KR101226778B1 - Structure of connecting steel beam and column having improved earthquake resistance ability - Google Patents

Abstract

PURPOSE: A connection structure of a steel beam and a steel column with improved seismic performance is provided to protect the connection of a steel beam and a steel column from an earthquake by moving a stiffener with a plastic hinge. CONSTITUTION: A connection structure of a steel beam and a steel column with improved seismic performance comprises a steel column(10), a steel beam(20), an upper stiffener(31), and a lower stiffener. The steel beam is vertically welded to the side surface of the steel column and has a web(21) with an opening(21a). The upper and lower stiffeners are vertically coupled to both surfaces of the web of the steel beam to reinforce the opening of the steel beam and has cutout portions(31a,32a).

Description

Structure of connecting steel beam and column having improved earthquake resistance ability}

The present invention relates to a joint of a steel beam and a steel column with improved seismic performance, and more specifically, at the beam-column joint of the moment resistance frame, an opening is formed at an end of the steel beam, and at least one stiffener is welded above and below the opening. The present invention relates to a structure of a joint part of a steel beam and a steel column in which a plastic hinge position is clarified to improve the seismic performance of the joint by forming a cutout.

In general, the floor structure of a building having a steel frame or a composite moment resistance frame type is a structure in which the slab is positioned on the steel beam, and when the composite pipe is located at the bottom of the beam, the height of the floor occurs. In order to solve this problem, a stiffener is generally installed in the web of steel beams to form and structurally reinforce openings for facility piping.

A prior art for reinforcing openings is the "opening reinforcing structure of steel beams" disclosed in Japanese Laid-Open Patent Publication No. 2001-317159. In this prior art, a structure in which a reinforcement, which is an inclined material intersecting obliquely to the reaxial axis of a steel beam, surrounds the opening of the steel beam, is fixed to the surface of the web, and a structure that transmits the shear force burden lost by the opening to the axial force generated in the inclined material of the reinforcement is Is disclosed.

Another prior art for reinforcing openings is the "opening reinforcing structure of steel beams" shown in Japanese Laid-Open Patent Publication No. 1993-331964. In this prior art, an H-shaped steel beam having an opening is added to a reinforcing member having a groove-shaped cross section that forms an opening having the same shape as the opening, but the reinforcing member penetrates the steel hole through a bolt through a loose hole formed in the corner. A reinforcing structure is disclosed in which a web is secured to a web and only a contact is made on a flange.

However, the reinforcing openings proposed in these prior arts have a bearing strength exceeding the plastic firing moment of the steel beams, thereby causing the position of the plastic hinge to move toward the joint and finally causing brittle fracture of the joint. Have

Steel frame or composite moment resistance frame has a structural feature to dissipate the energy input by the earthquake by forming a plastic hinge at the end of the steel beam joined to the steel frame or composite column. Steel frame or composite moment resistance frame has been widely used in high earthquake risk area because it is recognized as superior seismic performance compared to other structural types due to its excellent ductility.

However, due to the brittle fracture of the beam-column joint, which was widely identified in the 1994 Northridge earthquake in the United States and the 1995 Kobe earthquake in Japan, the seismic performance of steel or synthetic moment resistant frames was required. In Korea, reference is made to earthquake damage cases abroad, and the Korean Structural Design Standards (KBC2009) provide more stringent and detailed seismic design methods for steel structures.

One of the main features of the domestic seismic design criteria is to specify the joints belonging to the seismic force resistance system and to specify the size and location of the protected area where plastic hinge is expected to be specified in the design drawings and specifications.

Therefore, it is possible to prevent brittle fracture in the steel beam having openings in the web so that the facility pipes can be located within the dance of the steel beam to reduce the floor height. There is a need for a steel column-beam connection structure that can clarify the expected location.

The present invention has been made to solve this need and has the following objectives.

The present invention is to form openings at regular intervals over the end of the beam or the entire length in order to penetrate the facility pipe through the web of the steel beam in order to reduce the layer in the steel frame or composite moment resistance frame, and the opening located at the end of the beam with a stiffener In the case of reinforcement, it is an object of the present invention to provide a joint structure of a steel beam and a steel column to form a plastic hinge at the opening position, not near the joint portion, to form the seismic performance of the frame.

According to a preferred embodiment of the present invention, the steel frame pillar; An H-shaped steel beam which is strongly joined to the side of the steel column vertically, and has an opening formed in a web adjacent to the steel pillar side at a distance; And an upper and lower stiffeners each having a cutout portion formed on each side of the upper side and the lower side of the web, the side of which is joined to the web, respectively, wherein the upper and lower stiffeners have improved seismic performance. A structure is provided.

