JP4597660B2 - Building having seismic reinforcement structure and method for seismic reinforcement of building - Google Patents

Description

  The present invention relates to a multi-layer building having a seismic strengthening structure in which a seismic structure is disposed in an existing frame structure and a seismic strengthening method in which the seismic structure is disposed in a building.

Conventionally, as one of the vibration control structures of newly built buildings, many brace-type vibration control devices incorporating an oil damper as a vibration control structure have been proposed and implemented. Here, when a brace type vibration control device equipped with an oil damper is incorporated into a frame frame made of columns and beams, the vibration control device bears a damping force, so that the seismic performance of the entire building is improved.
However, as shown in FIG. 12, it is well known that the restoring force characteristic regarding the damping force / displacement of the oil damper is expressed in a substantially rectangular shape with the top and bottom cut off.
Therefore, when the oil damper expands and contracts at high speed, a very large layer shear force is generated just before the other direction reverses from one direction to the other. Therefore, it is necessary to reinforce the column / beam joint in the ramen frame. there were.
Therefore, the applicant firstly, the oil damper generates a damping force having a predetermined magnitude when the oil damper expands and contracts in the predetermined area, while the above-mentioned damping of the predetermined magnitude exceeds the predetermined area in the vicinity of the stroke end. A "decreasing vibration control type" vibration control device characterized by being configured to gradually reduce the force has been proposed (see Patent Document 1).

JP 2003-227243 A

However, the above-mentioned seismic reduction control device incorporates the damper in the middle of the brace member axial direction in the frame in which the brace material (diagonal material) is arranged in the opening surrounded by the column and the upper and lower beams. However, by focusing on the layer shear force (horizontal force) and making it a characteristic that does not have a peak portion, the column / beam joint can be made lighter than in the case of the prior art.
Therefore, it does not describe the case where the reduced seismic control system is applied to the seismic reinforcement of a multi-layer existing building having an existing frame structure.
The present invention provides a building capable of seismically reinforcing an existing frame structure with a seismic control device without reinforcing the cross-section of the existing pillars in each layer, and a seismic strengthening method for disposing the seismic structure in the building. With the goal.

(1) In order to achieve the above-mentioned object, the present invention is a multi-layer building having a seismic reinforcement structure in which a vibration control structure is disposed on an existing frame structure, and the seismic reinforcement structure is an existing frame structure. A damping structure is arranged in the opening surrounded by the existing columns facing each other and the upper and lower existing beams that are installed between these existing columns. The damping structure is equipped with a damper. The damper is constituted by a reinforcing frame, and the damper is a damper in which the damping force gradually decreases at a predetermined damping force / decreasing gradient as the deformation increases in a deformation region between the predetermined damping force / decreasing start deformation point and the stroke end. By constructing a restoring force and reducing the additional axial force acting on the existing columns to which the seismic control structure is connected, the existing columns form a no-column strength reinforcement structure even after reinforcement.
(2) In addition, the seismic control structure comprises a restoring force characteristic related to the inter-layer horizontal deformation after reinforcement and the post-reinforcement column additional axial force acting on the existing column connected to the seismic control structure, and In the force characteristics, the post-reinforcement column additional axial force of the existing column increases as the inter-layer horizontal deformation increases in the deformation region between the predetermined post-column additional axial force / decay start deformation point and the damper stroke end. Preferably, the existing column is configured to gradually decrease with a predetermined column additional axial force / decrease gradient, and the existing column is configured such that the post-reinforcing column additional axial force does not exceed the pre-reinforcing column additional axial force.
(3) The first restoring force characteristics regarding the inter-layer horizontal deformation before reinforcement and the additional axial force before reinforcement for the existing column before reinforcement, and the horizontal deformation and damping after reinforcement for the seismic structure after reinforcement Combined with the second restoring force characteristics of post-reinforcement column additional axial force acting on the existing column connected to the seismic structure part, the post-reinforcement horizontal horizontal deformation and post-reinforcement column Consists of the third restoring force characteristics related to the additional axial force. In the third restoring force characteristic, the point corresponding to the predetermined column additional axial force and the decrease starting deformation point of the damping structure, and the existing frame structure before reinforcement It is preferable that the existing column is configured such that the post-reinforcement column additional axial force does not exceed the post-reinforcement column additional axial force in a deformation region between points corresponding to the maximum horizontal horizontal deformation of the body.
(4) The existing frame structure has a foundation structure with a pile foundation in the lowest layer, and in the existing pillar in the lowest layer, the post-reinforcement column additional axial force does not exceed the column additional axial force before reinforcement. By being comprised, it is preferable that the foundation structure part comprises the non-addition pile pile reinforcement structure even after reinforcement.
(5) The building is preferably a high-rise building having an elongated front shape such that the tower ratio of the building (the maximum height of the building / the width of the building) exceeds 2.
(6) Furthermore, the seismic strengthening method according to the present invention is a seismic strengthening method in which a seismic structure is disposed in a multi-layered building having an existing frame structure. The seismic structure is composed of a reinforcing column and a reinforcing beam. The damper is composed of a reinforcing frame having a damper, and the damper has a predetermined damping force as the deformation increases in the deformation region between the predetermined damping force / decreasing start deformation point and the stroke end. -It is configured to have a damper restoring force that gradually decreases with a decreasing gradient, and is controlled by an opening surrounded by the existing columns facing each other of the existing frame structure and the upper and lower existing beams that are laid horizontally between these existing columns. By installing the seismic structure and reducing the additional axial force acting on the existing columns to which the seismic control structure is connected after reinforcement, the existing columns will have a no-column strength reinforcement structure even after reinforcement. It is composed.

