JP2024041990A - Joint structure of channel steel - Google Patents

Abstract

[Problem] To provide a channel steel joint structure that has the same level of joint strength as conventional channel steel joint structures, while reducing the number of parts, facilitating joint construction, and enabling the front side of the flange to be made flat. [Solution] A channel steel joint structure that joins a channel steel 10 to a steel material 14 having a plate portion 15, characterized in that when the thicknesses of the flange 12 and the web 13 of the channel steel are substantially the same, and when the connecting plate connecting the web 12 of the channel steel and the plate portion 15 of the steel material are joined by bolts 6, or when the web 13 of the channel steel and the plate portion of the steel material are joined by bolts 6, the restraint length (ls) of the connecting plate or the plate portion 15 of the steel material in the longitudinal direction of the web 13 of the channel steel is determined by the following formula (1): ls ≧ b × √3 ... (1) (wherein b represents the flange width) [Selected Figure] Figure 6

Description

The present invention relates to a joint structure for channel steel.

BACKGROUND ART Structures such as buildings use structural materials such as steel frames for their frames. As such structural materials, H-shaped steel is generally used from the viewpoint of bending rigidity, bending strength, etc., and building structures are made by assembling these according to the design of the building.

When joining H-beams in the construction of architectural structures, the bending moment applied to the ends of adjacent H-beams is mainly transmitted as axial force to the flange cross section, so the flanges of adjacent H-beams are In order to transmit the axial force in the axial direction, splints are applied to the front and back surfaces of the flange to sandwich the flange, and splints are placed on both sides of the web so that the shear force is transmitted to the web of the adjacent H-shaped steel. The two friction surfaces are friction-bonded by tightening bolts and nuts. Furthermore, the axial force applied to the H-beam is transmitted through both the flanges and the webs.

In such a conventional joint structure, in order to maintain high joint strength between adjacent H-beams, a large number of splints and many bolts and nuts are required to fix each splint. In such a bolt-and-nut connection, the bolt head, nut, and splint inevitably protrude from the surface of the flange. In such a joint structure, when installing other members such as a floor on the flange surface side of the joint, avoid the protruding bolt heads, nuts, and splints as they will get in the way. A design for this purpose is required. Therefore, it has been desired that the surface side of the flange be flat.

Therefore, as a method to eliminate protrusions from the flange surface side, we used a part with a thick recess at the tip of the upper flange to sink the bolt head, and formed it integrally with the flange by full penetration welding, thereby transmitting the force of the flange on site. A proposal has been made to arrange a corresponding splint inside the flange and connect it with a through bolt (see Patent Document 1). However, in the proposal of Patent Document 1, the parts with thick concave processing are expensive, the complete penetration welding of the part and the H-section steel flange is expensive, and the friction surface with the splicing plate is one-sided shear friction. Because it is a weld, there are problems such as the need for nearly twice the number of bolts compared to conventional two-sided shear friction welding.

On the other hand, in construction of architectural structures in recent years, channel steel (C channel) is used together with or in place of the above-mentioned H section steel. For example, when connecting two channel steels in the longitudinal direction, the ends of each flange and web are sandwiched from both sides by connecting plates and bolts and nuts are used, similar to the conventional joining of H-beam steels described above. It is joined.

Japanese Patent Application Publication No. 6-173340

However, channel steel webs are usually thin and bolted using splints. In addition, to connect flanges, it is necessary to sandwich both sides of the flanges between splicing plates and bolt them together, just as with webs, and since the flanges of channel steel have a trapezoidal cross section, it is necessary to consider the slope of the flanges. It took a lot of time to join. Also, similar to the conventional joining structure of H steel, there was a problem in that the bolt heads, nuts, and splints protruded from the flange surface side, making it impossible to flatten the joint structure.

The present invention has been made in view of the above circumstances, and has a joint strength comparable to that of conventional channel steel joint structures, reduces the number of parts, is easy to perform joint construction, and has a flange structure. The object of the present invention is to provide a joint structure for channel steel that can make the surface side flat.

