JP2009161937A - Damping frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping frame of an effective and proper structure, which enables a steel column and a steel beam to be joined together by a simple structure, and which enables the rational installation of a damping element. <P>SOLUTION: The steel column 1 and the steel beam 2 are joined together by semirigid jointing. An earthquake-resisting brace 3 is joined to a joint between the steel column 1 and the steel beam 2. The earthquake-resisting brace 3 combines a damping element, which exerts an energy absorbing function by being plastically deformed when undergoing a predetermined axial force, with an earthquake-resistant element which exerts strength while remaining in an elastic deformation range even if the damping element is plastically deformed. The steel column is composed of H-shaped steel or box steel; the steel beam is composed of H-shaped steel; bolting makes a flange of the steel beam joined to the steel column via a joint member 4, composed of a split T or an angle, without the intermediary of a diaphragm; and bolting makes the earthquake-resisting brace joined to the joint via the joint member. A joint position of the earthquake-resisting brace is set so that a line of action of the axial force of the earthquake-resisting brace can pass through the center of the joint between the steel column and the steel beam. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a building frame, and more particularly, to a seismic control frame including steel columns, steel beams, and anti-seismic braces.

As is well known, the structure type in a steel structure mainly composed of steel columns and steel beams is generally a pure ramen structure.
In that case, the frame by the steel column and the steel beam is constructed by joining them completely rigidly. Therefore, they are joined by welding, or all the upper and lower flanges and webs of the H-shaped steel as a steel beam are connected. It is necessary to do this by fastening the steel column with a number of high strength bolts. In any case, it is necessary to provide a diaphragm on the steel column in order to ensure the rigidity of the joint. Therefore, it has been inevitable that much cost and labor are required for both the production of the steel frame and the joining work in the construction of the frame by the conventional general steel frame rigid frame structure.

Therefore, as shown in Patent Document 1, for example, the entire frame is made highly rigid by incorporating a high-rigidity brace into the steel frame, thereby simplifying the joint form between the steel column and the steel beam. A seismic structure has been proposed that can be semi-rigidly joined and that can omit the diaphragm in the steel column.
JP 2002-146905 A

As described above, according to the earthquake-resistant structure in which a high-strength brace is incorporated into a steel frame, it is possible to simplify the column beam joints while ensuring the rigidity of the entire frame. However, with such a structure, the seismic control function required for buildings in recent years cannot be expected, and there is still room for improvement in that respect.
In addition, it is conceivable to incorporate braces into the steel frame as described above to increase the rigidity, and to incorporate various dampers for the purpose of further providing a vibration control function. The heavy installation not only makes the entire structure complicated, but also requires a space for installing them, which is of course costly and unrealistic.
Of course, simply installing the damper and omitting the brace is necessary to ensure the rigidity of the entire frame with only steel columns and steel beams, as in the previous structure, so it is necessary to join them completely rigidly, Since it is indispensable to install a diaphragm on the steel column, it cannot solve the problem at all if the vibration control effect is obtained.

  In view of the above circumstances, an object of the present invention is to provide a seismic control frame having an effective and appropriate structure in which a steel column and a steel beam can be joined with a simple structure and a seismic control element can be reasonably installed.

  The seismic control frame of the present invention includes a seismic control element that exhibits an energy absorbing function by plastic deformation when subjected to a predetermined axial force, with respect to a frame in which the joining type of the steel column and the steel beam is a semi-rigid joint. Further, the present invention is characterized in that an anti-seismic brace having a seismic element that remains in the elastic deformation range and exhibits proof strength even if the seismic control element is plastically deformed is incorporated.

In the seismic response control frame of the present invention, the steel column is made of H-shaped steel or box steel, the steel beam is made of H-shaped steel, and a flange of the steel beam is attached to the steel column with a diaphragm. It is good to join by bolt fastening via the joining member which consists of a split tee or an angle without going through, and join the anti-seismic brace to the joint by bolt fastening through the joining member.
Moreover, it is preferable to set the joint position of the seismic brace with respect to the joint so that the line of action of the axial force of the seismic brace passes through the center of the joint between the steel column and the steel beam.