(1) The invention according to claim 1 is a multi-layered building having a seismic reinforcement structure in which the seismic structure is disposed on the existing frame structure, and the damper of the seismic structure has a predetermined damping force / reduction In the deformation region between the starting deformation point and the stroke end, a damper restoring force is constructed in which the damping force gradually decreases with a predetermined damping force / decreasing gradient as the deformation increases, and the existing seismic control structure is connected. By reducing the additional axial force acting on the column, the existing column has a non-column strength reinforcement structure even after reinforcement.
In the deformation region between the predetermined damping force / decreasing start deformation point and the stroke end, the damping structure reduces the shear force (horizontal force) of the existing column by the damping force, and after the reinforcement, It is possible to prevent the generated column additional axial force from exceeding the column additional axial force before reinforcement.
Therefore, after reinforcement, the existing column “does not require the seismic reinforcement of the cross-sectional strength as a column member” over the entire length of the floor height, that is, constructing the “no-column strength reinforcement structure” Since the possibility of continuous use of this building with seismic reinforcement is improved significantly, its technical and economic effects are extremely high.
Since the existing frame structure can maintain the same collapse mechanism during a large earthquake before and after reinforcement, the seismic performance is improved and the stability can be maintained.
Because the overturning bending moment that occurs in the foundation structure during an earthquake is greatly reduced, there is no need for a reinforcing structure that increases the pulling resistance of the foundation structure (such as increasing the weight of the foundation footing or increasing the number of new piles) Become.
Furthermore, the response result of the seismic response analysis can be reduced with respect to the existing frame structure after reinforcement in which the damping structure is disposed.
(2) The invention according to claim 2 is characterized in that the damping structure portion includes the horizontal deformation after reinforcement, and the restoring force characteristics relating to the post-reinforcement column additional axial force acting on the existing column connected to the damping structure portion. In the restoring force characteristic, in the deformation region between the predetermined column additional axial force / decreasing start deformation point and the stroke end of the damper, after the reinforcement of the existing column as the interlayer horizontal deformation after reinforcement increases Since the column additional axial force is gradually reduced with a predetermined column additional axial force / decreasing gradient,
Even after reinforcement, the existing column can reliably constitute a “no-column-column strength reinforcement structure” that does not require seismic reinforcement of the column member cross-sectional strength.
(3) The invention according to claim 3 is characterized in that, in the third restoring force characteristic, the point corresponding to the predetermined column additional axial force / decrease start deformation point of the damping structure and the maximum of the existing frame structure before reinforcement In the deformation area between the points corresponding to the interlayer horizontal deformation, the existing column is configured so that the post-reinforcement column additional axial force does not exceed the post-reinforcement column additional axial force. For all earthquake levels that are the largest, the existing column is reliably configured so that the post-reinforcement column additional axial force does not exceed the maximum post-reinforcement column additional axial force.
(4) Since the invention according to claim 4 constitutes the “no-increase pile reinforcement structure” in which the foundation structure portion does not require additional pile reinforcement even after reinforcement,
Since it is difficult to reinforce piles in actual existing buildings, the technical and economic effects are extremely high when earthquake-proofing high-rise existing buildings.
(5) In the invention according to claim 5, the building is a high-rise building having an elongated front shape such that the tower ratio of the building (the maximum height of the building / the width of the building) exceeds 2.
Even existing high-rise buildings can be upgraded to seismic performance that meets the latest seismic design standards, extending the life cycle of the building.
Since the present invention constitutes a “no-column strength reinforcement structure” and a “no-addition pile reinforcement structure”, it is particularly suitable for an earthquake-proof reinforcement structure for high-rise buildings in which the tower ratio of the building exceeds 2.
(6) The invention according to claim 6 is a seismic strengthening method for disposing a vibration control structure in a multi-layered building having an existing frame structure, and the vibration control structure includes a reinforcing column and a reinforcing beam. The damper includes a reinforcing frame portion and a damper. The damper has a predetermined damping force / decreasing gradient as the deformation increases in a deformation region between a predetermined damping force / decreasing start deformation point and the stroke end. The damper restoring force gradually decreases at
A damping structure is placed in the opening surrounded by the existing columns facing each other and the existing beams above and below that are installed between the existing columns. Because we configure
Reinforcement work can be simplified to shorten the construction period and reduce the construction cost.
Furthermore, since the possibility of continuing to use existing buildings with seismic reinforcement is improved significantly by seismic reinforcement, the technical and economic effects are extremely high.

    The preferred embodiments of the present invention will be described with reference to the accompanying drawings. Note that the same reference numerals are used for the same elements in the drawings, and description thereof may be omitted as appropriate.

    Embodiments according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1 (a), the multi-layer building 1 has a substantially rectangular plane in which the plane shape of each layer (reference floor) is 3 spans in the beam-to-beam direction (Y direction) and 7 spans in the digit direction (X direction). It is an existing building with 30 floors above the ground.
The existing frame structure 2 before reinforcement forms a rigid frame structure composed of the existing columns 21 and the existing beams 22 in both the beam-to-beam direction and the cross-beam direction (FIG. 1A).
The existing frame structure 2 before reinforcement forms a pure ramen structure composed of the existing pillar 21 and the existing beam 22 having three spans in the direction between the beams and 30 stories above the ground.
The frame structure of the existing frame structure 2 is generally a ramen frame such as a column or a beam, but it is a frame that combines surface members such as earthquake resistant walls, vibration control walls, wall braces, and wall-type frame structures. It may be a structure that can resist structural forces against external forces such as seismic force.
The building 1 is applied to a wide range of building uses such as collective housing, offices, hotels, commercial facilities, and medical facilities.
The planar shape of the building 1 is not limited to the rectangular planar shape, and may be a plate-like planar shape or a shape having a hollow space inside (b-shaped or C-shaped).
In addition, although the building 1 of a present Example demonstrates the case where there is no basement, the case where a basement is provided may be sufficient.

