JP2006063771A - Slit plate spring and building earthquake-proof reinforcing system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a durable slit plate spring for reducing earthquake vibration to actualize easy earthquake-proof reinforcement of a new or existing building, particularly, a low-rise building having one or two floors, and to provide an earthquake-proof reinforcing system using the same. <P>SOLUTION: The upper side face of a band plate is curved downward to form round faces at both ends, its front end is curved downward in the opposite direction to the round faces at both ends of the upper side face so that the round faces are continuously formed in a S-shape or an inverted S-shape, and then the front end extends in a horizontal direction to form a lower side face. This one-pitch procedure is repeated to form a plate spring in a bending structure. The slit plate spring has equal- or unequal-width slits formed parallel in the longitudinal direction in a range from starting points on the round faces of the lower side face through the upper side face to final points on the round faces in the opposite direction. The building earthquake-proof reinforcing system uses the same. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a slit leaf spring and a seismic reinforcement method for a building using the slit leaf spring. More specifically, the present invention is a slit leaf spring that alleviates shock vibration acting on a building during a large earthquake, and applies this to a building. Then, it relates to a seismic reinforcement method for reducing damage.

Various methods have been studied for seismic reinforcement of buildings. This can be broadly divided into those related to reinforcement to give rigidity to the structure of the building itself, and those that relieve and absorb shock vibrations acting on the structure by wearing a base isolation body on the building. .
The former is a relatively small scale that simply stretches inside or outside the building frame, attaches struts, or attaches pillars or steel frames, or attaches reinforcing hardware or shock absorbers to the joints (joints) of the frame. It was inexpensive, but there were few reinforcement effects and there were doubts about durability.
The latter is a seismic shock absorber that relaxes and absorbs shock vibrations acting on the building during an earthquake, and is attached to the lower part (foundation, foundation slab) and upper part (mid-column, rooftop) of the building. Although it is large, it involves large-scale construction, so it is expensive and difficult to design and construct, and is limited to seismic construction for large buildings, and is limited to small-scale buildings. As described above, the present situation is that the effect has not yet been achieved sufficiently for the seismic reinforcement of low-rise buildings of about 1 to 2 stories except for high-rise large buildings.

The present inventor examined the investigation records of the large earthquake disaster, and in particular, many of the damaged buildings were low-rise wooden buildings, and many of them were concentrated on the first floor, and a large earthquake occurred. The fact that many collapsed in about 60 seconds after the initial movement, and caused great sacrifice.
And by extending the time until the momentary collapse of this earthquake, many of the victims can help and evacuate during this time, and a simple and effective seismic reinforcement method that can minimize the number of victims. I realized the need for development.

  In order to prevent the collapse of low-rise buildings of about 1 to 2 floors (hereinafter sometimes simply referred to as buildings) among existing buildings, one of the methods that has been adopted in the past is so-called “smooth”. There is a way to support the stick. This is a method of trying to prevent collapse anyway by installing sturdy diagonal materials and supporting pillars on the first floor of the building. However, even if a strong stick is firmly attached to the first floor of the building, it is completely incapable of vertical vibration at the time of the initial motion of the earthquake. The horizontal force applied to the second floor is increased by the momentum (moment of inertia) when the deformation of the first floor is suddenly restricted, and there is a risk that the second floor will be damaged and the first floor will collapse.

  The present invention has been made in view of the above points, and the object of the present invention is to provide seismic reinforcement for new and existing buildings, particularly low-rise buildings of about 1 to 2 floors. The purpose is to develop and provide a durable slit leaf spring that mitigates seismic vibrations and a seismic reinforcement method using this.

  The present invention uses a newly developed slit leaf spring that can buffer vibrations from three directions in order to mitigate earthquake vibrations at the time of impact vibration at the time of the initial earthquake. Interspersed and laid between the foundation slab and the foundation to extend the natural period of the building to suppress the amplification of seismic force due to resonance with the ground, and in the case of an existing building, it was attached to the side or top of the column A seismic support is installed around the outer wall of the building on the 1st floor to effectively absorb the vertical vibrations at the time of the earthquake's initial motion to suppress damage and to reduce the horizontal force caused by the rolling vibrations that come afterwards. By suppressing and restricting the deformation of the building softly, the increase in the deformation of the second floor is suppressed to prevent an instantaneous collapse, and in any case, at least to try to reduce the damage caused by the total destruction of the building at the time of the first earthquake. What to do That.