According to the seismic control frame of the present invention, the steel beam is joined to the steel column in the form of semi-rigid joint, so the structure of the column beam joint is greatly simplified compared to the case of completely rigid joining them. Since the diaphragm can be omitted from the steel column, not only the steel fabrication and joining work can be greatly streamlined, but also the rigidity of the entire frame can be reduced by joining the anti-seismic brace to the joint. The desired rigidity can be secured without any problem by compensation.
Moreover, since the anti-seismic braces have not only seismic elements but also anti-seismic elements, it is only necessary to install the anti-seismic braces, and the desired seismic control without installing any other anti-seismic elements such as dampers. Therefore, there is no need to secure the effort and cost for installing a special damper, and there is no need to secure the installation space. Is reasonable.

An embodiment of the vibration control frame of the present invention will be described with reference to FIGS.
FIG. 1 shows an overall schematic configuration of a seismic control frame according to the present embodiment, which is mainly intended to incorporate a seismic brace 3 into a steel frame mainly composed of a steel column 1 and a steel beam 2. Yes.
In the example shown in the figure, an example in which a pair of anti-seismic braces 3 are arranged in a “c” shape only in the center span of a frame for a building consisting of 9 spans and 3 spans. However, the scale of the entire building, the form of the frame, and the arrangement position and arrangement of the anti-seismic braces 3 may be designed according to the required seismic performance and damping performance.

In the present embodiment, as shown in FIG. 2, the steel column 1 and the steel beam 2 are both made of H-shaped steel, and the steel beam 2 is joined to the steel column 1 in a semi-rigid connection manner. It has been made.
That is, the split tee as the joining member 4 is directly brought into close contact with the flange and the web of the steel column 1 and fastened with a high-strength bolt. The upper and lower flanges of the steel beam 2 are higher than the joining member 4. The web of the steel beam 2 is not joined to the steel column 1 as in the case of the normal rigid connection, and is fastened by the force bolt. The diaphragm that is indispensable to be provided on the steel column 1 is also omitted.

  In addition, in the present embodiment, the anti-seismic brace 3 (3A, 3B) is joined to the above-described joint portion via the joint member 5 so as to be a semi-rigid joint. 3 to ensure the desired rigidity of the entire frame, and the anti-seismic brace 3 provides the desired seismic control effect.

The anti-seismic brace 3 according to the present embodiment has a damping element that plastically deforms to exhibit an energy absorption function when subjected to a predetermined axial force, and exhibits an proof strength by staying within the elastic deformation range even if the damping element is plastically deformed. It has both seismic elements to do.
Note that “anti-seismic” is a concept that encompasses both “earthquake resistance” and “seismic control”, and the “anti-seismic brace” in this embodiment exhibits excellent strength without easily yielding. A structural element that has both a function as an “earthquake-resistant brace” and a function as a “seismic brace (brace damper)” that yields a damper effect by yielding at an early stage. Specifically, the structure shown in FIG. 3 or FIG. Can be suitably employed.

The anti-seismic brace 3A shown in FIG. 3 is disclosed in Japanese Patent Application Laid-Open No. 2007-191987, which includes a strip-like core material 11 and an outer surface that restrains the out-of-plane buckling of the core material 11. It consists of the restraining member 12 which does.
The core material 11 is formed by laminating a plurality of steel plates having different yield displacements. The example shown in the figure is controlled by yielding at an earlier stage than the central first steel plate 11a functioning as an earthquake-resistant element. It is comprised from the 2nd steel plate 11b of 2 sheets of both sides which functions as a seismic element.
Specifically, the central first steel plate 11a is not yielded by the axial force received during a small and medium-sized earthquake, but remains in the elastic deformation region and exhibits proof stress. It is enough. On the other hand, the two second steel plates 11b laminated on both sides of the first steel plate 11a function as a steel damper by yielding and plastically deforming with an axial force received at the time of a small and medium earthquake. As a result, the vibration energy of the entire frame is effectively absorbed even in small and medium-sized earthquakes, and an excellent seismic control effect can be obtained.