As shown in FIG. 2, the building 1 includes an existing frame structure 2 and a foundation structure 6 having a pile foundation 61 on the lowest floor of the existing frame structure 2.
The foundation structure 6 is constituted by a pile foundation 61 disposed immediately below each existing pillar 21 and a foundation beam 62 that connects adjacent pile foundations 61 and 61 in the lateral direction.
Note that the foundation structure 6 may be a direct foundation on which the pile foundation 61 is not installed.

The existing frame structure 2 after reinforcement forms an earthquake-resistant reinforcement structure by arranging two vibration control structures 3 effective in the direction between the beams in plan view (see FIG. 1B).
As shown in FIG. 2, the building 1 forms a seismic reinforcement structure in which a vibration control structure 3 is incorporated into an existing frame structure 2 before reinforcement (before earthquake resistance reinforcement).
After reinforcement (after seismic strengthening), the existing frame structure 2 with 3 spans and 30 stories above the ground is arranged with multiple layers of damping structures 3 on the center span in the vertical direction. ing.
In this embodiment, the reinforced existing frame structure 2 has a 1-span 30-layer multi-story control system in which the vibration control structure 3 is arranged in multiple layers from the first floor to the top floor in the vertical direction. It constitutes a seismic structure.
In addition, the arrangement | positioning method of the damping structure 3 of this invention is not limited to a continuous layer type, For example, a distributed type may be sufficient.

The vibration control structure part 3 is constituted by a reinforcing frame part provided with a damper 4.
As shown in FIG. 3, the vibration control structure 3 is composed of existing columns 21, 21 opposite to each other of the existing frame structure 2, and upper and lower existing beams 22, 22 laid horizontally between these existing columns 21, 21. It is disposed in the enclosed opening, and is constituted by a reinforcing frame portion including a reinforcing column 31, a reinforcing beam 32, and a reinforcing diagonal member 33, and a damper 4, and is formed in a unit of one span and one layer in a front view. .
The two reinforcing columns 31 and 31 are arranged opposite to each other with a predetermined distance in the lateral direction (span direction), and arranged as a longitudinal member (column member) adjacent to the existing columns 21 and 21. Is done.
The two reinforcing beams 32 and 32 are arranged to face each other with a predetermined distance in the vertical direction (floor height direction), and in the vicinity of the existing beams 22 and 22 on the upper and lower floors, Member).
The reinforcing diagonal member 33 and the damper 4 are connected in a straight line to form a single diagonal member, forming a reverse V-shaped diagonal member (brace member) in front view.
In addition, although the reinforcement frame | skeleton part of a present Example demonstrated the case where it comprised the reinforcement pillar 31, the reinforcement beam 32, and the reinforcement diagonal member 33, the reinforcement diagonal member 33 is directly attached to the existing pillars 21 and 21 or the existing beams 22 and 22. The reinforcing column 31 and the reinforcing beam 32 may not be provided.
The damping structure 3 including the damper 4 and the reinforcing frame may be any structure that can exert a damping force by the damper 4 stroking during an earthquake, so that the reinforcing frame and the damper 4 themselves have a horizontal force. It may be configured as a stable structure capable of bearing the load, or a horizontal force is applied when the reinforcing frame portion and the damper 4 are attached to the existing frame structure 2 (existing columns 21, 21, and existing beams 22, 22). It may be configured as a stable structure that can bear the burden.

The vibration control structure 3 is disposed in an opening surrounded by the existing columns 21 and 21 facing each other and the upper and lower existing beams 22 and 22 laid across the existing columns 21 and 21 ( (See FIG. 3).
A longitudinal clearance CL1 is formed between the existing column 21 and the reinforcing column 31, and a lateral clearance CL2 is formed between the existing beam 22 and the reinforcing beam 32. A mortar or the like is provided in the longitudinal clearance CL1 and the lateral clearance CL2. Fill with filler.
The filler refers to a material having a predetermined compressive strength and adhesive strength, such as mortar, concrete, and adhesive.
An anchorless structure that transmits the longitudinal shearing force acting between the existing column 21 and the reinforcing column 31 and the transverse shearing force acting between the existing beam 22 and the reinforcing beam 32 by the filler. Can be configured.
The anchorless structure is a fixing member such as a reinforcing bar or a steel plate against a shearing force acting between the existing column 21 and the reinforcing column 31 or between the existing beam 22 and the reinforcing beam 32 ( An anchor is not arranged.

