unevenly.
In addition, when building a base-isolated building by the reverse driving method, there is a large difference in the amount of shrinkage between the structural pillars, and the amount of shrinkage of the laminated rubber is added, which may cause the building body to sink unevenly. .

Therefore, in order to solve this problem, it has been proposed that a load is applied to the laminated rubber in advance in the compression direction (hereinafter referred to as preload), and in this state, the laminated rubber is installed in the field ( Patent Document 1).
In this way, since the laminated rubber is compressed in advance by preloading, even if a design load is applied during installation of the seismic isolation device, the laminated rubber can be prevented from further shrinking, so that the building body sinks unevenly. Can be prevented.

  Specifically, a hydraulic jack is installed between the upper and lower flange plates of the laminated rubber, and the upper and lower flange plates are brought close to each other by this hydraulic jack, and a preload is introduced into the laminated rubber. Alternatively, by forming female threads on the upper and lower flange plates and screwing rod-shaped rods with screws engraved on both ends into these female threads, the upper and lower flange plates are brought close together to introduce preload into the laminated rubber. .

  And in the state which attached the hydraulic jack and the rod to the laminated rubber, the seismic isolation device is installed on the foundation, and the building body is constructed on the seismic isolation device in order from the lowermost layer upward. After the construction of the building body is almost complete, the preload of laminated rubber is released.

Japanese Patent Laid-Open No. 10-280705

However, in the method of introducing a preload using a hydraulic jack, it is necessary to attach a hydraulic jack to each laminated rubber, but it is necessary to prepare a plurality of devices such as a hydraulic jack, which increases the construction cost. was there.
In addition, preloading must be maintained for a period of time after the seismic isolation device is installed until the building body is constructed to some extent. Difficult to hold on.

  In addition, in the method of screwing the rods with screws engraved at both ends to the flange plate, it is necessary to loosen the rods in order to release the preload, but both the upper and lower flange plates are originally substantially horizontal and in the same position. Because things that are not necessarily compressed are forcibly compressed, not only compression force and tensile force but also bending force and shearing force act on the rod. There was a problem that could not be released easily.

  An object of this invention is to provide the preload holding | maintenance apparatus which can hold | maintain a preload over a long period of time at low cost, and can release a preload easily.

  The preload holding device according to claim 1 (for example, preload holding devices 40 and 40A described later) is a preload holding device that holds a preload of a seismic isolation device (for example, seismic isolation device 30 described later), and The seismic device includes a flat lower flange plate (for example, a lower flange plate 31 described later), a laminated rubber (for example, a laminated rubber 32 described later) provided on the lower flange plate, and the laminated A flat plate-like upper flange plate (for example, an upper flange plate 33 described later) provided on the rubber, and the lower flange plate and the upper flange plate include female screws (for example, female screws 38 and 39 described later). ), And a holding device main body (for example, a holding device main body 41 described later) disposed between the flange plates, and the holding device A lower bolt (for example, a lower bolt 42 described later) that passes through the main body and screwed into the female screw of the lower flange plate, and an upper side that passes through the holding device main body and screwed into the female screw of the upper flange plate And a bolt (for example, an upper bolt 43 described later).

According to this invention, the holding device main body is attached to the upper and lower flange plates with the upper and lower bolts. Therefore, a device such as a hydraulic jack is not required, and the construction cost can be reduced and the preload can be introduced over a long period of time.
In addition, if the building body applies a force greater than the axial force introduced at the time of preloading to the seismic isolation device, the distance between the upper and lower flange plates of the seismic isolation device decreases, and the tension of the lower and upper bolts decreases. Both bolts are easy to loosen. Therefore, it is possible to easily release the preload by loosening these upper and lower bolts and removing the holding device main body from the flange plate.

In the preload holding device of the present invention, the holding device main body is a shape steel having a predetermined length, and the lower bolt penetrates a lower flange (for example, a lower flange 411 described later) of the shape steel. screwed into the internal thread of the lower flange plate, the upper bolt, the upper flange of the shaped steel (e.g., upper flange 413 to be described later) to be screwed into the internal thread of the upper flange plate through the preferred.

Here, examples of the shape steel include H-shape steel, I-shape steel, groove-shape steel, and angle steel.
According to this invention, the shape steel is used as the holding device main body. Shape steel has high rigidity and can be purchased at low cost, so construction costs can be further reduced.

