JP7245513B2 - METHOD AND INSTALLATION STRUCTURE FOR SUPPRESSING DAMAGE TO MULTILAYER SHARE WALL - Google Patents

Description

The present invention relates to a method for suppressing damage to multi-layer load-bearing walls applied to multi-layer load-bearing walls of RC construction in RC building structures (reinforced concrete building structures), and installation of multi-layer load-bearing walls in foundation floor structures. and a damage control installation structure (hereinafter referred to as "method and damage control installation structure for suppressing damage to multi-layer bearing walls"). In the present invention, a "multi-story load-bearing wall" is a "load-bearing wall continuous from the first floor to the top floor".

Conventionally, as an earthquake-resistant means for a structure, there is known a configuration in which a structure is supported via a member that undergoes plastic deformation (see Patent Documents 1 to 6, etc.).

Patent Literature 1 describes a configuration in which the lower end of a structure (rack structure) is erected via a member that plastically deforms.

Patent Document 2 discloses a structure in which a structure (ceiling body) is supported from below by pillars through members that undergo plastic deformation. It is described to enable the members to effectively absorb the seismic energy even when the

Patent Document 3 describes a vibration damping structure provided with a damper that plastically deforms between members of a structure to absorb vibration energy, and that the shape of the damper can be changed in various ways.

Patent Document 4 discloses a seismic isolation device in which a building has a large inertial resistance during an earthquake, so plastic deformation occurs in a plurality of vertical plates, and this deformation reduces the vibration acceleration of the building. Are listed.

Patent Literature 5 describes an earthquake-resistant construction method in which a structural member (steel frame column) is erected via an absorbing member that plastically deforms into foundation concrete to absorb the seismic energy of an earthquake.

Patent Literature 6 describes a vibration damping device provided with a vibration damper that plastically deforms between constituent elements of a structure.

Furthermore, as a metal fitting for erecting a structural member, there is known a configuration for erecting and fixing a structural member or wall material with an L-shaped member (see Patent Documents 7 and 8).

Japanese Patent No. 4058697 Japanese Patent Application Laid-Open No. 2002-309801 Japanese Patent No. 3775219 JP-A-10-030293 Japanese Patent No. 4424638 JP-A-2000-204788 JP 2007-332551 A JP-A-8-86024

In building structures, when the horizontal force of an earthquake (the force due to the vibration energy of an earthquake) is applied to a multi-story bearing wall via the foundation floor structure, if the force is large, the multi-story bearing wall will be bent or sheared. Under the action of stress, a multi-layer bearing wall may develop damage, such as bending or shear cracking, in whole or in part, and spread significant damage across the wall.

Therefore, in the event of a large earthquake, the legs of the multi-layer bearing wall (the lower end portion of the multi-layer bearing wall) are partially lifted from the foundation floor structure that is fixed and supported, and the foundation floor structure The present inventor has devoted himself to research and development of a damage control technology that reduces the influence of the horizontal force of an earthquake transmitted from the pier and suppresses the damage that occurs in the multi-story bearing wall.

By the way, the techniques described in Patent Literatures 1 to 6 are all techniques that try to absorb the seismic energy of an earthquake by using a member that undergoes plastic deformation. It is effective in that it weakens the vibration applied to structures against earthquakes and reduces damage to structures to some extent.

However, there is no mention of the idea of partially lifting multi-story bearing walls in the event of a large earthquake to reduce damage to each floor of multi-story bearing walls and related structural members such as floor structures, or to structures connected to them. do not have.

In short, Patent Documents 1 to 6 are limited to the area of absorbing vibration energy to a portion of the structure, and the multi-story bearing wall is lifted to reduce the influence of the horizontal force of the earthquake on the multi-story bearing wall. It is not a technique aimed at suppressing damage etc. that occurs in

In the process of conducting research and development to partially float the multi-layer bearing wall from the foundation floor structure and avoid damage to the multi-layer bearing wall, the present inventor has developed a multi-layer bearing wall and a damper that causes plastic deformation. We conducted a test and analyzed the experimental results for the joint structure erected on the foundation floor structure. In this structure, the intervening dampers are fixed to the multi-story load-bearing wall and the foundation floor structure by bolts or the like.