In this case, the upper portion and the lower portion to which the upper and lower stiffeners are coupled may have a straight shape.

In addition, the cutout may be formed with two or more spaced apart from each other.

In addition, a stress transmission prevention hole may be drilled in the web of the steel beam between the opening and the steel column.

In addition, the steel column has a closed cross-sectional shape may be a concrete filled steel pipe pillar filled therein.

According to another suitable embodiment of the present invention, the steel frame pillar; A bracket rigidly joined to the side of the steel column; An H-shaped steel beam which is strongly bonded to the bracket and has an opening formed in a web adjacent to the bracket at intervals; And an upper and lower stiffeners each having a cutout portion formed on each side of the upper side and the lower side of the web, the side of which is joined to the web, respectively, wherein the upper and lower stiffeners have improved seismic performance. A structure is provided.

According to another suitable embodiment of the present invention, the steel frame pillar; A H-shaped steel beam which is strongly bonded to the side of the steel column vertically and has a plurality of openings at regular intervals over the entire length; And vertically coupled to both sides of the upper and lower webs of the enlarged opening formed by communicating two openings adjacent to the steel column among the plurality of openings formed in the steel beams, respectively, and having cutouts formed on the side surfaces joined to the web, respectively. Provided is a joint structure of a steel beam and a steel column with improved seismic performance, characterized in that the upper, lower stiffeners.

According to another suitable embodiment of the present invention, the steel frame pillar; A H-shaped steel beam which is strongly bonded to the side of the steel column vertically and has a plurality of openings at regular intervals over the entire length; And an upper side and a lower side of the web having an enlarged opening formed by communicating the second and third openings in order toward the center part by skipping the first outermost opening closest to the steel column among the plurality of openings formed in the steel beams. The vertically coupled to each side, and the side is joined to the web is provided with a joint structure of steel beams and steel pillars with improved seismic performance, characterized in that it comprises an upper, lower stiffener is formed in each cut portion.

According to another suitable embodiment of the present invention, the steel frame pillar; A bracket rigidly joined to the side of the steel column; An H-shaped steel beam strongly bonded to the bracket and having a plurality of openings formed at regular intervals over the entire length; And vertically coupled to both sides of the upper and lower webs of the enlarged opening formed by communicating two openings adjacent to the brackets with each other among the plurality of openings formed in the steel beams, and having cutouts at the sides joined to the webs, respectively. And, there is provided a joint structure of the steel beams and steel pillars with improved seismic performance comprising a lower stiffener.

The stiffener having a cutout for reinforcing the opening according to the present invention can be protected from the earthquake by acting like a plastic hinge when an earthquake occurs, with the reinforcing effect of the opening.

In addition, the stiffener can control the plastic hinge position and the holding strength, and has excellent energy dissipation capacity due to the virendil bending behavior, thereby enabling the construction of the steel / synthetic moment frame with improved seismic performance.

In addition, after the plastic hinge is formed in the stiffener, the stress transfer prevention hole serves as a secondary fuse for additional external force that may occur at the joint according to the moment redistribution, thereby improving the seismic safety of the frame.

In addition, it is possible to make the moment resisting frame have excellent energy dissipation capacity by drilling an opening in the junction structure of the steel column and the steel beam and reinforcing the opening with a stiffener having a cutout.

The following drawings, which are attached in this specification, illustrate the preferred embodiments of the present invention, and together with the detailed description thereof, serve to further understand the technical spirit of the present invention. It should not be construed as limited.
Figure 1 shows a column-beam connection structure according to an embodiment of the present invention, (a) is a perspective view (b) is a front view showing the cutout formed on the stiffener and (c) is a stiffener reinforced on the web It is sectional drawing cut | disconnected so that FIG. 2 is sectional drawing corresponding to FIG.1 (c), and its sectional drawing which showed the modification.
3 is a front view showing the column-beam connection structure according to another embodiment of the present invention.
4 is a view showing the column-beam connection structure according to another embodiment of the present invention.
5 is a view showing a column-beam connection structure according to another embodiment of the present invention, Figure 6 is a view showing a modification thereof.
7 is a view showing the column-beam connection structure according to another embodiment of the present invention, Figure 8 is a view showing the modifications thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto.

Figure 1 shows a column-beam connection structure according to an embodiment of the present invention, (a) is a perspective view (b) is a front view showing the cutout formed on the stiffener and (c) is a stiffener reinforced on the web It is sectional drawing cut | disconnected so that FIG. 2 is sectional drawing corresponding to FIG.1 (c), and its sectional drawing which showed the modification.