The joint structure for channel steel of the present invention has been made to solve the above technical problem, and is characterized by the following features.

First, the channel steel joining structure of the present invention is a channel steel joining structure in which a channel steel and a steel material having a plate portion are joined, and the thickness of the flange and web of the channel steel is substantially a connecting plate that connects the web of channel steel and the plate section of steel material is joined by bolts, or the web of channel steel and the plate section of steel material are joined by bolts. In the case of It is characterized by
ls≧b×√3...(1)
(In the formula, b represents the flange width)

Secondly, in the channel steel joint structure of the first invention, it is preferable that the plate portion of the steel material is a bracket plate that protrudes from the side surface of the steel pipe column.

The channel steel joint structure of the present invention has the same joint strength as conventional channel steel joint structures, while reducing the number of parts, making joint construction easier, and making it possible to make the surface side of the flange flat.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing a first embodiment of a joint structure for channel steel according to the present invention. FIG. 2 is a sectional view taken along line AA after bonding of the first embodiment in FIG. 1; 3 is a partially enlarged view of FIG. 2. FIG. FIG. 2 is an exploded perspective view showing a second embodiment of the joint structure for channel steel of the present invention. FIG. 2 is an explanatory perspective view for confirming a tensile force transmission mechanism at a joint of channel steel. FIG. 3 is an exploded perspective view showing a third embodiment of the joint structure for channel steel of the present invention. It is an exploded perspective view showing a 4th embodiment of the joint structure of channel steel of the present invention. FIG. 3 is a schematic explanatory diagram showing variations in the arrangement of bolts. FIG. 11 is a schematic cross-sectional view showing an embodiment in which a bracket plate protruding from the side surface of a steel pipe column is joined in the joining structure of the third embodiment. In the joint structure of the fourth embodiment, it is a schematic sectional view showing an embodiment joined to a bracket plate projected from the side surface of a steel pipe column.

The joint structure of channel steel according to the present invention will be described in detail below based on the drawings. FIG. 1 is an exploded perspective view showing a first embodiment of a joint structure for channel steel according to the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a partially enlarged view of FIG. .

<First embodiment>
The channel steel joining structure of the first embodiment shown in FIG. 1 joins a channel steel 10 and a channel steel 11 having the same shape as the channel steel 10, which is a steel material having a plate portion as a member to be joined. This is a joint structure of channel steel. The channel steels 10 and 11 are steel materials having a U-shaped cross section, each consisting of upper and lower flanges 12 and one web 13 that vertically connects the cross-sectional ends of each flange 12. The shape steels 10 and 11 are provided with a transmission plate 2 that is in close contact with one surface of the web 13 and welded to the back surface of the flange 12. Then, the channel steel 11 adjacent to the channel steel 10 is connected to the bolt 6 via the connecting plate 3 that connects the web 13 and transmission plate 2 of the channel steel 10 and the web 13 and transmission plate 2 of the channel steel 11. and are joined by a nut 7.

As shown in FIG. 2, the cross-sectional shape of the transmission plate 2 provided on the channel steels 10 and 11 is such that it comes into close contact with the joint between the flange 12 and the web 13. When the transmission plate 2 is formed to have an arcuate cross section, the corresponding edge of the transmission plate 2 is also formed to have an arcuate or chamfered cross section that closely fits thereto.

The transmission plate 2 and the flange 12 are welded so that force is transmitted between the edges of the transmission plate 2 and the flange 12. The welding strength between the transmission plate 2 and the flange 12 is preferably greater than or equal to the value obtained by subtracting the transmission strength to the web 13 from the allowable strength of the cross section of the flange 12.

