JP4452373B2 - Seismic isolation system and seismic isolation structure for column base of reinforced concrete columns - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seismic isolation method for a column base of a column and a technology for the seismic isolation structure of a reinforced concrete structure (hereinafter sometimes referred to as an RC structure) of a building that generates a lift associated with rocking vibration during an earthquake to reduce the seismic force. More particularly, the present invention relates to a seismic isolation method and a seismic isolation structure in which the allowable lifting structure associated with the rocking vibration is implemented at the column base of an RC column.
[0002]
[Prior art]
Conventionally, as a technology of seismic isolation construction method and seismic isolation structure that reduces the seismic input acting on a building that has a large aspect ratio and generates a lifting phenomenon due to rocking vibration at the time of an earthquake, for example, Japanese Utility Model Publication No. 6-18996, Various disclosures are known in Japanese Patent No. 2631486 (issued July 16, 1997).
[0003]
As shown in FIG. 5A, all of the conventional techniques disclosed in the above publications are based on a technical idea that allows the building a to be greatly displaced in the horizontal direction, and do not cause displacement in the vertical direction as much as possible. Therefore, it is based on a structure in which the contact point between the building a and the foundation b that supports the building a is fastened in the vertical direction.
[0004]
[Problems to be solved by the present invention]
However, in the case of a building with a large aspect ratio, as shown in FIG. 5B, the building movement during an earthquake is dominated by rocking vibration based on vertical displacement, and a large tensile axial force is applied to the seismic isolation device c. Works. Therefore, in the case of the structure in which the building a and the foundation b are tightly coupled as in the prior art, the seismic isolation device c and the foundation b that can withstand the tensile axial force are required, and they are coupled by a large number of rod-shaped members or fallen down. There is no choice but to use a laminated rubber body for prevention. In addition, since the same tensile axial force acts on the column of the building a, it is necessary to construct the column as such with a high strength structure.
[0005]
In addition, when the distance between adjacent buildings such as urban buildings is small, there is a risk that if the seismic isolation layer undergoes a large deformation, it will collide with adjacent buildings on the surface and cause a secondary disaster.
[0006]
By the way, in recent years, as disclosed in Japanese Patent Application No. 11-42759 (filed on Feb. 22, 1999), the present applicant has contact points between a building having a large aspect ratio and a supporting plate that supports the building. We have developed a seismic isolation method and seismic isolation structure that implements a structure that allows lifting to be associated with rocking vibration based on vertical displacements. This principle is as described in paragraphs [0017] to [0021] of the application specification and FIG. 4 of the drawings.
[0007]
However, a technology that implements the lifting allowance structure associated with the rocking vibration with an RC pillar has not been developed yet.
[0008]
Accordingly, an object of the present invention is to provide a seismic isolation method for a column base portion of a reinforced concrete column, which can be used for an RC structure with a floating allowance structure associated with rocking vibration during an earthquake, particularly for buildings with a large aspect ratio. To provide a seismic isolation structure.
[0009]
The next object of the present invention is to provide a technology for reducing the seismic force by allowing the building to lift up against an earthquake input to the building without connecting the building and the foundation, and a seismic isolation device such as laminated rubber It is necessary to provide a seismic isolation method and seismic isolation structure for the column base of a reinforced concrete column, which does not require the use of a reinforced concrete column and has no residual displacement when the earthquake ends.
[0010]
A further object of the present invention is to provide a reinforced concrete that can simplify the design of the RC column of the building without generating a tensile axial force, and can greatly rationalize the design and construction of the foundation when rebuilding an existing building. It is to provide a seismic isolation structure and seismic isolation structure for the column base of the column.
[0011]
[Means for Solving the Problems]
As means for solving the above-described problems, the seismic isolation method for the column base of the reinforced concrete column according to the invention described in claim 1 is as follows:
It is a seismic isolation method for the column base of a reinforced concrete column in a building that reduces the seismic force by raising the rocking vibration during an earthquake,
The column main reinforcement protrudes from the upper surface of the foundation concrete by the required length according to the amount of lift of the building,
On the upper surface of the foundation concrete, a bottom formwork combined steel plate is placed with a rising part that supports the reinforced concrete column and restrains the horizontal displacement of the reinforced concrete column. Let it penetrate through the through-hole provided in the steel sheet for both formwork and stand up,
The bottom formwork combined steel sheet is fixed to the basic concrete by a fixing jig such as a stud so that the compressive force in the vertical direction acting on the reinforced concrete column can be transmitted.
