JP2000008480A - Joint structure of steel structure and diaphragm body used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer diaphragm type joint structure, in which welding sections resulting in various problems in the joining sections of a steel structure are removed and no unexpected fracture is generated even at a time when failure load at the time of an earthquake, etc., works by comparatively simple structure and which has high reliability. SOLUTION: Outer diaphragm type joining members are joined onto the external surfaces of a penetrated column body, and the joining members and beam members are connected. Joining sections 12a, into which the column body 10 can be penetrated and which surround the whole circumference of the column body 10, are formed to upper-lower diaphragm bodies 12 constituting the joining members, and the upper-lower diaphragm bodies 12 are united with the column body 10 by bolts, and the upper-lower diaphragm bodies 12 and the beam members 40 are connected by bolt connection at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure between a column member and a beam member in a steel structure and a diaphragm used for the same.

[0002]

2. Description of the Related Art Conventionally, as a structure of a large building, a steel structure (S structure), a reinforced concrete structure (RC structure), a steel frame reinforced concrete structure (SRC structure), and the like are known. These are used properly. Among them, steel frames and steel-framed reinforced concrete structures allow for the production of most columns and beams in factories, and can be constructed in a short period of time because there is little work on site, and are recently adopted at many sites. It became so.

[0003] In the above-mentioned steel structure and steel-framed reinforced concrete structure, a technique particularly requiring a joint between a column member and a beam member is performed by using a joint member generally called a connection. Use columns for columns and H for beam members
In general, three types of through-diaphragm system, inner diaphragm system, and outer diaphragm system are known as so-called column-beam joints using a shaped steel (including a built-up H-shaped steel).

[0004] The through-diaphragm system is a column (column).
Is cut at the upper and lower flange positions of the beam member, and a diaphragm 40 to 50 mm larger than the column outer diameter is inserted and arranged in this part. The flange of the beam member is welded to the diaphragm, and the web of the beam member is directly attached to the column. It is a structure that is integrated by welding. This method fits well with the outer wall of ALC or the like, and is often used. On the other hand, as a processing problem, it is necessary to cut the column at several places and make it a single column again. There is a problem that it is difficult to put it out, the number of processing steps is increased, and the welding amount is larger than other methods.

On the other hand, in the inner diaphragm method, a column is cut once near the center of a beam member, a diaphragm is welded to the inside of the column at positions of upper and lower flanges of the beam, and the column is integrated again. This is the method of welding.
This cannot be adopted when the column diameter of the upper floor is different from that of the lower floor, and when the inner diaphragm mounting depth exceeds the column diameter, welding becomes difficult, so the beam members are necessarily limited. Etc.

[0006] The outer diaphragm method is also called a column penetration method, in which the height of the flange of the beam member is widened or the diaphragm is attached to the outer surface of the column at the flange position of the beam member without cutting the column at all. Although it has the advantage that it is not necessary to cut the column, it is difficult to reinforce the inside of the column, and the flow of stress is complicated as compared with other methods.

FIGS. 10 and 11 show a conventional connection structure using an outer diaphragm system. FIG. 10 is a longitudinal sectional view.
FIG. 11 shows plan views, respectively.

In the figure, 90 is a hollow column, 91 is an upper diaphragm which constitutes an outer diaphragm type joining member, 92 is a lower diaphragm, 93 is a connecting beam, 94 is a connecting beam 93 Is a splice plate (attachment plate) for connecting the connection beam 93 and the beam 94 by bolts.

In the above configuration, the upper diaphragm body 91
The lower diaphragm body 92 is composed of four divided plates 91a to 91d and 92a to 92d, respectively, and these divided plates 91a to 91d and 92a to 92d are provided.
, The split plates 91a to 91d, 92
a-92d, joint surface of columnar body 90, and connection beam member 93
And divided plates 91a91b, 91d, 92a, 92
The joining surfaces with b and 92d are joined by welding W, respectively.

[0010]

In recent years, in response to the catastrophic structure destruction caused by the Great Hanshin Earthquake, research has been conducted on the state of destruction of steel structures. In the connection structure of (1), breakage of the beam member and the joining member from the welded portion was remarkably observed.

[0011] Welding as a means of joining steel materials has gained considerable reliability in terms of strength with the advancement of its technology, but it still has a strong craftsmanship factor, and it has been mechanized. However, there is still a risk that the base material itself is weakened by heat generated during welding. Furthermore, when compared with a solid steel plate, the risk of brittle fracture remains high in the welded portion, which is considered to be a cause of catastrophic failure during an earthquake.

