JP7533181B2 - Steel beam-column joint construction method - Google Patents

Description

The present invention relates to a steel beam-column joining method for joining columns and columns and beams in steel-framed buildings.

When constructing a steel-framed building, if the columns are long and difficult to manufacture or transport at their original length, columns of the desired length are manufactured in a factory and then joined vertically on-site to form a single column. Usually, the lower column is erected first, and then the upper column is joined to the lower one. However, if the upper and lower columns are to be welded while the upper column is suspended by a crane, it is usually difficult to keep the upper and lower columns stationary in an accurately aligned state during welding. Therefore, when joining such divided columns together to form a single column, it is common to use an erection piece to temporarily erect the upper and lower columns, and then butt-weld the upper and lower columns to join them (see, for example, Patent Document 1). The erection piece is a member for temporarily fixing the upper and lower columns, and is equipped with a fixing plate fixed to the outer surface of the lower end of the upper column and the outer surface of the upper end of the lower column, respectively, and two clamping plates that sandwich the fixing plates fixed to the upper and lower columns from both sides. The upper and lower fixing plates are aligned and clamped together with the two clamping plates and bolted together, so that the upper and lower fixing plates are connected via the two clamping plates. In steel-framed buildings, hollow steel pipes with a roughly rectangular cross section are generally used as columns, but in this case, an erection piece is usually provided on each of the four sides of the column, and the upper and lower columns are temporarily erected by connecting each erection piece, and in that state, the upper and lower columns are joined and integrated by butt welding. The erection piece is used for temporary erection until the upper and lower columns are welded together, so it is removed after the upper and lower columns are welded.

On the other hand, as for beams, since it is usually difficult to transport columns and beams in a joined state from a factory to the site, the columns and beams are joined on-site. In steel-frame buildings, H-shaped steel is generally used as the beams, and when joining a hollow steel pipe column to an H-shaped steel beam, a diaphragm is provided at the joint between the column and the beam, and the beam is joined to the diaphragm, so that the hollow column does not deform when subjected to force from the beam. That is, a column is cut vertically in the axial direction, a steel plate that becomes a diaphragm formed slightly larger than the cross-sectional outline of the column is sandwiched between the cut column and the steel plate is butt-welded to integrate the cut column, and a through diaphragm is generally used, in which the diaphragm passes across the column (for example, Patent Document 2).

In the case of Patent Document 2, two diaphragms are welded to the square steel pipe column in advance at a factory with a distance approximately equal to the height of the H-shaped steel beam, and the upper and lower flanges of a bracket made of an H-shaped steel beam of the same shape but shorter length are welded to the ends of the two diaphragms, and the web is welded to the opposing surfaces of the square steel pipe column. Then, at the construction site, the ends of the bracket and beam of the erected square steel pipe column are placed opposite each other, and the joined upper flange, lower flange, and web are sandwiched between two splice plates and bolted to join and fix the square steel pipe column to the beam.

Furthermore, Patent Document 3 discloses a structure and method for joining a square steel pipe column to a beam by fabricating two diaphragms welded to the column in a factory with a gap of the height of the beam made of H-shaped steel, and then inserting the end of the beam made of H-shaped steel between the two diaphragms of the erected square steel pipe column at the construction site while moving it horizontally, and joining the joints of the overlapping diaphragms to the upper and lower flanges of the beam by bolting them together using reinforcing plates, and welding the web of the beam to the surface of the square steel pipe column using gusset plates.

According to the above-mentioned conventional technology, when a long rectangular steel pipe column is required, the construction method of Patent Document 1 is used, and when connecting a column and a beam, the construction method of Patent Document 2 or Patent Document 3 is used.

JP 2003-184312 A JP 2002-146907 A Japanese Patent Application Publication No. 10-317489

According to the above-mentioned conventional technology, in the case of Patent Document 1, a total of eight mounting plates are welded to the four sides of the upper and lower ends of the upper and lower columns at the factory, and the two corresponding upper and lower mounting plates welded to the four sides at the site are sandwiched between two fixing plates and lightly bolted together, then the elevation is adjusted and the plates are fully tightened, and the column joints of the upper and lower columns are welded together on site, and then the bolts for the bolt fastening are removed, and the eight mounting plates welded to the upper and lower ends of the columns are cut with gas or the like and further polished with a grinder or the like, which requires a lot of factory and on-site work. In other words, there are problems in that an erection piece consisting of multiple parts as described above is required, and that its installation and removal requires a lot of work and effort.