In addition, in the joint structure of channel steel according to the first embodiment, since the connecting plate 3 is provided in close contact with the surface of the transmission plate 2, the welded portion 21 between the transmission plate 2 and the flange 12 is attached to the surface of the transmission plate 2. It is desirable that the welding be done so that so-called beads that bulge along the edges do not protrude. In order to obtain such a welded state, for example, as shown in FIG. 3, it may be considered to form a chamfered portion 22 in advance on the edge of the welded portion 21 of the transmission plate 2. Normally, welding is performed by partial penetration welding so as to fill the inside of the chamfered portion 22, but by cutting the excess portion, it becomes possible to provide the transmission plate 2 and the connection plate 3 in close contact with each other. Further, it is also possible to form a chamfered portion 22 on the edge of the connecting plate 3 that is brought into close contact with the connecting plate 3 to prevent contact with the swell of the bead. Although the welding form of the abutting portion between the flange 12 and the transmission plate 2 is not particularly limited, in consideration of the above, partial penetration welding and excess cut is desirable. Note that it is also possible to attach the connecting plate 3 to the surface of the web 13 where the transmission plate 2 is not attached, but this is not desirable because the deviation between the center of the drawing of the channel steels 10 and 11 and the center of the connecting plate 3 becomes large. In this case, the welded portion 21 may protrude.

The connecting plate 3 is a member that connects the webs 13 to each other via the corresponding transmission plates 2 of the adjacent channel steels 10 and 11, and the connection of the webs 13 by the connecting plate 3 via the transmission plate 2 is , frictional welding or shear welding using bolts 6. Specifically, a through hole 5 coaxially passing through the connecting plate 3, the transmitting plate 2, and the web 13 is provided at a predetermined position in a portion where the transmission plate 2 and the connecting plate 3 overlap, and a bolt 6 is inserted into the through hole 5. Insert it through and tighten with nut 7 to join. At this time, the strength of the connecting plate 3 and the strength of the bolt connection are either the size obtained by dividing the allowable bending moment of the channel steels 10 and 11 by the distance between the bolt axes, or 1/2 of the allowable axial force of the channel steels. or greater strength is required. Note that if a shearing force is applied to the joint at this time, it is necessary to subtract the acting force.

The thickness, strength and number of bolts 6 are determined according to the required tightening strength. At this time, the length and thickness of the transmission plate 2 can be set by changing the pitch and number of bolts 6. In addition, a longer transmission plate 2 increases the strength transmitted from the joint between the web 13 and the flange 12, and allows for a longer weld length with the flange 12, so the weld size is smaller and the transmission plate 2 can be made thinner, and the length of the bolts 6 can be shortened, which is more economical.

Further, the material strength and cross-sectional area of the connecting plate 3 are determined depending on the required strength. In this case, as mentioned above, by reducing the thickness of the connecting plate 3, the length of the bolt 6 can be shortened, which is economical, but it is necessary to increase the width in order to obtain the necessary cross-sectional area. Care must be taken, as the distance between the axes of the bolts may become smaller and the joint strength may decrease. Further, in the case of friction bonding, it is desirable that the bonding surface between the connection plate 3 and the transmission plate 2 be subjected to red rust treatment or blasting treatment from the viewpoint of increasing the strength of the friction bond.

Although both are options in design, it is desirable to design appropriately depending on the size of the channel steels 10 and 11 to be joined. In the channel steel joint structure of the first embodiment shown in FIG. Since they are joined by the bolts 6, the bolted joint between the channel steel 10 and the channel steel 11 is a one-plane shear joint.

The force transmitted to the transmission plate 2, which is welded to one side of the web 13 and two places on the back side of the upper and lower flanges 12, is transmitted from the welded part 21 to the flange 12, but the transmission plate 2 and the web 13 are fastened together with bolts 6. Therefore, it is also transmitted to the web 13 and is transmitted from the joint between the web 13 and the flange 12 to the flange 12.

