JP2946473B2 - Beam steel frame through hole reinforcement structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing structure for a beam steel frame used as a beam in a building and having a web formed with a through hole for piping or the like.

[0002]

2. Description of the Related Art As shown in FIGS. 14 and 15, in a beam steel frame 1 having an H-shaped cross section used for a beam of a building, its web is inserted to insert, for example, piping of a facility of the building. A circular through hole 2 is formed in 1a.

[0003] In a beam steel frame 1 in which a through hole 2 is formed in a web 1a, a rectangular plate-shaped reinforcing plate 3 in which a through hole 3a having substantially the same diameter is formed to reinforce the web 1a around the through hole 2. Is overlapped with a position where the through holes 2 and 3a communicate with each other, and is fixed to the web 1a.

[0004]

SUMMARY OF THE INVENTION The present invention is to solve the following problems in the above-mentioned prior art.

[0005] That is, in the case of the reinforcing structure of the beam steel frame 1 described above, the processing of the reinforcing plate 3 is troublesome and the cost is increased.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above circumstances, and an object of the present invention is to fix a reinforcing steel bar to a beam steel web to improve the shear stress of the web. It is to provide a reinforcing structure.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a reinforcing structure for a through-hole of a beam steel beam, wherein at least one side of the beam steel beam web has an arc-shaped supplement.
A reinforcing bar surrounds the through-hole along the outline of the through-hole and ends
The parts are fixed in a wrapped form .

In order to achieve the same object, the reinforcing reinforcing bar is fixed at a position where the shear stress of the web is maximized.

Further, in order to achieve the above object, a reinforcing reinforcing bar formed linearly is fixed to one side surface of the web of the beam steel frame in pairs parallel to each other on both sides of the through hole. A pair of reinforcing bars parallel to each other on both sides of the through hole are also fixed to the other side surface of the web at a position substantially orthogonal to the pair of reinforcing bars on the one side. is there.

[0010]

In the reinforcing structure for a beam steel frame according to the present invention, the web around the through hole is reinforced by a reinforcing bar fixed to the web of the beam steel frame along the outer shape of the through hole.

[0011] Further, since the reinforcing reinforcing bar can be attached by being curved along the outer shape of the through-hole, there is no time and effort for the attaching operation.

[0012]

1 to 4 show a first embodiment of the present invention.
This will be described with reference to FIG.

The same components as those in FIGS. 14 and 15 are denoted by the same reference numerals, and description thereof will be simplified.

The greatest feature of the reinforcing structure of this embodiment is that one reinforcing reinforcing bar 10 curved in an arc shape is fixed so as to surround the through hole 2 along the outer shape of the through hole 2 of the web 1a. .

The reinforcing bars 10 are attached to the left and right sides or only one side of the web 1a with both ends wrapped. The reinforcing bars 10 have a maximum shear stress of the web 1a shown on the left side of FIG. It is fixed at a certain position.

In the reinforcing structure of the present embodiment configured as described above, a reinforcing structure similar to that of the reinforcing plate can be formed by the reinforcing bar 10.

Hereinafter, the effects of the present embodiment will be clarified by design equations.

For example, as shown in FIG. 3, in a beam steel frame 1 having an H-shaped cross section having a circular through-hole 2 having a diameter φ formed on a side surface, a reinforcing reinforcing bar 10 having a circular cross-section is formed by a flange from the upper end of the through-hole 2. 1b, the thickness of the web 1a is t
1. Assuming that the width of the flange portion 1b is t1, the sectional moment of inertia I of the beam steel frame 1 is a square cross section equivalent to the reinforcing bar 10.
z is calculated by the following equation 1.

[0019]

(Equation 1)

Further, from the relationship shown in Expression 2 below,
First moment Sy is calculated.

[0021]

(Equation 2)

The shear stress τ is obtained from the second moment of area Iz and the first moment Sy according to the following equation (3).

[0023]

(Equation 3)

As a result, the maximum shear stress .tau.
x is, from the values obtained by the above formulas (1), (2) and (3),
It is a value calculated by the following Expression 4.

[0025]

(Equation 4)

The allowable shear force RQa of the entire steel beam 1 is shown.
Is obtained by equalizing the maximum shear stress τmax of Expression 4 to the short-term allowable shear stress degree fs of the steel frame as shown in Expression 5. RQa is set to a value that does not deform or break the shear force Q acting on the beam.