As shown in FIG. 1, the pillar-beam joint structure according to the present invention includes a steel pillar 10 and a vertical connection to the side of the steel pillar 10, and an opening 21a in the web spaced apart from the steel pillar side. The formed steel beams 20 and the upper and lower stiffeners 31 and 32 to reinforce the openings 21a of the steel beams 20.

Steel column 10 in the drawings is shown as having an H-shaped cross-section, but the present invention is not limited to the cross-sectional shape of the steel column 10 shown in the steel column 10 having any cross-sectional shape known in the art Of course, both can be applied. For example, it can be applied to steel pillars having a closed cross-sectional shape, such as quadrangular and circular, or to composite columns in the form of filled steel pipes filled with concrete therein.

In the present invention, the steel beam 20 has an H-shaped cross-sectional shape, the opening portion 21a is formed in the web 21 on the end side at intervals with the side of the steel column. Although the shape of the opening 21a is illustrated as having a rectangular shape in the drawing, the shape of the opening 21a is not limited thereto, and the portion where the upper and lower stiffeners 31 and 32 are coupled has a straight shape. Any shape can be used as long as the upper side and the lower side are openings which form a straight line. This opening 21a formed in the web 21 can be used as a service hole for actual cost piping.

The present invention is to form a plastic hinge at the position of the stiffeners (31a, 31b) in the moment resistance skeleton of the steel beam 20 and the steel column 10 to form the seismic performance of the steel frame beam The end of the 20 is joined to the side of the steel pillar 10 by welding, that is, a steel joint (moment bonding). Although described later through other embodiments, when the bracket 40 is pre-welded to the steel column 10 for convenience of field joining between the steel column 10 and the steel beam 20, the steel beam 20 is a bracket ( And bolts). In addition to these steel bonding methods described herein, other types of steel bonding methods known in the art may be applied. For example, when a pillar in the form of a closed section is used as a steel pillar, the steel beam may be strongly bonded to the steel pillar in the form of an inner diaphragm or an outer diaphragm.

The upper stiffener 31 and the lower stiffener 32 are coupled to the upper side and the lower side of the opening 21a of the steel beam 20, respectively. The upper stiffener 31 and the lower stiffener 32 are respectively vertically coupled to both sides of the upper and lower webs 21 of the opening 21a to reinforce the opening 21a.

Cutouts 31a and 32a are formed on the side surfaces at which these stiffeners 31 and 32 are joined to the web 21, respectively. The cutouts 31a and 32a may be semi-circular or rectangular in shape and one or two or more spaced apart from each other may be formed as shown in FIG. 2. As described above, while achieving the original purpose of preventing deformation of the opening portion 21a by reinforcing the opening portion 21a by using the stiffeners 31 and 32 having the cutout portions 31a and 32a formed therein, the position at which the plastic hinge is additionally generated is determined. Be clear.

As mentioned earlier, openings reinforced with stiffeners without cutouts 31a and 32a have a strength beyond the plastic firing moment of the beam, so that the position of the plastic hinge moves toward the joint and finally the brittle fracture of the joint is prevented. Although it may be caused, by forming the cutouts 31a and 32a in the stiffeners 31 and 32 as in the present invention, the plastic hinge can be formed in the stiffeners 31 and 32, thereby preventing brittle fracture of the joint. have.

In the present invention, by adjusting the lengths of the cutouts 31a and 32a and in the case where two or more cutouts 31a and 32a are formed, the virendil bending strength at the plastic hinge position can be adjusted. In addition, the non-rendil flexural strength (actual force) that is adjustable through the length and spacing of the cutouts 31a and 32a is designed to be smaller than the member force (holding strength) to induce the generation of plastic hinges, thereby reducing the load acting on the joint portion. The seismic safety of the joint can be greatly improved.

3 is a view showing a column-beam connection structure according to another embodiment of the present invention.

As shown in FIG. 3, in this embodiment, a stress transfer preventing hole 50 is formed in the web 21 of the steel beam 20 between the opening 21a and the steel column 10 reinforced by the stiffeners 31 and 32. It is perforated. The stress transfer preventing hole 50 serves as a secondary fuse that prevents the transfer of additional external force induced to the joint by moment redistribution after the plastic hinge is generated. Through this, the seismic performance of the steel structure / composite moment frame can be further improved.

Although the stress transmission prevention hole 50 is shown as having a circular shape in the drawings, the present invention is not limited thereto, and any shape may be used as long as it can be confirmed that it can play a role of an effective secondary fuse by structural calculation or numerical analysis. The size and location can also be determined in the same way.