Further, in joining the channel steel 10 and the channel steel 11, the force transmitted from the connection plate 3 to the transmission plate 2 is transmitted to the flange 12 via the web 13 and the welded portion 21 of the transmission plate 2. Therefore, it is possible to create a joint that can transmit the bending moment, axial force, and shear force applied to the channel steels 10 and 11 only within the area surrounded by the back side of the flange 12 and the web 13, and with fewer parts than the conventional one. It becomes possible to bond with the same level of strength. This is due to the joint between the transmission plate 2 and the flange 12 at the welded portion 21, and the overall bonding force of tightening the web 13, the transmission plate 2, and the connection plate 3 together with the bolts 6. In addition, in the channel steel joining mechanism of the first embodiment, since the transmission plate 2 is welded to the back surface of the flange 12, it is possible to create a flat surface without any steps caused by protrusions or splints caused by the bolts 6. , it is possible to improve the workability on the surface side of the flange 12.

<Second embodiment>
As shown in FIG. 4, the joint structure of the channel steel according to the second embodiment of the present invention is similar to the joint structure of the channel steel of the first embodiment. A transmission plate 2 is provided which is in close contact and welded to the back side of the flange 12. The web 13 of the channel steel 10 and the transmission plate 2 are joined to the plate portion 15 of the steel material 14 by bolts 6.

That is, the joint structure of the channel steel of the second embodiment does not use the connection plate 3 in the first embodiment, but directly overlaps the web 13 and transmission plate 2 of the channel steel 10 with the plate portion 15 of the steel material 14. It is configured to be bolted together in this state. Note that, although the plate portion 15 of the steel material 14 in the second embodiment is simply plate-shaped, the steel material 14 may be formed into a groove shape to make the plate portion 15 thinner and have a smaller cross section. Even in such a joining structure, the action of the transmission plate 2 provided on the channel steel 10 makes it possible to join the steel material 14 having the plate portion 15 and the channel steel 10 with sufficient strength.

In the channel steel joining structure of the present invention, in addition to the structure in which the transmission plate 2 is provided on the web 13 of the channel steel 10 as in the first and second embodiments, the flange 12 of the channel steel 10 and the thickness of the web 13 are substantially the same, when joining the web 13 of the channel steel 10 and the plate portion 15 of the steel material 14, the thickness of the web 13 of the channel steel 10 in the longitudinal direction When the constraint length (ls) of the plate portion 15 satisfies the constraint length (ls) determined by the following formula (1), a joint structure without the transmission plate 2 can be used.
ls≧b×√3...(1)
In addition, in Formula (1), b represents the width dimension of the flange 12 of the channel steel 10.

Since the stress of the flange is transmitted to the web side from the cross section of the web connected to the flange, it is sufficient that the axial stress acting on the cross section of the flange and the shear stress acting on the cross section of the connected web are equal to or greater than the cross section of the flange.

The allowable strength (F) of channel steel is determined by the following formula.
F=√3×Fs
The allowable shear strength (Fs) of channel steel is determined by the following formula.
Af=b×t
The cross section (A) of the constraint portion of the flange and web is determined by the following formula.
A=ls×t

Since the transmission force due to the shear strength of the restraining portion only needs to be greater than the allowable strength of the flange cross section, the following equation holds true.
A×Fs≧Af×F
And from the above formula,
ls×t×Fs≧b×t×√3×Fs
It is expressed as,
ls≧b×√3...(1)
is derived.

In addition, in the present invention, the restraint length (ls) of the connecting plate in the longitudinal direction of the channel steel web is the total length of the bolt both end distance (db) and the bolt diameter (d).

From the above formula (1), in a channel steel whose flange and web have the same thickness, the stress of the flange can be transmitted to the web by restraining the web by at least a length equal to or greater than √3 times the flange width b. It was found that the bond could be bonded with sufficient strength. Below, an embodiment of a joining structure based on the above conditions will be described in detail.

