Abstract:
There is disclosed a brace-type damper mounting structure, which provides a highly-reliable stabilized joint member to produce sufficient damper functions against external turbulent force such as earthquakes and wind, and is so rational as to achieve higher workability. According to the mounting structure of the present invention, brace-type dampers are placed in V-shaped arrangement, for instance, to the inside of frames composed of columns and beams of a reinforced concrete structure. When the brace-type dampers are placed in the frames of columns and beams, one end of each brace-type damper is connected to a band-shaped reinforcing plate united to the outer surface part of each column through a gusset plate with a pin, separately from each beam. The other end of each brace-type damper is connected to a gusset plate, which is projecting from the upper surface of an anchoring member embedded in each beam, with a pin.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to a brace-type damper mounting structure useful in a reinforced concrete structure such as a building structure and a civil-engineering structure in order to produce resisting and damping forces against external turbulent force such as earthquakes and wind.  
           [0003]    2. Description of the Related Art  
           [0004]    As a structure for placing brace-type dampers in a reinforced concrete structure such as a building structure and a civil-engineering structure, it is well known that steel frame members are built in column-to-beam joints of reinforced concrete construction, before each brace-type damper is mounted through a gusset plate anchored to each steel frame member by welding so as to transmit resisting or damping force produced from the dampers to a main frame of columns and beams.  
           [0005]    The brace-type dampers are often placed in V-shaped or inverted V-shaped arrangement within a plane of structure. In this case, one end of each brace-type damper needs to be mounted to a beam center portion. As a structure for placing the brace-type dampers as described the above, it is generally used to set an anchor prior to placement of concrete for the beams, before one end of each brace-type damper is connected to the gusset plate mounted to the anchor.  
           [0006]    However, the above mounting structure of the brace-type dampers at the column-to-beam joint position presents the following problems.  
           [0007]    A large number of reinforcements for columns, as well as reinforcements for beams, are placed in the column-to-beam joints of reinforced concrete construction in every direction, so that the gusset plate or the like is extremely hard to be set as described above, and besides, a large number of holes allowing the reinforcements to pass are inevitably required for the gusset plate. That is, the above column-to-beam joints of reinforced concrete construction are supposed to be in more severe conditions than joints of steel-framed reinforced concrete construction.  
           [0008]    The use of steel-framed columns and beams only for arrangement of braces is supposed to be contrary to meet a demand for shorter term of construction works, so that the greater number of days is required for execution of construction works.  
           [0009]    A problem exists also in filling performance of concrete used after erection of the reinforcements, since the steel frame members and the gusset plates are placed in the embedded state in the column-to-beam joints.  
           [0010]    It is further well known that each gusset plate is mounted across the column and the beam. However, in case of making a design for a building, considerations are made to design so that energy of external turbulent force such as earthquakes may be absorbed by the action of hinge (a plastic region) produced at the beam end (the joint of the beam to the column). In this connection, because of the danger of damages to the beam end by earthquakes or the like, using the gusset plates mounted as described the above is not rational to mount the brace-type dampers in a stable state.  
           [0011]    Incidentally, problems with the mounting structure of the brace-type dampers at the beam center position are that using a normally available anchor is not enough to meet a demand for sufficient transmission of stress against force applied from the brace-type dampers to the beam center position, in addition to the need for time-consuming mounting works.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention is provided for solving the above problems in the prior art, and its object is to provide a brace-type damper mounting structure, which provides highly reliable stabilized joints to produce sufficient damping functions against external turbulent force such as earthquakes and wind and is so rational as to achieve higher workability.  
           [0013]    The present invention according to claim I relates to a structure for mounting a brace-type damper with a damper incorporated in a brace to the inside of each frame composed of columns and beams of a reinforced concrete structure, and this mounting structure comprises a reinforcing plate united to an outer surface part of each column making up the above frame, separately from each beam, wherein one end of the brace-type damper is connected to the reinforcing plate.  
           [0014]    The damper applicable to the brace-type damper includes an oil damper, a friction damper and other various kinds of conventional dampers having been developed for seismic response control. Incidentally, the present invention accepts the brace-type damper with the damper incorporated in the brace as equivalent to a damper functioning as the brace as a whole, without being limited to a damper mounted to an intermediate part of the brace.  
