Abstract:
A robust vibration damping device not suffering from destruction even when an earthquake force is increased. 
     A vibration damping wall structure includes a structural frame comprising a foundation, a beam, and vertical members. One set of vibration damping devices are attached to a first vertical member, and another set of vibration damping devices are attached at positions respectively opposing the one set of vibration damping devices to a second vertical member. Each of the vibration damping devices is connected with the vertical member by way of a brace. The vibration damping devices in the one set and opposing vibration damping devices in another set are connected each other in a lateral direction by lateral connection members between each of the sets. Further, the vibration damping devices of each of the sets are connected each other in a vertical direction by the vertical connection members respectively in each of the sets.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The disclosure of Japanese Patent Application No. 2015-030669 filed on Feb. 19, 2015 including the specification, drawings, and abstract is incorporated herein by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a structure for a vibration damping wall mainly used in wooden buildings or steel structure buildings for reducing an earthquake force that exerts on buildings to improve the horizontal capacity of structural frames, as well as a method of connecting vibration damping devices. 
         [0004]    2. Description of the Related Art 
         [0005]    Techniques relating to vibration damping devices installed to structural frames of buildings and techniques relating to methods of connecting the vibration damping devices and the structural frame for preventing buildings from destruction upon occurrence of huge earthquake have been provided so far (refer to JP-A No. 2009-275473). 
         [0006]      FIG. 6  and  FIG. 7  illustrate a vibration damping device and a method of connecting vibration damping devices and a structural frame shown in JP-A No. 2009-275473 of a building.  FIG. 6  illustrates a structure frame  60  of a building. The structural frame  60  comprises a foundation  61 , a beam  62  and vertical members  63  (first vertical member  63   a  and a second vertical member  63   b ). A first vibration damping device  70   a  is attached about at the midway of a first vertical member  63   a  by fixing means such as bolts or screws and a second vibration damping device  70   b  is attached about at the midway of a second vertical member  63   a  by fixing means such as bolts or screws. 
         [0007]    Corner fittings  71  are fitted each by way of fixing means such as bolts or screws at four corners defined by the first vertical member  63   a  and the second vertical member  63   b , the foundation  61 , and the beam  62 . The four corner fittings  71  and the vibration damping devices  70   a  and  70   b  are connected in an X-form by brace members  72  such as steel pipe brace members as illustrates in  FIG. 7 . 
         [0008]    The vibration damping device  70  is usually in a state as illustrated in  FIG. 8A  and, when an earthquake occurs, the lateral sides  73  expand or contract by the deformation of bend portions of the vibration damping device  70  as illustrated in  FIGS. 8B and 8C  due to earthquake shaking. Then, the earthquake energy is decayed by repeating expansion/contraction to absorb swaying of an entire building structure and prevent the building from destruction. 
       SUMMARY OF THE INVENTION 
       [0009]    Destruction of a building can be prevented effectively by installing the vibration damping devices  70  to the vertical members  63  and connecting them by brace members  72  as described above. 
         [0010]    However, along with reinforcement and scale enlargement of structural materials in recent years, their fixed loads have been increased. Thus, a shaking force due to the earthquake that exerts on the structural frame  60  of the building has been increased and the force exerting on the vibration damping device  70  has also been increased compared with existent cases. Accordingly, in a state of  FIG. 8B , the upper lateral side  73  contracts more largely than usual and the lower lateral side  73  extends more largely than usual. In a state of  FIG. 8C , the upper lateral side extends more largely than usual and the lower lateral side  73  contracts more largely than usual. When such large expansion and contraction repeat, the bending stress on the lateral sides  73  exceeds a limit and plastic cracks are generated to damage the vibration damping device  70 . Then, the vibration damping device  70  no more functions, which may possibly destroy the building finally. 
         [0011]    The present invention intends to solve such a problem and provide a vibration damping wall structure and a method of connecting the vibration damping devices, not leading to destruction of the building even when the earthquake force increases. 
