JP2012057333A - Beam member and construction method of beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a beam member which is formed by cutting H-shaped steel obliquely in the longitudinal direction, turning it into two members in the same shape and joining them, and is capable of demonstrating sufficient strength.SOLUTION: The beam member includes two steel main members 4 in a symmetrical shape with a vertical center line O as a symmetry axis to be tapered as separating from the center line in the view from the transverse direction. Each main member 4 is provided with a trapezoidal vertical base plate 6 including a pair of long and short sides in parallel with the center line, an almost horizontal upper side 8C, and a lower side 8D inclined relative to the horizontal direction, and is formed by attaching a flange 10 to only the lower side of the upper side and lower side of the vertical base plate over the entire length of the lower side further. The long sides of the respective vertical base plates and the opposing ends of the flanges are joined with each other respectively. Both main members are formed by cutting the web of the H-shaped steel A obliquely to the flange of the H-shaped steel.

Description

  The present invention relates to a beam member and a beam construction method.

  Generally, a building employs a beam structure such as a large beam or a small beam for supporting a floor or the like, and such a beam is formed of H-shaped steel. Moreover, in order to use the coupling | bonding force with a concrete floor, attaching a stud to steel materials is also performed (patent document 1).

  In addition, in order to open various duct insertion holes in the H-shaped steel web for beams, the H-shaped steel web was divided into two in a zigzag manner along a rectangular wave-like line with unevenness in the longitudinal direction. It has also been proposed to weld the convex portions of the two members (see FIG. 22 of Patent Document 2).

JP-A-2002-1882209 Patent No. 2699101

  The beams of Patent Documents 1 and 2 basically use a certain length of H-shaped steel as the beam of that length, but generally the force acting on each part in the longitudinal direction of the beam is not uniform. For example, when both ends of the beam are pin-joined, the above force is large at the center and small at both ends (see FIG. 5B). When both ends of the beam are rigidly joined, the force at both ends is relatively large (see FIG. 11B).

  Thus, even if a beam having a certain width is used as it is in a construction site where the distribution of force is different, the performance of the steel material cannot be sufficiently obtained.

  The first object of the present invention is to provide a beam member that can exhibit sufficient strength by cutting an H-shaped steel diagonally in the longitudinal direction and joining them together as two members having the same shape.

  The second object of the present invention is to propose a method for easily constructing a beam using the beam member.

The first means is
Consists of two steel main members with a symmetrical shape, with the vertical center line as the axis of symmetry, tapering away from the center line when viewed from the side,
Each main member has a trapezoidal vertical substrate including a pair of long and short sides parallel to the center line, a substantially horizontal upper side, and a lower side inclined with respect to the horizontal direction, and the lower side of the upper side and the lower side of the vertical substrate Only with a flange over the entire length of the lower side,
The long sides of each vertical substrate and the opposing ends of the flanges are joined together,
Both the main members are formed by cutting an H-shaped steel web obliquely with respect to the flange of the H-shaped steel.

  This means proposes a beam member comprising two main members 4 that are symmetrical with respect to the vertical center line O shown in FIG. Each main member has a vertical substrate 6 including an inclined lower side 8D with respect to the center line and a flange 10 provided over the entire length of the lower side, and the long side sides 8A of the vertical substrate and opposite ends of the flanges They are joined together. This beam member may be used for pin joints that have a greater force as they approach the center in the longitudinal direction. At this time, only the compressive force acts on the upper side 8C of the vertical substrate. This compressive force is preferably received by concrete via a connector described later. The two flanges 10 are shaped along the bending moment generated in the beam, and are more likely to exhibit the performance of steel than H-section steel. Therefore, the weight is relatively suppressed and the cost is reduced.

  The “beam member” is preferably used for a small beam, but is not limited thereto. The “main member” can be formed by equally dividing the H-section steel diagonally as shown in FIG. However, it is not essential to join main members cut from the same H-shaped steel. “Right and left symmetrical” means that the basic shape when the steel material is divided is symmetrical. Therefore, for example, even if the above-described duct insertion hole is provided at an asymmetric position later, the symmetry referred to in this specification is not inhibited.

The second means is a beam member of the first means,
The two main members have a bilaterally symmetric shape that tapers away from the centerline instead of a bilaterally symmetric shape that tapers away from the centerline.
Further, instead of joining the long sides of the vertical substrate, the short sides of the vertical substrate are joined.

  In this means, as shown in FIG. 9, the two main members 4 are joined so as to be narrow at the center. This configuration is preferably used for a rigid joint in which a relatively large force acts on both sides in the longitudinal direction. In this configuration, there is a point (inflection point) I where the stress becomes 0 on the upper side 8C of the vertical substrate, the compressive force is present at the upper side portion inside these two points, and the tensile force is present at the upper side portion outside both points. work.