           [0015]    The reinforcing plate is so united to the outer surface part of each column as to provide a structure having no effect on bar arrangement of the columns. The reinforcing plate is provided separately from each beam for the purpose of eliminating shearing or axial force transmitted from the brace-type dampers from directly acting on the beam ends possible to be plasticized when the earthquake happened. Thus, any reinforcing plate making no contribution toward substantially direct transmission of force will be enough, even if having a portion making contact with a beam portion depending on the need for surface finishing, for instance.  
           [0016]    Unless otherwise specified, a method for connecting the reinforcing plate to the end of each brace-type damper may be generally by mounting the gusset plate to the reinforcing plate by welding, for instance, before the end of each brace-type damper is connected to the gusset plate with a bolt or a pin.  
           [0017]    There is a danger that additional shearing or axial force to the columns will be increased by reason that at least one end of each brace-type damper is mounted only to the column side. However, when a damping device such as the oil damper is placed in the building, a phase difference is produced between the response of the building and the response of the damper. For that reason, the damper force does not always reach the maximum whenever the response of the building is maximized, so that there is less stress added as well in general.  
           [0018]    Using the oil damper or the like, for instance, also provides relief functions through valve operations or the like enough to put restrictions on the maximum damping force, resulting in a contribution also toward controlling the stress added.  
           [0019]    Incidentally, it is supposed that the reinforcing plate may be united to each column at its upper or lower end as described in claim 2.  
           [0020]    In case of the brace-type dampers placed in generally V-shaped or inverted V-shaped arrangement, it is efficient to connect each brace-type damper to the reinforcing plate, which is mounted to the upper end of each column for V-shaped arrangement or to the lower end of each column for inverted V-shaped arrangement, in relation to the end connected to each column.  
           [0021]    It is also supposed that the form of the reinforcing plate as described in claim 3 or 4 is available.  
           [0022]    In the brace-type damper mounting structure according to claim 1, a brace-type damper mounting structure according to claim 3 is characterized in that the above reinforcing plate includes a band-shaped reinforcing plate placed around the outer surface part of each column.  
           [0023]    A section closed in a ring shape is formed using the band-shaped reinforcing plate placed around the outer surface part of each column, so that the reinforcing plate itself provides high stiffness in the state of being united to each column.  
           [0024]    In the brace-type damper mounting structure according to claim 1, a brace-type damper mounting structure according to claim 4 is characterized in that the above reinforcing plate includes a band-shaped reinforcing plate placed around an outer surface part within a column section as equivalent to the above outer surface part of each column.  
           [0025]    The reinforcing plate placed as described the above is applied on the assumption that there is no desire to expose the reinforcement plate to the outer surface, from the viewpoint of designs.  
           [0026]    In the brace-type damper mounting structure according to claim 3 or 4, a brace-type damper mounting structure according to claim 6 is characterized in that inner partition plates located within the column section are provided on the inside of the band-shaped reinforcing plate.  
           [0027]    While deformation of the reinforcing plate may be controlled using the ring-shaped closed structure according to claim 3 or 4, using the inner partition plates connected to the inside of the reinforcing plate may minimize local deformation of the reinforcing plate at the brace-type damper mounting position or the like.  
           [0028]    As described the above, the present invention according to claims 1 to 4 and 6 may provide a rational and simple mounting structure, since the brace-type dampers are mounted to the inside of the frames of columns and beams by means of mounting each brace-type damper to the head or base of each column member, which is higher in proof stress and durability than the beams, to the exclusion of mounting to the beam end supposed to be damaged by external turbulent force such as earthquakes.  
           [0029]    Each brace-type damper is mounted to the reinforcing plate placed around the outer surface part of each column, and therefore, has no bad influence upon the reinforcements placed in the column-to-beam joints nor hinders execution of works for concrete filling, resulting in achievement of higher workability.  
           [0030]    The above mounting structure is for the brace incorporating the damper without increasing a burden on the column end, differently from the structure subjected to direct transmission of shearing or axial force like using a normally available brace with no damper, and therefore, is attributable to a rational mounting structure in a combination with brace-type damper functions.  
           [0031]    The present invention according to claim 11 relates to a structure for mounting a brace-type damper with a damper incorporated in a brace to the inside of each frame of columns and beams of a reinforced concrete structure, and this mounting structure comprises an anchoring member embedded in each beam making up the above frame, wherein one end of the brace-type damper is connected to a joint member, which so extends from the anchoring member as being projected from the upper or lower surface of each beam.  