The present invention is a seismic reinforcement method that can be applied not only to a new building but also to an existing building, and is applied to an existing low-rise building of about 1 to 2 floors that is expected to be damaged greatly when an earthquake occurs. The seismic reinforcement method equipped with the slit leaf spring and the slit leaf spring will be described in detail below.
In general, buildings are weak in resistance to horizontal force, but they are also vulnerable to large vertical movements that occur during direct earthquakes, and are prominent in low-rise buildings.
In the present invention, there is a slit plate spring which has pressure resistance and has a damping effect on vibrations in three directions such as seismic motion, and as a seismic support and a seismic reinforcement method using this, a slit plate for a new building. After mounting the spring on the building foundation or foundation slab, build the foundation beam of the building on it, and for existing buildings, install seismic support columns equipped with slit leaf springs around the outer wall of the building In this embodiment, the slit plate spring is joined to a pillar material of a building, a siding girder, or the like.

(1-1) Slit leaf spring The leaf spring (Japanese Utility Model Publication No. Sho 54-32110) previously devised by the present inventor was mainly intended to absorb and dampen up and down vibrations of heavy machinery. Absorption of vibrations in the biaxial directions of the long side direction (X axis) and the short side direction (Y axis) perpendicular to each other was not considered. Therefore, the slit leaf spring of the present invention is a newly developed technology that corrects its drawbacks and absorbs and attenuates earthquake vibrations in three axial directions (X, Y, and Z axes) such as earthquake motion. is there.
The form of the slit leaf spring in the present invention will be specifically described with reference to the drawings.
In FIG. 1 and FIG. 2, the slit leaf spring A is made of a metal or synthetic resin ribbon 1 and is bent downward so that both ends of the upper side surface 2 are R surfaces. The R side is curved downward in the opposite direction to the R surface so that the R surface is continuously formed into an S shape or an inverted S shape, and then both ends are slightly extended horizontally to form the lower side surface 3. One pitch is formed as it is formed, and this is repeated repeatedly in order. From the starting point of the R surface of the lower side surface 3 of the leaf spring to the end point of the R surface in the reverse direction through the upper side surface, It is formed by engraving parallel slits 4 of equal width in parallel to the length direction, and if necessary, elastically elastically or partially on the concave part of the bent part as shown in FIGS. The substance 6 can be applied or filled.
When the lower side surface 3 of the slit leaf spring A is placed parallel to the long side direction, the long side direction is the X axis direction, the short side direction is the Y axis direction, and the vertical direction is the Z axis direction. The main purpose of the leaf spring (Act No. 54-32110) is mainly to absorb vibration in the Z-axis direction, which is the vertical load direction. In order to absorb and dampen vibration in the direction and the Y-axis direction, it was necessary to reduce the rigidity.
For this reason, by setting it as the slit leaf spring A which engraved the parallel slit 4 from the starting point d of the R surface of the lower side surface 3 of the leaf spring to the end point d ′ of the R surface in the reverse direction through the upper side surface 2. The rigidity in the X-axis direction and the Y-axis direction is reduced, and vibrations in three axis directions (X-axis, Y-axis, and Z-axis) such as earthquake motion can be absorbed. Further, when the rubber-like elastic material 6 is applied or filled in all or part of the concave portion of the bent portion, when the slit leaf spring A is deformed as shown in FIGS. 11B and 11C by horizontal force, Due to the buffering action of the rubber-like elastic material 6, the deformation in the X-axis direction and the Y-axis direction is absorbed more softly, and the deformation recovery property is improved.