The damper 4 constitutes a “decreasing vibration control type” vibration control device.
Only the bypass path of the damper 4 will be described below.
FIG. 4 shows a longitudinal sectional view of the damper 4. 4A shows a case where the compression force CF is applied to the damper 4 when the piston 43 returns from the most extended state to the neutral state, and FIG. 4B shows a state where the damper 4 advances from the neutral state to the most compressed state. FIG. 4C shows the case where the tensile force TF is applied to the damper 4 where the piston 43 returns from the most compressed state to the neutral state.
The damper 4 is formed in a double rod shape, and the internal space of the cylinder body 40 is partitioned into two oil tanks 47 a and 47 b by a piston 43 fixed to the rod body 42. The piston 43 is formed with a valve 44a communicating with one oil tank 47a and a valve 44b communicating with the other oil tank 47b. The valves 44a and 44b are configured as one-way valves in which oil flows only in one direction.
A mounting portion 48 connected to the reinforcing diagonal member 33 of the reinforcing frame portion is provided on the outer end portion of the rod body 42 and the cylinder body on the opposite side. FIG. 4 does not show a bilinear characteristic damping valve.

On the inner wall of the cylinder body 40, two bypass groove portions 41a and 41b are provided at both end portions in the length direction of the damper 4 (direction in which the rod body 42 extends) as shown in FIG. 4A. (Length of S1) and is formed on a straight line.
Between the two bypass groove portions 41a and 41b (the length of S2 shown in FIG. 4A), the inner wall of the cylinder body 40 is a smooth surface without a groove portion.
Therefore, by forming the bypass groove portions 41a and 41b, the two oil tanks 47a and 47b are formed when the piston 43 is in a region near the "stroke end" where the piston 43 is reversed from one direction to the other direction in the cylinder body 40. A bypass path in which oil moves between the bypass grooves 41a and 41b, the entrance / exit hole 45, the communication hole 46, and the valves 44a and 44b functions.
That is, when the damper 4 strokes more than its thickness (the length of S3 shown in FIG. 4A) from when the piston 43 is in the neutral region in the cylinder body 40, the entrance / exit hole 45 of the piston 43 is moved. Since the bypass groove portions 41a and 41b communicate with each other, the bypass path starts to function (see FIG. 4B).
When the bypass path functions, the state in which the oil tanks 47a and 47b have been sufficiently pressurized by the piston 43 until then is released, so that the damping force of the damper 4 decreases.
Therefore, when the piston 43 is in the neutral region in the cylinder body 40, the stroke of the thickness (the length of S3 shown in FIG. 4A) is stroked and the stroke is reversed in the other direction. Since the bypass path functions in the deformation region between the ends, the damping force of the damper 4 approaches zero while gradually decreasing.

As shown in FIG. 4B, the bypass path functions in a state in which the compression force CF is applied to the damper 4 and the state proceeds from the neutral state to the most compressed state.
While being pressurized by the piston 43, the oil filled in one oil tank 47a moves to the other oil tank 47b through the bypass groove 41a, the entrance / exit hole 45, the communication hole 46, and the bypass path of the valve 44b. .
As shown in FIG. 4C, even if the piston 43 is not in the neutral region in the cylinder body 40, the valve 44b is configured as a one-way valve, so the bypass path does not function.

As shown in FIG. 5, the damper 4 has a predetermined damping force as the deformation increases in the deformation region between the predetermined damping force / decrease starting deformation points DB1, DB2 and the stroke ends DC1, DC2. -It constitutes a "decreasing vibration control type" damper restoring force that gradually decreases with decreasing gradients α1 and α2. This damper restoring force is derived on the assumption that the building 1 is constantly oscillating with a primary natural period.
The characteristic of the damping force with respect to the displacement in the damper 4 is a deformation type in which the vertical axis represents the damping force and the horizontal axis represents the deformation (stroke) in the length direction of the damper 4 and the upper side and the lower side are flattened. The damper restoring force of the hexagon (DA1-DB1-DC1-DA2-DB2-DC2 shown in FIG. 5) is configured.
The damping force / decrease start deformation points DB1 and DB2 can be set by a predetermined groove length (the length of S1 shown in FIG. 4A) of the two bypass groove portions 41a and 41b.
The predetermined damping force / decreasing gradients α1 and α2 can be set according to the groove length of the bypass groove portions 41a and 41b and the cross-sectional size of the groove portion related to the oil movement capability.
Therefore, the damping force generated in the damper 4 in the vicinity of the stroke ends DC1 and DC2 can be made extremely small with respect to the damping force at the damping force / decrease starting deformation points DB1 and DB2.

Therefore, with reference to FIG. 6, a method for configuring the restoring force characteristics of the single unit damping structure 3 during an earthquake will be described.
<Before seismic reinforcement>
(1) First step In the existing frame structure 2 before reinforcement, “maximum horizontal horizontal deformation” of each layer that occurs at the time of a large earthquake is set.
It is assumed that the existing column 21 and the existing beam 22 of each layer constituting the existing frame structure 2 before reinforcement are not destroyed when the maximum horizontal deformation occurs during a large earthquake.
For example, a large earthquake means a case where the seismic force generated in the existing frame structure 2 approaches the retained horizontal proof stress.
The retained horizontal strength is the horizontal force (seismic force) acting on the structure, and the whole or part of the structure forms a collapse mechanism, and the deformation increases rapidly with a slight increase in the horizontal force. The load at the time (collapse load).
Interlayer horizontal deformation refers to horizontal relative deformation that occurs between a floor of a certain layer and a floor immediately above or immediately below in a multi-layer building 1 during an earthquake.