           [0032]    Using the anchoring member embedded in an axial center portion of each beam, for instance, results in mounting one end of each brace-type damper to the axial center portion of each beam. Thus, the brace-type dampers may be received in a plane of structure in V-shaped or inverted V-shaped arrangement as the above general form of arrangement.  
           [0033]    Using the anchoring member embedded in a beam portion close to each column results in mounting one end of each brace-type damper to the beam portion close to each column. Thus, it may be modified to mount the individual brace-type damper to the beam portion close to each column.  
           [0034]    It is supposed that shape steel is available for the anchoring member as described in claim 13. Short H-sections or the like are suitably used, or otherwise, channels or T sections will be also enough. The anchoring member made up of the shape steel is embedded in the concrete and in this state, is bonded to its surrounding concrete, resulting in a contribution toward smooth transmission of the force produced from the brace-type dampers to the beams.  
           [0035]    As described in claim 14, the shape steel making up the anchoring member has flanges placed in parallel to a joint surface of the brace-type damper with each beam. The flanges of the shape steel will make resistance to the force, which shifts the anchoring member in the direction orthogonal to the axis of each beam.  
           [0036]    The brace-type dampers may be mounted to each joint member such as the gusset plate, which so extends from the anchoring member as being projected from the upper or lower surface of each beam, with bolts or pins. Incidentally, the use of an anchoring member united to the joint member will be also enough.  
           [0037]    As described the above, the present invention according to claim 11 makes a contribution toward not only reinforcement of portions affected by the force transmitted from the brace-type dampers but also smooth transmission of force between the anchoring member anchored in the concrete section and the concrete, since the brace-type dampers are mounted to the inside of the frames of columns and beams by means of mounting one end of each brace-type damper using the anchoring member provided in the section making up the section of each beam.  
           [0038]    In the brace-type damper mounting structure according to claim 11, a brace-type damper mounting structure as described in claim 15 is characterized in that flanges for preventing the anchoring member from being shifted in the axial direction are mounted to the anchoring member.  
           [0039]    While using only the anchoring member extending in the axial direction of each beam makes resistance basically under the influence of bond to the concrete, the anchoring member having the flanges may produce the damper functions of the brace-type dampers more surely since the flanges apply compressive force to the concrete enough to mount the anchoring member in the beam section more surely.  
           [0040]    In the present invention according to claim 15, while the flanges having the anchoring functions are mounted to the anchoring member to prevent the anchoring member from being shifted in the axial direction, transmission of the axial force from the brace-type dampers to the beams is smoothly made under the influence of the compressive strength of the concrete, together with the bond of the anchoring member to the concrete, since the flanges are functioning to apply the compressive force to the concrete at all times. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0041]    The foregoing and other objects and features of the invention will become apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings, in which:  
         [0042]    [0042]FIG. 1 is a perspective view showing the outline of the overall brace-type damper mounting structure according to the present invention;  
         [0043]    [0043]FIG. 2 is a horizontal cross-sectional view showing one embodiment of the brace-type damper mounting structure according to the present invention;  
         [0044]    [0044]FIG. 3 is a vertical cross-sectional view showing one embodiment of the brace-type damper mounting structure according to the present invention;  
         [0045]    [0045]FIG. 4 is a horizontal cross-sectional view showing one embodiment of the brace-type damper mounting structure according to the present invention;  
         [0046]    [0046]FIG. 5 is a vertical cross-sectional view showing one embodiment of the brace-type damper mounting structure according to the present invention;  
         [0047]    [0047]FIG. 6 is a horizontal cross-sectional view showing one embodiment of the brace-type damper mounting structure according to the present invention;  
         [0048]    [0048]FIG. 7 is a vertical cross-sectional view showing one embodiment of the brace-type damper mounting structure according to the present invention;  
         [0049]    [0049]FIG. 8 is a schematic view showing the overall brace-type damper mounting structure according to the present invention;  
         [0050]    [0050]FIG. 9 is a perspective view showing one embodiment of the brace-type damper mounting structure according to the present invention; and  
         [0051]    [0051]FIG. 10 is a perspective view showing one embodiment of the brace-type damper mounting structure according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0052]    [0052]FIG. 1 shows the outline of the overall brace-type damper mounting structure according to the present invention, wherein two pieces of brace-type dampers  3  are placed in V-shaped arrangement within each frame composed of columns  1  and beams  2  of a reinforced concrete structure.  
