JP2000027297A - Joining method for steel framed column and steel framed beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the vibration absorbing ability of a beam end in a simple structure, prevent the destruction of a beam joint with the input of over- vibration and prevent the deterioration of the vibration absorbing ability of the beam. SOLUTION: The connection end of an upper flange 12a of a steel framed beam 12 formed from a H-shape steel is welded to the outer periphery of a steel framed column 10 formed from a steel pipe by butt resistance welding. The connection end of a web 12c of the steel framed beam 12 is fillet-welded 24 to the side face 10a of the steel column 10. The connection end of a lower flange 12b of the steel framed beam 12 is abutted to the side face 10a of the steel framed column 10 in a non-fixed condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining a steel column and a steel beam in a building frame.

[0002]

2. Description of the Related Art Generally, in an S or SRC building frame constructed by joining a steel column and a steel beam, the connection between the steel column and the steel beam is performed by welding, bolts, and nuts. General. For example, FIG. 10 shows a joint using a steel pipe column 1 as a steel column and an H-shaped steel 2 for a steel beam. In this case, the joint is welded to the steel column 1, and the outer periphery of the lower diaphragms 3 and 3a is The ends of the upper and lower flanges 2a and 2b of the H-section steel 2 are welded by abutting each other, and the ends of the webs 2c are welded by abutting the side surface 1a of the steel pipe column 1.

[0003]

However, in such a conventional joining method of a steel column and a steel beam, if excessive vibration due to an earthquake is input to the building frame, the building frame deforms flexibly. As a result, a large compressive or tensile force is applied to the column / beam joint. At this time, the steel pipe column 1 is deformed in the inclined direction as shown in FIG.
When a tensile force acts on the lower flange 2b of the section steel 2, deformation such as excessive protrusion or the like occurs at the column joint of the lower flange 2b due to the Poisson's ratio of the steel material as shown in FIG. Cracks may occur in the welding of the parts. Further, even when a horizontal force is applied, the end of the beam is plasticized and absorbs energy, so that the portion undergoes residual deformation or undergoes plastic hardening, resulting in reduced vibration absorption capacity. For this reason, it is necessary to replace the steel beam after the excessive vibration is input, and there has been a problem that an extremely large-scale construction is required.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and has a simple structure to enhance the vibration absorption capacity of the beam end and prevent the beam joint from being destroyed even when excessive vibration is input. It is another object of the present invention to provide a method for joining a steel column and a steel beam, which prevents a reduction in the vibration absorbing ability of the beam.

[0005]

In order to achieve the above object, a method of joining a steel column and a steel beam according to a first aspect of the present invention is a building frame constructed by joining a steel column and a steel beam. Wherein the upper end of the steel beam is welded to the steel column, the intermediate portion between the upper and lower ends of the steel beam is welded to the steel column, or a bolt or nut is connected to the steel column, and the lower end of the steel beam is connected to the steel column. To a non-weld contact state.

According to a second aspect of the present invention, there is provided a method of joining a steel column and a steel beam in a building frame constructed by joining a steel column and a steel beam, wherein an upper end of the steel beam is connected to a steel frame. While welding to the column, welding the middle part between the upper and lower ends of the steel beam to the steel column or connecting it with bolts and nuts, and bringing the lower end of the steel beam into non-weld contact with the steel column. An energy absorbing member is provided between the part and the steel column.

Therefore, in the method of joining a steel column and a steel beam according to the present invention, the upper end portion of the steel beam is welded, and the intermediate portion is integrated with the steel column by welding or bolts and nuts. Fixed to And, in this state where the steel column and the steel beam are integrally joined, the lower end of the steel beam is brought into contact with the steel column and is in a non-weld contact state,
In a normal static load supporting state in which no vibration is input, the lower end of the steel beam is kept in contact with the steel column, and a predetermined rigidity is secured at the joint between the column and the beam.

In the state where the lower end of the steel beam is in contact with the steel column in this way, when vibration such as an earthquake is input and the stress acting on the steel beam increases, the lower end separates from the steel column. . Then, the rigidity of the beam-column joint, and hence the rigidity of the building frame, is reduced, and the vibration response value is reduced, whereby the vibration is damped and the building frame can be damped. At this time, since the steel beam itself has only an upper end portion and an intermediate portion joined to the steel column, the elastic region is maintained when the beam end portion is deformed, and vibrations such as an earthquake calm down. Is stopped, the steel beam itself returns, and the lower end portion is brought into contact with the steel column to support the load, and the predetermined rigidity of the beam-column joint is ensured.