  According to the present invention, the holding device main body is attached to the upper and lower flange plates with the upper and lower bolts. Therefore, a device such as a hydraulic jack is not required, and the construction cost can be reduced and the preload can be introduced over a long period of time. In addition, if the building body adds a force greater than the axial force introduced during preloading to the seismic isolation device, the distance between the upper and lower flange plates of the seismic isolation device decreases, so the tension on the upper and lower bolts is eliminated. Both bolts are easy to loosen. Therefore, it is possible to easily release the preload by loosening these upper and lower bolts and removing the holding device main body from the flange plate.

It is sectional drawing of the existing building to which the preload holding | maintenance apparatus which concerns on 1st Embodiment of this invention is applied. It is sectional drawing of the seismic isolation building which isolated the existing building which concerns on the said embodiment. It is an expanded sectional view of the part by which the seismic isolation apparatus of the existing building which concerns on the said embodiment is installed. It is a flowchart of the construction method of the seismic isolation building which concerns on the said embodiment. It is sectional drawing (the 1) for demonstrating the construction procedure of the seismic isolation building which concerns on the said embodiment. It is a perspective view which shows the state which attached the preload holding | maintenance apparatus to the seismic isolation apparatus which concerns on the said embodiment. It is a longitudinal cross-sectional view of the preload holding device according to the embodiment. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is sectional drawing (the 2) for demonstrating the construction procedure of the seismic isolation building which concerns on the said embodiment. It is sectional drawing for demonstrating the procedure which introduces a preload to the seismic isolation apparatus which concerns on the said embodiment, and attaches a preload holding | maintenance apparatus. It is a longitudinal cross-sectional view of the preload holding | maintenance apparatus which concerns on 2nd Embodiment of this invention. It is sectional drawing for demonstrating the procedure which introduces a preload to the seismic isolation apparatus which concerns on the said embodiment, and attaches a preload holding | maintenance apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the embodiments, the same constituent elements are denoted by the same reference numerals, and the description thereof is omitted or simplified.
[First Embodiment]
FIG. 1 is a cross-sectional view of an existing building 1 to which a preload holding device 40 according to a first embodiment of the present invention is applied.

FIG. 2 is a cross-sectional view of the seismic isolation building 2 in which the existing building 1 is seismically isolated.
The seismic isolation building 2 is a seismic isolation of the existing building 1. In this seismic isolation building 2, a part of the existing pillar 11 is removed, and the lower base isolation base 15 is provided at a place where the existing pillar 11 is removed from the base portion 13. It is provided on the lower seismic isolation base 15.
An upper base isolation base 23 is provided on the lower surface of the lowermost layer of the building body 20, and the base isolation device 30 supports the lower surface of the upper base isolation base 23.

FIG. 3 is an enlarged cross-sectional view of a portion where the seismic isolation device 30 of the existing building 1 is installed.
The seismic isolation device 30 includes a lower flange plate 31, a laminated rubber 32 provided on the lower flange plate 31, and an upper flange plate 33 provided on the laminated rubber 32.

The laminated rubber 32 is obtained by alternately laminating steel plates and rubber, for example.
The upper and lower flange plates 31 and 33 are provided with bolt insertion holes 34 and 35 through which fixing bolts 36 and 37 described later are inserted at predetermined intervals along the peripheral edge.

A lower base plate 16 is driven into the upper surface of the lower base isolation base 15. Female threads 17 are provided on the periphery of the lower base plate 16 at predetermined intervals in an annular shape.
An upper base plate 24 is driven into the lower surface of the upper seismic isolation base 23. On the periphery of the upper base plate 24, female threads 25 are provided in an annular shape at predetermined intervals.

  The lower flange plate 31 of the above-described seismic isolation device 30 is placed on the lower base plate 16. In this state, the fixing bolt 36 is inserted into the bolt insertion hole 34 of the lower flange plate 31, and the fixing bolt 36 is fastened and fixed to the female screw 17 of the lower base plate 16. Thereby, the base isolation device 30 is fixed to the lower base isolation base 15.

  Further, the upper flange plate 33 of the seismic isolation device is fixed to the upper base plate 24 by the fixing bolts 37 in the same manner as the lower flange plate 31.

Hereinafter, the procedure of making the existing building 1 seismic isolation to make the base isolation building 2 will be described with reference to the flowchart of FIG.
In step S1, as shown in FIG. 5, the vicinity of the existing column 11 is reinforced, and then a support 18 is installed at the reinforced portion. In this state, a part of the existing column 11 is cut and removed. To do.

  In step S2, as shown in FIG. 5, the lower seismic isolation foundation 15 is constructed at the location where the existing pillar is removed.

  In step S3, a preload is forcibly introduced into the seismic isolation device 30 in advance at a factory or the like, and in this state, the preload holding device 40 is attached to the seismic isolation device 30 as shown in FIGS. Step S3 will be described in detail later.