In the process, the present inventors have found that when a multi-story bearing wall receives the horizontal force of an earthquake, sliding deformation occurs in the joint, and the damper does not undergo plastic deformation and does not function sufficiently as a seismic resistance means. rice field.

Here, "slippage" in this structure means that a load greater than the frictional force between the materials ("slip resistance"; this point will be described in detail later) acts between the members in the high-strength bolt friction joint at the joint. This is a phenomenon in which slippage occurs in the

Furthermore, even if the damper is plastically deformed and functions to reduce the horizontal force of the earthquake against the multi-story bearing wall when no slip occurs in this structure, such function is applicable to medium and large scale earthquakes. However, there is a risk that it will not work for extremely large-scale earthquakes that exceed expectations.

That is, if a force greater than the yield stress for plastic deformation acts on the damper, the problem of breakage occurs, and the limit of the plastic deformation capacity of the damper is exceeded.

Therefore, the present inventors have proposed that when the wall is lifted by a certain amount or more, the damper is distorted and hardened, and the wall becomes an earthquake resistance element, thereby preventing the load-bearing wall from falling due to the lifting and bending yield of the tough load-bearing wall. By prioritizing destruction, we have come up with and developed a technology to ensure seismic safety against seismic loads that exceed expectations. The present invention seeks to embody such technology.

That is, the present invention is intended to solve the problems of the above-mentioned conventional technology, and as shown in the above-mentioned Patent Documents 1 to 6, a damper that causes plastic deformation is used to prevent an earthquake applied to a structure by an earthquake. In addition to simply absorbing energy, the multi-story load-bearing wall is partially lifted from the foundation floor structure in the event of a medium- to large-scale earthquake. A seismic resistance method capable of partially bending and yielding a multi-layer bearing wall to realize a desired failure state of the multi-layer bearing wall and avoiding a dangerous situation such as the overturning of the entire building structure, and therefor The object is to realize a damage-suppressing installation structure for multi-story load-bearing walls.

In order to solve the above-mentioned problems, the present invention provides a building structure in which a part of a multi-story load-bearing wall that is joined onto a foundation floor structure via a damper is attached to the foundation floor structure when a horizontal force is applied during an earthquake. A method of suppressing damage to a multi-layer bearing wall by making it possible to separate from the body, in which the damper is plastically deformed according to the force applied during an earthquake, and a part of the multi-layer bearing wall is removed from the foundation floor structure. By strain hardening of the damper, the part of the multi-layer bearing wall above the joint with the damper is broken by bending yielding, and a part of the multi-layer bearing wall can be separated from the foundation floor structure. To provide a method for suppressing damage to a multi-layer bearing wall, characterized by:

In order to solve the above-mentioned problems, the present invention provides a building structure in which a part of a multi-story load-bearing wall that is joined onto a foundation floor structure via a damper is attached to the foundation floor structure when a horizontal force is applied during an earthquake. A method for suppressing damage to a multi-layer load-bearing wall by allowing it to be separated from a body, wherein the damper uses a metal material that undergoes plastic deformation at a yield stress and strain hardens when a force greater than the yield stress acts, The bearing wall and the foundation floor structure are joined by bolts at the joints with a predetermined sliding bearing force. When a force equivalent to the yield stress is applied to the damper during an earthquake, the plastic deformation of the damper causes one part of the multi-story bearing wall. When a force greater than the yield stress of the damper and less than the predetermined slip resistance is applied during an earthquake, the damper is strain hardened, and the upper part of the multi-layer bearing wall above the joint with the damper Bend and yield the wall section to break it. Thus, there is provided a method for suppressing damage to a multi-layer load-bearing wall, characterized by allowing a portion of the multi-layer load-bearing wall to be separated from the foundation floor structure.