According to a second aspect of the present invention, in addition to the joining method of the first aspect, an energy absorbing member is provided between a lower end portion of the steel beam abutting on the steel column in a non-weld contact state and the steel column. Therefore, when an excessive horizontal force is input and the lower end of the steel beam is separated from the steel column, the displacement between the steel column and the steel beam when separated is input to the energy absorbing member, Along with the reduction of the vibration response value due to the decrease in the rigidity of the joint, the vibration energy is absorbed by the energy absorbing member, whereby the vibration damping is increased, and the vibration damping effect of the building frame is further increased. You.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a side view of a main part showing a first embodiment of a method of joining a steel column and a steel beam according to the present invention. The basic feature of the present invention is that a steel column 10 and a steel beam 12 are joined together. In the building frame to be constructed, the upper end 12a of the steel beam 12 is welded to the steel column, and the intermediate portion 12c between the upper and lower ends of the steel beam 12 is welded to the steel column 10 by bolts or nuts, and The lower end portion 12b of the steel beam 12 is brought into contact with the steel column 10 to make a non-weld contact state.

That is, in the method of joining a steel column and a steel beam according to the present embodiment shown in FIG. 1, a steel column 10 formed of a steel pipe having a rectangular cross section is used and a steel beam 12
Shows a case in which the upper and lower flanges 12a, 12b and the web 12c are used to form an H-shaped steel having an H-shaped cross section. The end of the steel beam 12 is vertically connected to the side surface 10a of the steel column 10.

[0012] The steel column 10 made of steel pipe is used for the steel beam 1.
2 is connected, in particular, the steel beam 1 made of H-shaped steel
2, corresponding to the position where the upper flange 12a serving as the upper end and the lower flange 12b serving as the lower end abut against each other.
An upper diaphragm 14 and an inner diaphragm 16 are provided below. Through-diaphragm 14 is steel column 1
While the 0 is vertically divided, its peripheral edge is arranged so as to protrude from the outer periphery of the steel column 10. And through diaphragm 1
Butt welding of the divided steel column 10 on the upper and lower surfaces
8, the steel column 10 and the through diaphragm 14 are integrated with the steel column 10. On the other hand, the inner diaphragm 1
6 is formed along the inside shape of the steel column 10, and the outer periphery of the inner diaphragm 16 is welded 20 to the inner periphery of the steel column 10 to be integrated.

In joining the steel beam 12 to the steel column 10, the connection end of the upper flange 12a of the steel beam 12 is butt-welded 22 to one side of the outer periphery of the through diaphragm 14, and the connection end of the web 12c is connected. To the side surface 10a of the steel column 10 by fillet welding 24. on the other hand,
The connection end of the lower flange 12b of the steel beam 12 is brought into contact with the side face 10a of the steel column 10 at a position corresponding to the inner diaphragm 16 in a non-welded state in a state where the upper flange 12a and the web 12c are welded.

When the steel beam 12 is joined to the steel column 10, the upper flange 12a is passed through the front end of the web 12c and retracted by the amount of the diaphragm 14 and the end of the web 12c on the side of the upper flange 12a is cut out. And a scallops 26 are formed. The lower flange 12b side end of the web 12c is
A gap 28 is formed by cutting out a substantially lower half of c.

In the method of joining a steel column and a steel beam according to the present embodiment described above, when the steel beam 12 is joined to the steel column 10, the upper flange 12 a of the steel beam 12 is welded to the steel column 12 by welding 22. The web 12 c is integrally fixed to the side surface 10 a of the steel column 10 by welding 24. Then, in a state where the steel column 10 and the steel column 12 are joined via the welds 22 and 24 in this manner, the lower flange 1 of the steel beam 12 is
The connection end of 2b is brought into contact with the side surface 10a of the steel column 10 in a non-weld contact state.

