JP7332505B2 - Joint structure of steel beams and steel columns - Google Patents

Description

The present invention relates to a steel beam and a steel column in which the upper and lower flanges of a steel beam are welded to the flange of a steel column, and the web of the steel beam is bolted to a gusset plate, or welded to the flange of the steel column via the gusset plate. It relates to a joint structure.

When welding a steel beam to a flange of a steel column, the flange of the steel beam needs to be welded over the entire length in the width direction. When welding the lower flange to a steel column in a downward position, it was common to form a scallop so that the web of the steel beam would not interfere with the welding work. It has been pointed out that the web tends to break due to reduced yield strength and stress concentration.

The inconvenience caused by the formation of scallops can be solved by not forming the scallops, but if one tries to rely on welding in the downward position, one must rely on factory work, which is usually reversible. On the other hand, by using a welding robot, upward welding has become possible, and there is a method of welding the lower flange without forming a scallop on the web of the steel beam even when welding on site (Patent Document 1 , 2).

However, in Patent Documents 1 and 2, the upper and lower flanges of the steel beam are welded to the diaphragm of the steel column (paragraph 0043 of Patent Document 1, paragraph 0070 of Patent Document 2), and the web of the steel beam is attached to the gusset plate. It is not assumed that it is welded to the flange of the steel frame column via (Patent Document 1, paragraph 0046, Patent Document 2, paragraph 0073). Due to this relationship, when welding the web of the steel beam to the steel column via the gusset plate, it becomes difficult to properly secure the root gap between the flange of the steel column and the end face (edge) of the web of the steel beam. You are likely to run into problems.

In detail, for example, when the web end face of the steel beam is aligned with the flange end face (edge) of the steel beam, as shown in Fig. 6-(a) and (b), the web end face of the steel beam and the steel column It may become difficult to properly secure the distance between the flange surfaces. For this reason, if the root gap becomes small when the web is to be welded to the flange of the steel frame column, sufficient penetration may not be obtained, and a situation may arise in which the welding quality cannot be ensured.

On the other hand, if the web end face of the steel beam is retracted from the flange end face of the steel beam to the opposite side of the steel frame column (the axially intermediate part side of the steel beam) (see Patent Document 3), FIG. 3-(d) It is considered possible to avoid the risk of scraping work as shown in .

JP 2015-33709 A (claim 1, paragraphs 0018 to 0046, FIGS. 1 to 5) Japanese Patent Application Laid-Open No. 2016-120510 (claim 1, paragraphs 0051 to 0071, FIGS. 6 to 9) Japanese Patent Application Laid-Open No. 10-263810 (paragraphs 0009 to 0014, FIGS. 1 and 3)

At the actual site, manufacturing or construction errors between steel columns and steel beams may affect welding work. For example, if the root gap between steel beam flanges and steel column flanges is smaller than specified In order to secure an appropriate root gap, it may be necessary to remove a part of the steel beam flange on the steel column side (closer to the end face).

In such a case, if a "web distance 12" aligned with the flange end surface is formed to avoid cross-sectional loss near the upper and lower flanges of the web as in Patent Document 3 (paragraph 0009, FIG. 1) , as shown in FIG. 3-(c), it is necessary to scrape the section of "web distance 12" together with a part of the steel frame beam flange near the end face, so there is a possibility that the scraping amount will increase.

In addition, as in Patent Document 1, when the web end face of the steel beam is aligned with the flange end face (edge) of the steel beam, as shown in FIGS. 3-(d) and (e), the steel beam flange Since it is necessary to scrape the entire length of the web together with a portion of the web near the end face, the scraping amount may increase further.

In view of the above background, the present invention provides a method for bolting a steel beam web to a gusset plate or welding to a steel column flange via a gusset plate without forming a scallop on the steel beam web. We propose a joint structure between a steel frame beam and a steel frame column for the purpose of reducing pinching as much as possible, or preventing interference between the welding of the gusset plate and the web end face.