The bending load capacity of the upper part of the junction with the damper in the multi-layer load-bearing wall needs to be smaller than the slip load capacity of the joint.

In order to solve the above-mentioned problems, the present invention provides a damage suppression installation structure in which a multi-story load-bearing wall is installed on a foundation floor structure via a damper in a building structure, wherein the damper is plastically deformed by yield stress. It is made of a metal material that strain hardens when a force greater than the yield stress acts, and is joined to the multi-story bearing wall and the foundation floor structure at the joint with bolts, and the damper in the multi-story bearing wall A multi-layer bearing wall characterized in that the bending strength of the upper part of the joint is greater than the damper yield stress, and is smaller than the sliding strength of the joint between the multi-layer bearing wall and the foundation floor structure. Provide a damage control structure.

Multi-layer load-bearing walls are applicable to enclosure walls that form the hoistway of a car in an elevator.

According to the present invention, the damper that causes plastic deformation is not limited to simply absorbing the energy applied to the structure by an earthquake. It causes uplift and, in addition, restrains this uplift during extreme earthquakes, but partially bends and yields the legs of the multi-story bearing wall. Since it can be separated from the foundation floor structure when it rises, the excessive stress applied to the multi-layer bearing wall due to an earthquake can be reduced, and damage to the multi-layer bearing wall can be reduced. The high horizontal rigidity and horizontal strength of the building structure can be demonstrated, and dangerous situations such as the entire building structure overturning can be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining an embodiment of the present invention, and schematically illustrates a state in which a multi-layer load-bearing wall is installed on a horizontal foundation structure for explaining an embodiment of a method for suppressing damage to a multi-layer load-bearing wall and an installation structure for suppressing damage. (a) is a front view, (b) is a side view, (c) is a cross-sectional view taken along line AA of (a), and (d) is a view of (a). It is a BB sectional view. In the said Example, it is a figure explaining a damper, (a) is a front view, (b) is a side view, (c) is a front view of a damper of another dimension. It is a figure explaining the operation|movement at the time of a medium-large scale earthquake of the said Example. It is a figure explaining the operation|movement at the time of an extremely large-scale earthquake of the said Example. FIG. 2 is a diagram schematically illustrating an example of a stress-strain diagram of steel used for dampers in the above examples.

EMBODIMENT OF THE INVENTION The form for implementing the method of suppressing the damage of the multi-layer bearing wall and the damage suppression installation structure which concerns on this invention is demonstrated below with reference to drawings based on an Example.

Embodiments of the damage control method and damage control installation structure for multi-layer bearing walls according to the present invention are described in detail below with reference to FIGS.

The building structure 1 of this embodiment schematically shown in FIG. 1 has a configuration in which the four sides are surrounded by a multi-layer load-bearing wall 2 in a rectangular shape as a whole, as shown in FIGS. As shown in FIGS. 1(b) and 1(d), an opening 3 is formed in the central portion of the multi-layer load-bearing wall 2 on the lateral side.

The multi-layer load-bearing wall 2 is erected (raised) on the upper surface of the base floor structure 6, and has a top plate 7 or the like on the upper end. FIG. 1 shows horizontal XY directions and vertical Z directions.

Although FIG. 1 shows a structure in which the damper 12 is installed on the outer surface of the multi-story load-bearing wall 2 in the building structure 1, FIG. In fact, there is a high possibility that the damper will be installed inside the multi-story load-bearing wall 2 in order to avoid rain.

In addition, although the building structure 1 shown in FIG. However, there is also a configuration that is not necessarily rectangular in plan view. For example, although not shown, when the multi-layer load-bearing wall 2 is applied as an elevator enclosure wall (to be described later), it has a U-shape in plan view.

In the damage suppression installation structure 8 in which the multi-layer bearing wall 2 is erected on the upper surface of the foundation floor structure 6, the reinforcing bars of the multi-layer bearing wall 2 are not embedded and fixed in the foundation floor structure 6. Simply, the multi-layer bearing wall 2 is placed on the upper surface of the foundation floor structure 6, and the leg portion 9, which is the lower end portion of the multi-layer bearing wall 2, is attached to the foundation floor structure 6 via the damper 12. attached by joining.