In particular, in the structures shown in FIGS. 10 and 11, the upper diaphragm body 91 and the lower diaphragm body 92
Are divided into four divided plates 91a to 91d and 92, respectively.
Since these members are constituted by a to 92d, when a breaking load is applied, they are broken at this joint, and the upper diaphragm body 91 and the lower diaphragm body 92 do not work as one.

That is, in the case of a solid material made of a continuous single plate (used in the present specification to mean a material which is not welded), for example, when a tensile force acts, first, a large elongation of the material itself occurs, Eventually leading to ductile fracture,
While the mechanism of the fracture can be predicted, when there is a joint by welding, a sudden tensile fracture occurs, and it is difficult to predict the fracture mechanism.

As described above, one of the causes of catastrophic destruction during an earthquake is that in the case of the outer diaphragm system, welding used for joining the diaphragm and the beam flange or welding between the diaphragm and the column, and further, the diaphragm body is used. It has been reported that the welding of the constituent split plates was completely broken, which caused the beam members and columns to fall. Therefore, in order to prevent catastrophic destruction and prevent human damage even in the event of an earthquake, it is necessary to allow structural members to be deformed to some extent, and to prevent beam members and columns from falling due to complete breakage. It is important.

An object of the present invention is to eliminate a weld which causes various problems in a joint of a steel structure, and to cause a sudden rupture even when a destructive load is applied in an earthquake or the like with a relatively simple structure. An object of the present invention is to provide a highly reliable outer diaphragm type joining structure that does not need to be performed.

[0016]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventor returned to the basics on the joint structure between the beam and the column, and as a result of earnest research, formed a bolt joint (hole) in the diaphragm. The inventors of the present invention came up with the idea of directly connecting the diaphragm and the beam member with bolts, and further connecting the diaphragm and the columns with bolts, and completed the present invention.

That is, the present invention relates to a joint structure of a steel structure in which an outer diaphragm type joining member is joined to an outer surface of a penetrated column, and further, the joining member and a beam member are joined. The upper and lower diaphragms constituting the member are formed with a joint that penetrates the column and surrounds the entire circumference of the column, and the upper and lower diaphragms are bolted to the column, and the upper and lower diaphragms are connected to the upper and lower diaphragms. The beam member is joined by bolt joining.

With such a structure, the upper and lower diaphragms and the beam member can be joined by bolts, and when a load greater than the design load is applied, such as in a huge earthquake, the welded portion is formed in a conventional manner. Without sudden breakage, it will be broken by ductile fracture of the diaphragm, flange of the beam member, and shear fracture of the bolt. Further, by adopting a structure in which the upper and lower diaphragm members are bolted to the column members, welding work at the site is eliminated, and improvement in quality and improvement in construction efficiency are achieved.

The upper and lower diaphragms constituting the joining member are integrally formed by casting or the like, and a notch is formed in the diaphragm so as to surround the entire circumference of the column, and the column is mounted so as to fit into the notch. Further, by joining the diaphragm body and the pillar body with bolts, the diaphragm body does not break at the end faces of the plurality of divided plates as in the related art, so that the diaphragm body works integrally, and the resistance to breakage is improved.

The present invention also relates to a joint structure of a steel structure for joining a beam member made of H-shaped steel having upper and lower flanges and a column with a joint member having upper and lower diaphragm members.
The column is penetrable in the upper and lower diaphragms constituting the joining member, and a joint is formed to surround the entire circumference of the column, and the upper and lower diaphragms are bolt-joined to the column and the beam member is The upper flange and the upper diaphragm body and the lower flange and the lower diaphragm body are directly joined by bolt joining.

Such a structure eliminates the need for a splice plate which was conventionally required for joining the column and the beam member, and has a simpler structure than the conventional one and has no sudden breakage from the welded portion. Highly reliable joining of the members is enabled.

Here, the diaphragm used has a plate portion having a bolt hole for connection with the beam member, a notch connected to the plate portion and surrounding the entire periphery of the column, and a connection with the column. It is desirable to use an integrally molded product by casting provided with a joint having a bolt hole for use.

It is desirable that the height of the surface at which the notch of the joint portion contacts the column is in the range of 3 to 5 times the thickness of the plate portion. If the height of the surface in contact with the column is less than three times the plate thickness, buckling is likely to occur when concentrated stress is applied. Even if the height is five times or more, the strength does not change, so the above range is desirable.

The effect of the present invention is that the weakest portion at the time of loading the design load is a bolted joint between the joining member and the beam member, and the shear failure of the bolt joining the diaphragm and the beam member at the time of loading the breaking load. Alternatively, it can be exhibited by joining such that the joining member or the beam member is broken by ductile fracture.