According to the conventional technology of Patent Document 2, the two upper and lower diaphragms must be welded to the bracket of an H-shaped steel of the same dimensions as the H-shaped steel of the beam, and the web of the bracket must also be welded to the surface of the square steel pipe column in the factory, which is problematic as the work in the factory is time-consuming. Furthermore, at the construction site, the ends of the bracket and the ends of the beam must be aligned, but this is difficult because they are lifted by a crane or the like. Furthermore, when the ends are in contact with each other and the adjacent upper flange, lower flange, and web are to be connected with a splice plate, the work is difficult because the beam is lifted by a crane or the like.

According to the conventional technology of Patent Document 3, two diaphragms are welded to an erected square steel pipe column with a gap in the vertical direction equal to the height of an H-shaped steel beam. When joining these two diaphragms to the beam, the end of the beam must be moved from its horizontal position and inserted between the two diaphragms, but the beam is often lifted by a crane or the other end is temporarily fastened to another column, making this work difficult. There is also the problem that it takes time to align the bolt holes in the beam and diaphragms.

Furthermore, even if a square steel pipe column and an H-shaped steel beam are welded or bolted together using the techniques of Patent Document 2 and Patent Document 3, if it is necessary to lengthen the column by adding another square steel pipe column, the technique of Patent Document 1 must be used, so the erection piece must be welded to the square steel pipe column in advance, and the work of connecting the other square steel pipe column must be carried out at the construction site according to the above-mentioned construction method. Therefore, there remains the problem that on-site work is forced to be carried out without resolving the above-mentioned problems of the conventional technique of Patent Document 1.

The present invention was made in consideration of the above circumstances, and aims to provide a steel column-beam joining method that requires less preparatory work at the factory and also saves on-site construction labor.

A steel column-beam joining method for joining a steel beam having a pair of upper and lower flanges and a web connecting the pair of upper and lower flanges to a joint between a lower steel pipe column and an upper steel pipe column joined in the vertical direction,
The lower steel pipe column includes a lower diaphragm having a lower joint portion joined to the lower flange of the steel beam, and the upper steel pipe column includes an upper diaphragm having an upper joint portion joined to the upper flange of the steel beam. The method includes a lower column erection process for erecting the lower steel pipe column, a beam temporary assembly process for placing the lower flange of the steel beam on the lower joint portion of the lower diaphragm of the lower steel pipe column erected in the lower column erection process and temporarily fastening the lower joint portion and the lower flange by bolt fastening, and a beam temporary assembly process for placing the upper flange of the steel beam on the upper flange of the steel beam temporarily fastened to the lower steel pipe column in the beam temporary assembly process. a column-beam joining process in which the upper joint of the upper diaphragm of a steel pipe column is placed and the upper joint and the upper flange are temporarily fastened by bolting to temporarily erect the upper steel pipe column above the lower steel pipe column; a column-beam joining process in which, after adjusting the erection of the upper steel pipe column temporarily erected in the upper column temporary erection process, the lower joint and the lower flange, and the upper joint and the upper flange are finally fastened by bolting to join the steel beam to the lower steel pipe column and the upper steel pipe column, respectively; an upper-upper column joining process in which the lower steel pipe column and the upper steel pipe column are joined by welding after the column-beam joining process; and a column-beam reinforcement process in which the steel beam is joined to the lower steel pipe column and the upper steel pipe column by gusset plates after the upper-upper column joining process.
Furthermore, the lower steel pipe column and the upper steel pipe column are square columns.
Furthermore, the lower diaphragm and the upper diaphragm each include a plurality of lower joints and upper joints.

According to the steel column beam joining method of the present invention, in the lower column erection process, the lower steel pipe column is erected on a foundation on the ground or on a steel pipe column that has already been erected below, and then the lower flange of the steel beam is placed from above on the upper surface of the lower joint of the lower diaphragm of the lower steel pipe column and temporarily fastened with bolts in the beam temporary assembly process. Next, the lower joint of the lower diaphragm of the upper steel pipe column is placed from above on the upper flange of the temporarily fastened steel beam and temporarily fastened with bolts to connect the upper steel pipe column to the lower steel pipe column. This method involves a temporary upper column erection process, where the upper steel pipe column is temporarily erected upwards, followed by an adjustment of the erection of the upper steel pipe column in the temporary erection state, followed by a column-beam joining process in which the temporarily fastened bolts are fully tightened to join the steel beam to the lower steel pipe column and upper steel pipe column, followed by an upper-lower column joining process in which the lower steel pipe column and upper steel pipe column are joined by welding, and finally a column-beam reinforcement process in which the web of the steel beam is joined to the lower steel pipe column and upper steel pipe column by welding or bolting with gusset plates.