FIG. 6 is a perspective view showing a state in which the preload holding device 40 is attached to the seismic isolation device 30. FIG. 7 is a longitudinal sectional view of the preload holding device 40. FIG. 8 is a cross-sectional view taken along the line AA of FIG.
The lower flange plate 31 and the upper flange plate 33 of the seismic isolation device 30 are respectively formed with female threads 38 and 39 along the peripheral edge. Each female screw 38, 39 is disposed between adjacent bolt insertion holes 34, 35.

The preload holding device 40 includes a holding device main body 41 disposed between the flange plates 31 and 33, a lower bolt 42 that fixes the holding device main body 41 to the lower flange plate 31, and the holding device main body 41 as an upper flange. An upper bolt 43 that is fixed to the plate 33.
The holding device main body 41 is obtained by cutting H steel with a predetermined length, and includes a lower flange 411, a web 412, and an upper flange 413.

Through holes 414 and 415 are formed on both sides of the lower flange 411 and the upper flange 413 with the web 412 interposed therebetween. As shown in FIG. 9, the through holes 414 and 415 are U-shaped slits extending to the edges of the flanges 411 and 413.
The lower bolt 42 is inserted into the through hole 414 of the lower flange 411 of the holding device main body 41 and screwed into the female screw 38 of the lower flange plate 31.
The upper bolt 43 is inserted into the through hole 415 of the upper flange 413 of the holding device main body 41 and screwed into the female screw 39 of the upper flange plate 33.

In step S4, as shown in FIG. 10, the seismic isolation device 30 to which the preload holding device 40 is attached is installed on the lower base isolation base 15.
In step S5, the upper base isolation base 23 is constructed on the base isolation device 30, as shown in FIG.

  In step S <b> 6, the support 18 is jacked down and the seismic isolation device 30 supports the load of the building body 20. Then, although the load of the building main body 20 is applied to the seismic isolation device 30, since the preload has already been introduced, no further contraction occurs.

  In step S7, the seismic isolation device 30 preload is released. Specifically, the preload introduced into the laminated rubber 32 is released by removing the lower bolt 42 or the upper bolt 43. When the lower bolt 42 or the upper bolt 43 cannot be removed, the lower flange 411 or the upper flange 413 may be heated or cut with a burner.

  In step S <b> 8, the above steps S <b> 1 to S <b> 7 are repeated for all existing pillars 11 to install all seismic isolation devices 30.

  Hereinafter, the procedure for introducing the preload to the seismic isolation device 30 in step S3 and attaching the preload holding device 40 will be described in detail with reference to FIG.

The preload is to forcibly apply a predetermined load close to a load expected at the time of installation in a direction in which the laminated rubber 32 is compressed. Here, the height of the preload before the introduction laminated rubber 32 (the distance between the upper and lower flanges plates 31, 33) and t _1, the height of the laminated rubber 32 after preload introduction and t ₂ (FIG. 7 reference). In this case, the amount of shrinkage due to the preload of the laminated rubber 32 is (t ₁ −t ₂ ), and the height dimension of the holding device body 41 is set to t ₃ lower than t ₂ .

First, as indicated by white arrows in FIG. 11, a predetermined load is applied to the laminated rubber 32 as a preload by a test apparatus at a factory.
Next, as shown in FIG. 11, the upper flange 413 of the holding device body 41 is fixed to the upper flange plate 33 using the upper bolt 43. In this state, a gap is generated between the lower end surface of the holding device main body 41, that is, between the lower flange 411 and the lower flange plate 31.

Next, the lower flange 411 of the holding device main body 41 is fixed to the lower flange plate 31 using the lower bolt 42. At this time, the torque of the lower bolt 42 is managed so that an excessive tensile force does not act on the preload holding device 40.
Next, the load applied to the laminated rubber 32 is unloaded by the test apparatus. Accordingly, the state shown in FIGS. 6 to 8 is obtained, and a preload (compressive force) acting on the laminated rubber 32 is held by applying a tensile force to the preload holding device 40.

According to this embodiment, there are the following effects.
(1) The holding device main body 41 is attached to the upper and lower flange plates 31 and 33 with the lower bolt 42 and the upper bolt 43. Therefore, a device such as a hydraulic jack is not required, and the construction cost can be reduced and the preload can be introduced over a long period of time.
Further, when the building body 20 applies a force close to the axial force introduced at the time of preloading to the seismic isolation device 30, the tension of the lower bolt 42 and the upper bolt 43 is reduced, and both the bolts 42 and 43 are easily loosened. Therefore, the lower bolt 42 and the upper bolt 43 can be easily loosened, the holding device main body 41 can be removed from the flange plates 31 and 33, and the preload can be easily released.