<Third embodiment>
As shown in FIG. 6, the joint structure of the channel steel of the third embodiment is such that the surface of the web 13 of the channel steel 10 on the opposite side from the flange 12 and the plate portion 15 of the steel material 14, which is the member to be joined, are overlapped. They are also joined together with bolts 6. The restraint length (ls) of the connecting plate 3 in the longitudinal direction of the web 13 of the channel steel 10 is set to be equal to or longer than the flange width b multiplied by √3, and the plate portion 15 and the web 13 of the channel steel 10 are overlapped. They are also firmly connected with bolt 6. In the present invention, the restraint length (ls) is, for example, the longest distance between the longitudinal ends of the bolts 6 that fix the web 13 of the channel steel 10 and the plate portion 15 of the steel material 14, as shown in FIG. It means the distance of

<Fourth embodiment>
As shown in FIG. 7, the joint structure of the channel steel of the fourth embodiment is such that the webs 13 of a pair of channel steels 10 sandwich both sides of the plate portion 15 of the steel material 14, and are joined by bolts 6. are doing. That is, in the joint structure of the channel steel according to the fourth embodiment, the joint is directly connected to the plate portion 15 of the steel material 14 without using the connecting plate 3, similarly to the third embodiment. Also in this configuration, the constraint length (ls) of the plate portion 15 in the longitudinal direction of the web 13 of the channel steel 10 is set to be greater than or equal to the flange width b times √3. Therefore, a transmission plate is not required.

Note that in the configurations of the second to fourth embodiments described above, the plate portion 15 of the steel material 14 is in the form of an integral plate, so various variations can be considered in the arrangement of the bolts. For example, the bolt arrangement diagram shown in FIG. 8 is a bolt arrangement with point G as a point target, and the principle of the method is that the bending stress is the sum of the distance from point G multiplied by the bolt joint reaction force. Note that each symbol shown in FIG. 8 represents the meaning of Table 2 below.

By arranging the bolt on the rectangular line L in FIG. 8 so that the distance ri from G to the bolt becomes large, it becomes possible to efficiently deal with bending stress.

In addition, the members to be joined in the channel steel connection structure of the present invention include a simple long channel steel 11 or a plate portion 15 of a steel material 14, as well as a horizontal or predetermined member from the side surface of a columnar steel material 14 such as a steel pipe column. It may be a short channel steel 11 or a plate portion 15 that protrudes at an angle of . Such joining of the channel steel 10 to the channel steel 11 or the plate portion 15 can be used, for example, for linear joining of beams, columns, braces, and the like. Furthermore, the arrangement of the transmission plate 2 with respect to any of the above-mentioned members to be joined is taken into consideration in consideration of the joining strength.

As the plate portion 15 provided on the side surface of the columnar steel material 14, for example, a bracket plate 41 provided so as to protrude from the side surface of the steel pipe column 4 as shown in FIG. 9 can be exemplified. In addition, since such a bracket plate 41 is a member that fixes and supports the channel steel 10 as a beam, it needs to be firmly fixed to the steel pipe column 4.

<Bracket plate configuration>
As shown in FIG. 9, the fixing structure of the bracket plate 41 is as follows: A slit 42 having a width equivalent to the thickness of the bracket plate 41 is provided on the side surface of the steel pipe column 4, and the bracket plate 41 is fitted into the slit 42 and welded. At the same time, it can be configured to be fixed by welding to the inner diaphragm 8 provided inside the steel pipe column 4. Thereby, one end of the bracket plate 41 as the plate portion 15 having strength can be provided so as to protrude from the side surface of the steel pipe column 4.

Note that in this embodiment in which the bracket plate 41 is fixed to the inner diaphragm 8, the bracket plate 41 can be firmly welded to the inner diaphragm 8 in advance, so that the bending stress from the channel steel 10 is transferred to the inside of the steel pipe column 4. It is sufficient that the welding strength is sufficient to transmit the signal to the inner diaphragm 8 that is inscribed therein, and if welding to the inner diaphragm 8 alone is insufficient, welding to the intersecting bracket plates 41 and connecting the intersecting bracket plates 41 and the inner diaphragm 8 is sufficient. Since the welding strength of the diaphragm 8 can be added, fillet welding or partial penetration welding is sufficient in design, and complete penetration welding is not necessary.