Because this construction method involves sequential steps, the steel beam can be lowered from above with a crane or similar device to the joining position of the lower joint of the lower diaphragm with ease and precision. In the subsequent process, the upper steel pipe column can be lifted with a crane or similar device and moved above the lower steel pipe column at a position above the steel beam, and then gradually lowered so that the upper joint of the upper diaphragm of the upper steel pipe column is placed on the upper surface of the upper flange of the steel beam. Therefore, there is no need to insert the steel beam laterally between the upper and lower diaphragms, and construction can be carried out with the easy task of simply lowering the members lifted with a crane or similar device into the designated position from the bottom up. Furthermore, because it is done in a lifted state, alignment can be done easily and accurately.

In addition, if the steel column is a rectangular column, all four surfaces are exposed, which has the advantage that it is easier to determine the direction in which the joint extends from the base of the diaphragm.

Furthermore, if a diaphragm with multiple joints in different directions is used on the upper and lower steel columns, multiple steel beams can be joined to a single steel column, which has the advantage of expanding the range of uses.

Furthermore, compared to the conventional method using erection pieces, the steel column beam joining method of this invention does not require welding mounting plates to the four sides of the upper and lower steel pipe columns in advance at the factory, and also does not require the work process of connecting the mounting plates of the upper and lower steel pipe columns with connecting plates at the work site. In addition, after welding the upper and lower steel pipe columns, the work of removing the connecting plates, the work of cutting and removing the mounting plates from the steel pipe column with a gas burner, etc., which must be done while the steel pipe column is upright, is no longer necessary, so the work process at the site can be simplified, made easy and accurate, and the overall construction costs are cheaper. Another advantage is that the joining of the steel beam and the steel pipe column can be done at the same time.

FIG. 2 is an explanatory perspective view of main components required for a column-beam joining method in accordance with one embodiment of the present invention; An explanatory diagram of the lower column erection process, in which the lower steel pipe column is erected on the ground, building foundation, or steel pipe column below, and an explanatory diagram of lowering the steel beam from an upper position onto the top of the lower joint of the lower diaphragm. Illustration of the temporary beam installation process and upper column erection process Upper and lower column joining process, Illustration of the column-beam reinforcement process using gusset plates A perspective view of a beam-column joint frame structure

One embodiment of the steel column beam joining method according to the present invention will be described below with reference to the drawings. However, the following is merely an example of an embodiment of the present invention, and the scope of the present invention is not limited to the following embodiment, and can be modified as appropriate without departing from the concept of the present invention.

The steel beam-column joint structure 1 in the steel beam-column joint construction method according to one embodiment of the present invention has a panel zone structure in which a steel beam 4 made of H-shaped steel is joined at the joint between a lower steel pipe column 2 and an upper steel pipe column 3, as shown in FIG. 1. The steel beam 4 is also joined to the lower steel pipe column 2 and the upper steel pipe column 3 by a gusset plate 5 that straddles the joint between the lower steel pipe column 2 and the upper steel pipe column 3.

As shown in Figs. 1 and 2, the lower steel pipe column 2 comprises a lower column base 21, a lower column upper end 22, and a lower diaphragm 23. The lower column base 21 is a hollow, long member with a closed cross section used as a column in a steel frame building, and is erected on the ground or building foundation, or fixed to a column on the lower floor in a second or higher story, and is made of a square steel pipe or round steel pipe that is generally used as a column in a steel frame building. In this embodiment, a square steel pipe is used for the explanation. The lower column upper end 22 is on the extension of the lower column base 21 and is made of a square steel pipe with the same cross section as the lower column base 21, and the lower diaphragm 23 is sandwiched between the lower column base 21 and the lower column upper end 22 and welded to form the lower steel pipe column 2. The lower diaphragm 22 is a plate material with a shape protruding from the lower steel pipe column 2, and includes a lower base plate portion 231 fixed between the lower column base portion 21 and the lower column upper end portion 22, and a lower joint portion 232 on which the steel beam 4 is placed and connected. The lower joint portion 232 is provided with a bolt hole 233 for connecting the steel beam 4. In addition, a backing metal 70 used during joining is welded to the inside of the upper end so that it protrudes upward.