In the bottom formwork combined steel sheet, the contact portion of the reinforced concrete column and the rising portion of the column main reinforcement are each subjected to edge cutting treatment with a release material,
Reinforced concrete columns are constructed by arranging the columns based on the bottom formwork and steel plate, assembling the formwork, and placing concrete to raise the rocks due to rocking vibration.
[0012]
The invention described in claim 2 is characterized in that, in the seismic isolation method for the column base portion of the reinforced concrete column described in claim 1, the bottom formwork combined steel plate is embedded in the concrete and fixed.
[0013]
The invention described in claim 3 is the seismic isolation method of the column base portion of the reinforced concrete column described in claim 1 or 2, wherein a dowel hole corresponding to the upper surface portion of the basic concrete and the lower surface portion of the reinforced concrete column is provided, A dowel pin penetrating the bottom formwork steel plate is fitted into the dowel hole.
[0014]
The invention described in claim 4 is the seismic isolation method for the column base portion of the reinforced concrete column described in any one of claims 1 to 3, wherein an impact buffering sheet or the like is provided on the upper surface of the bottom formwork steel plate. A shock-absorbing material is provided.
[0015]
According to a fifth aspect of the present invention, in the seismic isolation method for the column base portion of the reinforced concrete column according to any one of the first to fourth aspects, the shock absorbing material is provided at the top end of the rising portion of the bottom formwork steel plate. It is characterized by constructing a reinforced concrete column by assembling a mold and assembling a formwork.
[0016]
The seismic isolation structure of the column base of the reinforced concrete column according to claim 6 is a seismic isolation of the column base of the reinforced concrete column of the building that reduces the seismic force by generating a lift accompanying rocking vibration during an earthquake. Structure,
The column main reinforcement protrudes from the upper surface of the foundation concrete by the required length according to the amount of floating of the building,
On the upper surface of the foundation concrete, a bottom formwork combined steel plate is placed, which supports the reinforced concrete column and has a rising portion sufficient to restrain the horizontal displacement of the reinforced concrete column. Standing up through a through-hole provided in the steel sheet for formwork,
The bottom formwork combined steel sheet is fixed to the basic concrete by a fixing jig such as a stud so that a vertical compressive force acting on the reinforced concrete column can be transmitted,
A contact portion of the reinforced concrete column and a rising portion of the column main reinforcing bar in the bottom formwork combined steel plate are each subjected to edge cutting treatment with a release material, and have a structure that allows lifting due to rocking vibration.
[0017]
The invention described in claim 7 is characterized in that, in the base isolation structure of the column base portion of the reinforced concrete column described in claim 6, the bottom formwork combined steel plate is embedded and fixed in the foundation concrete.
[0018]
The invention described in claim 8 is the seismic isolation structure of the column base part of the reinforced concrete column described in claim 6 or 7, wherein a dowel hole corresponding to the upper surface part of the basic concrete and the lower surface part of the reinforced concrete column is provided. The dowel hole is inserted into the dowel hole so as to penetrate the bottom formwork steel plate.
[0019]
The invention described in claim 9 is the seismic isolation structure of the column base portion of the reinforced concrete column described in any one of claims 6 to 8, wherein the impact is applied to the gap between the reinforced concrete column and the bottom formwork steel plate. An impact cushioning material such as a cushioning sheet is provided.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
1 and 2 show an embodiment of a seismic isolation method for a column base portion of a reinforced concrete column according to the first aspect of the present invention. The seismic isolation method for the column base portion of the reinforced concrete column 1 is carried out in order to construct a building that reduces the seismic force by generating a lift associated with rocking vibration during an earthquake.