Generally, the bending moment acting on the rigid frame structure tends to be largest at the joint near the joint and high in stress, and tends to decrease as the distance from the joint increases. Therefore, as in the present invention, in order to break by a ductile failure of any of the beam member or the joint bolt prior to the fracture at the welded portion of the diaphragm and the column, from the bolt joint, that is, from the outer peripheral surface of the column. The distance to the tip of the joining member is desirably as short as possible from the contact point, that is, the welded portion between the diaphragm and the column, but it is desirably within 50 cm in consideration of construction and manufacturing convenience.

The joint structure of a steel structure according to the present invention can be applied to four directions where beam members intersect, three directions mainly used for walls, and two directions used for corners. It is.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a perspective view showing a joint structure according to an embodiment of the present invention, FIG. 2 is a perspective view of the diaphragm shown in FIG. 1, and FIG. 3 is a front view of the joint structure shown in FIG.

In FIG. 1, reference numeral 10 denotes a hollow column having a square cross section, reference numeral 12 denotes a diaphragm, reference numeral 14 denotes a gusset plate, and a pair of diaphragms 12 are vertically arranged at a distance from each other. The plate 14 constitutes a joining member for connecting the column 10 and the beam member 40 made of H-section steel.

The upper diaphragm 12 and the lower diaphragm 12 are so-called outer diaphragm type diaphragms of the same shape made of cast steel.
As is clearly shown in the perspective view of FIG.
A joining portion 12a having a notch S 2 mm larger than
Four plate portions 12b connected to each side of the joint portion 12a
It is composed of A total of 16 bolt holes H are formed on each side of the joint portion 12a, and six bolt holes H are formed on each plate portion 12b. The height t _{1 of the} surface where the notch of the joint 12 a is in contact with the column 10 is equal to the height of the plate 1.
The thickness t ₂ of the _second portion 2b is set to be three times, thereby effectively preventing the occurrence of buckling when concentrated stress acts without making the height of the joint portion 12a unnecessarily high.

Returning to FIG. 1, the column 10 and the diaphragm 1
No. 2 is not welded at all and is joined by inserting a one-side bolt B into a bolt hole H formed in the joint 12a. The one-side bolt B, which is inserted from one side of the material to be tightened without having a nut on the fastening side, then turns the pin tail to form a flange portion on the tightening material side, thereby enabling fastening. In the present embodiment, one-side bolt B is inserted from the diaphragm 12 side into a bolt hole H formed in the diaphragm 12 and a bolt hole (not shown) formed in the column body 10 and tightened. .

The upper flange 40b and the lower flange 40c of the beam member 40 are also provided with bolt holes H of the upper and lower diaphragms 12.
Bolt holes (not shown) corresponding to the beam members 4 are formed.
The upper flange 40b and the upper diaphragm 12 and the lower flange 40c of the beam member 40 and the lower diaphragm 12 are brought into close contact with each other and directly joined by bolting.

With such a structure, it is possible to join the column 10 and the beam member 40 with a simpler structure than before, without using a splice plate which was conventionally required for joining the column 10 and the beam member 40. It became. Further, by adopting a structure in which the upper and lower diaphragm bodies 12 are bolted to the column body 10, welding work at the site is eliminated, and improvement in quality and construction efficiency are achieved.

Further, the upper and lower diaphragm members 12 are made of cast steel, and are mounted so that the column members 10 are fitted into the notches S formed in the upper and lower diaphragm members 12, respectively.
Unlike the conventional case, there is no breakage at the end face as in the case of a plurality of split plates, and the diaphragm acts as one, resulting in an improvement in the strength against breakage.

In the present embodiment, one gusset plate 14 is provided on each surface of the column 10 and the web 40a of the beam member 40 is joined to this one gusset plate 14 by bolting. Alternatively, the web 40a may be sandwiched from both sides.

The upper and lower diaphragms 12 are formed with saw blade-shaped irregularities (not shown) for increasing the frictional force around the bolt holes on the joint surface side with the flanges 40b and 40c. When the bolts are tightened, the protruding portions of the saw blade partially bite into the surfaces of the flanges 40b and 40c, whereby the diaphragm 12 in a bolted state is formed.
And the flanges 40b, 40c have increased joint strength, thereby improving the resistance to load.