As shown in Figs. 1 and 3, the upper steel pipe column 3 comprises an upper column base 31, an upper column lower end 32, and an upper diaphragm 33. The upper column base 31 is the same square steel pipe as the lower column base 21, and the upper column lower end 32 is also formed of a square steel pipe having the same cross section as the upper column base 31, and the upper diaphragm 33 is sandwiched and welded between the upper column base 31 and the upper column lower end 32 to form the upper steel pipe column 3. The upper diaphragm 33 has an upper base plate portion 331 fixed to the upper column base 31 and the upper column lower end 32, and an upper joint portion 332 connecting the steel beam 4 protruding from the upper steel pipe column 3. The upper joint portion 332 has a bolt hole 333 for connecting the steel beam 4.

As shown in Figures 1 and 5, the gusset plate 5 is a plate material that connects the steel beam 4 to the lower steel pipe column 2 and the upper steel pipe column 3. A notch 51 is formed in the center of one end, and bolt holes 52 are provided on the plate surface for connecting and fixing to the steel beam 4 as necessary.

The steel beam-column joining method of this invention is a method for joining steel beams and columns using the lower steel pipe column 2, upper steel pipe column 3, steel beam 4, and gusset plate 5 described above, and is a method for joining steel beams and columns in the following order: lower column erection process, beam temporary assembly process, upper column temporary erection process, column-beam joining process, upper and lower column joining process, and column-beam reinforcement process. Each process will be explained in order below. In this embodiment, the steel beam 4 is an H-shaped steel consisting of a flange 42 as the upper flange 41 and a web 43 connecting them.

(Lower pillar erection process)
This is a process of erecting the lower steel pipe column 2 on the foundation of a building, etc. The lower end of the lower column base 21 is erected vertically by a normal construction method, so that the lower column upper end 22 and the lower diaphragm 23 are positioned upward.
(Beam temporary assembly process)
As shown in Figure 2, the steel beam 4 is hoisted with a crane or the like, and the lower flange 41 at its end is moved to a position above the lower joint 232 of the lower diaphragm 23 to roughly align it, and then it is gradually lowered as indicated by the arrow until it is overlapped as shown in Figure 3, and the bolt hole 233 of the lower joint 232 is aligned with the bolt hole 411 at the end of the lower flange 41, and the bolt 6 is inserted and temporarily fastened with a nut. If the crane or the like hoisting the steel beam 4 can be removed at this point, it is removed and used for the next step. If the opposite end of the steel beam 4 has already been fixed to another steel column in this step, the height position is already determined, so it is only necessary to shift the position horizontally.
(Temporary upper pillar construction process)
Next, as shown in Figure 3, the upper steel pipe column 3 is lifted by the same crane that has just finished its work or another crane, moved to a position above the lower steel pipe column 2, and after roughly aligning it, it is gradually lowered as shown by the arrow, aligning the bolt hole 333 of the upper joint 332 of the upper diaphragm 33 with the bolt hole 421 provided at the end of the upper flange 42, fitting the bolt 6 in, and temporarily fastening it with a nut. At the same time, it is confirmed that the lower end 32 of the upper column is positioned above the upper end 22 of the lower column, and then it is further lowered and temporarily erected.
(Column-beam joining process)
After adjusting the erection of the temporarily erected upper steel pipe column 3, the lower joint 232 and the lower flange 41, and the upper joint 332 and the upper flange 42 are finally tightened by tightening the nuts of the bolts 6, as shown in Figure 4, to join the steel beam 4 to the lower steel pipe column 2 and the upper steel pipe column 3.
(Upper and lower pillar joining process)
Then, the weld joints 71 formed around the lower end of the upper column lower end 32 and around the upper end of the lower column upper end 22 are welded together using molten metal, and a weld bead 7 is formed around the weld joint 71 as shown in Figure 6.
(Column and beam reinforcement process)
After the welding is completed, as shown in Fig. 5, the lower steel pipe column 2 and the upper steel pipe column 3 are connected and reinforced to the steel beam 4 by the gusset plate 5 across the weld bead 7. The weld bead 7 is avoided by the cutout 51. The gusset plate 5 and the lower steel pipe column 2 and the upper steel pipe column 3 are joined by welding, and the joining of the steel beam 4 to the web 43 may be performed by matching the bolt hole 431 of the web 43 with the bolt hole 52 of the gusset plate 5 and fastening with the bolt 6 as shown in the figure, or the outer periphery of the gusset plate 5 and the web 43 may be joined by welding. The web 43 and the lower steel pipe column 2 and the upper steel pipe column 3 may each use a different gusset plate 5. It is to be noted that this column-beam reinforcement process may be performed prior to the upper and lower column joining process.