         [0012]    In order to solve the subject, the present invention intends to provide a vibration damping wall structure including; 
         [0013]    a plurality of first vibration damping devices attached to a first vertical member that constitutes a structural frame of a building, 
         [0014]    a plurality of second vibration damping devices attached to a second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices, 
         [0015]    a first brace member for connecting the first vertical member and the second vibration damping devices, 
         [0016]    a second brace member for connecting the second vertical member and the first vibration damping devices, 
         [0017]    lateral connection members for connecting the first vibration damping devices and the second vibration damping devices opposing thereto, 
         [0018]    a first vertical connection member for connecting the plurality of the first vibration damping devices to each other, and 
         [0019]    a second vertical connection member for connecting the plurality of the second vibration damping devices to each other. 
         [0020]    In the vibration damping wall structure of the present invention, the plurality of the first vibration damping devices attached to the first vertical member that constitutes the structural frame of the building and the plurality of the second vibration damping devices attached to the second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices are connected by the lateral connection members and the vertical connection members. 
         [0021]    Thus, earthquake shaking is transferred uniformly from the vertical members by way of the brace members and the lateral connection members and the vertical connection members to the vibration damping devices. 
         [0022]    For solving the subject described above, the present invention also provides a method of connecting vibration damping devices of connecting a plurality of first vibration damping devices attached to a first vertical member that constitutes a structural frame of a building and a plurality of second vibration damping devices attached to a second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices, the method including: 
         [0023]    connecting the first vertical members and the second vibration damping devices by a first brace member, 
         [0024]    connecting the second vertical member and the second vibration damping devices by a second brace member, 
         [0025]    connecting the first vibration damping devices and the second vibration damping devices opposing the first vibration damping devices by lateral connection members, 
         [0026]    connecting the plurality of the first vibration damping devices to each other by the first vertical connection member and 
         [0027]    connecting the plurality of the second vibration damping devices to each other by the second vertical connection member. 
         [0028]    In the method of connecting the vibration damping devices of the present invention, the plurality of the first vibration damping devices attached to the first vertical member that constitutes the structural frame of the building and the plurality of the second vibration damping devices attached to the second vertical member that constitutes the structural frame so as to oppose the first vibration damping devices are connected by the lateral connection members and the vertical connection members. 
         [0029]    Thus, earthquake shaking is transferred from the vertical member by way of the brace member and the lateral connection member and the vertical connection member uniformly to all of the vibration damping devices. 
         [0030]    According to the present invention, the earthquake shaking is transferred from the vertical members by way of the brace members and the lateral connection members and the vertical connection members to all of the vibration damping devices. In this condition, since deleterious deformation of the upper plane of the vibration damping device is restricted by the lateral connection members and the vertical connection members, expansion and contraction in the direction of the height of the lateral side is decreased to reduce the burden on the lateral bend portion  74 . 
         [0031]    Thus, plastic cracks are not generated on the lateral side of the vibration damping device, and the vibration damping device does not suffer from damages and deformation of the structural frame of the building can be reduced finally. That is, by the new method of connecting the vibration damping devices and the brace members, the lateral connection members, and the vertical connection members, since they are operationally associated and restrict the swaying by earthquake, the remarkable effect described above can be provided (this is to be described specifically in preferred embodiments). 
     
    
     
       DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         [0032]      FIG. 1  is a front elevational view illustrating a vibration damping wall structure and a method of connecting vibration damping devices according to a first embodiment of the present invention; 
           [0033]      FIG. 2  is a front elevational view illustrating a mode of transmitting earthquake shaking; 
           [0034]      FIG. 3  is a view illustrating a state where a vibration damping device absorbs earthquake shaking; 
           [0035]      FIG. 4  is a front elevational view of a damping device of a substantially Ω-shaped configuration; 
           [0036]      FIG. 5  is a perspective view of a vibration damping device of a substantially π-shaped configuration; 
           [0037]      FIG. 6  is a view illustrating an existent example of a vibration damping wall structure and a method of connecting vibration damping devices; 
           [0038]      FIG. 7  is a view illustrating a connection portion of the vibration damping device; 
           [0039]      FIGS. 8A-8C  are views illustrating a state that the vibration damping device absorbs earthquake shaking; 
           [0040]      FIG. 9  is a front elevational view illustrating a vibration damping wall structure and a method of connecting vibration damping devices according to a second embodiment of the present invention; 
           [0041]      FIG. 10  is a front elevational view illustrating a transfer mode of earthquake shaking in the second embodiment; and 
           [0042]      FIG. 11  is a view illustrating a state of attaching a vibration damping device and a connection plate of the second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     First Embodiment 
       [0043]    A first embodiment describes an example of a vibration damping wall structure and a method of connecting vibration damping devices in a wooden building. 