As the shape dimension of the slit 4 engraved on the slit leaf spring A, the slit 4 having the same width and the same interval as shown in FIG. 3A or the wide slit 4 shown in FIG. 3 (c), there is a slit 4 in which both are mixed, the slit width is about 1 to 5 mm, the interval between the slits 4 is about 5 to 50 mm, and the number of imprints of the parallel slit 4 is the width of the slit 4 2 to 10 depending on the interval.
As the material and dimensions of the strip-shaped plate 1 used as the slit plate spring A, when it is made of metal, spring steel, stainless spring steel or the like is preferably used, and its thickness is preferably 0.2 to 16 mm, preferably Is 0.6 to 2.3 mm, and its width is 20 to 200 mm, preferably 50 to 150 mm. Further, when it is made of a synthetic resin, an engineering resin, FRP or the like is preferably used, and its thickness and width are the same as or slightly thicker than those of the metal. The height of the slit leaf spring 4 constituted by the above materials and dimensions is 10 to 100 mm, preferably 20 to 50 mm.
In the manufacture of the slit leaf spring A, the slit 4 having the shape and size shown in FIGS. 3A to 3C is preliminarily engraved in the portion where the slit 4 of the leaf spring made of the strip plate 1 is formed. It is configured by bending it.
In addition, as shown in FIG. 4, the superposed slit leaf spring B in which the upper side surfaces 2 of the 1 pitch slit leaf spring A are orthogonal to each other back to back and the overlapping portions are joined to each other has a narrow use site. This is effective when a smaller spring constant is required.

Further, as shown in FIGS. 5A and 5B, if the rubber-like elastic material 6 is applied or filled over the entire surface of the slit leaf springs A and B or the concave portions of the bent portions, This is effective in preventing abnormal deformation of the slit leaf springs A and B due to the deflection of the horizontal force during an earthquake.
Examples of the rubber-like elastic substance 6 include synthetic rubber, natural rubber, viscoelastic resin, and the like, and metal powder, mica powder, metal fiber, and the like can be mixed therein as a vibration damping material. The rubbery elastic material 6 preferably has a hardness of 30 ° to 75 °.

(1-2) Seismic struts The seismic struts are fitted with slit leaf springs A or B at the tip of the metal strut 7, and the column base is firmly built outside the building outer wall to be reinforced. At the initial movement, the building is elastically supported.
The earthquake-proof struts used for the seismic reinforcement of existing buildings are steel materials such as steel pipes, square steel pipes, H-shaped steels, or aluminum alloy molds, and various sizes of 100 to 500 mm are used.
FIG. 6 shows an upright type earthquake-proof column C, in which a spacer 9 is joined as a connection hardware to a side surface of a front end portion of a column 7 having a height of a first floor girder to be reinforced, and a slit plate The upper side surface 2 or the lower side surface 3 of the spring A is mounted. The spacer 9 is made of a metal mold or a steel plate, and it is possible to mount a vertically long spacer 9 as shown in FIG. 6 or a horizontally long spacer 9 as shown in FIG.
FIG. 7 shows a seismic support D having a straight arm 10, the arm 10 is joined to the column head of the support 7 or its side, and the arm 10 is slit on the side of the building outer wall or on the side and top. A leaf spring A is attached.
When the seismic support D is attached to the corner of the building, the seismic support D, in which the L-shaped arm 10 is horizontally joined to the column head of the support 7, is installed at the corner of the outer wall of the building. The slit plate spring A is joined via the upper side surface 2 or the lower side surface 3 so that the L-shaped arm 10 is in contact with the outside of the outer wall.
FIG. 8 shows an earthquake-proof column E in which a column 7 is used as an oblique member, a gusset plate is joined to the tip of the column 7 via a spacer 9, and a superposition type slit leaf spring B is attached thereto.
In addition, when the fabric foundation footing width of the building is large, in order to make the independent foundation 12 independent from the building, only the columns 7 of the earthquake-proof columns C, D, and E can stand upright as diagonal materials as shown in FIG. Is possible.
As described above, the earthquake-proof strut according to the present invention can be mounted by changing the shape of the arm 10 or selecting the number of pitches and the mounting direction of the slit leaf springs A according to the structure and mounting part of the building. What has the structure matched with the position of the independent foundation 12 which changes with the location conditions of a building can be used arbitrarily.
When the slit leaf spring A is used for the earthquake-proof struts C, D, and E, the rubber-like elastic material 6 can be omitted.