An anti-seismic brace 3B shown in FIG. 4 is disclosed in Japanese Patent Application Laid-Open No. 2007-191988, which includes a strip-shaped core member 13 as an earthquake-resistant element and vibration control elements arranged on both sides thereof. It consists of a viscoelastic damper 14 as an element and a restraining member 12 (same as the restraining member 12 in the above-mentioned anti-seismic brace 3A).
Like the first steel plate 11a in the anti-seismic brace 3A, the core 13 stays in the elastic deformation region without yielding with an axial force that is received during a small and medium earthquake, and exhibits proof strength. The viscoelastic damper 14 includes a viscoelastic body 14b interposed between the steel plate 14a and the restraining member 12 integrally laminated on the core material 13, and the viscoelastic body 14b is deformed when the steel material 14a is deformed together with the core material 13. It exhibits a damper effect when subjected to plastic deformation.

In both the anti-seismic brace 3A shown in FIG. 3 and the anti-seismic brace 3B shown in FIG. 4, the restraining member 12 is a pair of groove steels 21 combined in a back-to-back state, and the groove steel 21 It is composed of a pair of cover plates 22 connecting the flanges, and they are assembled into an H shape as a whole. A rib plate 23 for stiffening is welded to the key points of the grooved steel 21. Has been.
In the anti-seismic brace 3 </ b> A shown in FIG. 3, the core material 11 is accommodated inside the restraint member 12 via the rubber packing 24, thereby allowing axial deformation of the core material 11 and out-of-plane buckling. 4 and the anti-seismic brace 3B shown in FIG. 4 can accommodate the core material 13 and the viscoelastic damper 14 inside the restraining member 12 so as to be deformable in the axial direction, thereby preventing out-of-plane buckling. Has been.

  Further, the second steel plate 11b as the vibration control element in the anti-seismic brace 3A and the core material 13 as the anti-seismic element in the anti-seismic brace 3B both have the rigidity due to the formation of the constricted part 25 at the center. And the yield displacement can be adjusted appropriately. Further, both ends of the first steel plate 11a as the seismic element in the anti-seismic brace 3A and the core material 13 as the anti-seismic element in the anti-seismic brace 3B are welded with the rib plates 26 to have a cross-shaped cross section. A large number of bolt holes for joining these anti-seismic braces 3 (3A, 3B) to the frame by bolt fastening are formed there.

As already described, the anti-seismic brace 3 is arranged at the main point of the frame, and one end thereof is bolted to the joint portion between the steel column 1 and the steel beam 2 via the joint member 5. However, at that time, the acting line of the axial force of the anti-seismic brace 3 passes through the center of the joint between the steel column 1 and the steel beam 2, that is, as shown in FIG. 2 (a), the steel column 1 and the steel beam. It is preferable to strictly set the joint position of the anti-seismic brace 3 with respect to the column beam joint so that the center axis 2 of the anti-seismic brace 3 intersects at one point.
Further, the joining member 5 for joining the anti-seismic brace 3 to the column beam joint has a cross-shaped cross section welded to a split tee which is a joining member 4 for joining the steel beam 2 to the steel column 1. The seismic element in the anti-seismic brace 3 (that is, the first steel plate 11a in the anti-seismic brace 3A or the core material 13 in the anti-seismic brace 3B) is a high-strength bolt via the splice plate. The bolt may be fastened with
In the case where two anti-seismic braces 3 are arranged in a C shape in the frame as in this embodiment, the other end of the anti-seismic brace 3 is appropriately connected to the central portion of the steel beam 2. The bolts may be fastened via a joining member, but in general, the other end of the anti-seismic brace 3 may be joined to the column beam joint with the same structure as described above.