         [0053]    As viewed in terms of one plane of structure, an upper end of each of two pieces of brace-type dampers  3  placed in V-shaped arrangement is connected to a band-shaped reinforcing plate  4  united to the outer surface of an upper column end just beneath each column-to-beam joint (a panel zone).  
         [0054]    Incidentally, in one embodiment according to the present invention, a gusset plate  5  is mounted to each reinforcing plate  4  by welding, and the end of each brace-type damper  3  is connected to the gusset plate  5  with a pin  6 . While the reinforcing plate  4  is united to the upper end of each column  1  in the above embodiment, it is to be understood that it may be also modified to unite the reinforcing plate to the lower end of each column  1 .  
         [0055]    [0055]FIGS. 2 and 3 show one embodiment of the reinforcing plate  4 . In FIG. 2, reference numeral  1   a  denotes a main reinforcement of the column  1 , and  1   b  is a hoop. Concrete in the column  1  is not shown in FIG. 2.  
         [0056]    This embodiment has the similar features to that of FIG. 1 to the extent that each brace-type damper  3  is connected to the gusset plate  5 , which is mounted to the band-shaped reinforcing plate  4  around the outer surface of the upper end of each column  1 , with the pin  6 . However, according to this embodiment, inner partition plates  7  are further provided on the inside of the reinforcing plate  4  placed around the outer surface part of each column  1  into a quadrangular prismatic shape, and studs  8  serving as shear connectors are mounted to the inner partition plate  7  and the inner surface of the reinforcing plate  4  by welding to provide more enhanced unitedness with the concrete for the columns  1  enough to prevent the reinforcing plate  4  from being deformed.  
         [0057]    As shown in FIG. 3, a half pre-cast beam member  2   a  is used for each beam  2  in the above embodiment, so that each beam  2  is formed by means of uniting the half pre-cast beam member with cast-in-place concrete (not shown). The reinforcing plate  4  is out of contact with the bottom surface of the half pre-cast beam member  2   a  making up each beam  2 , thus providing a structure which eliminates shearing or axial force transmitted from the brace-type dampers  3  from directly acting on the beams  2 .  
         [0058]    Incidentally, since a portion having the reinforcing plate  4  is reinforced with the reinforcing plate  4  together with the inner partition plates  7 , the hoop  1   b  of each column  1  may be used as it is, or otherwise, the use of no hoop will be also enough. The use of no hoop  1   b  makes it easy to place the reinforcing plate  4  inclusive of the inner partition plates  7 .  
         [0059]    [0059]FIGS. 4 and 5 show modifications of the inner partition plates  7  provided on the inside of the reinforcing plate  4 . Having described the embodiment in FIG. 2 in relation to the inner partition plates  7  placed in parallel to one-directional side plates making up the band-shaped reinforcing plate  4 , the inner partition plates  7  in the modification shown in FIG. 4 are placed in cross-shaped arrangement.  
         [0060]    More specifically, in the embodiment shown in FIG. 2, the central inner partition plate  7  continuously extending to the gusset plate  5  mounted to the central position of the reinforcing plate  4  (in the quadrangular prismatic width direction) is placed in parallel to other inner partition plates  7  on both sides of the central inner partition plate  7 .  
         [0061]    On the contrary, in the modification shown in FIG. 4, the central inner partition plate  7  continuously extending to the gusset plate  5  mounted to the central position of the reinforcing plate  4  (in the quadrangular prismatic width direction) and another central inner partition plate  7  orthogonal to the above central inner partition plate  7  are placed in cross-shaped arrangement.  
         [0062]    [0062]FIGS. 6 and 7 show a different embodiment of the reinforcing plate  4 . The reinforcing plate  4  in this embodiment is formed in the shape of a band so as to be placed around the outer surface part in the column section as equivalent to the outer surface part of each column  1  into one body.  
         [0063]    The reinforcing plate placed as described the above is applied on the assumption that there is no desire to expose the reinforcing plate  4  to the outer surface, from the viewpoint of designs, for instance.  
         [0064]    The following is a conceivable situation applied to the case where there is no desire to expose the reinforcing plate to the outer surface. That is, the reinforcing plate will be placed around the outer surface part of each column  1  into one body as described the above on the assumption that the columns  1  and the beams  2  are constructed using concreting in site, whereas there is no need for placing the reinforcing plate around the outer surface part of each column  1  in case of erecting columns and beams made up of pre-cast members into construction.  
