Static structures (e.g. – buildings) – Means compensating earth-transmitted force
Reexamination Certificate
2001-02-20
2002-10-01
Friedman, Carl D. (Department: 3635)
Static structures (e.g., buildings)
Means compensating earth-transmitted force
C052S167800, C052S745100, C052S745090
Reexamination Certificate
active
06457284
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a structure for installing a viscous vibration-damping wall and a method of installing the same, and more particularly to a structure for installing a viscous vibration-damping wall whose connecting structure is simple and which, while possessing a sufficient withstanding force, can be manufactured at low cost and installed speedily by making improvements on the structure for installing the viscous vibration-damping wall on a main frame structure, as well as a method of installing the same.
BACKGROUND ART
Measures for enhancing the damping performance of structures have been adopted since ancient times to enhance the safety of earthquake resistance of building structures and improve the dwelling ability of structures against the wind and other dynamic external forces. As specific solutions therefor, viscous vibration-damping walls have been put to practical use, and the number of the viscous vibration-damping walls actually adopted has been on an increasing trend in recent years.
The viscous vibration-damping wall is constructed such that an upper-end open housing, which is formed by a pair of steel-made side plates mounted on a base plate and a pair of flange plates disposed on both sides of the pair of side plates, is integrated with a lower-floor girder, an intermediate plate integrated with an upper-floor girder is inserted in it, and a viscous material or a viscoelastic material is placed in the gap therebetween with a predetermined thickness.
To build the vibration-damping wall, connection to a main frame structure is required, but under the present circumstances connection metal plates from the main frame structure for connection to the viscous vibration-damping wall include a large number rib plates and make the joints complex, constituting a factor for higher cost.
Referring to
FIG. 8
, a description will be given of the connection between a conventional viscous vibration-damping wall and the main frame structure. A base plate
32
of a housing
31
making up a vibration-damping wall
30
is bolted to a flange surface of a rising metal plate
34
disposed on a lower-floor girder
33
, while an intermediate plate
35
of the vibration-damping wall has a top plate
36
welded to its tip portion and is bolted to a flange surface of a mounting plate
38
disposed on an upper-floor girder
37
.
In this state, when the vibration-damping wall
30
bears a horizontal force due to an external force, bending moment due to the borne shearing force occurs between the top plate
36
and the base plate
32
at the upper and lower ends.
The stress applied to the joints acts as the horizontal shearing force with respect to the bolts at the plane of connection, and at the same time a vertical axial force which is distributed widely at the edge portions of the vibration-damping wall
30
occurs in the bolts at the plane of connection due to the bending moment. As a result, large bending stresses occur in the top plate
36
and the base plate
32
having bolt holes arranged horizontally, so that it is necessary to adopt countermeasures for the respective plates.
Consequently, as shown in the drawing, a multiplicity of vertical rib plates
39
and
40
are fixed to the base plate
32
and the top plate
36
as well as the rising metal plate
34
and the mounting plate
38
corresponding thereto, and large-scale reinforcement is provided particularly at the edge portions of the vibration-damping wall. This results in an enormously large increase in cost, and constitutes a hindrance to the connection to a member perpendicular to a girder, and to through holes of sleeves of the facility.
Since the damping performance which can be added to a structure is proportional to the quantity of vibration-damping walls that are installed, it is desirable to adopt a large number of vibration-damping walls. However, since the cost required in the installation is also proportional to the quantity used, it is an important problem to reduce the cost of the building construction of the vibration-damping walls and to prevent adverse effects from being exerted on other execution of works.
To overcome this problem, as shown in
FIG. 9
, a method of building construction has been proposed in which all the upper and lower flange portions are removed. (Refer to JP-A-10-46865)
In this proposal, as shown in the drawing, a bolting steel plate
52
is provided which has the same thickness as an inner wall steel plate
51
of a vibration-damping wall
50
to be fixed to the underside of an upper-floor girder or a reinforced portion thereof, and the inner wall steel plate
51
of the vibration-damping wall is disposed immediately therebelow. A pair of bolting reinforcing plates
53
are disposed on both sides of the inner wall steel plate
51
, and the three steel plates are tightened by high-strength bolts
54
so as to be integrated.
In addition, on a lower floor side, a bolting lower steel plate
56
is welded in advance to lower sides of a pair of outer wall steel plates
55
, and a steel plate
57
of the same thickness as the bolting lower steel plate
56
is provided on a lower-floor girder, and is integrated therewith in the same way as the upper side.
An assertion is made that it is possible to substantially reduce the cost required for the overall building construction of the vibration-damping wall, since the mechanism for transmitting the stress can be rationalized and the fabrication of the vibration-damping wall itself and the fixing portions can be both simplified by virtue of the construction in which flanged connections in the upper and lower portions are eliminated, as described above.
However, with the vibration-damping wall according to this proposal, the vibration-damping wall itself is specially provided with the bolting lower steel plate, the inner wall steel plate is provided with an upper reinforced portion, and the friction-type high-strength bolted connection for jointing adopts a structure in which a multiplicity of bolts are arranged on end portion sides of the vibration-damping wall. Such a construction is a natural consequence of the fact that the bolting lower steel plate and the inner wall steel plate need to simultaneously withstand both the shearing force and the tensile force with respect to the bending moment occurring in the vibration-damping wall. A substantial thickness must be inevitably secured for the bolting lower steel plate, so that the cost of the vibration-damping wall itself is not much different from other conventional vibration-damping walls.
In addition, concerning the handling of the vibration-damping wall, since the structure adopted is such that the vibration-damping wall cannot be self-supported, special attention is required for safety and workability under the circumstances of transportation, storage, and on-site setting.
The present invention provides a structure for installing a viscous vibration-damping wall which is simple while possessing a sufficient withstanding force, and which can be manufactured at low cost and installed speedily by making improvements on the structure for connection at the time of installing the viscous vibration-damping wall on a main frame structure, as well as a method of installing the same.
DISCLOSURE OF INVENTION
The structure for installing a viscous vibration-damping wall in accordance with the present invention is basically a structure for installing a viscous vibration-damping wall in which a housing with its upper end open is formed by uprightly setting a pair of steel-made side plates on a base plate and by disposing a pair of flange plates on both sides of the pair of side plates, an intermediate plate is inserted in the housing, and a viscous material or a viscoelastic material is placed in its gap portion, characterized in that a rising metal plate is fixed on a flange of a lower-floor girder, that the base plate and each of the flange plates are respectively connected to base-plate connecting hole portions provided in an upper surface of the rising metal plate and a fla
Glessner Brian E.
Nixon & Vanderhye
Shimizu Corporation
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