(1-3) Seismic reinforcement with earthquake-proof struts Seismic reinforcement with earthquake-proof struts is mainly applied to existing buildings.
The seismic struts C, D, and E having the above-described configuration can be selected with the most appropriate configuration in terms of seismic reinforcement depending on the structure of the building to be reinforced, the structure, the location conditions in the site, or the ground condition. . For example, when the site is small and there is little room around the building, the vertical column type earthquake-proof column C as shown in FIG. 6 is suitable. When the building is old and weak, The seismic support D having the arm 10 of FIG. 7 is also desirable for reinforcement, and when there is an obstacle near the building, the seismic support E using the support shown in FIG. 8 as an oblique material is used.
The seismic struts C, D and E selected as described above are arranged on the outside of the outer wall of the existing building, about two on each vertical surface, or on the corners depending on the building scale and seismic reinforcement purpose. One is addressed to the position of the pillar 20 of the building or the girder 21 of the building.
After that, the upper side surface 2 or the lower side surface 3 of the slit leaf springs A and B mounted on the arm 10 at the top or the tip of the support column 7 is brought into close contact with the wall surface 19, and the wall surface with the hole-in anchor bolt 17 or the same effect material. 19. After fixing to the floor girder 21 and fixing the building, the column base of the column 7 is rigidly joined to the independent foundation 12.
The independent foundation is constructed sufficiently away from the building foundation so that the seismic vibration applied to the building does not synchronize with the seismic columns C, D, E.

(1-4) Seismic reinforcement of foundations and foundation beams with slit leaf springs Seismic reinforcement with slit leaf springs A interposed between foundations or foundation slabs 22 and foundations or foundation beams 16 is mainly applicable to new buildings. is there. As shown in FIG. 10, this seismic reinforcement method is a method of floating a building from the ground and avoiding resonance with seismic motion, and is a wide thin film under a foundation or foundation beam 16 on a foundation slab 22 of a new building. After laying and fixing the sliding plate 8 made of a stainless steel plate or a resin-coated steel plate, the slit plate spring A is laid horizontally on the base beam 16 along the length direction in the ε direction or γ direction, On top of this, a building base or foundation beam 16 is placed and aligned. Other construction procedures may be the same as the conventional construction method.

In this way, the building and the foundation slab 22 are kept in a vibration-insulated state by the slit leaf spring A, and the building is also subjected to a horizontal force by the frictional force between the building weight and the slit leaf spring A on the foundation slab 22. Is stable on the foundation slab 22. When the horizontal component of the seismic force exceeds this frictional force, the base or foundation beam 16 and the slit leaf spring A slide on the sliding plate 8, and the seismic force is transmitted to the building through the base or foundation beam 16. To alleviate. The same applies when wind pressure acts on the building.
The building frame on the slit leaf spring A can be arbitrarily selected from a wooden structure, a steel structure, a precast concrete structure, etc., but is constructed so as to maintain structural rigidity, and the horizontal force is transmitted to the foundation slab 22 in a balanced manner. To be loaded. The building is stationary on the sliding plate 8 with the slit leaf spring A interposed.
When the horizontal component due to seismic force or wind pressure is within the frictional force due to the gravity of the building, the building is stationary and the slit leaf spring A effectively acts to attenuate the horizontal component.
At this time, the natural period of the building constructed on the slit leaf spring A (the number of seconds of one reciprocal swing unique to the building) is preferably about 2 to 4 seconds. Since the natural period of a strong building ground is 1 second or less, resonance between the building and the ground motion by this seismic reinforcement method does not occur, and amplification of seismic force can be avoided.
If an earthquake motion with a longer period than expected is applied, the building slides on the sliding plate 8 so as to release the horizontal force due to the earthquake, but the building is excessively abnormal due to the sliding on the sliding plate 8. In order to restrain the variation, the restraint channel 11 attached to the lower part of the foundation beam 16 and the horizontal damper G with the slit leaf spring A mounted inside the rising web of the steel angle are shown in FIGS. As shown in FIG. 13, it is attached to a key point of the pit rise 13 to increase safety.

