JP6054101B2 - Ladder bearing wall - Google Patents

Description

  The present invention relates to a ladder-type load-bearing wall frame used for a building such as a steel frame.

As a load bearing wall frame used in a building, a ladder-shaped load bearing wall provided with two metal vertical members standing in parallel and a plurality of metal horizontal members laid up and down between the vertical members. A frame is known (for example, Patent Document 1).
In the ladder-type bearing wall frame disclosed in Patent Document 1, as shown in FIG. 7, the cross member 23 has an H-shaped cross-section and is laid between the vertical members 22 and 22 so that the web is vertical. By forming a plurality of plastic deformation holes 25 in the web 23, a portion around the holes 25 is formed as a plastic deformation portion that is plastically deformed by a horizontal force during an earthquake. Further, ribs (not shown) are formed on the periphery of the hole 25 to prevent cracks from entering from the periphery of the hole.

JP 2005-325637 A

  In the case of the ladder-type bearing wall frame having the above-described configuration, out-of-plane deformation is likely to occur in the abdomen of the vertical member 22 to which the end of the cross member 23 is welded. In particular, when the vertical member 22 is a square pipe and there is no diaphragm or the like, out-of-plane deformation is likely to occur at the vertical member flange. Decrease in yield strength and rigidity associated with this out-of-plane deformation becomes a problem.

  As a measure for avoiding this problem, it is possible to join the end of the cross member 23 to the abdomen of the vertical member 22 via the contact plate 24 as shown in FIG. Decreases, and a new problem of increasing costs arises.

Further, in the ladder-type load-bearing wall frame configured as described above, when the distance between the two vertical members 22 and 22 is wide, a decrease in yield strength and rigidity is also a problem. That is, when the interval between the two vertical members 22 is wide, the length of the cross member 23 to be installed becomes long and the bending rigidity is lowered. As a result, the proof stress / rigidity of the load bearing wall decreases. Further, when the length of the cross member 23 becomes a certain length or more, the bending yield becomes dominant. However, when it is attempted to forcibly yield the shear, the number of holes 25 provided in the web of the cross member 23 is increased. There is a need to. However, in this case, the cross-sectional defect of the web becomes large, and it is difficult to say that steel is economically used.
If it is going to raise proof stress and rigidity with said structure, it will be necessary to enlarge the cross section of a vertical member or a transverse member, and cost increase cannot be avoided.

  An object of the present invention is to provide a ladder-type load-bearing wall frame capable of improving yield strength, rigidity, and energy absorption capacity.

The ladder-type load-bearing wall frame of the present invention includes a ladder-type load-bearing wall provided with two metal vertical members standing in parallel, and a plurality of metal cross members arranged vertically between the vertical members. In the frame,
Plate opposite ends of the cross member is being respectively joined to the transverse member to the both longitudinal member via a stiffening member for stiffening the stiffening member is in surface contact with and joined to the surface of the longitudinal member parts and the crosspiece side in contact over surface throughout the height direction of the side surface of possess a plate portion joined, the plate portion joined in contact with a side surface of the lateral member, the lateral It has a length in the longitudinal direction of the cross member that can form a rigid region at the end of the material and reduce the shear span ratio of the cross member .

  According to this configuration, since both ends of the cross member are joined to both vertical members via the stiffening members that stiffen the cross member, a rigid region is formed at the end of the cross member. Yield strength and rigidity in the vicinity of the end can be ensured. Even when the distance between the two vertical members is wide, both ends of the cross member are joined to the vertical member via the stiffening member as described above, so that a rigid region is formed at the end of the cross member, The shear span ratio of the material can be reduced, and shear yield can be easily achieved. In other words, when the cross member yields a bending yield, the yield strength is reduced due to the buckling of the compression flange due to repeated loading, so it is preferable to use the shear yield, but when using the shear yield, the shear span ratio of the cross member is a problem. It becomes. However, since a rigid zone is formed as described above and the shear span ratio is easily reduced, shear yielding occurs. By becoming shear yielding, it becomes easier to absorb stable energy than in the case of bending yielding.