[0021]
First, the column main reinforcement 2 is protruded from the upper surface of the foundation concrete 3 by a required length corresponding to the amount of floating of the building. Next, on the upper surface of the foundation concrete 3, the bottom formwork combined steel plate 4 provided with a rising portion 4 a that supports the RC column 1 and restrains the horizontal displacement of the RC column 1 is placed. Then, the column main reinforcement 2 is caused to penetrate through a through hole (not shown) provided in the bottom formwork and steel plate 4 to rise. The bottom formwork and steel plate 4 is fixed to the foundation concrete 3 by a fixing jig such as a stud 8 so that the vertical compression force acting on the RC pillar 1 can be transmitted. Edge cutting treatment with a release material such as application of a release agent (not shown) and attachment of a release sheet 9 to the abutting portion of the RC column 1 and the rising portion of the column main reinforcement 2 in the bottom mold / steel plate 4. Apply. Reinforced concrete columns are constructed with the main reinforcement 6 and the strip 7 as the base, and the formwork 5 is assembled and the concrete is placed by the bottom formwork and steel plate 4 as a base, and the floating is caused by the rocking vibration. (Invention of Claim 1)
[0022]
As shown in FIG. 2, a total of eight columnar reinforcing bars 2 are protruded in a well-balanced manner along the position in the vicinity of the inner side surface of the rising portion 4 a of the bottom formwork and steel plate 4. The number of column main bars 2 is not limited to this, and the number of column main bars 2 can be surely transmitted to the foundation concrete 3 in the horizontal shearing force acting on the RC column 1. Further, the protruding height of the column main reinforcement 2 is set to be higher than the design lifting height of the building due to the rocking vibration.
[0023]
Even when the bottom formwork steel plate 4 serves as a support point when it is lifted due to the rocking vibration, the bottom mold frame steel plate 4 can withstand an overload from the RC column 1 and can withstand a drop impact force of the RC column 1. And installed at the floor level. In addition, in order to transmit the horizontal shearing force acting on the RC column 1 to the foundation concrete 3 more reliably, the bottom mold / steel plate 4 may be embedded and fixed in the foundation concrete 3. (Invention of Claim 2), as shown in FIGS. 4A and 4B, in the substantially central portion of the bottom formwork and steel plate 4, there is a dowel that coincides with the upper surface of the foundation concrete 3 and the lower surface of the RC column 1 The hole 12 may be provided, and the dowel pin 11 penetrating the bottom formwork and steel plate 4 may be fitted into the dowel hole 12 (the invention according to claim 3).
[0024]
Edge cutting with a release material applied to the abutting portion of the RC column 1 and the rising portion of the column main reinforcement 2 in the bottom mold-frame steel plate 4 is performed by applying a release agent to the bottom mold-frame steel plate 4. The rising portion of the columnar reinforcement 2 is carried out by sticking a peeling sheet 9. The edge cutting treatment is not limited to this, and may be performed only by applying a release agent, or may be performed only by attaching the release sheet 9. Of course, the bottom mold-frame steel plate 4 may be attached by attaching a release sheet 9, and the rising portion of the column main reinforcement 2 may be applied by applying a release agent.
[0025]
Of course, the edge cutting treatment with the release material is not limited to the application of the release sheet 9 and the application of the release agent. Even when the rising portion of the columnar muscle 2 is covered with a sheath pipe (not shown) covering the whole, the same effect can be obtained. The bottom mold and steel plate 4 can provide substantially the same effect even if an impact cushioning material such as an impact cushioning sheet 13 described later is installed.
[0026]
Further, on the upper surface of the bottom formwork combined steel plate 4, an impact cushioning material such as an impact cushioning sheet 13 for relaxing the vertical impact force in the RC column 1 is installed (the invention according to claim 4). . As the shock-absorbing material, a laminated rubber sheet having a thickness of about several centimeters or a lead plate is used.
[0027]
As shown in FIG. 1A, the main bars 6 have the same number and arrangement as the pillar main bars 2 as viewed in plan, and are located immediately above the column main bars 2 as shown in FIG. 1B. It is arranged. In addition, the number and arrangement | positioning of the said main reinforcement 6 are not limited to this.
[0028]
As shown in FIG. 1A, the band 7 is arranged to surround the main muscle 6 as usual, as shown in FIG. 1A, and as shown in FIG. In addition, the bars are arranged so as to surround the peeling sheet 9 that covers the column main bars 2. Further, as shown in FIG. 1B, it is preferable that the stirrup 5 is densely arranged on the column base portion of the RC column 1 in terms of the structural design.