The damper 12 has a horizontal mounting portion 13 and a vertical mounting portion 14, as shown in FIGS. The vertical mounting portion 14 stands vertically from one end of the horizontal mounting portion 13 and is reinforced by reinforcing ribs 15 attached to the horizontal mounting portion 13 .

The horizontal mounting portion 13 and the vertical mounting portion 14 are formed with bolt insertion holes 16 through which bolts (not shown) are inserted for mounting to the base floor structure 6 and the leg portions 9 of the multi-story load-bearing wall 2, respectively. .

The damper 12 is a steel damper 12 in this embodiment, and its vertical mounting portion 14 has a narrow plastic section 21 as shown in FIG. , it undergoes plastic deformation (plasticization) when a yield stress acts, and strain hardening occurs when a larger force acts. An example of a stress-strain diagram of the plastic section 21 of the steel damper 12 used in this embodiment is schematically shown in FIG.

Such a stress-strain diagram can be obtained by appropriately setting specifications such as the grade of the steel material of the damper 12 (e.g., LYP100, LYP225, etc.), the width dimension of the plastic section 21, and the vertical dimension of the plastic section 21. It is possible to design the yield stress at which the plastic section 21 of the damper 12 undergoes plastic deformation (the yield stress at which deformation starts is referred to as "yield strength"), tensile strength, and the like.

To be precise, in this embodiment, the plastic section 21 of the damper 12 is plastically deformed, and the strain hardening characteristic described later is used, but in this embodiment, the damper 12 is simply plastically deformed and strain hardened. The expression

FIG. 2(c) shows a modified damper 22 in which the width dimension of the plastic section portion 21 is increased compared to the damper 12 shown in FIG. 2(a). If the material is the same, it is possible to increase the yield stress by increasing the width dimension of the plastic section 21 .

Also, although not shown, when a plurality of dampers 12 are provided, in addition to the above specifications, depending on the number of dampers 12 installed, the size of the yield stress, tensile strength, etc. of the plurality of dampers 12 as a whole can be designed. is possible.

In the present invention, the material of the damper 12, the width dimension of the plastic section 21, the plastic section The specifications such as the vertical dimension of the portion 21 and, depending on the case, the number of dampers 12 and the like are appropriately set (designed).

In the present invention, medium- and large-scale earthquakes are referred to as medium- and large-scale earthquakes, and the magnitudes of medium- and large-scale earthquakes are assumed to be design seismic loads defined by the Building Standards Act. In addition, the maximum scale earthquake described later is an earthquake that is even larger than the large earthquake, and its magnitude is assumed to exceed the design seismic load of the above large earthquake.

By the way, in the damage control installation structure 8 according to the present invention, the damper 12 is attached to the leg portion 9 of the multi-story load-bearing wall 2 and the foundation floor structure 6 by bolts passing through the bolt insertion holes 16, respectively, as shown in FIG. Bonded as shown. The joints of the damper 12 to the leg 9 of the multi-layer bearing wall 2 and the subfloor structure 6 are referred to herein as joints 23 .

In the high-strength bolt friction joining, the load when a load larger than the frictional force between the members acts on such a joint 23 to cause slippage between the members is called "sliding strength". The slip strength of the joint 23 is determined by the tension and number of bolts, the coefficient of friction between the members of the joint 23, and the like.

For example, in a demonstration test conducted by the inventors of this embodiment, the damper 12 is mounted on a high nut (fixed length 105 mm) embedded in the side surface of the leg 9 of the multi-layer load-bearing wall 2, and six high-strength bolts M16 (F10T) was used for bonding.

In this case, the slip strength of the bolt joint 23 obtained from the standard bolt tension (117 kN) is 117 kN x 6 bolts x 0.3 = 211 kN, assuming that the friction coefficient of the interface between concrete and steel is 0.3. .