Therefore, in a normal static load supporting state in which no vibration is input, the connection end of the lower flange 12b of the steel beam 12 is kept in contact with the steel column 10, and the load is supported by this contact portion. The upper flange 12 a and the web 12 welded to the steel column 10.
The predetermined rigidity of the beam-column joint is ensured in cooperation with c. Then, when vibration such as an earthquake is input in a state where the lower flange 12b is in contact with the steel column 10, the horizontal force increases and an excessive tensile force acts on the lower end of the beam-column joint. The connection end of the lower flange 12b is separated from the steel column 10. Then, the fixed portion between the steel column 10 and the steel beam 12 is only the upper flange 12a and the web 12c. As a result, the rigidity of the beam-to-column joint, and hence the rigidity of the building frame, is reduced, and the vibration response value is reduced. This reduction in the response value improves the vibration damping effect and dampens the building frame. can do.

At this time, since the steel beam 12 itself has only the upper flange 12a and the web 12c, that is, only the upper end portion and the middle portion of the steel beam 12 are connected to the steel column 10, the beam end is deformed. Since the lower end of the steel beam 12, that is, the lower flange 12b is not plastically deformed,
The connection end of the steel beam 12 maintains the elastic region. For this reason, when the input of vibration is stopped due to a calming of the earthquake or the like, the steel beam 12 itself returns and returns to the lower flange 12.
b comes into contact with the side surface 10a of the steel column 10, and the load is supported by the lower end of the steel beam 12b, so that the predetermined rigidity of the beam-column joint is ensured. Also, the lower flange 12
b is prevented from breaking due to local deformation.

The lower flange 12 of the steel beam 12
Since the welding of b is omitted, the number of welding points is of course reduced, and in particular, the lower flange 12b is a place where on-site welding is difficult, and the welding of this difficult welding point is omitted. Construction efficiency is significantly improved. Then, it is possible to bring such welded portion welding amount is reduced by is reduced, the environment better results by reducing the amount of CO ₂ generated by the welding.

Further, since it is not necessary to weld the lower flange 12b to the steel column 10 to which the lower flange 12b contacts, the inner diaphragm 16 does not need to be provided with a through-diaphragm at a position corresponding to the lower flange 12b. Can be done. Of which diaphragm 16
Since it is sufficient to fix the inside of the steel column 10, the amount of welding may be smaller than that of the through-diaphragm, and the amount of generated CO ₂ can be suppressed from this point as well.

In this embodiment, the web 12c is connected to the steel column 10 by welding 24. However, the present invention is not limited to this, and the web 12c can be connected by bolts and nuts as shown in FIG. That is, in the same figure, a gusset 30 is welded in advance to a position corresponding to the web 12c on the side surface 10a of the steel column 10 and vertically protruded, and the web 12c is superimposed on the gusset 30, and these two are combined. Fastening is performed via bolts and nuts not shown.

FIGS. 3 and 4 show a second embodiment of the present invention, in which the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted. FIG. 3 is a side view of an essential part showing a joint part between the steel column and the steel beam, and FIG. 4 is a plan sectional view of an essential part of the joint part, showing a section taken along the line III-III in FIG.

In this embodiment, an energy absorbing member is provided between the lower end of the steel beam 12 and the steel column 10 in addition to the column-beam joint shown in FIG. 1 or FIG. That is, in this embodiment, the low-yield steel 50 is used as an energy absorbing member, and the low-yield steel 50 is arranged so as to surround the steel column 10 as shown in FIGS. 12 are connected.

Further, in this embodiment, similarly to the above embodiment, a state is shown in which a steel beam 12 is connected to each side surface 10a of a steel column 10 formed of a steel pipe having a rectangular cross section. The method is the same as that shown in FIG. 1 or FIG. In FIG. 3, for convenience, the steel beam 12 joined to the right side shows a web 12c butt-welded 24 as shown in FIG. 1, while the steel beam 12 joined to the left side has a gusset as shown in FIG. Although a bolt and a nut are connected via 30, these two connecting structures are not applied to one steel column 10 at the same time, and either one of the connecting structures is adopted. Also in this embodiment, the upper flange 12a and the web 12c are integrally fixed to the steel column 10, and the lower flange 12b is in contact with the steel column 10 in a non-weld contact state.

In this embodiment, gussets 52 are welded to the lower surfaces of the end portions of the lower flanges 12b so as to protrude from both sides, and the low-yield steel 50 is straddled between the protruding portions of the adjacent gussets 52. Are connected via bolts and nuts not shown. The low-yield steel 50 is
Each of the low-yield steels 50 is horizontally arranged, and both ends thereof are joined to the gusset 52.