According to the seismic control frame of the present embodiment, only the flange of the steel beam 2 is bolted to the steel column 1 so that their joint type is semi-rigid joint. In comparison, the structure of the joint can be greatly simplified, and the diaphragm can be omitted from the steel column 1, so that both the steel frame manufacturing and the joining work can be greatly rationalized.
And since the anti-seismic brace 3 is joined with respect to a joining part on that, the rigidity fall of the frame by a junction part being made into semi-rigid junction is compensated by the anti-seismic brace 3, and desired rigidity is set to the whole frame. Can be secured without hindrance.
Moreover, since the anti-seismic brace 3 has not only an anti-seismic element but also an anti-seismic element, it is possible to obtain a desired anti-seismic effect only by installing this anti-seismic brace 3. It is extremely reasonable and effective without installing special damping elements such as dampers, and therefore without having to secure the labor, cost, and installation space.
From this point of view, the seismic control frame of the present invention is different from a conventional general seismic control frame and a seismic frame as shown in the prior document 1, and as described above, “seismic control” and “seismic resistance” It can be said that it should be an anti-seismic frame with a “anti-seismic” function, which is a concept that encompasses the above.

In the embodiment described above, only the flange of the steel beam 2 is bolted using the split tee as the joining member 4 in order to semi-rigidly join the steel column 1 and the steel beam 2. It is possible to use an angle instead of the split tee, and the point is that the steel column 1 and the steel beam 2 are joined on the premise that the anti-seismic brace 3 is joined to the column beam joint. As long as the form is structurally semi-rigid joint, as long as the specific structure of semi-rigid joint and the joining member 4 used for it are arbitrary, the steel column 1 is made of H-section steel. Of course, box steel can be used instead.
In the above embodiment, two types of configuration examples suitable as the anti-seismic brace 3 are illustrated. However, as the anti-seismic brace 3, the seismic element capable of exhibiting a desired seismic function required for the frame and the desired seismic control What is necessary is just to have the damping element which can exhibit a function, and the specific structure and form of the anti-seismic brace 3 are arbitrary as long as it is not limited to what was illustrated to the said embodiment.

It is a figure which shows the outline | summary of the seismic control frame which is embodiment of this invention. It is a figure (detail drawing of the II section in Drawing 1) which shows the structure of the joined part of a steel column and a steel beam. It is a figure which shows an example of an anti-seismic brace. It is a figure which shows the other example of an anti-seismic brace.

Explanation of symbols

1 Steel column 2 Steel beam 3 (3A, 3B) Anti-seismic brace 4 Joint member (split tee)
5 Joining member 11 Core material 11a First steel plate (seismic element)
11b Second steel plate (damping element)
12 Restraint member 13 Core material (seismic element)
14 Viscoelastic damper (damping element)
14a Steel plate 14b Viscoelastic body 21 Channel steel 22 Cover plate 23 Rib plate 24 Rubber packing 25 Constricted part 26 Rib plate

Claims (3)

  A seismic element that exhibits a function of absorbing energy by plastic deformation when a predetermined axial force is applied to a frame in which the steel column and steel beam are joined semi-rigidly, and the seismic element is plastically deformed An anti-seismic frame that incorporates an anti-seismic brace that also has seismic elements that remain within the elastic deformation range and exhibit strength.   2. The seismic response control frame according to claim 1, wherein the steel column is made of H-shaped steel or box steel and the steel beam is made of H-shaped steel, and a flange of the steel beam is connected to the steel column via a diaphragm. A seismic control frame characterized in that it is joined by bolt fastening through a joining member having a split tee or an angle, and the anti-seismic brace is joined to the joint by bolt fastening through a joining member. .   3. The vibration control frame according to claim 1, wherein the line of action of the axial force of the anti-seismic brace passes through the center of the joint between the steel column and the steel beam. A seismic control frame characterized by setting the joint position of braces.

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