By the way, assuming that the cross-sectional area of the plastic section of the damper 12 is 35 mm × 14 mm = 490 mm2, the low yield point steel LYP225 is used, the yield strength is 245 N / mm2, and the yield strength increase rate is 1.5, the damper 12 is 1 The design load of each bolted joint 23 is 490 mm 2 ×245 N/mm 2 ×1.5=180 kN.

In the present invention, the slip strength of the joint 23 in the damage suppression installation structure 8 is set to be greater than the yield stress of the damper 12 (see FIG. 5). As a result, the damper 12 is plastically deformed and stretched before slippage occurs at the joint 23 due to a medium- or large-scale earthquake or the like, and the multi-layer load-bearing wall 2 is lifted (see FIG. 3).

The damper 12 according to the present invention will be further described with reference to FIG. 5. In addition to the plastic deformation described above, a steel damper 12 having the following characteristics is used. That is, when a force greater than the yield stress is applied to the damper 12 from the plastic region where plastic deformation occurs, the damper 12 shifts to the strain-hardening region where the strain hardens, and the load stress of the damper 12 increases.

Here, strain hardening refers to the fact that as the degree of plastic deformation increases, the resistance to deformation increases and the material becomes harder than the undeformed material, and is also called "hardening." The damper 12 constrains (stops) plastic deformation when strain hardened.

In the present invention, the material of the damper 12, the width dimension of the plastic section 21, the width of the plastic section 21, and the Specifications such as the vertical dimension of the dampers 12 and the number of dampers 12 are appropriately set (designed).

By the way, the horizontal force of an earthquake acts as a bending stress on the upper part of the joint 23 of the leg 9 of the multi-story bearing wall 2 where the damper 12 is joined. The upper portion of the joint 23 in the leg 9 of the yields in bending. This predetermined bending stress for bending yield is called "bending yield strength".

In the present invention, the bending yield strength acting on the upper portion of the joint 23 is a stress (stress for strain hardening of the damper 12) that is greater than the yield stress and smaller than the slip yield strength of the joint 23 (Fig. 5 ), the strength of the portion above the joint 23 in the leg 9 of the multi-layer bearing wall 2 is set according to the thickness of the wall, the thickness and number of reinforcing bars, the materials used, and the like.

As a result, when the damper 12 is subjected to strain-hardening stress (see FIG. 5) that is greater than the yield stress due to an extremely large-scale earthquake or the like, the damper 12 shifts from the plastic region to the strain-hardening region and undergoes plastic deformation. Restrain (stop).

Then, when the strain hardening stress is greater than the bending strength of the upper portion of the joint 23, no slippage occurs in the joint 23, and the upper portion of the joint 23 in the leg 9 of the multi-layer bearing wall 2 is 4(a) and 4(b), the damper 12 is plastically deformed and floated, and then transitions to bending yielding to avoid brittle fracture.

As described above, in the present invention, a steel damper 12 having plastic deformation and strain hardening characteristics is used, and the yield stress of the damper 12 and the upper portion of the joint 23 in the leg 9 of the multi-layer bearing wall 2 are The specification of the steel damper 12, the strength of the leg 9 in the multi-layer bearing wall 2, the joint The slip resistance of the portion 23 is set, and the setting of this predetermined magnitude relationship is described in (1) to (4) in descending order (ascending order) in contrast to the stress-strain diagram shown in FIG. If you organize it, it will be as follows.

(1) Yield stress of damper 12
This is the stress that plastically deforms the damper 12, and is set so as to correspond to the stress acting in a medium- to large-scale earthquake.
(2) Bending strength of the upper portion of the joint 23 of the leg 9 of the multi-layer bearing wall 2 (3) Slip resistance of the joint 23 in the joint structure (4) Stress in the tensile strength of the damper 12 Stress of the damper 12 Maximum stress on the strain diagram

Although FIG. 5 shows the case where the slip strength of the joint 23 in the joint structure is smaller than the tensile strength of the damper 12 , it may be set to be larger than the tensile strength of the damper 12 . In short, the above (3) and (4) may be reversed in magnitude.