         [0044]    For the first embodiment,  FIG. 1  illustrates a vibration damping wall structure and a method of connecting vibration damping devices according to the present invention. 
         [0045]    Since  FIG. 1  shows a lot of constitutional elements that are identical with those of  FIG. 6  explained as the prior art, identical reference numerals are used for identical constitutional elements and only the differences are to be explained. 
         [0046]    This embodiment has a constitution as illustrated in  FIG. 1 , which is different from the existent embodiment in  FIG. 6  with respect to the followings. 
         [0000]    (1) Vibration damping devices are provided each by one on the right and left not but provided each by two on the right and left. It is assumed here that 
         [0047]    the vibration damping device provided to an upper portion of a vertical member  63   a  is referred to as a damping device  70   a,    
         [0048]    a vibration damping device provided at a lower portion of the vertical member  63   a  is referred to as a vibration damping device  70   c,    
         [0049]    a vibration damping device provided to the upper portion of a vertical member  63   b  is referred to as a vibration damping device  70   b , and 
         [0050]    a vibration damping device provided at a lower portion of the vertical member  63   b  is referred to as a fourth vibration damping device  70   d.    
         [0000]    (2) The vibration damping device  70   a  and the vibration damping device  70   b  are connected by a lateral connection member  1   a , and the vibration damping device  70   c  and the vibration damping device  70   d  are connected by a lateral connection member  1   b.  
 
(3) The vibration damping device  70   a  and the vibration damping device  70   c  are connected by a vertical connection member  2   a , and the vibration damping device  70   b  and the vibration damping device  70   d  are connected by a vertical connection member  2   b.  
 
         [0051]    Then, a step of connecting the members of the present invention is to be described. 
         [0052]    First, as a first step, corner fittings  71  are mounted to corners of the structural plane that constitutes the structural frame  60  of a building respectively and, subsequently, the vibration damping device  70   a  is attached to a first vertical member  63   a  by about 250 mm to 500 mm above the center of the first vertical member  63   a . The vibration damping device  70   b  is attached to the second vertical member  63   b  at a position opposing thereto. The vibration damping device  70   c  is attached to the first vertical member  63   a  at a position about 250 mm to 500 mm below the center of the first vertical member. The vibration damping device  70   d  is attached to the second vertical member  63   b  at a position opposing thereto. 
         [0053]    As a second step, crossing steel pipe braces (braces  72 ) are attached to upper and lower stages of the structural plane each at a position between each of the corner fittings  71  and each of the vibration damping devices  70 . 
         [0054]    As a third step, the vibration damping device  70   a  and the vibration damping device  70   b  are connected by the lateral connection members  1   a  and the vibration damping device  70   c  and the vibration damping device  70   d  are connected by the lateral connection members  1   b  respectively. Further, the vibration damping device  70   a  and the vibration damping device  70   c  are connected by the vertical connection member  2   a  and the vibration damping device  70   b  and the vibration damping device  70   d  are connected by the vertical connection member respectively. 
         [0055]    As a fourth step, after adjusting the plumbing of the structural plane, connection points are tightly connected by high tension bolts and nuts thereby providing a vibration damping wall structural plane. 
         [0056]    Then, the function and the effect of the first embodiment are to be described with reference to  FIG. 2 . 
         [0057]    In  FIG. 2 , stress of an earthquake force is transmitted from the first vertical member  63   a  and the second vertical member  63   b  through the upper brace member  72  (upper cross steel pipe brace member) and the lower brace member  72  (lower cross steel pipe brace member) to the lateral connection members  1 . 
         [0058]    In this condition, the lateral connection member  1   a  operates in a mode like crank movement by vertical sliding of each of the vibration damping devices  70   a  and  70   b  in the direction of the height of the structure plane. 