We have explained the joining method for joining the lower steel pipe column 2 and the upper steel pipe column 3, and for joining one steel beam 4 to this joined steel pipe column, but the same procedure and steps can be used even when there are two or more steel beams 4. In this case, the number of lower joints 231 and upper joints 332 of the lower diaphragm 23 and upper diaphragm 33, respectively, can be increased to two to four in the perpendicular direction, and the same steps can be repeated one by one for the upper and lower joints extending in each direction, allowing efficient construction.

Figure 6 shows a frame structure constructed using this beam-column joint construction method. Construction up to the second floor has been completed, and construction on the third floor is in progress. When building on higher floors, the upper steel pipe column 3 is joined. As is clear from this figure, the steel pipe column on the second floor serves as both the lower steel pipe column 2 and the upper steel pipe column 3 described above, so an upper diaphragm 33 is attached between the lower end 32 of the upper column and the base 31 of the upper column at the bottom, and a lower diaphragm 23 is attached between the upper end 22 of the lower column and the base 21 of the lower column at the top. By repeating this process, the steel beam-column joint construction method of this invention can be used up to the upper floors. At each floor, the steel beam 4 is lifted by a crane or the like and then lowered onto the top surface of the diaphragm joint, making the work easy, accurate, and efficient.

The steel column-beam joining method of the present invention can be applied to all buildings constructed using steel pipe columns and steel beams, so it has a wide range of applications and is expected to become widespread in the construction and building industries.

REFERENCE SIGNS LIST 1 Steel column beam joint structure 2 Lower steel pipe column 21 Lower column base 22 Lower column upper end 23 Lower diaphragm 231 Lower base plate 232 Lower joint 233 Bolt hole 3 Upper steel pipe column 31 Upper column base 32 Upper column lower end 33 Upper diaphragm 331 Upper base plate 332 Upper joint 333 Bolt hole 4 Steel beam 41 Lower flange 411 Bolt hole 42 Upper flange 421 Bolt hole 43 Web 431 Bolt hole 5 Gusset plate 51 Cutout 52 Bolt hole 6 Bolt 7 Weld bead 70 Backing metal 71 Welded joint

Claims (3)

A steel column-beam joining method for joining a steel beam having a pair of upper and lower flanges and a web connecting the pair of upper and lower flanges to a joint between a lower steel pipe column and an upper steel pipe column joined in the vertical direction,
The lower steel pipe column includes a lower diaphragm having a lower joint portion joined to the lower flange of the steel beam,
The upper steel pipe column is provided with an upper diaphragm having an upper joint portion joined to the upper flange of the steel beam,
A lower column erection process for erecting the lower steel pipe column;
A beam temporary assembly process in which the lower flange of the steel beam is placed on the lower joint of the lower diaphragm of the lower steel pipe column erected in the lower column erection process, and the lower joint and the lower flange are temporarily fastened by bolt fastening;
an upper column temporary erection process in which the upper joint of the upper diaphragm of the upper steel pipe column is placed on the upper flange of the steel beam temporarily fastened to the lower steel pipe column in the beam temporary assembly process, and the upper joint and the upper flange are temporarily fastened by bolt fastening to temporarily erect the upper steel pipe column above the lower steel pipe column;
a column-beam joining process in which, after adjusting the erection of the upper steel pipe column temporarily erected in the upper column temporary erection process, the lower joint portion and the lower flange and the upper joint portion and the upper flange are finally tightened by bolt fastening to join the steel beam to the lower steel pipe column and the upper steel pipe column, respectively;
An upper and lower column joining process of joining the lower steel pipe column and the upper steel pipe column by welding after the column-beam joining process;
A steel column-beam joining method comprising: a column-beam reinforcing process for joining the steel beam to the lower steel pipe column and the upper steel pipe column using gusset plates after the upper and lower column joining process. The steel column-beam joining method according to claim 1, characterized in that the lower steel pipe column and the upper steel pipe column are square columns. The steel beam-column joining method according to claim 1 or 2, characterized in that the lower diaphragm and the upper diaphragm each have multiple lower joints and upper joints.

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