In this invention, the stiffening member has a flat plate shape, the both plate portions continue in the same plane, and are aligned with the surface parallel to the wall surface of the load bearing wall of the vertical member and the same plane. You may make it join to the said side surface of the said cross member, respectively.
In the case of this configuration, the portion where the stiffening member of the longitudinal member is joined is a surface along the longitudinal direction of the transverse member, so that unlike the case of joining to the surface perpendicular to the longitudinal direction of the transverse member, The problem of out-of-plane deformation at the joint portion of the material is eliminated, and the yield strength and rigidity are further improved.

  In this invention, the said stiffening member is an L-shape comprising a plate portion in surface contact with a surface perpendicular to the wall surface of the load bearing wall in the longitudinal member and a plate portion in surface contact with the side surface of the transverse member. It may be a shape. In the case of this configuration, the stiffening member does not protrude from the surface parallel to the wall surface of the vertical member, and the fit is improved.

In the present invention, that put the two ends of the crosspiece, pre-SL only in the vicinity of its junction with a portion deviating from the joint between the stiffening member may be is provided holes for shear yield induced . In this case, the holes for the shear yield inducing provided in each portion which becomes both end portions of the crosspiece may each be plural.
In addition to reducing the shear span of the cross member by the stiffening member and facilitating the shear yield, when the holes for inducing shear yield are provided at both ends of the cross member in this way, the shear yield of the cross member is further increased. Can be encouraged. Further, when the hole is provided at both ends of the cross member, a plastic hinge is formed at the end of the cross member, and the plastic deformation region becomes large. As a result, the deformation allowance at the time of large deformation can be earned and the plastic deformation ability can be improved.
In addition, when a hole for shear yield induction is provided, in addition to adjusting the shear strength and stiffness of the cross member by designing the size of the stiffening member, the shear strength and stiffness can be adjusted depending on the size and number of the holes. It becomes possible.

The ladder-type load-bearing wall frame of the present invention includes a ladder-type load-bearing wall provided with two metal vertical members standing in parallel, and a plurality of metal cross members arranged vertically between the vertical members. In the frame, both end portions of the cross member are joined to the vertical members via stiffening members that stiffen the cross member, and the stiffening members are joined in surface contact with the surface of the vertical member. a plate portion that is, the crosspiece side in contact over surface throughout the height direction of the side surface of possess a plate portion joined, the plate portion joined in contact with a side surface of the crossmember Since it has a length in the longitudinal direction of the cross member that can reduce the shear span ratio of the cross member by forming a rigid region at the end of the cross member, it is possible to improve proof stress, rigidity, and energy absorption capacity .

(A) is a front view of the ladder-type bearing wall according to one embodiment of the present invention, (B) is a side view of the same. It is a front view which shows one construction example of the ladder type bearing wall frame. It is the front view, top view, side view, and rear view of the junction part of the vertical member and cross member in the ladder-shaped bearing wall. It is explanatory drawing which shows the change of the plastic deformation capability by the difference in the hole position in the cross member of the ladder-shaped bearing wall. It is the front view, top view, side view, and rear view of the junction part of the vertical member and cross member in the ladder-shaped load-bearing wall frame concerning other embodiment of this invention. It is a perspective view of an example of the stiffening structure in the junction part of the vertical member and horizontal member in a prior art example. It is a front view of the conventional ladder-shaped bearing wall.

  An embodiment of the present invention will be described with reference to FIGS. FIGS. 1A and 1B are a front view and a side view of the ladder-type bearing wall frame. The ladder-shaped load-bearing wall frame 1 includes two parallel vertical metal members 2 and 2, and a plurality of horizontal metal members 3 arranged vertically between the vertical members 2 and 2. Is provided. In the example shown in the figure, an example is shown in which four cross members 3 are laid up and down at equal intervals. A square steel pipe is used for the vertical member 2 and a grooved steel is used for the cross member 3. As shown in FIG. 3C, the cross member 3 made of channel steel is constructed between the vertical members 2 and 2 in a posture in which the web portion 3a is vertical, and the side surface which is the outer surface of the web portion 3a is formed. The longitudinal members 2 are aligned with the surface 2a on the back side of the bearing wall. The cross member 3 made of channel steel bears a shearing force at the web portion 3a and bears a bending moment at the flange portion 3b.