To summarize, in FIG. 5, the force assumed to act on the multi-story bearing wall 2, the foundation floor structure 6, and the joint 23 during a medium- to large-scale earthquake is about the yield stress corresponding to the plastic deformation region. Thus, the material, shape, number, etc. of the dampers 12 used in the present invention are designed.

In addition, so that the assumed force acting on the multi-story bearing wall 2, the foundation floor structure 6, the joint 23, etc. during an extremely large-scale earthquake is about the stress that causes strain hardening of the damper 12 in (2) above. The material, shape, number, etc. of the dampers 12 used in the present invention are designed.

In addition, as shown in (2) to (4) above, the strain hardening stress of the damper 12, the bending strength of the upper portion of the joint 23 with the damper 12 in the leg 9 of the multi-layer bearing wall 2, the joint The size relationship between the sliding strength of the portion 23 and the tensile strength of the damper 12 is designed.

In the present invention, a steel material is used as the damper 12, and by utilizing its characteristics (plastic deformation and strain hardening shown in FIG. 5), the Also, it features a method and a configuration that allow the multi-layer bearing wall 2 to be partially separated from the foundation floor structure 6 .

As a result, the excessive stress applied to the multi-layer bearing wall 2 due to an earthquake is reduced, and the high horizontal rigidity and horizontal strength inherent in the multi-layer bearing wall 2 are exhibited, thereby suppressing damage to the multi-layer bearing wall 2. As a result, it is possible to exhibit the characteristic function of the present invention, which is to prevent the entire building structure 1 from collapsing.

This point will also be described in the operation to be described later, but the outline thereof is as follows. In the event of a medium- or large-scale earthquake, even if the force acts on the damage suppression installation structure 8 and the damper 12, the joint 23 of the joint structure of the damper 12 does not slip, and the damper 12 stretches due to plastic deformation. One end side of the multi-layer load-bearing wall 2 is used as a fulcrum, and the other end side is lifted.

That is, when the damper 12 is plastically deformed and the plastic section 21 is stretched, the multi-layer load-bearing wall 2 is deformed in each of the X direction and the Y direction in plan view, as shown in FIGS. Normally, one end side is used as a fulcrum, and the other side is partially tilted so that it can be lifted from the base floor structure 6 and separated.

When a force greater than the yield stress is applied to the damper 12 during a very large earthquake, the plastic deformation transitions to a strain hardening state, and the elongation due to the plastic deformation of the plastic section 21 is restrained (stopped), resulting in a continuous layer. It suppresses (restricts) the operation of lifting the load-bearing wall 2 from the foundation floor structure 6. - 特許庁

Instead, the force due to the extreme earthquake acts as a bending stress on the upper part of the joint 23 of the damper 12 in the multi-layer bearing wall 2 without slipping at the joint 23 in the joint structure of the damper 12. , part of the upper side of the joint 23 in the leg 9 of the multi-layer bearing wall 2 yields in bending.

Therefore, as shown in FIGS. 4(a) and 4(b), the multi-layer load-bearing wall 2 has one end side as a fulcrum in each of the X direction and the Y direction in a plan view, and the other end side extends from the foundation floor structure 6. It can be tilted and partially separated. In addition, as shown in FIG. 4, the reinforcing bar 24 is exposed at the fractured portion due to the bending yield.

As a result, during a medium- or large-scale earthquake, as described above, the damper 12 is extended and the multi-story bearing wall 2 is lifted. Also, in the event of a large-scale earthquake, the upper portion to which the damper 12 is attached yields in bending, avoiding brittle fracture.