(2-1) Seismic action of slit leaf spring A An example of the seismic reinforcement method in which the slit leaf spring A is interposed between the building and the ground will be explained. Assuming that a lump is on the rock, rocking the desk slowly rocks the stone lump according to its mass and the softness of the heel.
At this time, if the stone block is a sufficiently rigid building, the desk is a strong ground with a certain period of predominance, and the heel is considered to be replaced with a slit leaf spring A having a unique spring constant. it can.
Now, when the slit leaf spring A is horizontally placed on the foundation or the foundation slab 22, vibrations from three directions of the X axis direction, the Y axis direction, and the Z axis direction act on the slit leaf spring A during an earthquake. To do.
FIG. 11A shows the state in which the slit leaf spring A is elastically deformed up and down when the seismic vibration in the Z-axis direction acts on the slit leaf spring A up and down. FIG. 10B shows a state in which the slit plate spring A is elastically deformed when vibration in the X-axis direction is applied in the long side direction. FIG. 11C shows the slit plate spring A. On the other hand, a state in which elastic deformation occurs when vibration in the Y-axis direction acts in the short side direction is shown.
FIG. 10 is a perspective view showing an earthquake resistance method when the slit leaf spring A is laid on the foundation slab 22 of the new building. The slit leaf spring A is laid in the ε direction or γ direction in the horizontal direction on the sliding plate 8 on the basic slab 22.
Here, when the horizontal force due to the earthquake is within the friction force between the building and the foundation slab 22, the slit leaf spring A acts to absorb the horizontal force. Here, when the slit 4 is not engraved on the slit leaf spring A, the vertical vibration in the Z-axis direction can be absorbed, but the vibration in the X-axis direction and the Y-axis direction is elastically deformed due to its rigidity. This prevents the vibration from being effectively absorbed and damped.
On the other hand, when the slit 4 is engraved on the leaf spring, the spring constant is small with respect to the horizontal force within the limit of the frictional force, and the elastic deformation is effectively performed against the vibration in three directions. The vibration in the X-axis direction and the Y-axis direction can be effectively absorbed and damped.
If the horizontal force due to the earthquake exceeds the friction force between the building and the foundation slab 22, the slit leaf spring A laid in the ε and γ directions slides on the sliding plate 8 by the amplitude of the ground vibration. And, the influence of the horizontal force on the building that absorbs the displacement of the ground is small.

(2-2) Seismic action of seismic struts The seismic struts C, D, and E attached to the floor girder height on the outside of the first floor of existing buildings have a relatively short time during a direct earthquake. A large vertical vibration acts in the axial direction, and then a horizontal force due to a large roll vibration acts on the axis.
If the building is not reinforced with seismic support columns, vertical vibrations cause momentary excessive vertical forces on the frame of the building, and many of the building pillars have rattled due to buckling failure. In many cases, the rolling vibrations that hit afterwards result in partial destruction or collapse.
On the other hand, in the building provided with the above-mentioned seismic struts C, D and E, the slit leaf springs A or B mounted on the seismic struts joined to the spar girders or through columns and pipe columns buffer the vertical stress. However, a part of it is transmitted to the column 7 to reduce the components of the axial direction and bending moment acting on the structure of the building, prevent damage at the time of the first earthquake, and the horizontal stress due to the subsequent roll is also resistant to the earthquake. Since the slit leaf spring A or B attached to is soft and restrains deformation, it is possible to prevent the progress of damage to the building, and at least to extend the time until collapse.

FIG. 12 shows a deformed state of the frame when P1 and P2 act on the frames R1 and R2 as a horizontal force. The deformation angles of the frames R1 and R2 when the seismic support column in FIG. 12 (a) is not provided are δ1 and δ2.
FIG. 12 (b) shows that the deformation of the first floor frame R1 due to the horizontal force (P1 + P2) is significantly reduced by the seismic reinforcement of the first floor frame R1 with a stick that has been conventionally performed. This shows a situation where the horizontal force P2 and the moment of inertia act, and the deformation of the two-story frame R2 increases. At this time, the deformation angle δ3 of the first floor frame R1 is approximately 0, and the deformation angle of the second floor frame R2 is δ4.
FIG. 12 (c) shows the deformation of the frames R1 and R2 when the earthquake-proof columns C, D and E according to the present invention are applied, and the earthquake resistance with the slit leaf springs A and B which reinforce the first-floor frame R1. Since the horizontal force (P1 + P2) acting on the first floor frame R1 is buffered by the support and the deformation generated in the frame R1 is softly restrained, the load caused by the horizontal force P2 acting on the second floor frame R2 and the moment of inertia is minimized. obtain. The deformation angle of the first floor frame R1 is δ5, and the deformation angle of the second floor frame R2 is δ6.
Here, the qualitative relationship between the deformation angles is 0≈δ3 <δ5 <δ6 <δ2 <δ1 <δ4, and the deformation angles when the seismic support column of the present invention is attached are the smallest in total in the upper and lower floors.
As described above, the seismic reinforcement by the seismic struts C, D, and E in the present invention suppresses the occurrence of deformation of the frames R1 and R2 of the building at the time of the first earthquake by the buffer action of the slit leaf springs A and B in a balanced manner. As the building is supported while being supported, the time until the moment of the earthquake's initial wreck and collapse can be extended, as well as major damage can be prevented.