         [0059]    Thus, the lateral connection member  1   a  restricts excess deformation of the upper plane  28   a  by sliding like a piston movement while pressing the upper plane of the vibration damping devices  70  downward upon forward pressing and pulling upward the upper plane upon backward pressing (sliding only for a relative position without changing an absolute distance in the upper plane) ( FIG. 4 ). 
         [0060]    Accordingly, excess deformation of the vibration damping device  70  can be restricted to a necessary and sufficient extent even when the support member  22  ( FIG. 4 ) is not present and the bearing performance can also be enhanced while improving the vibration damping performance. 
         [0061]    The restrictive phenomenon described above is due to the crank movement of the lateral connection members. 
         [0062]    As described above, the stress exerting from the brace member  72 , and the vertical connection member  1  and the lateral connection member  2  to extensions thereof by the continuous sliding of the upper plane  28   a  ( 28   b ) ( FIG. 4 ) of the vibration damping device does not converge to a point since the lateral side bend portion  74  ( FIGS. 8A-8C ) as a fulcrum of stress transmission moves vertically and right to left like a roller. 
         [0063]    By the remarkable effect of dispersing the stress exerted from the brace member  72 , and the vertical connection member  1  and the lateral connection member  2  over a wide range of a bottom plate  29  of the vibration damping device  70 , the reaction caused by an excessive earthquake force is received substantially uniformly over the entire bottom area of the bottom plate  29  and, as a result, damages that may likely to occur by bending deformation of the vertical member  63  to the the vibration damping device attached at about the center of the vertical member  63  of the structural plane frame of the building can be prevented effectively. 
         [0064]    Meanwhile, the sliding movement of the vibration damping devices  70   a  and  70   b  brings about vertical movement of the vertical connection members  2   a  and  2   b . The vibration damping devices  70   c  and  70   d  also operate simultaneously to induce the crank movement of the lateral connection member  1   b  thereby causing the damping phenomena described above to reliably restrict the excess deformation of the vibration damping device  70  by co-operation of upper and lower vibration damping devices, so that the vibration damping effect can be improved and bearing performance can be enhanced. 
         [0065]    As described above, since the earthquake force is transmitted further uniformly to the vibration damping devices  70  entirely, expansion and contraction of the lateral sides  73  are decreased further ( FIG. 3 ) compared with those in  FIGS. 8A-8C , a risk of damaging the vibration damping device  70  by plastic cracks can be decreased further and, in addition, destruction of the vertical member  63  can be decreased remarkably. The material and the shape of the lateral connection member  1  and the vertical connection member  2  may be identical with those of the brace member  72 , or they may comprise other rod-like members. 
         [0066]    Then, the vibration damping device  70  is to be described specifically. The vibration damping device  70  includes two types depending on whether the device has a support member  22  or not. In this embodiment, a vibration damping device of a type having the support member  22  is to be described specifically.  FIG. 4  illustrates a substantially Ω-shaped vibration damping device  70  having a support member  22 . The substantially Ω-shaped vibration damping device  70  comprises a vibration damping element  21  made of a low yield point steel and a support member  22  for supporting the vibration damping element  21 . 
         [0067]    The vibration damping element  21  comprises a steel strip that causes plastic deformation when undergoing a stress beyond an elastic limit and has a first attaching plane  23   a  and a second attaching plane  24   a  for attachment to a vertical member  63 , a first rising portion  25   a  rising from the inner end of the first attaching plane  23   a , a second rising portion  26   a  rising from the inner end of a second attaching plane  24   a , and an upper plane  28   a  that connects the first rising portion  25   a  (lateral side  25   a ) and a second rising portion  26   a  (lateral side  26   a ) and receives an earthquake shaking transmitted from the structural frame  60  by way of a brace member  72  and an attaching plate  27 . The vibration damping element  21  absorbs earthquake shaking as shown in  FIG. 8B  and  FIG. 8C , thereby improving the earthquake resistance of a building. 
         [0068]    The support member  22  is a cylindrical member. That is, the support member  22  has a first arcuate lateral side  31  and a second arcuate lateral side  32  and is disposed in a space surrounded by an upper plane  28   a , the first rising portion  25   a  and the second rising portion  26   a . The first lateral side  31  is disposed in the inside near the first bend portion  33  formed of the first rising portion  25   a  and the upper plane  28   a , and the second lateral side  32  is disposed in the inside near a second bend portion  34  formed of the second rising portion  26   a  and the upper plane  28   a.    