In the joint structure of a steel beam and a steel column according to claim 1, a groove whose upper side is open is formed on the end face of the upper flange of the steel beam on the side of the steel column, and the lower flange of the steel beam on the side of the steel column. A groove with an open bottom is formed in the end face of the, the upper flange and the lower flange are welded to the flange of the steel column, the web of the steel beam is welded to the flange of the steel column, and the A joint structure of a steel beam and a steel column joined by at least one of bolting to a gusset plate joined to the flange of the steel column,
The web edges on the upper flange side and the lower flange side of the steel column side end surface of the web are aligned with the web side flange edges of the upper flange and the lower flange,
An intermediate section of the end surface of the web on the side of the steel frame column, excluding at least the section near the upper flange and the section near the lower flange, is located on the axially intermediate side of the steel beam from the flange edge,
When the web is viewed in the thickness direction, the end sections of the web near the upper flange and near the lower flange, excluding the intermediate section, form a continuous line from the edge of the web to the intermediate section. It is a configuration requirement.

The "groove 2a in which the upper side of the upper flange 2 of the steel frame beam 1 is open" in claim 1 has a shape that is open from the bottom to the top as shown in FIG. It is a groove with a shape suitable for welding. The "groove 3a in which the lower side of the lower flange 3 is open" means a groove that opens downward from above and is suitable for welding in an upward posture.

"The web 4 of the steel beam 1 is joined to the flange of the steel column 5 by at least one of welding and bolting to the gusset plate 6" means that the web 4 of the steel beam 1 is joined to the steel column 5. It may be welded to the flange 51, bolted to the gusset plate 6 welded to the flange 51 of the steel column 5, or joined to the flange 51 by a combination of welding and bolting. means that The above-mentioned "the web 4 is welded to the flange 51" means that the web 4 is welded to the flange 51 or welded to the flange 51 via the gusset plate 6 welded to the flange 51. Say things. The above-mentioned "through the gusset plate 6" means the case where the web 4 of the steel beam 1 overlaps the gusset plate 6 and is welded to the flange 51 of the steel frame column 5 using the gusset plate 6 as a backing metal, and the case where it is bolted. say that there are times when

The "end face of the web 4 on the steel column 5 side" is the edge facing the steel column 5 (flange 51) side of the web 4, and the web edge (edge) 41 on the side of the upper flange 2 and the lower flange 3 is basically Specifically, as shown in FIG. 2-(a), in the end face of the web 4 on the steel column 5 side, it refers to a line that intersects with the line of the upper and lower flanges 2 and 3 on the web 4 side. The lines on the web 4 side of the upper and lower flanges 2 and 3 are "flange edges (end edges) 21 and 31 on the web 4 side of the flanges 2 and 3" in claim 1. FIG.

The web edge 41 is the intersection of the line of the web 4 on the steel column 5 side and the line of the upper and lower flanges 2 and 3 on the web 4 side when the web 4 is viewed in the thickness direction. Flange edges 21 and 31 of the upper and lower flanges 2 and 3 on the web 4 side refer to lines near the web 4 or lines crossing the web 4 in the end faces of the flanges 2 and 3 on the steel column 5 side. "When the web 4 is viewed in the thickness direction" means "when the web 4 is viewed in the thickness direction".

Web edge 41 is aligned with flange edges 21 , 31 so that flange edges 21 , 31 are substantially continuous with web edge 41 . "The web edge 41 is aligned with the flange edges 21, 31" means that when the web 4 is viewed in the thickness direction, the web edge 41 and the flange edges 21, 31 are substantially Matching does not necessarily mean that the flange edges 21 , 31 are completely (exactly) continuous (coinciding) with the web edge 41 .

"Intermediate section 4A of the end surface of the web 4 on the steel column 5 side, excluding at least the section near the upper flange 2 and the section near the lower flange 3 " It refers to the section excluding section 4B. In the case of using the gusset plate 6, of the end surface of the web 4 on the steel column 5 side, the section overlapping at least the gusset plate 6 becomes the intermediate section 4A. "Overlaps the gusset plate 6" means that the web 4 overlaps the gusset plate 6 in the thickness direction of the web 4. Since it is "a section that overlaps at least the gusset plate 6", the intermediate section 4A may include a section (excluding the end section 4B) shifted from the section that overlaps the gusset plate 6 to the upper and lower flanges 2, 3 side. In other words, the section where the web 4 overlaps the gusset plate 6 may be the intermediate section 4A and the section where the gusset plate 6 is not overlapped may be the end section 4B.