[0027]

(Equation 5)

Hereinafter, specifically, the section has a height H = 650 m.
m, distance h2 from the upper end of through hole 2 to the upper end of web 1a
200mm, thickness of web 1a t1 = 12mm, flange 1b
Steel beam 1 with a width t2 of 57mm (material: SS41)
In the web 1a, a circular through hole 2 having a diameter of 200 mm
And a reinforcing bar 10 having a cross section of 10.14 cm ² formed in a circular shape with a diameter of 400 mm with both ends wrapped is fixed around the through hole 2 at a position surrounding the through hole 2. I do.

In the above case, the permissible shearing force Qa when the through-hole 2 of the beam steel structure 1 is not formed is 66.5 t as shown in the equation (6).

[0030]

(Equation 6)

In the case where the through-hole 2 is formed and the reinforcing bar 10 is not provided, the allowable shearing force Qa is reduced to 44.3 t as shown in Expression 7.

[0032]

(Equation 7)

The secondary moment of area Iz of the beam steel frame 1 as an equivalent section to the reinforcing steel bar 10 is 8
It is calculated as 04 cm ² .

[0034]

(Equation 8)

The allowable shear stress τmax is represented by a shear force Q ′ as shown in Expression 9.

[0036]

(Equation 9)

Then, τmax is, as shown in Expression 10,
Is calculated.

[0038]

(Equation 10)

By equalizing the value of the maximum shear stress τmax and the short-term allowable shear stress fs, the shear force Q ′ is calculated to be 202t.

Therefore, the allowable shearing force Qa becomes 202t as shown in Expression 11 from the relationship of Expression 5.

[0041]

[Equation 11]

As a result, as shown in Expression 12, the beam steel frame 1 is reinforced by the reinforcing bar 10 of the reinforcing structure of the present embodiment to about three times the strength as compared with the case where the through hole 2 is not formed. It is shown that it is done.

[0043]

(Equation 12)

According to the reinforcing structure of the present embodiment configured as described above, the reinforcing reinforcing bar 10 is easy to manufacture,
In addition, since the reinforcing steel used for building the building can be used, the work efficiency of the reinforcement is improved, and the cost of the reinforcement of the beam steel frame 1 is reduced.

Further, since the reinforcing bars are lighter than the conventional reinforcing plate 3, it is easy for an operator to carry a plurality of reinforcing bars, and the work of fixing the reinforcing bars 10 is improved.

Hereinafter, a second embodiment of this embodiment will be described with reference to FIG.

The only difference between the reinforcing structure according to the present embodiment and the reinforcing structure according to the first embodiment is the reinforcing bar indicated by reference numeral 11.

In the reinforcing structure of this embodiment, two reinforcing reinforcing bars 11, 11 curved in an arc shape are provided on both the left and right sides of the web 1a so as to surround the through hole 2 along the outer shape of the through hole 2 of the web 1a. The biggest feature is that it is fixed.

The reinforcing bars 11 are attached to the upper and lower sides of the web 1a with their respective ends wrapped. The reinforcing bars 11 are located at positions where the shear stress of the web 1a shown in FIG. The position is fixed.

The reinforcing structure of this embodiment configured as described above can also have the same reinforcing structure as the reinforcing plate by the reinforcing steel bars 11.

According to the reinforcing structure of this embodiment, the first
Not only that the effect of the reinforcing structure of the embodiment is exerted, but also the reinforcing bar 11 can be formed in a shape suitable for the through-hole 2 more than the reinforcing bar 10 because the reinforcing bar is of a combination type.

Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.

The difference between the reinforcing structure of the present embodiment and the reinforcing structure of the first embodiment is only the reinforcing bars 12a and 12b.

As shown in FIGS. 5 and 6, the reinforcing structure according to the present embodiment includes a reinforcing bar 12a having a circular cross section formed linearly on one side of a web 1a of the beam steel frame 1 and a through-hole 2a. And reinforcing bars 12b which are parallel to each other on both sides of the through hole 2 and are fixed to each other on both sides of the web 1a.
Are fixed at a position that intersects the pair of reinforcing bars 12a on one side substantially at right angles.