The third means includes the first means or the second means, and a connector for coupling with the concrete on the upper side of the vertical substrate.

  In this means, it is proposed to provide a connector 12 with concrete on the upper side 8C of the vertical substrate. This is because the vertical substrate is plate-shaped and may be refracted by compression in the longitudinal direction, whereas concrete is excellent in compression resistance. The connector may be provided on at least a portion of the upper side of the vertical substrate where the compressive force acts (the entire upper side in the beam member in FIG. 1).

The fourth means is a beam construction method,
A step of setting two cutting points of the steel material in order to cut an H-shaped steel part having a length L from the H-shaped steel of the beam forming D, wherein the length L is set between the two support portions of the structure. A first stage of approximately half the distance;
A second stage of cutting two cut points of the H-shaped steel along two first cut lines inclined with respect to the direction of beam formation;
Dividing the H-shaped steel portion into two main members having the same trapezoidal shape when viewed from the horizontal direction along a second cut line perpendicular to the first cut line, the first cut line A third stage in which the cut portion is divided into a long side and a short side by a second cut line,
A fourth stage in which the long sides of the two main members or the short sides and the flanges are joined together to form one beam member;
A fifth stage in which both ends of the beam member are joined to the two support portions of the structure with the flanges facing downward;
Consists of.

  This means proposes a beam construction method including a method for producing beam members. As shown in FIG. 8 (A), a part of the longitudinal direction of the H-section steel A is selected and cut along the diagonal line as shown in (B), and the material cut out as shown in (C) is perpendicular to the diagonal line. And (D) a step of joining the divided portions in the longitudinal direction to form a beam member, and a step of attaching the beam member to the support portion as shown in FIG.

  According to the invention relating to the first means and the second means, since the ends of the two members formed by connecting the H-shaped steel obliquely to the flange are joined, the length is twice that of the original steel material. The beam member can be obtained, and the performance of the steel material can be efficiently utilized corresponding to the load distribution at the installation location.

  According to the first aspect of the invention, since the central portion is wider than the tapered end portions, the durability of the beam can be increased in a place where a large force is applied to the central portion.

  According to the invention relating to the second means, since the both ends of the beam are thicker than the center, the endurance can be exhibited in a place where a large force is applied to both ends.

  According to the third aspect of the invention, since the connector for coupling with the concrete is provided on the upper side of the vertical substrate, the compressive force acting on the upper side can be received by the concrete.

  According to the invention relating to the fourth means, one steel material is cut along the first cut line inclined in the beam forming direction and the second cut line perpendicular to the first cut line. There is little waste of material.

It is a front view of the beam member concerning a 1st embodiment of the present invention. It is a top view of the beam member of FIG. It is a perspective view of the beam member of FIG. It is a longitudinal cross-sectional view of the application example of the beam member of FIG. 4A is a front view of the application example of FIG. 4, and FIG. 4B is a bending moment diagram of the application example of FIG. It is action | operation explanatory drawing of the beam member of FIG. It is a figure which shows the reference example of this invention for comparing with the beam member of FIG. It is explanatory drawing of the manufacturing procedure of the beam member of FIG. It is a front view of the beam member concerning a 2nd embodiment of the present invention. It is a longitudinal cross-sectional view of the application example of the beam member of FIG. 9A is a front view of the application example of FIG. 9, and FIG. 9B is a bending moment diagram of the application example of FIG.

  1 to 8 show a beam member 2 according to a first embodiment of the present invention.

  The beam member 2 is formed by two main members 4 and a connector 12 as shown in FIG. The beam member 2 in the illustrated example is symmetrical with respect to the vertical symmetry plane P except for the arrangement of the connectors.

  The main member 4 is a steel member and is a steel member that is symmetric with respect to a vertical center line O as an axis of symmetry. In the drawings, each main member is drawn for convenience of drawing, but is actually integrally joined. Each main member 4 is formed by a vertical substrate 6 and a flange 10.

  In the illustrated example, the vertical substrate 6 includes a long side 8A perpendicular to the center line O, a vertical short side 8B, a horizontal upper side 8C, and a lower side 8D extending obliquely upward from the center line. It is surrounded by a horizontally long trapezoid. By forming the long side 8A and the upper side 8C at right angles, the upper sides of the two main members 4 are formed to be flush with each other when the long sides of the two main members 4 are brought into contact with each other. .

  The upper part 9 of the vertical substrate 6 is a part embedded in floor concrete as will be described later. A fixed width (fixing margin) may be set from the upper side 8C so as to be an upper portion of the vertical substrate. The upper part of the vertical board is also a place for attaching a connector to floor concrete described later.