(2) Second Step In the existing frame structure 2 before reinforcement, the first restoring force characteristic regarding the “inter-layer horizontal deformation before reinforcement” and “column additional axial force before reinforcement” is configured for the existing column 21 ( (See FIG. 6).
In FIG. 6, for a certain existing column 21, the correlation between the interlayer horizontal deformation before reinforcement (horizontal axis direction) and the post-reinforcement column additional axial force (vertical axis direction) acting in the vertical direction is shown as a linear linear type. The restoring force characteristics are shown.
In FIG. 6, M1 and M2 indicate points at the time of the maximum interlayer horizontal deformation (first step) of the existing frame structure 2 before reinforcement, and the maximum interlayer horizontal deformation at the maximum interlayer horizontal deformation point M1 is FD1 and the maximum column additional axis. The force is FN1, the maximum interlayer horizontal deformation at the maximum interlayer horizontal deformation point M2 is indicated by FD2, and the maximum column additional axial force is indicated by FN2.
The column additional axial force of the existing column 21 is an axial force (compression force, tensile force) generated in the vertical direction on the existing column 21 when a seismic force (horizontal force) is applied to the existing frame structure 2. In addition, it does not include axial forces generated by long-term vertical loads (self-weight, load capacity, etc.).
In a pure ramen frame, the difference in shearing force between the beams on both sides generated during an earthquake accumulates and appears as an additional axial force of the existing column 21 in each layer.
It is preferable to calculate the “additional axial force before reinforcement” generated in the existing column 21 in the state of the existing frame structure 2 before reinforcement for all the existing columns 21 in which the damping structure 3 is incorporated.
In addition, about the existing pillar 21, although the restoring force characteristic of the interlayer horizontal deformation | transformation before reinforcement and the column additional axial force before reinforcement was expressed by the linear type, you may comprise by nonlinear types (for example, bilinear, trilinear etc.). .

<After seismic reinforcement>
(3) Third step In the existing reinforced frame structure 2 that incorporates the vibration control structure 3, the vibration control structure 3 is connected to the “horizontal deformation after reinforcement” and the vibration control structure 3. The second restoring force characteristic relating to “the post-reinforcing column additional axial force” acting on the existing column 21 is configured (see FIGS. 7 and 8A).

First, with reference to FIG. 7, “the post-reinforcement column additional axial force” acting on the existing column 21 from the post-reinforcement damping structure 3 will be described.
The vibration control structure 3 is front-faced by a pair of diagonal members (brace members) each including a reinforcing diagonal member 33 and a damper 4 inside a substantially rectangular frame-shaped reinforcing frame portion including the reinforcing columns 31 and the reinforcing beams 32. A brace structure having a reverse V-shape is formed. Therefore, when the interlayer horizontal deformation occurs, the damping structure 3 bears a horizontal force (shearing force) as a damping force, so that the horizontal force (shearing force) borne by the existing column 21 constituting the ramen frame is reduced. It is reduced.
“Reinforced column additional axial force” acting on the existing column 21 by the seismic control unit 3 is the horizontal force (shearing force) QQ (i) borne by the seismic control unit 3 on both sides. 21 is a column additional axial force generated at 21.
7, the vertical component of the axial component BC (i) of the diagonal member (brace member) composed of the reinforcing diagonal member 33 and the damper 4 of the damping member 3 of the arbitrary layer (i layer) is provided. The sum of the axial force (compressive force, tensile force) and the column additional axial force N (i + 1) of the upper layer (i + 1 layer) is the i layer additional axial force N (i).

In the second restoring force characteristic regarding the “horizontal horizontal deformation after reinforcement” and “post-additional axial force after reinforcement” of the damping structure 3, predetermined additional axial force / decrease starting deformation points B1 and B2 and the damper 4 In the deformation region (inter-layer horizontal deformation) between the stroke ends C1 and C2, the post-reinforcement column additional axial force of the existing column 21 is increased by a predetermined column additional axial force. A restoring force characteristic that gradually decreases with decreasing gradients β1 and β2 is configured (see FIG. 8A).
Referring to FIG. 8A, with respect to the seismic control structure 3 after reinforcement, “interlayer horizontal deformation after reinforcement” and “an after reinforcement” acting on the existing column 21 connected to the seismic control structure 3 A method of constructing the restoring force characteristic regarding the “column additional axial force” will be described.
In FIG. 8 (a), the correlation between the inter-layer horizontal deformation after reinforcement (horizontal axis direction) and the post-reinforcement column additional axial force (vertical axis direction) acting on the existing column 21 is shown for a certain damping structure 3. , Constituting the restoring force characteristic of a substantially hexagonal shape (hexagonal shape indicated by A1-B1-C1-A2-B2-C2 in the drawing).
B1 and B2 in FIG. 8A indicate that the post-reinforcement column additional axial force acting on the existing column 21 starts to decrease as the damping force (horizontal force) borne by the damping structure 3 decreases. C1 and C2 indicate points of “stroke end” of the damper 4 of the vibration control structure 3.
The “column additional axial force / decrease starting deformation points” B1 and B2 of the damping structure 3 correspond to the “damping force / decreasing starting deformation points DB1 and DB2” of the damper 4 shown in FIG. 5 correspond to the damping force / decreasing gradients α1 and α2 of the damper 4 shown in FIG. 5, and the “stroke end” C1 and C2 of the damping structure 3 are shown in FIG. Correspond to DC1 and DC2 of the damper 4 shown in FIG.
In constructing the restoring force characteristic of the damping structure 3 in the present invention, the column additional axial force / decrease start deformation points B1, B2, the stroke ends C1, C2, and the column additional axial force / decreasing gradient β1, β2 Is an important factor.