In claim 1, "the intermediate section 4A is positioned closer to the axial intermediate portion of the steel beam 1 than the flange edges 21 and 31" means that when the intermediate section 4A is viewed from the axial intermediate portion of the steel beam 1, It means that the end surface of the web 4 in the section 4A recedes from the flange edges 21, 31 to the opposite side of the steel column 5. The end section 4B refers to the section transitioning from the web 4 side line (flange edges 21, 31) of the upper and lower flanges 2, 3 to the intermediate section 4A.

When the web 4 is viewed in the thickness direction, the section near the upper flange 2 and the section near the lower flange 3 excluding the intermediate section 4A is the "end section 4B", so the intermediate section 4A excludes the flanges 2 and 3. The total height of the web 4 portion is the section excluding the end section 4B. The "end section 4B" is, at its longest, a section excluding the "section overlapping the gusset plate" as the intermediate section 4A. This "end section 4B" refers to a section where a continuous line is drawn from the web edge 41 to the intermediate section 4A when the web 4 is viewed in the thickness direction (claim 1).

In claim 1, "the end section 4B draws a continuous line from the web edge 41 to the intermediate section 4A" means the line of the end surface of the web 4 when the web 4 is viewed in the thickness direction (web 4 The line drawn by the end face) does not bend or meander from the web edge 41 to the intermediate section 4A, and draws a continuous straight line, a continuous curved line (claim 2), or a combination of both. "Continuous curve" means a curve whose curvature does not become discontinuous. In addition to drawing four circular arcs, it includes curves with continuously changing curvatures. It is appropriate that the boundary between the end section 4B and the intermediate section 4A of the end face of the web 4 is a curved surface whose curvature continuously changes from a curved surface to a flat surface so that a clear boundary line does not appear.

When the web 4 is viewed in the thickness direction, the end section 4B draws a continuous line, so that the web 4 transitions from the flanges 2 and 3 on the end surface of the web 4 to the intermediate section 4A without causing a cross-sectional loss in the web 4. The vertical cross-sectional area of the web 4 up to the section (portion) does not have a sudden change like the case where the web 4 is scalloped. For this reason, it becomes difficult for the yield strength of the web 4 to decrease and the stress concentration in the web 4 to occur partially due to the formation of a sudden change in the cross-sectional area.

In particular, when the end surface of the web 4 is curved (claim 2), the curve makes the curve continuous from the web edge 41 (end section 4B) to the intermediate section 4A (the curvature is continuous). ), so no corners are formed as in the case where the end section 4B is straight. As a result, changes in the vertical cross-sectional area of the web 4 are moderated, so there is the advantage that stress concentrations are less likely to occur than in the case of a straight web.

In addition, when the web 4 end surface of the intermediate section 4A retreats toward the axially intermediate portion of the steel beam 1 (from the steel beam 5), there is a manufacturing error or a construction error between the steel beam 5 and the steel beam 1. Also, in comparison with the case where a part of the intermediate section 4A of the web 4 shown in FIG. In addition, the pinching amount of the web 4 section to be pinched together with the portions of the flanges 2 and 3 near the end faces is reduced. In comparison with the case where the entire length of the intermediate section 4A of the web 4 shown in FIGS. The stripping amount of the web 4 section to be stripped together with the side portion is greatly reduced.

Due to some error, the root gap between the flange 2, 3 end surface and web 4 end surface of the steel beam 1 and the flange 51 of the steel frame column 5 becomes small and inappropriate, and the flange 2, 3 end surface and web 4 end surface For example, let us consider a case in which it is inevitable to pick up, using the examples shown in FIGS. 3-(c) and (d). When the end faces of the web 4 near the flanges 2 and 3 are aligned with the end faces of the flanges 2 and 3 excluding the grooves 2a and 3a, the intermediate portion in the height direction of the web 4 indicated by the vertical and oblique broken lines Assuming that it is necessary to scrape off the part protruding from the near end face to the steel column 5 side, in the examples of FIGS. 3-(c) and (d), the hatched areas should be scraped. become.