  The vertical plate 6 is formed to a thickness that does not deform against an external force. However, as shown in FIG. 4, the vertical plate portion 6 in the illustrated example is formed thinner than the flange 10. Since the tensile force on the lower side of the vertical plate portion is resisted by the flange 10 and the compressive force on the upper side of the vertical plate portion is resisted by the concrete connected by the connector, the thickness of the vertical plate portion can be relatively suppressed. It is.

  The flange 10 is provided over the entire length of the lower side 8D of the vertical substrate, and protrudes from the vertical substrate 6 to the front and rear with the same protrusion width w. Further, the end face in the longitudinal direction of the flange 10 is a vertical face that is flush with the end face of each side of the vertical substrate.

As shown in FIG. 3, the two main members 4 are joined together by welding the vertical substrates 6 to each other at the opposing end surface E ₁ and welding the flanges 10 to each other at the opposing end surface E ₂ . According to the configuration of the present embodiment, as shown in FIG. 5B, for the stress distribution in which the stress is maximum at the beam center, the long side sides 8A that are widest in the vertical direction are centered on the main members. A strong resistance force can be obtained because the flange is joined to the pulling force acting on the lower side of the beam central portion by the joining force of the flange.

  The connector 12 is attached to the upper part 9 of the vertical board 6 and has a strength capable of joining the board part on the upper side and the concrete. The connector in the illustrated example is a plurality of rod-like protrusions arranged along the upper side 8C. A large number of protrusions can be quickly implanted using conventionally known stud welding. In the illustrated example, the protrusions are alternately arranged (staggered arrangement) on both the front and rear sides of the vertical substrate. However, the protrusions may be arranged in parallel so as to face each other on the front and rear sides (parallel arrangement). However, the illustrated structure can be changed as appropriate. In the present embodiment, since the compressive force acts on the entire upper side of the vertical substrate, it is preferable to provide the connector 12 over the entire upper side. Further, the connector 12 is also preferably a method in which the upper portion 9 of the vertical board 6 is cut and a conventionally known reinforcing bar is penetrated to weld the vertical board 6 and the reinforcing bar.

  As shown in FIG. 5, the beam member 2 has its both ends pin-bonded to the support portion 101 of the column 100 by the bonding means 102 and functions as a beam. In the illustrated example, the portion on the upper side 8 </ b> C side of the vertical substrate 6 is embedded in the concrete 104.

As shown in FIG. 6, the main member 4 is obtained by dividing the H-section steel A having both inclined faces parallel to each other along a line (second cut line) C ₂ perpendicular to the inclined faces. Can be produced. The manufacturing process will be further described later. The reason for inclining the both end faces of the H-shaped steel is to make the upper side 8C formed along the above line a substantially flush horizontal plane.

  As a comparative example, FIG. 7 shows an example in which a main member is manufactured from H-section steel A having both end faces as vertical faces. In this example, as shown, the flanges of the two main members are horizontal, and the upper side is an inclined surface. If the flange 10 is placed on the stigma or the like, the oblique upper side 8C side of the vertical substrate is fixed to the concrete. However, this configuration is inconvenient because the penetration width (fixing allowance) of the vertical substrate into the concrete differs depending on the location. In the configuration of FIG. 6, there is no such inconvenience, and a fixed fixing cost can be secured in the vertical direction. In addition, by making the upper side of the vertical substrate a substantially flat horizontal surface, only the compressive force acts on the upper side, and this force can be received by the concrete through the connector.

  According to the above configuration, the lower side of the upper and lower sides of the two vertical substrates 6 of the beam member 2 is provided with the flange 10 and is formed in a shallow V shape corresponding to the stress distribution. Therefore, as a structure of the beam member itself, a resistance force against an external force (mainly tensile force) is large. The upper sides of the two vertical boards 6 embed the upper part 9 of each board in the concrete 104 and receive external force (compressive force) with concrete having excellent compression resistance through the connector 12 attached to the upper part. I am doing so. Therefore, buckling deformation and the like are unlikely to occur, and an equivalent supporting force can be obtained with less steel than H-section steel.

Next, a method for manufacturing the beam member will be described. First, the vertical width d _{1 at} the center of the beam member 2 shown in FIG. 8 and the vertical width d _{2 at} both ends are determined. d ₁ may be calculated from the set value of the force applied to the beam. d ₂ may be set so as to secure a fixing cost to the concrete and a mounting space for the joining means.

Next, as shown in FIG. 8 (A), the radius d ₁ + d ₂ is centered on an arbitrary base point T on the upper side of the H-shaped steel whose distance between the surfaces of the two flanges 10 (hereinafter referred to as “synthetic”) is D. An arc is drawn, and an intersection U between the arc and the lower surface of the H-section steel A is obtained. The angle θ formed by the line segment TU and the vertical line is defined as the inclination angle of the end face of the H-section steel. Then draw the two cut lines C ₁ approximately half the inclination angle at intervals of θ of the distance between the supporting portion to be bridged beams, cut parallelogram steel along these cut lines. When a plurality of beam members are formed at a time, it is preferable to first cut _one H-section steel A at equal intervals along the mutually parallel cut lines C1 inclined in the vertical direction.