(4) Fourth Step In the existing frame structure 2 after reinforcement, the third restoring force characteristic regarding “interlayer horizontal deformation after reinforcement” and “column additional axial force after reinforcement” is configured for each existing column 21. (See FIG. 8 (b)).
First restoring force characteristics (second step) regarding “horizontal deformation between layers before reinforcement” and “additional axial force before reinforcement” for each existing pillar 21 before reinforcement, and each damping structure 3 after reinforcement The second restoring force characteristic (third step) regarding the “horizontal deformation after reinforcement” and the “additional axial force after reinforcement” acting on the existing pillar 21 connected to the damping structure 3 As a result, the third restoring force characteristics relating to “inter-layer horizontal deformation after reinforcement” and “column additional axial force after reinforcement” are configured for each of the existing pillars 21 after reinforcement.

In FIG. 8B, for the existing column 21 connected to the damping structure 3, the correlation between the inter-layer horizontal deformation after reinforcement (horizontal axis direction) and the post-reinforcement column additional axial force (vertical axis direction). Is a restoring force characteristic of a substantially hexagon (a hexagon represented by P1-M1-Q1-P2-M2-Q2 in the figure).
This restoring force characteristic after reinforcement shows an elongated substantially hexagonal shape similar to a spindle shape inclined at a predetermined width along an inclined straight line connecting M1 and M2 (corresponding to the linear restoring force characteristic of the second step).
M1 and M2 in FIG. 8B indicate points corresponding to the maximum interlayer horizontal deformation of the existing frame structure 2 before reinforcement in the second step. P1 corresponds to the column additional axial force / decrease start deformation point B1 in the third step, P2 corresponds to the column additional axial force / decrease start deformation point B2 in the third step, and Q1 corresponds to A2 and Q2 in the third step. Each corresponds to A1 of the third step.

In the third restoring force characteristic, points P1 and P2 corresponding to the predetermined column additional axial force / decrease starting deformation point of the damping structure and points corresponding to the maximum interlayer horizontal deformation of the existing frame structure 2 before reinforcement In the deformation region between M1 and M2, in the existing column, the post-reinforcement column additional axial force is configured not to exceed the pre-reinforcement column additional axial force (see FIG. 8B).
Therefore, in the existing pillars 21 of each layer, the restoring force characteristics of the seismic structure 3 of each layer are configured so that the post-reinforcement column additional axial force does not exceed the pre-reinforcement column additional axial force. Even after reinforcement, the column 21 constitutes a “no-column proof structure”.
In FIG. 8B, when the column additional axial force value N1 fluctuating in the deformation region between the P1 point and the M1 point does not exceed the column additional axial force value FN1 of the M1 point, and from the P2 point to the M2 point If the column additional axial force value N2 which fluctuates in the deformation region between the two columns does not exceed the column additional axial force value FN2 at the point M2, the post-reinforcing column additional axial forces N1 and N2 are Since the column additional axial forces FN1 and FN2 before reinforcement are not exceeded, a “no-column strength-proof reinforcement structure” that does not require member cross-section reinforcement of the existing column 21 is configured.
Here, since there are two types of column additional axial force, positive and negative (compressive force, tensile force), it is preferable to compare FN1, FN2, N1, and N2 with absolute values.
It is preferable to calculate the column additional axial forces N1 and N2 generated in the existing column 21 after reinforcement in the state of the existing frame structure 2 after reinforcement for all the existing columns 21 in which the damping structure 3 is incorporated.

The “no-column strength reinforcement structure” of the existing column 21 is a column structure that can satisfy the seismic performance of the existing frame structure 2 after reinforcement while maintaining the cross-section of the existing member of the existing column 21. A structure that does not require seismic reinforcement of the cross-sectional strength of the member over its entire length.
There are three types of member cross-sectional strength of the existing column 21 as “column structural members”: axial strength (compression strength, tensile strength), bending strength (determined by the axial force and bending moment), and shear strength.
Here, the member cross-sectional proof stress in the “no-column proof strength reinforcement structure” refers to the axial proof strength and bending proof strength related to the column additional axial force.
For example, as a method of reinforcing the shaft strength and bending strength, there are a method of covering the cross section of the existing column 21 with a steel plate, a method of covering with an additional reinforced concrete, and the like.
As shown in FIG. 7, the existing column 21 of the i layer is located at the height of the floor (indicated by h in FIG. 7) between the cross-sectional height of the column / beam joint (joint portion) and the upper and lower columns / beam joints It is divided into the middle part. However, since the existing beam 22 is joined to the existing column 21 from two directions in plan view at the column / beam joint (joint portion), it is difficult to construct a reinforcing structure of the member cross-sectional strength of the existing column 21. .
Therefore, after reinforcement, the fact that “there is no need for seismic reinforcement of the cross-sectional strength of the member” over the entire length of the floor height, that is, the construction of the “no-column proof strength reinforcement structure” is the seismic reinforcement of the existing building 1 Therefore, the technical and economic effects are extremely high.

  For the existing column 21, even if the post-reinforcement column additional axial forces N1, N2 exceed the post-reinforcement column additional axial forces FN1, FN2, the post-reinforcement column additional axial forces N1, N2 and the long-term vertical load The member cross-sectional proof stress of the existing column 21 is less than the allowable range due to the column axial force synthesized by the axial force generated by (self-weight, loading load, etc.) and the bending moment generated at the points M1 and M2 corresponding to the maximum horizontal deformation. If it is, the member cross-section reinforcement of the existing pillar 21 is not required.