4 is a view showing the column-beam connection structure according to another embodiment of the present invention.

As shown in FIG. 4, the pillar-beam joint structure according to the present invention includes a steel pillar 10, a bracket 40 vertically bonded to the side surface of the steel pillar 10, and the bracket 40 bonded to the bracket 40. It consists of steel beams 20 having an opening 21a formed in the web 21 at intervals from the 40, and upper and lower stiffeners 31 and 32 reinforcing the openings 21a of the steel beams 10.

That is, the pillar-beam joint structure according to this embodiment is different from the above-described embodiments in that the steel beam 20 is bonded to the steel column 10 through the bracket 40, and the rest of the configuration is the same.

The method of joining the steel column 10 and the steel beam 20 using the bracket 40 is a well-known method used for convenience of joining in the field, and the bracket 40 is the same as the steel beam 20 in the H type. It has a cross-sectional shape and is welded to the side of the steel column 10 by welding in advance in the factory. Steel beam 20 is welded or bolted to the bracket (40). In the case of bolting, the steel beam 20 and the bracket 40 are both flanged and web joined through the plate.

On the other hand, the bracket 40 may be punched in the stress transmission prevention hole 50 as described in FIG. The stress transfer preventing hole 50 serves as a secondary fuse that prevents the transfer of additional external force induced to the joint by moment redistribution after the plastic hinge is generated. Through this, the seismic performance of the steel structure / composite moment frame can be further improved.

Although not shown in this embodiment, as illustrated in FIG. 2, one or more cutouts 31a and 31b may be formed in the stiffeners 31 and 32 at regular intervals from each other.

5 is a view showing a column-beam connection structure according to another embodiment of the present invention, Figure 6 is a view showing a modification thereof.

As shown in FIG. 5, the column-beam connection structure according to this embodiment is a steel beam (cellular beam, castile beam, honeycomb beam, or hollow hole, in which an opening is preformed over the entire length instead of the steel beam shown in FIG. 1). The following is an example of applying cellular) to the present invention.

In the drawing, the opening 21b formed in the web 21 of the cellular beam 20a (indicated by reference numeral 21b to distinguish it from the aforementioned opening) is shown as a circle, but the shape of the opening 21b is not limited thereto. As shown in (a) it may be a variety of shapes, such as hexagonal or elliptical as in Figure 6 (b).

When the cellular beam 20a is applied, the stiffeners 31 and 32 having the cutouts 31a and 32b are formed in the first opening 21d closest to the steel column among the openings 21b formed in the cellular beam 20a and other openings. 2d and 3rd openings communicate with each other in order toward the center to form an enlarged opening portion 21c, and are respectively coupled to the upper side and the lower side of the enlarged opening portion 21c. do. The first opening 21d may function as the stress transmission preventing hole 50 shown in FIG. 2.

Alternatively, when the stress transmission preventing hole 50 is not formed, the stiffeners 31 and 32 having the cutouts 31a and 32b may have two openings adjacent to the steel column among the openings 21b formed in the cellular beam 20a. The enlarged opening portion 21c is formed in communication with each other, and is coupled to the upper side and the lower side of the enlarged opening portion 21c, respectively.

The cutouts 31a and 32b formed in the stiffeners 31 and 32 may be two or more spaced apart from each other, as shown in FIG. 2, and may have a circular shape.

7 is a view showing the column-beam connection structure according to another embodiment of the present invention, Figure 8 is a view showing the modifications thereof.

As shown in FIG. 7, the column-beam connection structure according to this embodiment is applied to the present invention by applying the cellular beam 20a having an opening formed over the entire length in the column-beam connection structure using the bracket shown in FIG. 4. An example is shown.

In this embodiment, the stiffeners 31 and 32 having the cutouts 31a and 32b communicate with each other through the two openings adjacent to the bracket 40 among the openings 21b formed in the cellular beam 20a, thereby expanding the opening 21c. And are coupled to the upper side and the lower side of the enlarged opening portion 21c, respectively.

The cutouts 31a and 32b formed in the stiffeners 31 and 32 may be two or more spaced apart from each other, as shown in FIG. 2, and may have a circular shape. In addition, as shown in FIG. 4, the stress transmission preventing hole 50 may be drilled in the bracket 40.

At this time, the shape of the opening 21b may be a variety of shapes, such as a hexagon as shown in (a) of FIG. 8 or an oval as shown in (b) of FIG.