  (2) H-shaped steel was used as the holding device main body 41. Since H-section steel has high rigidity and can be purchased at a low price, construction costs can be further reduced.

  (3) The through holes 414 and 415 are U-shaped slits extending to the edges of the flanges 411 and 413. Therefore, it is possible to easily remove the bolts 42 and 43 from the through holes 414 and 415 by shifting the holding device body 41 in the horizontal direction.

[Second Embodiment]
FIG. 12 is a cross-sectional view of a preload holding device 40A according to the second embodiment of the present invention.
The present embodiment is different from the first embodiment in that the holding device main body 41 is not an H-shaped steel and is configured by combining two substantially L-shaped steel materials 44.
That is, the holding device main body 41 is configured by joining a pair of substantially L-shaped steel materials 44 with the joining bolt 45 and the nut 46.
The steel material 44 includes a flat plate-like base portion 441 provided along both the flange plates 31 and 33, and an extending portion 442 extending upward from the base portion 441.
Each base 441 is formed with a through hole 443.
Further, the extending portions 442 of the pair of steel materials 44 are arranged to overlap each other, and the extending portions 442 are joined to each other by the joining bolt 45 and the nut 46 at the overlapping portion.

  Also in this embodiment, as shown in FIG. 13, the preload is introduced into the seismic isolation device 30 and the preload holding device 40 is attached in the same procedure as in the first embodiment.

  According to this embodiment, the same effects as the above (1) and (3) are obtained.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.
For example, in each of the above-described embodiments, the holding device main body 41 is fixed to the upper flange plate 33 and the gap is provided between the lower end surface of the holding device main body 41 and the lower flange plate 31. The holding device body 41 may be fixed to the lower flange plate 31 and a gap may be provided between the upper end surface of the holding device body 41 and the upper flange plate 33.

  In each of the above-described embodiments, the support 18 is jacked down every time the seismic isolation devices are installed in steps S6 and S7. However, the present invention is not limited to this, and after all the seismic isolation devices 30 are installed. Alternatively, jacking down may be performed at once while synchronizing the supporting works 18 around the seismic isolation devices 30.

  Moreover, in each above-mentioned embodiment, although the seismic isolation apparatus 30 using the preload holding | maintenance apparatus 40 of this invention was attached to the existing building 1, it can attach not only to this but a new building.

DESCRIPTION OF SYMBOLS 1 ... Existing building 2 ... Base-isolated building 10 ... Foundation 11 ... Existing pillar 12 ... Pile 13 ... Foundation part 14 ... Mountain retaining wall 15 ... Lower seismic isolation base 16 ... Lower side base plate 17 ... Female screw 18 ... Supporting work 20 ... Building body 23 ... Upper base isolation base 24 ... Upper base plate 25 ... Female thread 30 ... Seismic isolation device 31 ... Lower flange plate 32 ... Laminated rubber 33 ... Upper flange plate 34 ... Bolt insertion hole 35 ... Bolt insertion hole 36 ... Fixing bolt 37 ... Fixed Bolt 38 ... Female screw 39 ... Female screw 40, 40A ... Preload holding device 41 ... Holding device body 42 ... Lower bolt 43 ... Upper bolt 44 ... Steel material 45 ... Joint bolt 46 ... Nut 411 ... Lower flange 412 ... Web 413 ... Upper flange 414 ... through hole 415 ... through hole 441 ... base 442 ... extension part 443 ... through hole

Claims (1)

A preload holding device for holding a preload of a seismic isolation device,
The seismic isolation device comprises a flat lower flange plate, a laminated rubber provided on the lower flange plate, and a flat upper flange plate provided on the laminated rubber,
A holding device body disposed between the two flanges plate, and a lower bolt for fixing the holding apparatus body before Symbol lower flange plate, and the upper bolt for fixing the holding apparatus body before Symbol upper flange plate, With
The holding device body includes a web, a lower flange provided on the web and disposed on an upper surface of the lower flange plate, and an upper flange provided on the web and disposed on a lower surface of the upper flange plate. With
Each of the lower flange plate and the upper flange plate is formed with a female thread,
The lower flange and the upper flange are formed with through-holes that are U-shaped slits extending to the edges of the lower flange and the upper flange, respectively.
The lower bolt is inserted through the through hole of the lower flange and screwed into the female screw of the lower flange plate,
The preload holding device , wherein the upper bolt is inserted into a through hole of the upper flange and screwed into a female screw of the upper flange plate .

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