In this case, as shown by hatching, the flanges 2 and 3 protruding from the end surface of the web 4 near the middle in the height direction toward the steel frame column 5 are pinched, and the portions of the web 4 that are continuous with the flanges 2 and 3 (Patent Document 3 corresponding to "web distance 12"), and the amount of scraping to the web 4 increases. When the web end face is aligned with the flange end face as in the examples shown in FIGS. 3-(d) and (e), the web and gusset plate are welded to the steel frame column 5 via the gusset plate. It is necessary to remove the overlapping portion over the entire length.

In comparison with the example shown in FIG. 3-(c), in the present invention, the intermediate section 4A of the web 4 retreats from the steel frame column 5 as shown in FIG. Section 4B draws a continuous line from web edge 41 (claim 1). For this reason, when the web 4 is viewed in the thickness direction, the area (on the vertical surface) of the web 4 in the section (end section 4B) near the flanges 2 and 3 is hatched in FIG. 3-(a). The size of the area becomes smaller than that in the case where the end faces of the web 4 near the flanges 2 and 3 are partially aligned with the end faces of the flanges 2 and 3 shown in (c).

The smaller area is the distance (height) of the section corresponding to "web distance 12" in Patent Document 3 x the extension length (toward the steel column side) from the web end surface other than "web distance 12" In the present invention, the web is prevented from being pinched by this area, so the amount of pinching is reduced as compared with Patent Document 3.

As described above, in the present invention, the width (in the axial direction of the flange) of the flanges 2, 3 and the web 4 for securing the root gap of the flanges 2, 3 is the intermediate section 4A of the web 4 (height of the web 4). In the case of the distance to the position where it is aligned with the end surface near the middle part of the direction), the part to be pinched together with the flanges 2 and 3 protrudes from the middle section 4A of the end section 4B of the web 4 toward the steel column 5 side. Only the part that is there is enough.

Also, for example, when the end face of the web does not recede from the steel frame column and the end face of the flange and the end face of the web are aligned (Patent Document 1, etc.), in order to secure the root gap of the web, at least the section overlapping the gusset plate It is thought that it will be necessary to cut. In contrast, in the present invention, since the intermediate section 4A of the web 4 including at least the section overlapping the gusset plate 6 is retracted from the steel column 5, when the web 4 is welded to the steel column 5 via the gusset plate 6, , the need for pinching the web 4 to ensure a proper root gap of the web 4 is essentially eliminated.

When the web 4 is bolted to the gusset plate 6, as shown in FIGS. 7-(a) and (b), the larger the thickness of the gusset plate 6 to which the web 4 is bolted, the greater the amount of weld metal. Problems may arise as a result. For example, when both sides of the gusset plate 6 are welded to the flange 51 of the steel frame column 5, a sufficient root gap is not secured between the end face of the web 4 and the weld metal of the gusset plate 6, and it is assumed that the two interfere with each other. be done. FIG. 7-(a) shows the welded state of the gusset plate 6 when the thickness of the gusset plate 6 is relatively small, and (b) shows the welded state when the thickness of the gusset plate 6 is larger than that of (a).

The amount of weld metal required for welding the gusset plate 6 varies depending on the thickness of the gusset plate 6. The smaller the thickness, the smaller the amount of metal, and the larger the thickness, the larger the amount of metal. In this relation, when the thickness of the gusset plate 6 is relatively small, the gap d1 between the webs 4 of the steel frame beam 1 is likely to be sufficiently secured as shown in FIG. 7-(a). On the other hand, when the thickness of the gusset plate 6 is relatively large as in (b), the gap d2 becomes smaller than in the case of (a), making it difficult to ensure a sufficiently large gap d1. Therefore, the two may interfere in some cases.

In such a case, as shown in Figs. By retreating to (the axially intermediate portion side of the steel frame beam 1), interference between the end surface of the web 4 and the weld metal of the gusset plate 6 can be avoided.

The web edge on the upper and lower flange sides of the steel column side end face of the steel beam web is aligned with the flange edge on the web side of the flange, and the intermediate section of the web end face that overlaps at least the gusset plate is on the axially intermediate part side of the steel beam web from the flange edge. , it is possible to prevent the formation of a sudden change in the vertical cross-sectional area of the web from the upper and lower flanges of the web end face to the section transitioning to the intermediate section without causing cross-sectional loss in the web. As a result, it is possible to prevent a reduction in yield strength of the web and a partial concentration of stress in the web due to the formation of a sudden change in cross-sectional area.