(3-1) Effect due to elastic deformation of slit leaf spring A Since the slit leaf spring A is elastically deformed, vibrations from three directions due to earthquake motion can be attenuated. By the elastic deformation represented by the dotted line indicating the deformation state, the slit leaf spring A can cope with earthquake vibrations in three directions.
(3-2) Effect of mounting the slit leaf spring A on the earthquake-proof column When the slit plate spring A is mounted on the earthquake-proof column, the horizontal displacement of the first floor column head is slightly increased compared to the case where it is not mounted. The horizontal displacement of the head of the second floor shows a tendency to be almost halved, and it is clear that the seismic reinforcement method of the seismic strut according to the present invention is excellent.
(3-3) Effect of making the building have a long natural period When the structure is given rigidity and the column base is fixed, the natural period of the building itself is about 0.1 to 0.2 seconds, on the slit leaf spring A If the natural period of the building constructed in 2 is about 2 to 4 seconds, the seismic force will not cause the building to resonate with the ground motion that dominates the ground that occupies the majority of large-scale earthquakes within 1 second. Amplification can be prevented.
Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

A strip 1 made of stainless spring steel having a thickness of 1 mm and a width of 100 mm is cut to a length of 8 pitches, the upper side surface 2 is horizontally extended by 67 mm, and both ends thereof are curved to a radius of 9 mm, as shown in FIG. When a perpendicular line s is taken down from the protruding tip a of the R surface to the bottom and the intersection with the lower side surface 3 is a C point, the radius is opposite to the upper side surface 2 as the next R surface comes inward from the C point. After bending so as to form a 9 mm round surface, the lower end surface 3 is formed by extending its tip horizontally by 25 mm from the point C, and this is referred to as a 1-pitch slit leaf spring A.
In the strip plate 1 of the slit leaf spring A, three continuous slits 4 having a width of 5 mm from the starting point d of the R surface of the lower side surface 3 through the upper side surface 2 to the end point d 'of the R surface in the reverse direction are engraved. As shown in FIG. 2, neoprene rubber having a hardness of 50 ° as a rubber-like elastic body is filled as a rubber-like elastic material 6 in the bent portion recesses of the belt-like plate 1 every other pitch, and the long side direction (X Axis) and the spring constant in the short side direction (Y-axis) could be controlled small.
The 1-pitch slit leaf spring A constructed in this way is continuously formed for 8 pitches to form a slit plate spring A having a total length of 1 m, and this is attached to a seismic support column according to the purpose of use. It can be used for the seismic reinforcement method of the building mounted on the building and the foundation slab 22.
As described above, the slit leaf spring A has a small spring constant in the long side direction (X axis) and softens the rigidity in the short side direction (Y axis) by forming the slit 4. Therefore, the rubber-like elastic material 6 filled in the bent portion concave portion of the belt-like plate 1 can suppress the deformation more smoothly and has good resilience.
Since the slit leaf spring A is elastically deformed, vibrations from three directions due to earthquake motion can be damped. Therefore, the elastic deformation represented by the dotted lines indicating the three-direction deformation state by experiment as shown in FIG. It was confirmed that the leaf spring A was able to cope with earthquake vibrations in three directions.