Therefore, in this embodiment, an excessive horizontal force is input and the lower flange 12b of the steel beam 12 is
When separated from zero, the displacement between the steel column 10 and the steel beam 12 at the time of the separation is input to the low-yield steel 50 provided on both sides of the steel beam 12 to plastically deform it. Vibration energy is spent on plastic deformation, which in turn absorbs this energy. For this reason, as described in the above-described embodiment, the lower flange 12b is set in the non-weld contact state, and the rigidity of the beam-column joint is reduced and the vibration response value is reduced. By absorbing the vibration energy by the yield steel 50, the vibration damping is increased, and the vibration damping effect of the building frame can be further increased.

After the vibration energy is absorbed by the low-yield steel 50, the vibration input is stopped and the building frame, that is, the steel beam 12 is returned to the original state.
Only 0 needs to be replaced. For this reason, the low yield steel 50
Despite the great vibration damping effect,
After the fact, it is a simple construction that only the low yielding steel 50 is replaced,
The building frame can be restored to its original state.

By the way, in the joining method of this embodiment, the energy absorption function of the low-yield steel 50 is more effectively performed by applying the method to a portion of the building frame having a relatively small amplitude, for example, the vicinity of the periphery of the building core. be able to. The low-yield steel 50 is formed in a plate shape and horizontally connected to each other between the steel beams 12, but is not limited to this, and as shown in FIG. The lower surface of the lower flange 12b and the steel column 1
Even if the steel column 10 is mounted at a right angle across the side surface 10a, the displacement between the steel column 10 and the steel beam 12 can be absorbed by the triangular low-yield steel 50.

FIGS. 6 and 7 show a third embodiment of the present invention, in which the same components as those in the above-described embodiment are denoted by the same reference numerals and will not be described. FIG. 6 is a side view of an essential part showing a joint part between the steel column and the steel beam, and FIG. 7 is a sectional plan view of the essential part of the joint part, taken along line VII-VII in FIG.

In this embodiment, a friction generating mechanism 60 is used as an energy absorbing member.
Numeral 0 denotes a gusset 62 projecting horizontally from the steel column 10 at a position corresponding to the lower surface of the lower flange 12b of the steel beam 12.
And a biasing means 64 for slidingly contacting the upper surface of the gusset 62 and the lower surface of the lower flange 12b to apply a pressing force therebetween. The urging means 64 has a configuration in which a bolt 66 penetrates through the lower flange 12b and the gusset 62 and is tightened with a nut 66a through a disc spring washer 68. Also, the lower flange 12
At least one of the insertion holes for the bolt 66 formed in the b and the gusset 62 has an elongated hole in the beam direction.

Therefore, when the lower flange 12b of the steel beam 12 is separated from the steel column, the friction generating mechanism 60 is used.
The lower flange 12b and the gusset 62 are biased by the urging means 6
4 is slid with a large pressing force. At this time, a large frictional force is generated, and vibration energy is consumed to generate the frictional force and the energy is absorbed. Also,
In this embodiment, in particular, since the disc spring washer 68 is used, it is possible to constantly generate a constant elastic force against a change in the bending of the disc spring washer 68 by effectively utilizing the nonlinear characteristic of the disc spring washer 68. Accordingly, the frictional force generated between the lower flange 12b and the gusset 62 can be made constant.

In this embodiment, the friction generating mechanism 60 is used as an energy absorbing member. Therefore, when the building frame returns to the original state due to the stop of the vibration input, the lower flange 12b and the gusset 62 are not broken, Since the relative positions of these two also return to the original state, there is no need to replace them after the vibration input.

In this embodiment, the case where the gusset 62 is horizontally protruded and slidably contacted with the lower flange 12b is disclosed. However, the present invention is not limited to this, and as shown in FIG. The frictional force can also be generated by using gussets 62a and 62b vertically protruding from the column 10.

That is, in the embodiment shown in FIG. 8, the gusset 62a is vertically protruded from the side surface 10a of the steel column 10 below the lower flange 12b, while the lower flange 1
From 2b, a friction plate 70 is suspended from the gusset 62a in parallel with the gusset 62a to bring the gusset 62a into sliding contact with the friction plate 70, and the friction generating mechanism 60 is provided between the two. Further, in the embodiment shown in FIG.
A gusset 62b is provided vertically above the lower flange 12b from the side surface 10a of the gusset 62b.
Is brought into sliding contact with the web 12c, and these gussets 62
The friction generating mechanism 60 is provided between the web b and the web 12c.