In addition, since the web end surface of the intermediate section recedes toward the axially intermediate side of the steel beam, the intermediate section of the web does not recede even if there is an error in the manufacturing or construction of the steel frame column and steel beam. Compared to the case without it, it is possible to reduce the pinching amount of the web section to be pinched together with the end-face portion of the flange.

(a) is an elevational view showing the relationship between the end portion of the steel frame beam, the steel frame column flange, and the gusset plate, and (b) is a cross-sectional view taken along line xx of (a). (a) is a perspective view showing an example of the shape of the end of the steel frame beam shown in FIG. 1, and (b) is a perspective view showing a modification of (a). (a) is an elevational view showing the steel frame beam flange and web pinching area of the present invention, (b) is a horizontal cross-sectional view of (a), (c) and (d) are the conventional art compared with the present invention FIG. 10(e) is a horizontal sectional view of FIG. 1(d). (a) is an elevation view showing the relationship between the end of the steel beam, the steel frame column flange, and the gusset plate when grooves are formed in the web of the steel beam; (b) is the yy line of (a). Sectional drawing, (c) is an enlarged view of the lower flange part of (a). Fig. 4 is a perspective view showing the relationship between the web of the steel frame beam shown in Fig. 4-(a) and the gusset plate; (a) is an elevational view showing the relationship between a conventional steel frame beam end portion, a steel frame column flange, and a gusset plate, and (b) is a cross-sectional view taken along line zz of (a). (a) is a horizontal sectional view showing the relationship between the web of the steel beam and the gusset plate when the gusset plate is welded to the flanges of the steel column on both sides; FIG. 4 is a horizontal cross section showing the relationship between the web and the gusset plate when the thickness is large;

FIGS. 1-(a) and (b) show an upper flange 2 of a steel beam 1 in which a groove 2a whose upper side is open on the end face of the steel column 5 is formed, and a groove whose lower side is open on the end face of the steel column 5. The lower flange 3 of the steel beam 1 formed with the tip 3a is welded to the flange 51 of the steel column 5, and the web 4 of the steel beam 1 is joined to the gusset plate 6 welded to the flange 51 of the steel column 5. 1 and a steel frame column 5 are shown.

The web 4 may be bolted to the gusset plate 6 or welded to the steel column 5 via the gusset plate 6 . The bolts 7 in FIG. 1-(a) are bolts when the web 4 is bolted to the gusset plate 6, or temporarily join the web 4 to the gusset plate 6 when the web 4 is welded to the steel column 5. shows the bolts for

The upper flange 2 of the steel beam 1 is welded to the flange 51 of the steel column 5 in a downward posture, and the lower flange 3 is welded to the flange 51 in an upward posture. In this connection, the backing strip 2b for the upper flange 2 is arranged below the upper flange 2 and the backing strip 3b for the lower flange 3 is arranged above the lower flange 3. Upward welding of the lower flange 3 to the flange 51 mainly depends on the welding robot.

Web edges (edges) 41, 41 on the side of the upper flange 2 and the side of the lower flange 3 of the end surface of the web 4 of the steel beam 1 on the side of the steel column 5 are shown in FIGS. 2-(a) and (b). The flange edges (edges) 21, 31 on the web 4 side of the flange 2 and the lower flange 3 are aligned completely or nearly. 2-(a) shows an example in which the web edge 41 completely coincides with the flange edges 21 and 31, and (b) shows an example in which the web edge 41 is positioned between the flange edges 21 and 31 in the axial direction of the steel beam 1. It is located on the part side and retreats toward the flange 51 of the steel column 5. FIG. The web edge 41 may be located closer to the steel column 5 than the flange edges 21 and 31 .

On the other hand, the intermediate section 4A of the end surface of the web 4 on the steel column 5 side, which includes at least the section overlapping the gusset plate 6 in the thickness direction, is shown in FIG. 1-(a) and FIG. It is located on the axially intermediate side of the steel frame beam 1 from the flange edges 21 and 31 of the steel frame column 5 and recedes toward the flange 51 of the steel frame column 5 .