As shown in FIG. 9, two seismic support columns D are provided on each elevation surface around the outer wall of the building, respectively, according to the position of the column material 20 of the building. In FIG. 7, the seismic support D is made of 150 × 150 × 6 mm square steel pipe made of galvanized arm 10 and the length of the support is 3.5 m from the top of the arm 10 up to the height of the first floor girder 21 and within the independent foundation 12. The total value is 4 m including the 500 mm portion.
The length of the arm 10 is 1.2 m, and it is distributed from the support column 7 to the left and right. The upper side surface 2 of the slit leaf spring A having a pitch of 1 m and a length of 1 m is mounted in the length direction on the side surface of the building of the arm 10 on the outer wall side, and is bolted.
As shown in FIG. 9, the column base of the seismic support D is an independent foundation 12, and a steel pipe 18 having a diameter of Φ400 × 6 mm and a length of 1.5 m is placed in the ground. The seismic support D is installed, the lower side 2 of the slit leaf spring A is brought into close contact with the outer wall 19 of the building, and fixed with the hole-in anchor bolt 17 that is fixed to the spar 21 to adjust the installation of the support 7 After that, the steel pipe 18 is filled with concrete and rigidly connected.
The seismic support D constructed in this way was able to bear the vertical stress and horizontal stress acting on the building at the time of the initial motion of the earthquake, and reliably reduce the displacement of the building when the horizontal force was applied.

以上のとおり、耐震支柱７にスリット板バネＡを装着した場合は、装着しなかった場合に較べて１階柱頭部の水平変位はやや増加するが、２階柱頭部の水平変位はほぼ半減する傾向を示し、本発明による耐震支柱の耐震補強方式が優れていることが明らかである。In addition, in order to investigate the effect of the seismic reinforcement method using the seismic strut, the slit plate when the seismic strut D is constructed as described above using the aged two-story wooden building to be demolished and then subjected to a horizontal impact. The magnitude of the horizontal displacement with and without the spring A was measured.
As a horizontal impact, when the two cement bags were swung down and collided with the vicinity of the first column through the column head of the column near the center of the target building, the horizontal displacement of the column head was as shown in the table below. .

As described above, when the slit leaf spring A is attached to the seismic support column 7, the horizontal displacement of the first-floor column head is slightly increased compared to the case where it is not attached, but the horizontal displacement of the second-floor column head is almost halved. It is clear that the seismic reinforcement method of the seismic strut according to the present invention is excellent.

In FIG. 10, a stainless steel plate having a thickness of 1.2 mm is fixed as the sliding plate 8 with an anchor 14 at a position where the foundation beam 16 is laid on the foundation slab 22 of the target steel building. Since the maximum displacement of the ground up to now is 200 mm, the width of the sliding plate 8 is 600 mm. The foundation beam 16 is laid on the slit plate spring A laid on the sliding plate 8 in the ε direction and the γ direction with the center line aligned, and fixed with the temporary fixing screw 15. When the load of the building is small, the slit leaf spring A can be limited to the vicinity of the lower part of the column member 20 of the foundation beam 16. When the weight and the total of legal loading weights of the two-story building of the building area of 75m ² to 50 tons, and the friction force is 20 tons, also wind pressure and the seismic force is to estimate the maximum at the time, following friction force In this range, the slit leaf spring A does not slide, and the ground vibration is absorbed within the limits of the vibration system of the building and the slit leaf spring A. If the horizontal force exceeds the frictional force, the slit leaf spring A slides on the sliding plate 8 in the ε direction or γ direction, and absorbs the displacement of the ground. The maximum displacement at the time of recent earthquakes in Japan is about 200 mm. When the maximum displacement is exceeded, the horizontal damper G mounted on the pit rise 13 with the adjusting bolt 5 and the restraint channel 11 restrain the abnormal displacement of the building. FIG. 13 shows an example of attachment of the horizontal damper G. When the building is small-scale, the sliding plate 8 is omitted, and the smoothness of the foundation slab 22 is carefully increased in surface finish. The subsequent construction procedure is the same as before.