Furthermore, in connection with the bracket plate 41 protruding from the side surface of the steel pipe column 4, in addition to the above configuration, as shown in FIG. It is also possible to have a structure in which they are sandwiched between the webs 13 of a pair of channel steels 10 and joined by bolts 6 and nuts 7.

The mounting structure of the bracket plate 41 in this joint structure is similar to the above embodiment, in which the bracket plate 41 is fitted into the slit 42 and welded, and the inner diaphragm 8 to which the bracket plate 41 is welded is welded into the steel pipe column 4. It is possible to have a structure in which it is fixed by hand. In addition, when aligning the column core and the beam core as in this embodiment, since both sides of the bracket plate 41 are sandwiched between the webs 13 of the pair of channel steel 10, the protruding position of the bracket plate 41, that is, the steel pipe The slit 42 of the column 4 is formed at the center of the width of the steel pipe column 4.

Although the joint structure of channel steel of the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the invention. It is.

For example, in the configuration for connecting the channel steel 10 to the bracket plate 41, in addition to the configuration without a transmission plate 2, such as the connection of the third embodiment shown in FIG. 9 and the connection of the fourth embodiment shown in FIG. 10, it is also possible to provide a transmission plate 2 or use a connecting plate 3 for the connection, such as the connection of the first embodiment shown in FIG. 1 and the connection of the second embodiment shown in FIG. 4.

Furthermore, in connection with the bracket plate 41, the bracket plate 41 is welded to the inner diaphragm 8 in order to obtain a predetermined strength. It can also be arranged on the side of the

Specifically, at least two or more bracket plates 41 are provided so as to fit into slits 42 provided on the side surface of the steel pipe column 4 so as to protrude, and the fitting portions of the slits 42 and the bracket plates 41 are welded together. , a configuration in which each of the plurality of bracket plates 41 is welded within the steel pipe column 4 can be exemplified.

With the above configuration, the bracket plate 41 can be arranged to protrude from the side surface of the steel pipe column 4 with a predetermined strength without providing the inner diaphragm 8.

In addition, in the joint structure of channel steel to the bracket plate 41, the bracket plate 41 is provided so as to protrude from the side surface of the square steel pipe column 4. It can also be applied to Furthermore, by shifting the position of the slit 42 of the square steel pipe column 4, the bracket plate 41 can be arranged so as to protrude from the corner side.

In addition, while the above embodiment uses high-strength bolts 6 and nuts 7 for frictional connection, it is also possible to use normal bolts, rivets, or other fasteners for shear connection.

According to the joint structure of channel steel of the present invention having the above configuration, it has a joint strength equal to or higher than that of the conventional joint structure of channel steel, the number of parts can be reduced, and the joint construction is easy. Furthermore, it is possible to make the flange surface side flat. Furthermore, the steel pipe column used in the present invention can improve loading efficiency on a truck during transportation.

10, 11 Channel steel 12 Flange 13 Web 14 Steel material 15 Plate portion 2 Transmission plate 21 Welded portion 22 Chamfered portion 3 Connection plate 4 Steel pipe column 41 Bracket plate 42 Slit 5 Through hole 6 Bolt (high strength bolt)
7 Nut 8 Inner diaphragm

Claims (2)

A channel steel joining structure for joining a channel steel and a steel material having a plate portion,
The flange and web of the channel steel have substantially the same thickness,
When the connecting plate connecting the channel steel web and the steel plate part is joined by bolts, or when the channel steel web and the steel plate part are joined by bolts,
The restraint length (ls) of the connecting plate or the plate portion of the steel material in the longitudinal direction of the web of the channel steel is the restraint length (ls) determined by the following formula (1). Joint structure of channel steel.
ls≧b×√3...(1)
(In the formula, b represents the flange width) The joint structure of channel steel according to claim 1, wherein the plate portion of the steel material is a bracket plate protruding from a side surface of the steel pipe column.