As a result, when the web 4 of the steel beam 1 is viewed in the thickness direction, the end sections 4B near the upper flange 2 and the lower flange 3 excluding the intermediate section 4A of the web 4 are shown in FIGS. As shown, a continuous straight line or curve is drawn from the web edges 41, 41 on the upper flange 2 side and the lower flange 3 side to the intermediate section 4A. The curves include curves with continuously varying curvatures and no clear boundary line between the end section 4B and the intermediate section 4A.

FIG. 3-(a) shows that when welding the upper and lower flanges 2 and 3 of the steel beam 1 to the flange 51 of the steel column 5, due to manufacturing errors and construction errors, the end faces of the upper flange 2 and the lower flange 3, and As a result of the end surface of the web 4 approaching the steel column 5 side, for example, the end section 4B of the web 4 is scraped together with a part of the flanges 2 and 3 on the steel column 5 side. showing.

In this case, from the proper root gap position of the flanges 2 and 3 indicated by the vertical dashed line (the position retreated from the tip of the flanges 2 and 3 by the required distance), the range (region) protruding to the steel column 5 side is removed. 3-(a), only the hatched areas in FIG. In this example, as shown in (b), the web 4 does not need to be pulled at all or very little.

In comparison with the examples shown in (c) and (d) in which there is no end section 4B near the upper and lower flanges 2 and 3 of the web 4 of the present invention, the flanges 2 and 3 of the web 4 are parallel to the steel column flange 51. It can be seen that the amount of scraping is reduced by an area equivalent to a rectangle on the elevation including the portion continuing to . More specifically, even if the amounts (a) and (c) of the flanges 2 and 3 are the same, the amounts (c) and (d) of the web 4 in (a) are the same. It is reduced by the area corresponding to the rectangle obtained by subtracting the thinned area of (a) from the area. In the case of (a), as shown in (a) and (b), there is substantially no pinched portion on the web 4, whereas in the case of (c), it corresponds to the end section 4B of the present invention. It is necessary to pull the web for the section. In the example (d), it is necessary to scrape the entire length of the web.

FIG. 4 shows an example in which the web 4 of the steel beam 1 is welded to the steel column 5 via the gusset plate 6. As shown in FIG. The groove 4a of the web 4 is formed from the opposite side of the gusset plate 6 as shown in FIG.

In FIG. 4, in order to reduce the pinching amount when the root gap becomes small as shown in FIG. It is retracted to the opposite side of the pillar 5. FIG. 4-(c) is a specific example of (a), and the distance (root gap) between the end face of the lower flange 3 excluding the groove 3a and the steel frame column flange 51 is 7 mm, and the end face of the lower flange 3 to the middle of the web 4 An example in which the end face of the section 4A is set back by 3 mm from the steel column 5 is shown.

1 …… steel beams,
2 ... upper flange, 2a ... groove, 2b ... backing metal, 21 ... flange edge,
3...lower flange, 3a...groove, 3b...backing metal, 31...flange edge,
4... web, 41... web edge, 4A... middle section, 4B... end section, 4a... groove,
5... Steel column, 51... Flange,
6 …… gusset plate,
7 …… bolts.

Claims (3)

A groove whose upper side is open is formed on the end face of the upper flange of the steel beam on the steel column side, and a groove whose lower side is open is formed on the end face of the lower flange of the steel beam on the steel column side, and the upper flange and The lower flange is welded to the flange of the steel column, and the web of the steel beam is at least welded to the flange of the steel column and bolted to a gusset plate joined to the flange of the steel column. It is a joint structure of steel beams and steel columns joined at one side,
The web edges on the upper flange side and the lower flange side of the steel column side end surface of the web are aligned with the web side flange edges of the upper flange and the lower flange,
An intermediate section of the end surface of the web on the side of the steel frame column, excluding at least the section near the upper flange and the section near the lower flange, is located on the axially intermediate side of the steel beam from the flange edge,
When the web is viewed in the thickness direction, the end sections of the web near the upper flange and near the lower flange, excluding the intermediate section, form a continuous line from the edge of the web to the intermediate section. A joint structure of a steel frame beam and a steel frame column characterized by: 2. The steel beam according to claim 1, wherein when the web of the steel beam is viewed in the thickness direction, the end section draws a continuous curve from the web edge to the intermediate section. and steel column joint structure. 3. The joint structure of a steel frame beam and a steel frame column according to claim 1, wherein a groove is formed on one side in the thickness direction of the intermediate section of the web.

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