         [0069]    By the provision of the support member  22 , when an earthquake shaking is transmitted to the vibration damping device  21 , excess deformation of the first bend portion  33  and the second bend portion  34  is supported and restricted more reliably by the support member  22  and, accordingly, damages of the vibration damping device  70  caused by generation of plastic cracks can be prevented. 
         [0070]      FIG. 5  illustrates a substantially π-shaped vibration damping device  70 . 
         [0071]    The constitution of the substantially π-shaped vibration damping device  70  is similar to that of the substantially Ω-shaped vibration damping device  70  in  FIG. 4 , but is different therefrom with respect to the following points. That is, in the substantially π-shaped vibration damping device  70 , each of a first rising portion  25   b  and a second rising portion  26   b  is formed by bending a steel strip made of low yielding point steel into a substantially L-angled shape being rounded at a corner, and fixed on the bottom plate  29  such that angled edges are outwarded and opposed at a predetermined distance. 
         [0072]    Compared with the substantially Ω-shaped vibration damping device, since the π-shaped vibration damping device  70  has only two opposed portions (first rising portion  25   b  and the second rising portion  26   b ) formed by bending the lower portions, earthquake shaking is directly transmitted to the opposed portions. Accordingly, the device of this type has an advantage that the first rising portion  25   b  and the second rising portion  26   b  can be deformed simply and, on the other hand, the support member  22  has to be mounted for restricting excess deformation. Excess deformation less occurs by so much as the shape is simple and short. 
         [0073]    On the other hand, the upper plane  28   b  is made of common steel (SS 330 •SS 400 •SS 540 , etc.) and has a constitution of intending to exclusively rely on the rigidity and the strength of the upper plane for firmly holding an attaching plate  35  that fixes chord members such as the brace member  72 , the lateral connection member  1 , the vertical connection member  2 , etc. Then, for making the joint with the L-shaped angle member more firmly, each of the top ends is hooked in the direction of the first attaching plane  23   b  and the second attaching  24   b.    
       Second Embodiment 
       [0074]    A second embodiment describes an example of a vibration damping wall structure and a method of connecting vibration damping devices. 
         [0075]    In this embodiment,  FIG. 9  illustrates a vibration damping wall structure and a method of connecting vibration damping devices according to the present invention. 
         [0076]    Since  FIG. 9  shows a lot of constitutional elements that are identical with those of  FIG. 1  explained as the first embodiment, identical reference numerals are used for identical constitutional elements and only the differences are to be explained. 
         [0077]    The second embodiment has a constitution as illustrated in  FIG. 9 , which is different from the first embodiment (shown in  FIG. 1 ) in that the vibration damping devices  70  are connected not by the lateral connection member  1  and the vertical connection member  2  but by a connection plate member  36  comprising a structural plywood or a metal plate or a composite plate integrally. 
         [0078]    The connection plate member  36  is joined at each of corners to an attaching plate  27  of a vibration damping device  70  by means of high tension bolts  75  and nuts in the same manner as in the case of the lateral connection member  1  and the vertical connection member  2  of the first embodiment. In the first embodiment, a rectangular frame of an instable structure is formed by the lateral connection member  1  and the vertical connection member  2 , which tends to be deformed into a parallel piped shape following the deformation of the building upon exertion of an earthquake force. On the other hand, in the second embodiment, the connection plate member  36  per se is a plate member having a large in-plane rigidity, which repeats rotational movement swinging right and left while keeping a quadrangular shape following the sliding movement of the upper plane  28  of the vibration damping device  70  due to deformation of the building upon exertion of the earthquake force. 
         [0079]    Next, the function and the effect of this embodiment are to be described with reference to  FIG. 10 . 
         [0080]    In  FIG. 10 , stress of an earthquake force is transmitted from the first vertical member  63   a  and the second vertical member  63   b  by way of the upper brace member  72  (upper cross steel pipe brace) and the lower brace member  72  (lower cross steel pipe brace) by way of the vibration damping devices  70  to the connection plate member  36 . 