In this joint structure, the joint member consisting of the upper and lower diaphragms 12 and the gusset plate 14 and the beam member 40 are bolted together, and this joint is the weakest part in the main joint structure, and is designed like a huge earthquake. When a load equal to or greater than the load is applied, the upper and lower diaphragms 12 and the beam members 40 do not suddenly break like a welded portion.
The flanges 40b and 40c of the beam member 40 slide, and then are broken by ductile fracture of either the flange 40b or 40c of the beam member 40 or the bolt. As described above, the slippage or deformation occurs before the fracture occurs, thereby absorbing seismic energy and effectively preventing sudden fracture such as a weld.

Next, referring to FIGS. 4 to 7, FIG.
The procedure for constructing the joint structure shown in FIG. 3 will be described.

FIG. 4 is a perspective view of the structure used in the embodiment of the present invention. As shown in FIG. 4, the column 10 and the lower diaphragm 12 of the outer diaphragm type are bolted at the factory.
Further, an outer diaphragm type upper diaphragm 12 having a cutout portion penetrating the column body 10 is penetrated through the column body 10 and is temporarily fixed at about 15 cm above a predetermined connection position. Therefore, in this state, the upper diaphragm 12 and the column 10 are not joined. In the figure, reference numeral 20 denotes a cross section L for temporarily fixing the upper diaphragm 12 to the column body 10.
The mounting bracket 20 is attached to the upper diaphragm 12 by welding using a V-shaped mounting bracket.
By inserting a bolt through a hole (not shown) provided in the upper diaphragm 1 and a hole (not shown) provided in the column 10, the upper diaphragm 1
2 is temporarily fixed approximately 15 cm above a predetermined connection position. The factory is manufactured to this state, and the installation is performed at the construction site as shown in the figure.

Next, as shown in FIG. 5, a beam member 40 made of H-section steel is suspended by a crane (not shown) and moved in the direction of the arrow, and as shown in FIG. Gazette plate 14
To align with the bolt holes. Thereafter, the gusset plate 14, the web 40a, and the lower flange 40c of the beam member 40 and the lower diaphragm 12 are bolted to each other. At this time, since the upper diaphragm 12 is temporarily fixed at a position away from the predetermined position, the space between the lower diaphragm 12 and the upper diaphragm 12 can be widened, and therefore, the upper diaphragm 12 is restrained by the upper diaphragm 12 at all. The connection work of the beam members 40 can be performed without the need, and the workability of positioning the beam members 40 can be improved.

Next, a bolt (not shown) temporarily fixing the upper diaphragm 12 is removed, and the bottom surface of the upper diaphragm 12 and the upper surface of the upper flange 40b are brought into close contact with each other as shown in FIG.

Next, the upper diaphragm 12 and the upper flange 40b are bolted to each other.
As described above, the column and the column 10 are joined by the one-side bolt B, thereby completing the joining operation as shown in FIGS.

Next, the superiority of the present invention will be described based on the results of actual experiments in which a seismic load is applied to a beam member. FIG. 8 shows a hysteresis curve in the joint structure by the bolted joint of the present invention, and FIG. 9 shows a hysteresis curve in the joint structure described in the related art. In FIG. Respectively.

The experimental results show that the joint structure of the present invention showed stable behavior after sliding, and did not show an extreme decrease in proof stress such as breakage, whereas the conventional joint structure showed a beam member The behavioral characteristics appeared, and the initial loading stage did not reach the full plastic moment, and after sufficient deformation, the flange weld fractured.

Further, as is apparent from the figure, since the joint structure of the present invention involves the sliding of bolts, the hysteresis curve is greatly different from that of the conventional joint structure. This is equivalent to the energy absorbed by the joint, is equivalent to energy consumption during an earthquake, and has a larger area inside the hysteresis curve. It turns out that it is excellent in the effect to make it. In addition, in the case of the conventional joint structure, a sudden tensile fracture occurs, but in the case of the joint structure of the present invention, a fracture mechanism in which a slip of the bolt or a tensile fracture is caused in a section of the bolt hole that is missing in the bolt hole. Because it was easy to understand, it was possible to predict this hysteresis curve at the time of design, and it was confirmed that it could be easily reflected in seismic design.

In addition to the above, a load assuming a short-term load shows an elastic load-deformation relationship, and the subsequent load causes the first slip of the bolted joint when the total plastic moment is exceeded. In addition, on the opposite side where the load was reversed, slippage occurred without reaching the total plastic moment. Immediately after slipping, the proof stress was reduced, but the proof stress was restored with deformation, and the bearing became a bearing state. After the slippage occurred again, the yield strength was restored after a large deformation. As is generally said, with the deterioration of the friction surface after the occurrence of slippage and the decrease of the bolt tension, the slip-type load-deformation relationship was established. It did not completely disappear.