The reinforcing reinforcing bars 12a and 12b are fixed to the web 1a. However, when sufficient fixation cannot be taken in a straight line, each of the ends has a bent portion 12c formed by bending one of the ends at an appropriate angle, and the bent portion 12c is substantially horizontally turned toward the other side. The position is set so as to surround the through hole 2 and the fixing length is set.

Hereinafter, the effects of the present embodiment will be clarified by design equations.

For example, as shown in FIG. 7, when a shear load is applied, the shear strain γ of the H-shaped section steel beam 1 is represented by a distance D 2
Is calculated from the deformation amount δw of the beam steel frame 1 per unit, the shear force acting on the beam steel frame 1 with no opening is Q, the lateral elastic modulus is G, the shape factor for the shear deformation of the member is k, and the beam steel frame 1 is calculated. Assuming that the cross-sectional area of the web 1a is Aw, the following equation 1 is obtained.
It is represented as 3.

[0058]

(Equation 13)

If a circular through hole 2 having a diameter φ is formed in the side surface of the beam steel structure 1, the shear strain γ shown in FIG. 11 is expressed by the following equation (14), where the shear force borne by the web 1a is Q ′. Is represented as

[0060]

[Equation 14]

As a result of the action of the shear load, each reinforcing steel 12
Assuming that the shearing force borne by a and 12b is Q ″, the shearing force Q ″ borne by the reinforcing steel bar 12 is obtained by equalizing δw and δr. Then, the deformation amount δr of the reinforcing reinforcing bars 12a and 12b
Is given by the following formula 15 where Ar is the cross-sectional area of the reinforcing steel bars 12a and 12b and E is the longitudinal elastic modulus, and this value is equal to the deformation amount δw of the beam steel frame 1.

[0062]

(Equation 15)

As a result, the reinforcing bar amount (cross-sectional area) Ar of the reinforcing bars 12a and 12b required for reinforcing the beam steel frame 1 provided with the through holes 2 is expressed by the following equation (16) as an equivalent cross section of the web 1a.
Required by However, in this case, the shearing force Q (the sum of Q ′ and Q ″) borne by the opening of the through hole 2 of the beam steel frame 1
Is equal to or greater than the shearing force Q of the non-opening portion where the through hole 2 is not formed as shown in Expression 17.

[0064]

(Equation 16)

[0065]

[Equation 17]

Hereinafter, specifically, the section has a height H = 650 m.
m, distance h from the upper end of through hole 2 to the upper end of web 1a
225mm, thickness of web 1a t1 = 12mm, flange 1b
Reinforcing bars 12a, 12b required for reinforcing the beam steel 1 (material SS41) when the web 1a is formed with a circular through hole 2 having a diameter of 200 mm in the beam steel 1 formed with a width t2 = 25 mm. The case where the amount of reinforcing bar (cross-sectional area) is obtained will be described. However, the material forming the beam steel frame 1 has a longitudinal elastic modulus E = 2.1 × 10 ⁶ kg / cm ² and a lateral elastic modulus G =
0.81 × 10 ⁶ kg / cm ² .

In the above case, the cross-sectional area Aw of the web 1a when the beam steel frame 1 is not opened is calculated by the following equation (18).
Calculated as 2.0 cm ² .

[0068]

(Equation 18)

A through-hole 2 is formed, and the cross-sectional area Aw 'of the web 1a in a vertical cross-section located at the diameter of the through-hole 2
Is calculated to be 24.0 cm ² by the following equation (19).

[0070]

[Equation 19]

The allowable shear force Qa acting on the beam steel frame 1 when there is no opening is 66.5 t as shown in the following equation (20).

[0072]

(Equation 20)

In this case, the shear strain γ of the beam steel frame 1 is:
As shown in Expression 21, it is 1.37 × 10 ⁻³ .

[0074]

(Equation 21)

On the other hand, the shearing force Q ′ borne by the web 1a at the opening of the through hole 2 is given by
As shown in FIG. 2, it is calculated as 44.4t.

[0076]

(Equation 22)

From the above results, the shear force Q ″ borne by the reinforcing steel bars 12a and 12b can be obtained from the above equation (17).
As shown in FIG.