Next, as shown in FIG. 8 (B), the second part of the parallelogram steel material web portion that is perpendicular to the first cut line and bisects the first cut line into lengths d ₁ and d ₂ . draw a cut line _{C 2.} When the steel material is divided along the cut line, two main members 4 are formed.

  Then, as shown in FIGS. 8C to 8D, one of the two main members 4 is reversed in the front-rear direction to weld the vertical substrates of the main members and the opposing surfaces of the flanges. Thereafter, when the connector is welded to the upper side of the vertical substrate, the beam member 2 is obtained. Both ends of the beam member are pin-joined to the support part of the building. Furthermore, if a formwork is formed on the upper side of the beam and concrete is driven in, a beam structure is completed.

What is important in the above procedure is to equally divide the H-section steel by _two cut lines C ₁ and C ₂ which are inclined with respect to the longitudinal direction (horizontal direction) of the steel material and orthogonal to each other. Thus, by simply welding each long side 8A, it is possible to easily form a beam member in which the upper side 8A is flush and the vertical width gradually changes from the center to the end in the longitudinal direction.

  The inclination angle θ formed by the lower side 8D of the vertical substrate 6 with respect to the horizontal direction may be determined according to the stress distribution applied to the beam member 2 shown in FIG. That is, the inclination angle is preferably increased as the tendency of the stress to increase from the end of the installation location toward the center portion is increased.

  9 to 11 show a beam member according to the second embodiment of the present invention.

  In the present embodiment, the short sides 8B of the main members are joined together. By forming the short side 8B and the upper side 8C at right angles, the upper sides of the main members 4 are flush with each other when the short sides of the two main members 4 are brought into contact with each other. . The other configuration is basically the same as that of the first embodiment.

  The beam member 2 of the present embodiment is suitable when both ends of the beam member 2 are rigidly joined to the support portion by the joining means 102 as shown in FIG. This is because the stress increases on both sides of the beam member as shown in FIG.

  In the present embodiment, a compressive force acts on the upper side portion between the inflection points I in FIG. Therefore, the connector 12 may be provided along at least the upper side portion.

  The above embodiment is a preferred example of the present invention, and does not prevent the specific configuration from being changed unless it is contrary to the nature of the present invention.

2 ... Beam member 4 ... Main member 6 ... Vertical substrate 8A ... Long side 8B ... Short side 8C ... Upper side 8D ... Lower side 9 ... Upper part of vertical substrate
10 ... flange 12 ... connector 100 ... pillar 101 ... support portion 102 ... joining means 104 ... concrete A ... H-shaped steel C 1 _... first cut line C 2 _... second cut line E 1 _... vertical substrate facing end surface E ₂ ... Opposing end face of flange I ... Inflection point M ... O ... Center line P ... Symmetry plane T ... Base point U ... Intersection point w ... Flange protrusion width

Claims (4)

Consists of two steel main members with a symmetrical shape, with the vertical center line as the axis of symmetry, tapering away from the center line when viewed from the side,
Each main member has a trapezoidal vertical substrate including a pair of long and short sides parallel to the center line, a substantially horizontal upper side, and a lower side inclined with respect to the horizontal direction, and the lower side of the upper side and the lower side of the vertical substrate Only with a flange over the entire length of the lower side,
The long sides of each vertical substrate and the opposing ends of the flanges are joined together,
The main members are formed by cutting an H-shaped steel web obliquely with respect to the flange of the H-shaped steel. The beam member according to claim 1,
The two main members have a bilaterally symmetric shape that tapers away from the centerline instead of a bilaterally symmetric shape that tapers away from the centerline.
Furthermore, instead of connecting the long sides of the vertical substrate, the short members of the vertical substrate are connected.   The beam member according to claim 1 or 2, wherein a connector for joining with concrete is attached to an upper side of the vertical board. A step of setting two cutting points of a steel material in order to cut an H-shaped steel part having a length L from a H-shaped steel of a beam H. The length L is set between two support parts of a structure. A first stage of approximately half the distance;
A second stage of cutting two cut points of the H-shaped steel along two first cut lines inclined with respect to the direction of beam formation;
Dividing the H-shaped steel portion into two main members having the same trapezoidal shape when viewed from the horizontal direction along a second cut line perpendicular to the first cut line, the first cut line A third stage in which the cut portion is divided into a long side and a short side by a second cut line,
A fourth stage in which the long sides of the two main members or the short sides and the flanges are joined together to form one beam member;
A fifth stage in which both ends of the beam member are joined to the two support portions of the structure with the flanges facing downward;
A beam construction method consisting of