         [0081]    In this condition, the connection plate member  36  moves vertically and right to left by vertical sliding movement of the upper planes  28   a  and  28   b  of each of the vibration damping devices  70   a  and  70   b  in the direction of the height of the wall plane (vertical direction). 
         [0082]    Thus, since the connection plate member  36  slides the upper planes  28   a  and  28   b  of the vibration damping devices  70  while pressing downward upon forward pressing and pulling the upper planes upward upon backward pressing (sliding only for a position without changing an absolute distance between the upper planes). 
         [0083]    Accordingly, excess deformation of the vibration damping device  70  is restricted to a necessary and sufficient extent and also the bearing performance can be enhanced while improving the vibration damping performance even when the support member  22  ( FIG. 4 ) is not present in the same manner as in the first embodiment. The damping phenomenon described above is due to the action of the connection plate member  36 . 
         [0084]    As described above, stress exerting from the brace member  72  and the connection plate member  36  to the extensions thereof by continuous sliding of the upper plane  28   a  of the vibration damping device ( FIG. 11 ) does not converge to a point since the lateral side bend portion  74  ( FIG. 8 ) moves vertically and right to left following the sliding movement like a roller in the same manner as in the first embodiment. 
         [0085]    Accordingly, by the remarkable effect that the stress exerting from the brace member  72  and the connection plate member  36  to the extensions thereof less converges to a point of the vertical member  63  of the building structure frame but disperses over a wide range of the bottom plate  29  of the vibration damping device  70 , the reaction caused by an excessive earthquake force is dispersed at random over the entire bottom of the bottom plate  29  and, as a result, damages caused by the bending deformation of the vertical member  63  that tends to be formed in the vibration damping device attached near the central portion of the vertical member  63  of the structural wall frame of the building can be prevented effectively. 
         [0086]    On the other hand, the sliding movement of the upper plane  28   a  of the vibration damping device  70   a  and the upper plane  28   b  of the vibration damping device  70   b  brings about a vertical movement of the connection plate member  36  in the longitudinal direction (vertical direction), in which the vibration damping devices  70   c  and  70   d  operates simultaneously thereby inducing the lateral (horizontal) rotational action of the connection plate member  36 , which can control the over deformation of the vibration damping device  70  reliably by the cooperation of the upper and lower vibration damping devices  70 , thereby improving the vibration damping performance and enhancing the bearing performance. 
         [0087]    As described above, upon occurrence of an earthquake, since the action thereof is transmitted entirely by the vibration control devices  70  and the connection plate member  36  more uniformly, expansion and contraction of the lateral side  73  are decreased compared with those in the prior art ( FIGS. 8A-8C ), and the risk of damaging the vibration damping device  70  by plastic cracks can be decreased further. As a result, destruction of the vertical member  63  of the building structural frame  60  by the damages of the vibration damping device  70  can be avoided and the earthquake energy can be absorbed and decayed effectively. 
         [0088]    In addition, for the connection plate member  36 , it is not particularly necessary to provide a plate member designed previously to a prescribed size and the connections plate member  36  sized in situ depending on the condition of the spot can be manufactured and assembled and the cost can be decreased. 
       DESCRIPTION OF REFERENCE SIGNS 
       [0000]    
       
         P external force 
           1   a ,  1   b  lateral connection member 
           2   a ,  2   b  vertical connection member 
           21  vibration damping element 
           22  support member 
           23   a ,  23   b  first attaching plane 
           24   a ,  24   b  second attaching plane 
           25   a ,  25   b  first rising portion 
           26   b ,  26   b  second rising portion 
           27  attaching plate 
           28   a ,  28   b  upper plane 
           29  bottom plate 
           31  first lateral side 
           32  second lateral side 
           33  first bend portion 
           34  second bend portion 
           35  attaching plate 
           36  connection plate member 
           60  structural frame 
           61  foundation 
           62  beam 
           63   a ,  63   b  vertical member 
           70  ( 70   a ,  70   b ,  70   c ,  70   d ) vibration damping device 
           71  corner fitting 
           72  brace member 
           73  lateral side 
           74  Bend portion of lateral side 
           75  high tension bolt