As described above, the stiffeners 31 and 32 having the cutouts 31a and 32a according to the present invention, together with the reinforcing effect of the openings 21a and 21c, behave like plastic hinges during an earthquake to protect the joint from earthquakes. have. In addition, the stiffeners (31, 32) is capable of adjusting the plastic hinge position and the holding strength, and has an excellent energy dissipation capacity by virendil bending behavior to enable the construction of the steel / composite moment frame with improved seismic performance. In addition, the stress transmission prevention hole 50 serves as a secondary fuse for the additional external force that may occur in the joint after the plastic hinge is formed in the stiffeners (31,32) to improve the seismic stability of the frame.

Meanwhile, in the above description, the case where the steel beams are joined to one side of the steel column is described as an example. However, when the steel beams are joined in a straight line to both sides of the steel column and are joined at a right angle to each other, three steel beams are attached to the steel column. The same may be applied to the case in which the two steel beams are joined to each other at right angles to each other, and to the steel columns.

In addition, in the above description, the case of mainly stretching the moment resistance frame is described, but as shown in FIGS. 1 to 3, the perforations of the opening 21a and the cutouts 31a and 32b are formed in the junction structure of the existing steel column and the steel beam. The opening 21a may be reinforced with the formed stiffeners 31 and 32 so that the moment frame has excellent energy dissipation capacity.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the above teachings. will be. The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

10: Steel Column
20: steel beam
21: Web
21a: opening
21b: opening of cellular beam
21c: enlarged opening
21d: outermost opening of cellular beam
31: Upper stiffener
32: lower stiffener
31a, 32a: cutout
40: bracket
50: stress transfer prevention hole

Claims (9)

Steel column;
An H-shaped steel beam which is strongly joined to the side of the steel column vertically, and has an opening formed in a web adjacent to the steel pillar side at a distance; And
Joined structure of the steel beam and the steel column with improved seismic performance, characterized in that the upper and lower sides of the opening are respectively perpendicularly coupled to each other, and the side joined to the web includes upper and lower stiffeners formed with cutouts, respectively. . The method according to claim 1,
The opening portion is a joint structure of the steel beams and the steel pillars, characterized in that the upper and lower portions to which the upper, lower stiffeners are coupled to have a straight shape. The method according to claim 1,
The cutout is a joint structure of the steel beam and the steel pillars, characterized in that at least two formed with a distance from each other. The method according to claim 1,
The joint structure of the steel beam and the steel column, characterized in that the stress transmission prevention hole is drilled in the web of the steel beam between the opening and the steel column. The method according to claim 1,
Steel column has a closed cross-sectional shape and the inside of the joint structure of the steel beam and the steel column, characterized in that the concrete filled steel pipe pillar filled with concrete. Steel column;
A bracket rigidly joined to the side of the steel column;
An H-shaped steel beam which is strongly bonded to the bracket and has an opening formed in a web adjacent to the bracket at intervals; And
Joined structure of the steel beam and the steel column with improved seismic performance, characterized in that the upper and lower sides of the opening are respectively perpendicularly coupled to each other, and the side joined to the web includes upper and lower stiffeners formed with cutouts, respectively. . Steel column;
A H-shaped steel beam which is strongly bonded to the side of the steel column vertically and has a plurality of openings at regular intervals over the entire length; And
Among the plurality of openings formed in the steel beams, the two openings adjacent to the steel pillars are connected to each other perpendicularly to both sides of the upper and lower webs of the enlarged opening, and the cutouts are formed on the side surfaces joined to the webs, respectively. The junction structure of the steel beam and the steel column with improved seismic resistance, characterized in that it comprises a lower stiffener. Steel column;
A H-shaped steel beam which is strongly bonded to the side of the steel column vertically and has a plurality of openings at regular intervals over the entire length; And
On both sides of the upper and lower webs of the enlarged opening formed by communicating the second and third openings in order toward the center part by skipping the first outermost opening closest to the steel column among the plurality of openings formed in the steel beams. The joint structure of the steel beams and steel pillars with improved seismic performance, characterized in that the vertically coupled, the side is joined to the web, each of which has an upper, lower stiffener formed with cutouts. Steel column;
A bracket rigidly joined to the side of the steel column;
An H-shaped steel beam strongly bonded to the bracket and having a plurality of openings formed at regular intervals over the entire length; And
Among the plurality of openings formed in the steel beams, the two openings adjacent to the brackets are connected to each other to be perpendicular to the upper and lower sides of the enlarged opening, respectively, and the cutouts are formed on the side surfaces joined to the webs. The joint structure of the steel beam and the steel column with improved seismic performance, characterized in that it comprises a lower stiffener.

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