The existing frame structure 2 is provided with the foundation structure portion 6 having the pile foundation 61 in the lowermost layer. In the existing pillar 21 in the lowermost layer, the post-reinforcement column additional axial force is greater than the column additional axial force before reinforcement. By configuring the restoring force of the damping structure 3 so as to be small, it is possible to configure a “no-increase pile reinforcement structure” that does not require additional pile reinforcement.
“Non-addition pile reinforcement structure” refers to a foundation structure that can satisfy the seismic performance required for the existing frame structure 2 after reinforcement, with the pile foundation 61 of the existing foundation structure 6 remaining as it is. .
Incremental reinforcement of piles is based on the existing pile foundation when the column axial force (compressive force, tensile force) acting on the existing pile foundation 61 during an earthquake exceeds the allowable support force or allowable tensile resistance force of the pile. Reinforcement work that constructs a new pile foundation 61 in the vicinity of 61.
Therefore, since it is extremely difficult to construct an additional pile reinforcement structure in an actual existing building, it is possible to constitute a “no-increase pile reinforcement structure” that does not require additional pile reinforcement according to the present invention. What can be done is extremely high technical and economic effects when retrofitting existing high-rise buildings.
In particular, even in a building having an elongated front shape in which the tower ratio of the building (the maximum height of the building / the width of the building) exceeds 2, even if the existing frame structure 2 is seismically reinforced by the damping structure 3 Since it does not require additional reinforcement of piles, its technical effect is great.

FIG. 9 and FIG. 10 show an example of an elastic seismic response analysis result for the beam direction (Y direction) of the building 1 shown in FIG.
9 and 10, three analysis cases are examined. Case 1 is the case according to the present invention (indicated by □ in the figure), and case 2 is a case where a conventional oil damper is incorporated (in the figure, marked with ●). Case 3 shows a case of a pure ramen structure without a vibration control device (indicated by ▲ in the figure).
In FIG. 9, the vertical axis represents the layer, and the horizontal axis represents the column additional axial force. Comparing the column additional axial force in the lowermost layer (one layer), the column additional axial force by case 1 (present invention) is reduced to about 70% of case 2 (conventional oil damper) and case 3 (pure ramen structure). is doing.
In FIG. 10, the vertical axis represents the layer, and the horizontal axis represents the interlayer horizontal deformation angle (= interlayer horizontal deformation / floor height). Comparing the interlayer horizontal deformation angle in the lowermost layer (one layer), the interlayer horizontal deformation angle in case 1 (invention) is almost the same as in case 2 (conventional oil damper), but case 3 (pure ramen structure) It is reduced to about 70%.
The present invention exerts an effect of reducing the “additional post-reinforcement axial force” acting on the existing column 21 connected to the vibration control structure 3 to about 70% in the existing frame structure 2 after reinforcement. .

FIG. 11 shows a modification of the vibration control structure 3.
The difference between the damping structure 3 of the modified example and the damping structure 3 shown in FIG. 3 is that the pair of dampers 4 and the lateral member 34 are configured as a straight horizontal member, and a pair of reinforcing columns 31 is provided. , 31 are connected.
A pair of reinforcing diagonal members 33, 33 alone forms a diagonal V-shaped diagonal member (brace material), and the intersection of the pair of reinforcing diagonal members 33, 33 is joined to the substantially central portion of the transverse member 34.
In the present invention, the seismic control structure 3 may be a structure that bears the horizontal (shearing force) as a damping force when the interlayer horizontal deformation occurs, and thus may be not only various brace structures but also a stud-type structure.

Next, the earthquake-proof reinforcement method which arrange | positions the damping structure part 3 in the multilayer building 1 which has the existing frame structure 2 is demonstrated.
(1) First, the vibration control structure 3 is constituted by a reinforcing frame having a reinforcing column 31 and a reinforcing beam 32, and a damper 4 (see FIG. 3).
In the deformation region between the predetermined damping force / decrease starting deformation points DB1 and DB2 and the stroke ends DC1 and DC2, the damper 4 has a predetermined damping force / decreasing gradient α1 and α2 as the deformation increases. The damper is configured to have a gradually decreasing damper restoring force (see FIG. 5).
In the damper 4, predetermined groove lengths (the length of S1 shown in FIG. 4A) of the two bypass groove portions 41a and 41b are set so as to constitute the damping force / decrease start deformation points DB1 and DB2.
The predetermined damping force / decreasing gradients α1 and α2 are set according to the groove lengths of the bypass groove portions 41a and 41b and the cross-sectional size of the groove portions related to the oil moving ability.
(2) In the existing frame structure 2 before reinforcement, “maximum interlayer horizontal deformation” of each layer occurring at the time of a large earthquake is set (first step).
In the existing frame structure 2 before reinforcement, the first restoring force characteristics relating to “interlayer horizontal deformation before reinforcement” and “column additional axial force before reinforcement” are configured for the existing column 21 (second step, FIG. 6). reference).
In the existing frame structure 2 after the reinforcement incorporating the vibration control structure 3, the vibration control structure 3 acts on the existing column 21 connected to the vibration control structure 3 and “inter-layer horizontal deformation after reinforcement”. The second restoring force characteristic relating to the “post-added axial force after reinforcement” is configured (see the third step, FIG. 7 and FIG. 8A).
In the existing frame structure 2 after reinforcement, a third restoring force characteristic relating to “inter-layer horizontal deformation after reinforcement” and “column additional axial force after reinforcement” is configured for each existing column 21 (fourth step, FIG. 8 (b)).
(3) Reinforcement in which the damping structure 3 is disposed in the opening surrounded by the existing columns 21 facing each other of the existing frame structure 2 and the upper and lower existing beams 22 laid across these existing columns 21 The seismic resistance of the later building 1 is confirmed by seismic response analysis.
By reducing the additional axial force acting on the existing column connected to the seismic control structure 3, it is confirmed in the analysis that the existing column will form a no-column strength reinforcement structure even after reinforcement. be able to.
(4) The vibration control structure 3 constituted by the reinforcing frame 31 including the reinforcing column 31, the reinforcing beam 32, and the reinforcing diagonal member 33 and the damper 4 is connected to the existing columns 21 and 21 facing each other of the existing frame structure 2. It attaches to the opening part enclosed by the upper and lower existing beams 22 and 22 laid across between these existing pillars 21 and 21. As shown in FIG.

