JP4766624B2 - Through-hole reinforcing member for steel beam and its through-hole reinforcing structure - Google Patents

Description

  The present invention relates to a technique for reinforcing a through-hole formed in a steel beam web for piping or the like in a steel structure or the like.

As a means for reinforcing the through hole formed in the steel beam, a plate-like reinforcing member is fixed to one side of the web around the target through hole by welding or the like (refer to the prior art in Patent Document 1). ), And a plate-like reinforcing member fixed to both sides of the web in the periphery of the target through-hole by welding or a high-strength bolt (see Patent Document 2). In addition, a truss-type member that is welded with a sleeve-shaped reinforcing member penetrating the target through-hole, or a diamond-shaped reinforcing member that is fixed to the web around the target through-hole by welding or the like. Things are also known. However, among these conventional techniques, in the case of a type in which flat reinforcing members are fixed to both surfaces of the web in the peripheral portion of the target through-hole, a large reinforcing action can be secured relatively easily. Since the number of reinforcing members to be doubled on both sides and the number of welds also doubled, there was a problem in workability regarding the fixing work of the reinforcing members. In addition, in the case of a type in which a flat reinforcing member or a diamond-shaped reinforcing member is fixed to one side of the web in the periphery of the target through-hole, workability related to fixing work is good, but necessary reinforcing action If the size of the reinforcing member is made large in order to ensure the above, there is a problem that it is restricted by interference with the flange portion of the beam. That is, in the case of a type in which the reinforcing member is fixed to both sides of the web, there is a problem in the workability of the fixing work, and in the case of the type in which the reinforcing member is fixed to one side of the other web, sufficient reinforcing action There was a problem in securing. In the case of welding with a sleeve-shaped reinforcing member penetrated through the target through-hole, not only is the reinforcing effect small and unsuitable for securing the proof stress, but the degree of freedom of piping is restricted by the sleeve. There was a problem that. There is also a problem that the effective opening area of the through hole formed in the web is reduced by the amount of the sleeve.
JP 63-35946 A Japanese Utility Model Publication No. 5-57149

  The present invention has been developed in view of the above-described conventional technical situation, and has good workability regarding the fixing work of the reinforcing member to the steel beam, and sufficient reinforcing action for the through-hole with less material. It is an object of the present invention to find and provide an efficient reinforcing technique that can ensure the above.

In the present invention, in order to solve the above problems, as a result of various experiments and simulation analysis, is formed in a ring shape to have a substantially opening of the same shape and the through hole formed in the steel beams, and the outer peripheral portion A reinforcing member welded at a contact portion with the web , and the reinforcing member is (1) 0.15 ≦ Ar / Aw ≦ 0.7, (2) 0.6 ≦ Vr / Vw ≦ 3.3, (3) The technical means of forming a ring shape having a rectangular cross section that satisfies the three conditions of 0.5 ≦ Hr / Tr ≦ 5.0 was adopted. Here, Ar is the cross-sectional area of the reinforcing member, Aw is the cross-sectional area of the missing portion of the web due to the through hole, Vr is the volume of the reinforcing member, Vw is the volume of the missing portion of the web due to the through hole, and Hr is the reinforcing member's volume. Height, Tr is the thickness of the reinforcing member.

According to the present invention, by using a ring-shaped reinforcing member having a rectangular cross section formed so as to satisfy the above three conditions, it is possible to suppress a decrease in yield strength due to a through hole and an out-of-plane buckling of a web. The reinforcing action can be secured very easily and accurately. As a result, it is also very effective for standardization of reinforcement work for the through-hole formed in the steel beam. In addition, with regard to the welding location, a welding configuration is adopted in which welding is performed at the contact portion between the outer peripheral portion of the reinforcing member and the web, and welding is not performed at the inner peripheral portion of the reinforcing member. Troubles such as cracks can be avoided. Therefore, combined with the use of the welding form by the outer peripheral portion of the reinforcing member, the reinforcing effect that satisfies the above three conditions can be accurately maintained. Therefore, since sufficient reinforcing action can be ensured only by welding to one side of the web around the through hole formed in the steel beam, it is effective in improving workability. In addition, since the thickness of the reinforcing member can be suppressed, interference with the flange portion of the steel beam is also reduced, so that the restriction on the size of the through hole formed in the steel beam is also reduced. Furthermore, the reinforcing member is extremely cut by simply cutting out from a cylindrical material such as a cylindrical shape or a rectangular shape having a predetermined thickness according to the shape of the through hole at a predetermined height or a dimension with a finishing allowance added. The effect that it can manufacture simply is also acquired .