The effect of the seismic reinforcement method for a building in which a slit leaf spring is mounted on the foundation or foundation slab 22 is as follows. The natural period of a wooden or steel-framed low-rise building by the conventional construction method is about 0.1 to 0.2 seconds, the response acceleration of the building during an earthquake is large, and the seismic force acting on the building is also a feature. It has been recognized in recent earthquake observations that the natural period tends to decrease as the natural period increases to about 2 to 4 seconds.
The foundation beam 16 in which the slit plate spring A of the present invention is interposed and mounted on the foundation or the foundation slab 22 has a buffering action between the building and the foundation slab 22 and has a suitable spring constant and a large spring constant. By interposing the spring A, the building can be lifted from the ground and the natural period of the building can be extended to about 2 to 4 seconds. Therefore, from the dominant short period component (about 0.1 to 1.0 seconds) of the hard ground The natural period of the entire building can be separated, the resonance between the seismic force and the building can be avoided, the seismic force can be reduced, and the vibration of the ground other than the earthquake, for example, the ground vibration due to transportation can be reduced.
When the building is a heavy structure, a wide foundation beam having a sufficiently high rigidity is constructed on the column base, and a slit leaf spring A is inserted between the foundation and the foundation slab 22 in the long side direction. The above-mentioned seismic reinforcement effect can be obtained if it is constructed so as to support the building by mounting more than one row.

  Perspective view of slit leaf spring A   Vertical sectional view of slit leaf spring A   X-X 'sectional view of slit leaf spring A   Perspective view of slit leaf spring B   Damper material 6 filling section longitudinal section   Perspective view of earthquake-proof column C   Perspective view of seismic support D   Perspective view of seismic support E   Anti-seismic column mounting rectangle   Seismic reinforcement type perspective view with slit leaf spring A   Slit leaf spring A deformation diagram   Frame displacement map   Horizontal damper G mounting part and Y-Y 'cross section

Explanation of symbols

A Slit leaf spring B Slit leaf spring C Seismic strut D Seismic strut E Seismic strut G Horizontal mount damper R1 First floor frame R2 Second floor frame δ1 to δ6 Displacement angle a Bending point c Intersection of perpendicular line s Slit origin d 'Slit end point ε Fabric foundation coordinates γ Fabric foundation coordinates 1 Strip-like plate 2 Upper side surface 3 Lower side surface 4 Slit 5 Adjustment bolt 6 Rubber-like elastic material 7 Strut 8 Slide plate 9 Spacer 10 Arm 11 Restraining channel 12 Independent foundation 13 Pit rise 14 Anchor 15 Temporary fixing screw 16 Base or foundation beam 17 Hole-in anchor bolt 18 Steel pipe 19 Wall surface 20 Column material 21 Girder 22 Foundation or foundation slab

Claims (6)

  Curved downward so that both ends of the upper side surface of the belt-shaped plate become R surfaces, and the tips are curved downward in the opposite direction to the R surfaces at both ends of the upper side surface, and the R surface is continuously S-shaped or reversed. From the starting point of the R surface of the lower side surface of the leaf spring, which is formed to be S-shaped, and further formed by extending the tip horizontally and forming the lower side surface as one pitch, and repeatedly bending this. A slit leaf spring in which continuous slits of equal width or unequal width extending from the upper side surface to the end point of the R surface in the reverse direction are formed in parallel in the length direction.   A slit leaf spring formed by superimposing one pitch of the slit leaf springs according to claim 1 so that the upper side surfaces thereof are back to back, and joining the overlapping portions.   The earthquake-proof support | pillar formed by mounting | wearing the front-end | tip part side surface of a support | pillar with the upper side surface or lower side surface of the slit leaf | plate spring in any one of Claims 1-3.   A straight or L-shaped arm is horizontally joined to the column head of the column, and the upper side surface or the lower side surface of the slit leaf spring according to any one of claims 1 to 3 is attached to the side surface or the side surface and the upper surface. Seismic support.   The seismic support column according to any one of claims 4 to 5 is disposed at a predetermined position outside the outer wall of the building, and the slit leaf spring according to any one of claims 1 to 3 attached thereto is interposed. A seismic reinforcement method for buildings, in which the column base is fixed to an independent foundation after joining the outer wall surface of the building to the pillar and / or spar.   A building formed by building a foundation, a building, etc. on the top or bottom side of the slit leaf spring according to any one of claims 1 to 3 on a building foundation or a foundation slab. Seismic reinforcement method.

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