Incidentally, in each of the above embodiments, the steel column 1
Although a case where a steel pipe having a rectangular cross-section is used as 0 and an H-shaped steel is used as the steel beam 12 is disclosed, the steel column 10 is not limited to this, and uses a steel pipe or a steel pipe having a circular cross-section or another polygonal shape. Alternatively, the steel beam 12 may be made of a section steel other than the H-section steel or a steel material having another cross-sectional shape.

[0035]

As described above, in the method for joining a steel column and a steel beam according to the first aspect of the present invention, the upper end of the steel beam is welded, and the intermediate portion is welded or bolted. While the nut is integrally fixed to the steel column, the lower end of the steel beam is brought into contact with the steel column in a non-weld contact state, so in a normal static load support state where vibration is not input, the lower end of the steel beam is A load is supported while maintaining the state of contact with the steel column, and a predetermined rigidity can be secured at the beam-column joint.

On the other hand, when a vibration such as an earthquake is input and the stress acting on the steel beam increases, the lower end is separated from the steel column, and the rigidity of the beam-column joint, that is, the rigidity of the building frame is increased. As a result, the vibration response value is reduced, whereby the vibration is damped and the building frame can be effectively damped. At this time, since the steel beam itself has only an upper end portion and an intermediate portion joined to the steel column, the elastic region is maintained when the beam end portion is deformed, and vibrations such as an earthquake calm down. Is stopped, the steel beam itself returns, and the lower end abuts against the steel column to support the load, and a predetermined rigidity can be secured at the beam-column joint.

Further, since it is not necessary to weld the lower end of the steel beam, the workability of the building frame is improved, and the amount of welding is reduced to suppress the generation of CO ₂ , which is good for the environment. Can be brought.

According to a second aspect, in addition to the joining method of the first aspect, an energy absorbing member is provided between the lower end portion of the steel beam that abuts on the steel column in a non-weld contact state and the steel column. When the excessive horizontal force is input and the lower end of the steel beam is separated from the steel column, the amount of displacement between the steel column and the steel beam when separated is input to the energy absorbing member,
Vibration energy can be absorbed, thereby providing an excellent effect that vibration damping is increased and the vibration damping effect of the building frame can be further increased.

[Brief description of the drawings]

FIG. 1 is a side view of a main part showing a first embodiment of the present invention.

FIG. 2 is a main part side view showing another embodiment of the first embodiment of the present invention.

FIG. 3 is a main part side view showing a second embodiment of the present invention.

FIG. 4 is a main part plan sectional view showing a second embodiment of the present invention.

FIG. 5 is a main part side view showing another embodiment of the second embodiment of the present invention.

FIG. 6 is a main part side view showing a third embodiment of the present invention.

FIG. 7 is a main part plan sectional view showing a third embodiment of the present invention.

FIG. 8 is a main part side view showing another embodiment of the third embodiment of the present invention.

FIG. 9 is a side view of a main part showing still another embodiment of the third embodiment of the present invention.

FIG. 10 is a main part side view showing a conventional method for joining a steel column and a steel beam.

FIG. 11 is a side view of a main part showing a vibration input state of a steel column and a steel beam connected by a conventional joining method.

[Explanation of symbols]

 Reference Signs List 10 steel column 12 steel beam 12a upper flange (upper end) 12b lower flange (lower end) 12c web (middle part) 50 low yield steel (energy absorbing member) 60 friction generating mechanism (energy absorbing member)

Claims (2)

[Claims] In a building frame constructed by joining a steel column and a steel beam, an upper end of the steel beam is welded to the steel column, and an intermediate portion between upper and lower ends of the steel beam is connected to the steel column. A method of joining a steel column and a steel beam, wherein the steel beam is connected to a steel column by welding or bolts and nuts, and the lower end of the steel beam is not welded to the steel column. 2. In a building frame constructed by joining a steel column and a steel beam, an upper end of the steel beam is welded to the steel column, and an intermediate portion between upper and lower ends of the steel beam is connected to the steel column. And a lower end of the steel beam is brought into non-weld contact with the steel column, and an energy absorbing member is provided between the lower end and the steel column. How to join steel columns and steel beams.