As described above, according to the present invention, the multi-story load-bearing wall 2 can be tilted and separated from the foundation floor structure 6 in both cases of medium- and large-scale earthquakes and extremely large-scale earthquakes. As a result, the multi-layer bearing wall 2 is able to reduce the excessive stress applied to the multi-layer bearing wall 2 due to an earthquake, is not subjected to excessive bending or shearing force, and has a high tensile strength inherent to the multi-layer bearing wall 2. Horizontal rigidity and horizontal strength can be exerted, damage such as cracks caused by bending and shearing force can be suppressed, and overturning of the entire building structure 1 can be prevented.

In this embodiment, the damper 12 is made of steel, but other metal materials may be used as long as they have properties equivalent to those of this embodiment. In other words, any metallic material can be used as long as it has the ability to stretch and has a large deformation area to undergo strain hardening.

(action, etc.)
The method for suppressing damage to a multi-story load-bearing wall and the damage suppression installation structure according to the present invention are as described above. Hereinafter, further explanation will be given including actions (operations), etc., to clarify the features of the present invention. .

The basic method and configuration of the present invention is that, in a building structure 1, a multi-layer load-bearing wall 2, which is erected by being joined to a foundation floor structure 6 via a damper 12, is temporarily lifted by a force applied during an earthquake. It is possible to partially separate from the base floor structure 6 with the side as a fulcrum.

The resulting action is to reduce the excessive stress applied to the multi-story load-bearing wall 2 due to an earthquake, thereby greatly reducing damage to the wall. Furthermore, when the lifting is restrained, the original high horizontal rigidity and horizontal strength of the multi-story bearing wall 2 are exhibited to prevent the entire building structure 1 from collapsing.

The very characteristic method and action of the present invention are as follows. That is, during a medium- or large-scale earthquake, the multi-layer load-bearing wall 2 is tilted with one end side as a fulcrum by the plastic deformation of the damper 12, causing it to float up, so that it can be partially separated from the foundation floor structure 6. As a result, damage to the multi-story load-bearing wall 2 is suppressed, and the entire building structure 1 is prevented from collapsing.

If the ceiling wall, etc. above the multi-layer bearing wall 2 is poorly arranged (imbalanced arrangement), it tends to cause twisting behavior in the event of an earthquake, but it can be lifted up as described above. By doing so, the effect of suppressing twisting behavior can be expected.

In addition, during an extremely large-scale earthquake, strain hardening of the damper 12 suppresses (limits) the movement of the multi-layer bearing wall 2 to rise, and the upper side of the joint 23 of the damper 12 in the multi-layer bearing wall 2 The part is flexurally yielded.

As a result, the multi-layer load-bearing wall 2 can be tilted and partially separated from the foundation floor structure 6 with one end side as a fulcrum, thereby producing a backup function, thereby suppressing damage to the multi-layer load-bearing wall 2. In addition, it is to prevent the entire building structure 1 from collapsing.

In this way, it is possible to suppress the destruction of the multi-layer load-bearing wall 2 by utilizing the characteristics of the damper 12 being plastically deformed and strain hardened in response to medium- and large-scale earthquakes and extremely large-scale earthquakes. do.

Therefore, in the present invention, the damper 12 uses a metal material that undergoes plastic deformation at its yield stress and strain hardens when a force greater than the yield stress acts to constrain the plasticization. The bending yield strength of the upper portion of the joint 23 is set to be greater than the yield stress of the damper 12 (within the strain hardening stress range) and smaller than the slip yield strength of the joint 23 .

With such a setting, when the force applied to the damper 12 is about the yield stress during a medium- or large-scale earthquake, the yield stress is smaller than the slip strength of the joint 23, so that no slip occurs in the joint 23. As shown in FIGS. 3A and 3B, the plastic section of the damper 12 is plastically deformed and elongated. For this purpose, the multi-layer load-bearing wall 2 is tilted with one end side thereof as a fulcrum so that the other end side is partially lifted from the foundation floor structure 6 as shown in FIGS. 3(a) and 3(b).