The fixing means of the reinforcing member to the contact Keru steel beam web to the present invention employs the welding. For the welding point of that, it is assumed to be welded at the contact portion between the outer peripheral portion and the web of the reinforcing member, and shall not weld between the inner circumferential portion and the web of the reinforcing member. Regarding the specific shape of the reinforcing member, not only a circular ring shape but also a square ring shape is possible depending on the shape of the through hole of the steel beam. By the way, if the value of Ar / Aw according to (1) is below the lower limit of 0.15, a sufficient reinforcing effect cannot be expected, and the desired yield strength (yield strength / maximum strength) and initial rigidity are satisfied. In addition, it becomes difficult to satisfy the desired plastic deformation performance by causing out-of-plane buckling of the web at an early stage. On the other hand, if the upper limit value of 0.7 is exceeded, excessive reinforcement or stress transmission will be a factor, which is uneconomical because the reinforcement efficiency is reduced and a larger cross section is required. If the value of Vr / Vw according to (2) is below the lower limit of 0.6, a sufficient reinforcing effect cannot be expected, and the desired yield strength (yield strength / maximum strength) and initial rigidity are also satisfied. In addition, it becomes difficult to satisfy the desired plastic deformation performance by causing out-of-plane buckling of the web at an early stage. On the other hand, if the upper limit value of 3.3 is exceeded, excessive reinforcement or stress transmission may be hindered, which is uneconomical because the reinforcement efficiency is reduced and a larger cross section is required. If the value of Hr / Tr according to (3) is below the lower limit of 0.5, a sufficient reinforcing effect cannot be expected, and the desired yield strength (yield strength / maximum strength) and initial rigidity are also satisfied. In addition, it becomes difficult to satisfy the desired plastic deformation performance by causing out-of-plane buckling of the web at an early stage. On the other hand, if the upper limit of 5.0 is exceeded, excessive reinforcement or stress transmission may be hindered, which is uneconomical because the reinforcement efficiency is reduced and a larger cross section is required. Incidentally, the above conditions (1) to (3) do not exist separately, but are necessary for reinforcing the through holes formed in the steel beam by organically combining these conditions. Each dimension of the member is reasonably narrowed down. Incidentally, it is desirable that the Hr is up to about 100 mm, and if it is higher than that, it takes time to pass the piping, and the workability tends to be lowered.

1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a front view showing the embodiment, and FIG. 3 is an enlarged sectional view showing a section of a reinforcing member. In the figure, 1 is a steel beam, 2 is a web constituting the steel beam 1, and 3 and 4 are flange portions. In the figure, 5 is a through hole formed in the web 2, and 6 is a reinforcing member welded to the web 2 around the through hole 5. In this embodiment, the case where the circular through-hole 5 having the diameter Dw is reinforced with respect to the web 2 having the wall thickness Tw constituting the steel beam 1 is shown. As shown in FIG. 2, as the reinforcing member 6, a circular ring-shaped member having an inner diameter Da corresponding to the circular through-hole 5 and an outer diameter Db was adopted. Incidentally, in the present embodiment, the case where the inner diameter Da of the opening 7 of the reinforcing member 6 is equal to the diameter Dw of the through hole 5 is shown, but the diameters Da and Dw on the opening 7 side or the through hole 5 side of the reinforcing member 6 are shown. the may be smaller rather than shape formed slightly. As shown in FIG. 1, the reinforcing member 6 is welded to one side of the web 2 around the through hole 5. As described above , the welding is performed at the contact portion between the outer peripheral portion of the reinforcing member 6 and the web 2 and is not welded between the inner peripheral portion of the reinforcing member 6 and the web 2. . As shown in FIG. 3, the reinforcing member 6 has a rectangular cross section having a thickness of Tr and a height of Hr.

Next, an example regarding each dimension of the reinforcing member 6 that satisfies the above three conditions corresponding to the diameter Dw of the through hole 5 is shown in Table 1. Here, Dw is the diameter of the through-hole 5, Tw is the thickness of the web 2, Tr, Hr, Da, and Db are the thickness, height, inner diameter, and outer diameter of the reinforcing member 6, and the unit is mm. . Incidentally, the cross-sectional area Ar of the reinforcing member 6 is Tr × Hr, the cross-sectional area Aw of the web defect portion by the through hole 5 is Dw × Tw, and the volume Vr of the reinforcing member is {(Db / 2) ² − (Da / 2) ² } × π × Hr, the volume Vw of the missing portion of the web due to the through hole can be determined by (Dw / 2) ² × π × Tw, respectively.

In Table 1, an example of each dimension of the reinforcing member 6 that satisfies the above three conditions corresponding to the diameter Dw of the through hole 5 is shown. However, as illustrated in Table 2 below, Needless to say, various examples of dimensions are possible. In short, any reinforcing member that satisfies the above-described three conditions can be freely selected for each dimension.

It is the longitudinal cross-sectional view which showed the Example of this invention. It is the front view which showed the same Example. It is an expanded sectional view showing a section of a reinforcing member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Steel beam, 2 ... Web, 3, 4 ... Flange part, 5 ... Through-hole, 6 ... Reinforcing member, 7 ... Opening part, Dw ... Diameter of through-hole, Tw ... Thickness of web, Tr ... Reinforcing member , Hr: height of the reinforcing member, Da: inner diameter of the reinforcing member, Db: outer diameter of the reinforcing member

Claims (2)

Formed in a ring shape to have a substantially opening of the same shape and the through hole formed in a steel beam, a reinforcing member is welded at the contact portion between the outer peripheral portion and the web, and the following three conditions A through-hole reinforcing member for a steel beam, which is formed in a ring shape having a rectangular cross section to be filled.
(1) 0.15 ≦ Ar / Aw ≦ 0.7
(2) 0.6 ≦ Vr / Vw ≦ 3.3
(3) 0.5 ≦ Hr / Tr ≦ 5.0
However, Ar is the cross-sectional area of the reinforcing member, Aw is the cross-sectional area of the missing portion of the web due to the through hole, Vr is the volume of the reinforcing member, Vw is the volume of the missing portion of the web due to the through hole, Hr is the height of the reinforcing member, Tr is the thickness of the reinforcing member. A ring-shaped reinforcing member having a rectangular cross section satisfying the three conditions of claim 1 having an opening substantially the same shape as a through-hole formed in a steel beam, and an outer peripheral portion of the reinforcing member and a web A through-hole reinforcing structure for a steel beam, wherein the through-hole formed in the steel beam is reinforced by welding and integrating at the contact portion .

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