[0029]
Incidentally, when the pillar part of the reinforced concrete column 1 is buried and constructed by the mold 5, the shock absorbing material 10 is installed at the top end of the rising part 4a of the bottom mold and steel plate 4 and the mold is buried. The frame 5 is assembled to construct a reinforced concrete column (the invention according to claim 5).
[0030]
In the seismic isolation structure of the column base part of the reinforced concrete column 1 constructed by the above-mentioned seismic isolation method, the column main reinforcement 2 protrudes from the upper surface of the foundation concrete 3 by the required length according to the amount of lifting of the building. On the upper surface of the foundation concrete 3, the bottom formwork combined steel plate 4 provided with a rising portion 4a that supports the reinforced concrete pillar 1 and restrains the horizontal displacement of the reinforced concrete pillar 1 is placed, The columnar reinforcement 2 stands up through a through hole provided in the bottom formwork combined steel plate 4. The bottom formwork combined steel plate 4 is fixed to the foundation concrete 3 by a fixing jig such as a stud 8 so that a vertical compressive force acting on the reinforced concrete column 1 can be transmitted. The abutting portion of the reinforced concrete column 1 and the rising portion of the column main reinforcement 2 in the bottom formwork / steel plate 4 are each subjected to edge cutting treatment by a release material such as application of a release agent and pasting of a release sheet 9 and the like. The structure is a structure that allows lifting due to vibration (the invention according to claim 6).
[0031]
Further, an impact cushioning material such as an impact cushioning sheet 13 is provided in the gap between the reinforced concrete column 1 and the bottom formwork combined steel plate 4 (invention 9).
[0032]
Therefore, the seismic isolation structure is separated from the bottom formwork combined steel plate 4 that supports the RC pillar 1 in the case of rocking vibration at the time of the earthquake, as shown in FIG. The floating phenomenon can be caused. Further, since the bottom formwork combined steel sheet 4 is firmly fixed to the basic concrete 3 by the studs 8, as shown in FIG. 3, the bottom formwork combined use steel sheet when the RC column 1 is lifted due to the rocking vibration. No 4 will slide up.
[0033]
Therefore, when rocking vibration occurs during an earthquake, the RC column 1 is separated from the bottom formwork and steel plate 4 supporting the RC pillar 1 and is displaced in the vertical direction as shown in FIG. It moves up and down and consumes the energy that enters the building due to the earthquake.
[0034]
In short, the above-mentioned seismic isolation structure allows the vertical compressive force acting on the RC column 1 to be reliably transmitted to the foundation concrete 3 through the bottom mold and steel plate 4 and the horizontal shear force is the column. Although it is reliably transmitted to the basic concrete 3 through the main reinforcement 2, the structure is configured such that no vertical tensile force is transmitted to the basic concrete 3.
[0035]
In addition, although illustration is abbreviate | omitted, the space | interval of adjacent RC pillars 1 is adjusted according to the magnitude | size of the earthquake which a design lift arises.
[0036]
[Effects of the present invention]
According to the seismic isolation method and the base isolation structure of the column base portion of the reinforced concrete column according to the invention described in claims 1 to 9, the aspect ratio is not used without using a base isolation device such as a base isolation rubber as in the prior art. Seismic isolation of large buildings can be realized, and the seismic isolation layer premised on the installation of such devices can be reduced to almost zero, increasing the effective utilization of the building. Moreover, no residual displacement occurs when the earthquake ends.
[0037]
If a building is lifted during an earthquake, the seismic force acting on the building will not increase any further. Therefore, it is possible to set the upper limit of the seismic force acting on the building, and even when an earthquake larger than the assumed earthquake acts, the damage to the building can be made to be below a certain level.
[0038]
Since tensile axial force does not act on the building columns, there is no need to consider it, and the design of the columns can be simplified.
[0039]
When rebuilding an existing building, the existing foundation and lower frame are also left, and a new building is built by providing contact points on the foundation, so that the design and construction of the foundation can be greatly rationalized.
[Brief description of the drawings]
FIG. 1A is a plan view showing an embodiment of the present invention, and B is an elevation view.
FIG. 2 is a view taken along the line AA in FIG. 1B.