During a very large-scale earthquake, when the damper 12 is subjected to a force greater than the yield stress and greater than the bending strength of the upper portion of the joint 23 with the damper 12 in the layer bearing wall 2, the damper 12 is strain hardened and the strata The load-bearing wall 2 is restrained from rising from the foundation floor structure 6, and the joint 23 does not slip, and the upper part of the joint 23 with the damper 12 in the multi-layer load-bearing wall 2 bends and yields. Avoid brittle fracture.

As a result, as shown in FIGS. 4(a) and 4(b), the multi-layer bearing wall 2 can be partially separated from the foundation floor structure 6 on the other end side with one end side thereof serving as a fulcrum. While suppressing the damage of 2, it can prevent that the whole building structure 1 collapses.

By the way, in the building structure 1, the multi-story load-bearing wall 2 is installed as a wall forming a room space of each layer, and is installed as a surrounding wall forming a hoistway of an elevator car. Damage to the elevator enclosure wall during an earthquake can create a dangerous situation in which the car is restrained by the damaged enclosure wall while it is ascending or descending, becoming unable to ascend or descend and being trapped inside the enclosure wall.

If the method for suppressing damage to the multi-layer load-bearing wall 2 and the damage-suppressing installation structure 8 according to the present invention is applied to the enclosure wall of an elevator, it is possible to avoid or suppress the possibility of occurrence of such a dangerous condition as described above. can.

As described above, the method for suppressing damage to a multi-layer bearing wall and the damage suppression installation structure according to the present invention have been described based on examples, but the present invention is limited to such examples. Rather, it goes without saying that there are various embodiments within the scope of the technical matters described in the claims.

Since the method for suppressing damage to multi-story bearing walls and the damage suppression installation structure according to the present invention are configured as described above, they can be applied not only to structural walls that form room spaces in building structures, but also to cages in elevators. It can also be applied to a surrounding wall or the like that forms a hoistway.

1 Building structure
2-story bearing wall
3 opening
6 Foundation floor structure
7 top plate
8 Damage suppression installation structure
9 Legs of multi-story bearing walls
12 damper
13 Horizontal mounting part
14 Vertical mounting part
15 Reinforcement rib
16 bolt hole
21 plastic section
22 modified damper
23 joint
24 rebar

Claims (3)

In a building structure, a part of a multi-story load-bearing wall that is joined to the foundation floor structure via a damper can be separated from the foundation floor structure when a horizontal force is applied during an earthquake. A method for suppressing damage to a load-bearing wall, comprising:
The damper uses a metal material that undergoes plastic deformation at the yield stress and strain hardens when a force greater than the yield stress acts. , the bending strength of the upper part of the joint with the damper in the multi-layer bearing wall is smaller than the sliding strength of the joint,
When a force equivalent to the yield stress is applied to the damper during an earthquake, plastic deformation of the damper lifts a part of the multi-story load-bearing wall from the foundation floor structure.
During an earthquake, when a force greater than the yield stress of the damper and less than the predetermined slip strength is applied, the damper strain hardens, and the portion of the multi-layer bearing wall above the joint with the damper yields in bending, resulting in brittle fracture. A method for suppressing damage to a multi-layer load-bearing wall, characterized in that a part of the multi-layer load-bearing wall can be separated from a foundation floor structure by avoiding In a building structure, a damage suppression installation structure in which a multi-story load-bearing wall is installed on a foundation floor structure via a damper,
The damper is made of a metallic material that undergoes plastic deformation at the yield stress and strain hardens when a force greater than the yield stress acts, and is joined to the multi-story load-bearing wall and the foundation floor structure at the joints with bolts,
The flexural strength of the upper part of the joint with the damper in the multi-layer bearing wall shall be greater than the damper yield stress, and shall be smaller than the sliding strength of the joint between the multi-layer bearing wall and the foundation floor structure. Damage suppression installation structure for multi-story load-bearing walls. 3. The multi-layer load-bearing wall damage-suppressing installation structure according to claim 2, wherein the multi-layer load-bearing wall is a surrounding wall that forms a hoistway for a car in an elevator.

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