         [0065]    In this case, using the band-shaped reinforcing plate  4  placed around the outer surface part in the section of each column  1  (embedded in each column  1 ) may improve the appearances as the pre-cast members, while producing the effects of the reinforcing plate  4  of the present invention.  
         [0066]    In the embodiment shown in FIG. 1, the lower end of each brace-type damper  3  is connected to the joint member (the gusset plate  10 ), which is projecting from the upper surface of the short H-section-made anchoring member  9  embedded in the center of each beam  2 , with the pin  6 .  
         [0067]    While the gusset plate  10  as the joint member in the above embodiment is projecting from the upper surface of the anchoring member  9 , it is to be understood that the gusset plate  10 , when applied to the case of placing two pieces of brace-type dampers  3  in inverted V-shaped arrangement, is modified to project from the lower surface of the anchoring member  9 , as a matter of course.  
         [0068]    When two-pieces of brace-type dampers  3  are placed in inverted V-shaped arrangement, the lower end of each brace-type damper also needs to be connected to the reinforcing plate  4  united to the outer surface of a lower column end just above each column-to-beam joint as a matter of course.  
         [0069]    Incidentally, having described the embodiment in FIG. 1 in relation to the anchoring member  9  embedded in the center portion of each beam  2 , it is to be understood that it may be modified to embed the anchoring member in a beam portion close to each column  1  for pin-connection of the individual brace-type damper  3  to the anchoring member  9  (the gusset plate  10 ), as shown in FIG. 8.  
         [0070]    [0070]FIG. 9 shows one embodiment of the anchoring member  9  more specifically. In FIG. 9, reference numeral  2   a  denotes an upper end reinforcement of the beam  2 , and concrete in the beam  2  is not shown.  
         [0071]    This embodiment has the similar features to that of FIG. 1 to the extent that the short H-section is used for the anchoring member  9 , and the lower end of each brace-type damper  3  is connected to the gusset plate  10 , which is united to the upper surface of an upper flange of the H-section, with the pin  6 .  
         [0072]    Studs  11  serving as shear connectors are mounted to the H-section web of the anchoring member  9  by welding to provide more enhanced bond of the beams  2  to the concrete. The H-section flanges of the anchoring member  9  are placed in parallel to a joint surface of the brace-type dampers  3  with each beam  2  to make a contribution toward resistance to the force, which shifts the anchoring member in a direction orthogonal to the axis of each beam  2 .  
         [0073]    Further, disk-shaped flanges  12  are respectively mounted to the opposite ends of the anchoring member  9  by welding. These flanges  12  make resistance with their faces to the force, which shifts the anchoring member  9  in the axial direction in the concrete for the beams  2 , by means of applying the compressive force to the concrete in any axial direction, resulting in more enhancement of stability of the anchoring member  9 .  
         [0074]    Other different forms of the anchoring member  9  include an anchoring member having no stud  11  and an anchoring member having an axial force resisting flange  12  at an intermediate portion other than the opposite ends of the anchoring member  9 , in place of the studs  11 , and so on.  
         [0075]    A modification of the anchoring member  9  as shown in FIG. 10 is available, for instance. In FIG. 10, reference numeral  10   a  denotes a reinforcing rib mounted to the gusset plate  10  in parallel to the flanges of the anchoring member  9 .  
         [0076]    The anchoring member  9  in this modification is applied as a member for reinforcing the gusset plate  10 , inclusively of its projecting portion from each beam  2 , by providing an intermediate flange  12  other than the opposite flanges, in place of the studs  11 , while extending the opposite and intermediate flanges  12  upward so as to reach up to the projecting portion.  
         [0077]    More specifically, the opposite flanges  12  of the anchoring member  9  reach up to the projecting portion of the gusset plate  10  from each beam  2  so as to be one with the opposite end faces of the gusset plate  10  and those of the reinforcing rib  10   a.  The intermediate flange  12  of the anchoring member  9  also reaches up to the projecting portion of the gusset plate  10  from each beam  2  so as to be one with an intermediate portion of the gusset plate  10  and that of the reinforcing rib  10   a.    
         [0078]    Using the anchoring member in the above modification permits the flanges  12  to make a contribution toward enhancing the strength of the gusset plate  10  inclusively of its projecting portion from each beam  2 , together with the strength of the anchoring member  9 .