[0078]

(Equation 23)

Then, from the value obtained from the above result,
The reinforcing bar amount Ar of the reinforcing reinforcing bars 12a and 12b required for reinforcing the beam steel frame 1 is calculated to be 10.86 cm ² as shown in the following Expression 24 by Expression 16 above.

[0080]

(Equation 24)

[0081] Therefore, to reinforce the beam steel frame 1 as described above, the cross-sectional area 5.43cm ² or more reinforcing rebar 12a, 1
2b needs to be fixed.

As shown in FIGS. 5 and 6, when one reinforcing bar 12 is fixed around the through hole 2, when the reinforcing bars 12 are arranged in parallel, the reinforcing bar 12 has a diameter 22.
mm (cross section: 3.87 × 2 cm ² / line) or more.

The first embodiment also has the reinforcing structure of the present embodiment.
The same effect as the embodiment and the second embodiment can be obtained, and of course, the shape of the reinforcing bars 12a and 12b is
It is simple and easy to process as compared with 0 and 11, the configuration of the reinforcing structure is more simple than in each of the above embodiments, and the work efficiency of the construction of the reinforcing structure is improved.

As shown in FIGS. 12 and 13,
Two reinforcing bars 12a and 12b may be arranged together at predetermined locations.

[0085]

As described above, according to the through-hole reinforcing structure for a beam steel frame of the present invention, (1) at least one side of the web of the beam steel frame is provided with a reinforcing bar having an arc shape having a through-hole. of
Surrounded the through hole along the outline and wrapped its end
Fixed in a form , and (2) the reinforcing steel,
(3) In order to achieve the above object, (3) a reinforcing reinforcing bar formed linearly on one side of the web of the beam steel frame in order to achieve the above object. A pair of reinforcing bars that are parallel to each other on both sides of the through hole and are fixed to each other, and a pair of reinforcing bars that are parallel to each other on both sides of the through hole are also provided on the other side surface of the web. It is characterized in that it is fixed at a position that intersects at a right angle to the reinforcing bar, so that the reinforcing steel can be easily manufactured according to the shape of the through-hole, and the cost is low. improves.

Further, the reinforcing reinforcing bar is lighter in weight than the above-mentioned conventional reinforcing plate, and a large number of workers can carry the reinforcing bar at one time.

[Brief description of the drawings]

FIG. 1 is a front view showing a reinforcing structure for a through hole in a beam steel frame according to a first embodiment of the present invention.

FIG. 2 is a view taken along the line II-II.

FIG. 3 is a schematic side view of the same.

FIG. 4 is a front view showing a second embodiment of the present invention.

FIG. 5 is a front view showing a third embodiment of the present invention.

FIG. 6 is a view taken along line VI-VI.

FIG. 7 is an enlarged side view of the same.

FIG. 8 is a schematic front view of the same.

FIG. 9 is a schematic front view for the analysis.

FIG. 10 is a view taken along line XX of FIG. 8;

FIG. 11 is a side view showing the shear strain.

FIG. 12 is a front view showing a case where two reinforcing bars 12 are provided.

FIG. 13 is a view taken along the line XIII-XII.

FIG. 14 is a front view showing a conventional example.

FIG. 15 is a side sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Beam steel 1a Web 2 Through-hole 10 Reinforcing bar 11 Reinforcing bar 12 Reinforcing bar

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E04C 3/00-3/46 E04B 1/24

Claims (3)

(57) [Claims] 1. A through-hole reinforcing structure for a beam steel frame used as a beam of a building and having a through hole for piping or the like formed in a web, wherein at least one side of the web of the beam steel frame has an arc shape. Success
A reinforcing reinforcing bar surrounds the through-hole
A reinforcing structure for a through-hole in a beam steel frame, wherein the structure is fixed by wrapping the ends of the through-holes. 2. The method according to claim 1, wherein the reinforcing reinforcing bar is fixedly located at a position where the shear stress of the web is maximized .
The reinforcing structure for a through hole in a beam steel frame according to claim 1. 3. A reinforcing steel bar formed in a straight line is fixed to one side surface of the web of the beam steel frame in a pair parallel to each other on both sides of the through-hole, and is provided on the other side of the web. <br/> beam steel reinforcement rebar to side form a parallel pair to each other on both sides of the through hole, characterized in that it is fixed in a position intersecting at substantially right angles with the pair of reinforcing rebar of the one side Through-hole reinforcement structure.