As described above, according to the joint structure of the present embodiment, a highly reliable outer diaphragm which is relatively simple and does not suddenly break even when a destructive load such as an earthquake is applied. It is possible to obtain a joint structure of the type.

[0047]

According to the present invention, the following effects can be obtained.

(1) A joint is formed in the upper and lower diaphragms constituting the joining member so that the column can penetrate and surround the entire circumference of the column, and the upper and lower diaphragms are bolted to the column and bolted together. By connecting the diaphragm body and the beam member with bolts, when a load greater than the design load is applied, such as a huge earthquake, the welded portion does not suddenly break as in the past, and the diaphragm and the beam member Of the flange due to ductile fracture and shear fracture of the bolt. In addition, by adopting a structure in which the upper and lower diaphragms are bolted to the column, there is no need for welding work at the site, thereby improving quality and improving construction efficiency.

(2) The diaphragm body has a plate portion having a bolt hole for joining to the beam member, a notch connected to the plate portion and surrounding the entire periphery of the column member, and a bolt hole for joining to the column member. By using an integrally molded product by casting with a joint having, in addition to the above effects, breakage at the end face as in the case of a plurality of split plates is eliminated, and the diaphragm acts as one, resulting in The proof strength against breakage is improved.

(3) By processing the joint surface between the upper and lower diaphragms and the upper and lower flanges of the beam member to increase the frictional force, the resistance to the load can be improved by the frictional force.

(4) Breaking load At the time of loading, the joining structure is such that the diaphragm and the flange of the beam member are broken by ductile breaking and the bolt is broken by shear breaking.
The simulation at the time of breakage becomes easy without sudden breakage unlike the breakage of a conventional weld.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a joining structure according to an embodiment of the present invention.

FIG. 2 is a perspective view of the diaphragm shown in FIG.

FIG. 3 is a front view of the joining structure shown in FIG. 1;

FIG. 4 is an explanatory view showing a procedure for applying the joint structure shown in FIG. 1;

FIG. 5 is an explanatory view showing a procedure for applying the joining structure shown in FIG. 1;

FIG. 6 is an explanatory diagram showing a procedure for applying the joining structure shown in FIG. 1;

FIG. 7 is an explanatory view showing a procedure for applying the joint structure shown in FIG. 1;

FIG. 8 is a graph showing test results of the method of the present invention.

FIG. 9 is a graph showing test results of a conventional method. .

FIG. 10 is a longitudinal sectional view showing a joining structure by a conventional outer diaphragm method.

11 is a plan view of the bonding structure shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Column body 12 Diaphragm body 12a Joint part 12b Plate part 14 Gazette plate 20 Mounting bracket 40 Beam member 40a Web 40b Upper flange 40c Lower flange H Bolt hole B One side bolt S Notch

Claims (6)

[Claims] 1. A joining structure of a steel structure for joining an outer diaphragm type joining member to an outer surface of a penetrated column body and further joining the joining member and a beam member, and constitutes the joining member. A joint is formed in the upper and lower diaphragms so that the column can penetrate and surround the entire circumference of the column, and the upper and lower diaphragms are bolted to the column, and the upper and lower diaphragms and the beam member are bolted together. A joint structure for a steel structure, which is joined by joining. 2. A joint structure of a steel structure in which a beam member made of H-shaped steel having upper and lower flanges and a column are joined by a joining member having upper and lower diaphragm bodies, wherein the upper and lower diaphragms constituting the joining member are provided. Forming a joint that allows the column to penetrate the body and surrounds the entire circumference of the column, and bolts the upper and lower diaphragms to the column, and the upper flange and the upper diaphragm of the beam member and A joint structure for a steel structure, wherein the lower flange and the lower diaphragm are directly joined by bolt joining. 3. The joint structure for a steel structure according to claim 1, wherein the weakest portion when the design load is applied is a bolt joint between the joint member and the beam member. 4. The diaphragm body and the beam member are joined so as to be broken by a shear failure of a joint bolt or a ductile fracture of the joint member or the beam member when a breaking load is applied. Joint structure of steel structure. 5. A diaphragm portion of an outer diaphragm type, which is joined to an outer surface of a penetrated column member and used for joining with a beam member, wherein the plate portion has a bolt hole for joining with the beam member; A diaphragm connected to the column, a notch surrounding the entire circumference of the column, and a joint having a bolt hole for bonding to the column. 6. The diaphragm according to claim 5, wherein the diaphragm is an integrally molded product by casting, and the height of the joint is in a range of 3 to 5 times the height of the plate. Diaphragm body.