FIG. 3 is an elevational view showing a state in which a lifting phenomenon occurs in the column base portion of the RC column.
FIG. 4A is a plan view showing a different embodiment of the present invention, and B is an elevational view.
FIGS. 5A and 5B are explanatory diagrams of the principle of reducing seismic energy according to the present invention; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reinforced concrete pillar 2 Column main reinforcement 3 Foundation concrete 4 Bottom formwork combined steel plate 4a Standing part 5 Formwork 6 Main reinforcement 7 Band reinforcement 8 Stud 9 Sheet for peeling 10 Shock absorbing material 11 Dowel pin 12 Dowel hole 13 Shock absorbing sheet

Claims (9)

It is a seismic isolation method for the column base of a reinforced concrete column in a building that reduces the seismic force by raising the rocking vibration during an earthquake,
The column main reinforcement protrudes from the upper surface of the foundation concrete by the required length according to the amount of lift of the building,
On the upper surface of the foundation concrete, a bottom formwork combined steel plate is placed with a rising part that supports the reinforced concrete column and restrains the horizontal displacement of the reinforced concrete column. Let it penetrate through the through-hole provided in the steel sheet for both formwork and stand up,
The bottom formwork combined steel sheet is fixed to the basic concrete by a fixing jig such as a stud so that the compressive force in the vertical direction acting on the reinforced concrete column can be transmitted.
In the bottom formwork combined steel sheet, the contact portion of the reinforced concrete column and the rising portion of the column main reinforcement are each subjected to edge cutting treatment with a release material,
Reinforced concrete pillars that are reinforced concrete pillars that perform column reinforcement based on the bottom formwork combined steel sheet and assemble the formwork and place concrete to raise the rocks due to rocking vibration. Seismic isolation method for the column base. The seismic isolation method for a column base of a reinforced concrete column according to claim 1, wherein the bottom formwork combined steel sheet is embedded and fixed in the foundation concrete. 3. A dowel hole corresponding to the upper surface portion of the basic concrete and the lower surface portion of the reinforced concrete column is provided, and a dowel pin penetrating the bottom formwork combined steel sheet is fitted into the dowel hole. Seismic isolation system for column bases of reinforced concrete columns. The base isolation part of the column base part of the reinforced concrete column according to any one of claims 1 to 3, wherein an impact cushioning material such as an impact cushioning sheet is installed on the upper surface of the bottom formwork steel plate. Construction method. The shock absorbing material is installed at the top end of the rising portion of the bottom formwork steel plate, and the reinforced concrete pillar is constructed by assembling the formwork and assembling the formwork. Seismic isolation method for column bases of reinforced concrete columns as described in the section. A seismic isolation structure for the column base of a reinforced concrete column in a building that reduces the seismic force by raising the rocking vibration during an earthquake,
The column main reinforcement protrudes from the upper surface of the foundation concrete by the required length according to the amount of floating of the building,
On the upper surface of the foundation concrete, a bottom formwork combined steel plate is placed, which supports the reinforced concrete column and has a rising portion that is sufficient to restrain the displacement of the reinforced concrete column in the horizontal direction. Standing up through a through-hole provided in the steel sheet for formwork,
The bottom formwork combined steel sheet is fixed to the basic concrete by a fixing jig such as a stud so that a vertical compressive force acting on the reinforced concrete column can be transmitted,
The contact portion of the reinforced concrete column and the rising portion of the column main reinforcing bar in the bottom formwork combined steel sheet are each subjected to edge cutting treatment with a release material, and are allowed to rise with rocking vibration. Seismic isolation structure for column base of reinforced concrete columns. 7. The base-isolated structure for the column base of a reinforced concrete column according to claim 6, wherein the bottom formwork combined steel plate is embedded and fixed in the foundation concrete. 8. A dowel hole corresponding to an upper surface portion of the foundation concrete and a lower surface portion of the reinforced concrete column is provided, and a dowel pin penetrating the bottom formwork steel plate is fitted into the dowel hole. Seismic isolation structure for column bases of reinforced concrete columns as described in. The reinforced concrete column according to any one of claims 6 to 8, wherein an impact buffering material such as an impact buffering sheet is provided in a gap between the reinforced concrete column and the bottom formwork steel plate. Seismic isolation structure of the column base.

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