  The embodiments of the present invention have been described with reference to the examples. However, the present invention is not limited to the above-described examples, and appropriate additions, modifications, and the like can be made within the scope of the gist of the present invention. is there.

(A) is a top view before reinforcement of the building 1, (b) is a top view after reinforcement of the building 1. FIG. It is the 1A-1A sectional view taken on the line of FIG.1 (b), Comprising: It is a side view of the existing frame structure 2 after reinforcement. 3 is a front view of a vibration control structure 3; FIG. (A) (b) (c) is a longitudinal sectional view of the damper 4. It is explanatory drawing which shows the damper restoring force of the damper. It is explanatory drawing which shows the 1st restoring force characteristic regarding the existing pillar 21 before reinforcement regarding "the horizontal deformation | transformation between layers before reinforcement" and the "column additional axial force before reinforcement". It is explanatory drawing which shows "the column additional axial force after reinforcement" which acts on the existing pillar 21 from the damping structure part 3 after reinforcement. (A) is the second restoring force characteristic regarding the post-reinforcement damping structure 3 regarding the “horizontal deformation after reinforcement” and the “additional axial force after reinforcement” acting on the existing column 21, (b) It is explanatory drawing which shows the 3rd restoring force characteristic of the interlayer horizontal deformation | transformation (horizontal axis direction) after reinforcement regarding the existing pillar 21, and the column additional axial force (vertical axis direction) after reinforcement. It is an elastic seismic response analysis result (column additional axial force) about the beam direction of building 1. It is an elastic seismic response analysis result (interlayer horizontal deformation angle) about the beam direction of building 1. FIG. 6 is a front view showing a modified example of the damping structure 3. It is a restoring force characteristic regarding the damping force and displacement of a conventional oil damper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Building 2 ... Existing frame structure 3 ... Damping structure part 4 ... Damper 6 ... Foundation structure part 21 ... Existing pillar 22 ... Existing beam 31 ... Reinforcement Column 32 ... Reinforcement beam 33 ... Reinforcement diagonal 40 ... Cylinder body 41a, 41b ... Bypass groove
42 ... Rod body
43 ... Piston 44a, 44b ... Valve
47a, 47b ... Oil tank 48 ... Mounting part 61 ... Pile foundation 62 ... Foundation beam α1, α2 ... Damping force / decreasing gradient β1, β2 ... Column additional axial force / decreasing gradient

Claims (2)

It is a multi-layered building having a seismic reinforcement structure that arranges the damping structure on the existing frame structure,
The seismic reinforcement structure is configured by arranging a damping structure in the opening surrounded by the existing columns facing each other of the existing frame structure and the upper and lower existing beams that are laid across these existing columns,
The damping structure is composed of a reinforcing frame with an oil damper,
In the deformation region beyond that, the deformation of the oil damper in which the increment of the damping force of the oil damper is negative with respect to the increment of the deformation of the oil damper is defined as a predetermined damping force / decrease starting deformation point,
The oil damper, the predetermined damping force-decrease start transformation point and stroke - the deformation region between the-end, so that the damping force of the oil damper at the maximum deformation of the oil damper is zero, increased deformation of the oil damper By constructing a damper restoring force in which the damping force gradually decreases with a predetermined damping force / decreasing gradient as
The column additional axial force acting on the existing column to which the damping structure is connected during the earthquake is reduced so that it does not exceed the allowable column additional axial force .
The building is characterized in that the existing pillars, even after reinforcement, constitute a no-column strength structure. A seismic reinforcement method for arranging a damping structure in a multi-layer building having an existing frame structure,
The seismic reinforcement structure is configured by arranging a damping structure in the opening surrounded by the existing columns facing each other of the existing frame structure and the upper and lower existing beams that are laid across these existing columns,
The damping structure is composed of a reinforced frame with an oil damper,
In the deformation region beyond that, the deformation of the oil damper in which the increment of the damping force of the oil damper is negative with respect to the increment of the deformation of the oil damper is defined as a predetermined damping force / decrease starting deformation point,
The oil damper, the predetermined damping force-decrease start transformation point and stroke - the deformation region between the-end, so that the damping force of the oil damper at the maximum deformation of the oil damper is zero, increased deformation of the oil damper The damping force is configured to have a damper restoring force that gradually decreases with a predetermined damping force / decreasing gradient as
By disposing the vibration control structure in the opening surrounded by the existing columns facing each other of the existing frame structure and the existing beams above and below the existing columns,
The column additional axial force acting on the existing column to which the damping structure is connected after reinforcement is reduced so that it does not exceed the allowable column additional axial force .
A seismic reinforcement method for buildings, in which the existing pillars, even after reinforcement, constitute a no-column strength structure.

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