Both ends of the cross member 3 are joined to the vertical member 2 via stiffening members 4 that stiffen the cross member 3. Here, a rectangular flat plate-shaped steel plate is used as the stiffening member 4. Specifically, as shown in FIGS. 3A to 3D, a front view, a plan view, a side view, and a rear view of the joining portion of the end portion of the cross member 3 to the longitudinal member 2 are used as flat plate-shaped auxiliary members. The rigid member 4 is in a vertical posture parallel to the wall surface of the load bearing wall, and one of the left and right plate portions 4a and 4b is in surface contact with the surface 2a parallel to the wall surface of the longitudinal member 2. And joined by welding. The other plate portion 4b is joined to the outer surface of the web portion 3a serving as a side surface of the cross member 3 by welding in contact with the entire surface in the height direction of the outer surface . The other plate portion 4b has a length in the longitudinal direction of the cross member that can form a rigid region at the end of the cross member 3 and reduce the shear span ratio of the cross member 3.

  At both ends of the cross member 3, holes 5 for inducing shear yielding are provided at locations where the web portion 3a is removed from the joint with the stiffening member 4. There are a plurality of shear yield inducing holes 5 provided at the respective ends which are both ends of the cross member 3, and here, two holes 5 are provided side by side. The number of the holes 5 may be one or three or more, and it is not always necessary to provide them.

For example, as shown in FIG. 2, the ladder-type load-bearing wall frame 1 is provided between a foundation 11 and a first-floor beam 12 at an arbitrary position between adjacent columns 10 and 10 in a steel-framed ramen structure building A. Placed in. The ladder-shaped load-bearing wall frame 1 may be disposed between the upper beam and the lower beam of each level of the building A, or may have a height across a plurality of levels. The building A may be a detached house, an apartment house, an office, a building that becomes a commercial facility, or any two-story, three-story, more, or one-story building. It may be a hierarchical building.
For example, when the module of the building A is 1P, the width of the ladder-shaped load-bearing wall frame 1 is 0.5P or 1P. The module is designed to have an arbitrary length according to a module design specification such as 910 mm and 1000 mm, for example.

  According to the ladder-type bearing wall frame 1 having this configuration, both ends of the cross member 3 are joined in surface contact with the side surface of the cross member 3 and the stiffener member 4 for stiffening the cross member 3 is used to connect the vertical member. Since it joined to 2, the proof stress and rigidity of the edge part and edge part vicinity can be ensured. Further, the stiffening member 4 has a flat plate shape, and the portion where the stiffening member 4 of the longitudinal member 2 is joined becomes the surface 2a along the longitudinal direction of the transverse member 3, so that the longitudinal direction of the transverse member 3 is increased. Unlike the case of joining to the vertical surface with the contact plate 24 as in the conventional example of FIG. 6, there is no problem of out-of-plane deformation of the longitudinal member flange at the joining portion of the longitudinal member 2, and the proof stress is further improved. . In the contact plate 24 of FIG. 6, all-around welding around it is necessary. However, in the stiffening member 4 of this embodiment, the productivity can be improved by avoiding the all-around welding, and the cost can be reduced.

Further, even when the interval between the two vertical members 2 standing in parallel is wide, both ends of the horizontal member 3 are joined to the vertical member 2 via the stiffening member 4 as described above. A rigid region is provided in the vicinity of the end portion of 3, the shear span of the cross member 3 can be reduced, and the shear yield can be easily performed. Thereby, the stable energy absorption with respect to a vibration etc. can be performed.
That is, in the bending yield type, the energy absorption capacity decreases while the loop is repeated due to buckling of the compression side flange portion of the upper and lower flange portions 3b, 3b of the cross member 3 and vibration energy absorption at the welded portion. Go. On the other hand, in the shear yield type of the web portion 3a, the yield of the plate element is dominant, and thus stable energy absorption is likely to occur.

Further, in this embodiment, as described above, the shear span of the cross member 3 is reduced by the interposition of the stiffening member 4 to facilitate shear yielding, and shear yield inducing holes are formed at both ends of the cross member 3. Since 5 is provided, the shear yield of the cross member 3 can be further promoted. Since the shear yield inducing hole 5 is provided in the web portion 3a of the cross member 3 that bears the shearing force, it is more effective in promoting shear yield. Further, since a plastic region is formed around the hole 5, the plastic deformation ability after the maximum proof stress is enhanced.
Further, since the holes 5 are provided at both end portions of the cross member 3, plastic hinges are formed at both end portions of the cross member 3, and the plastic deformation region becomes large. As a result, a deformation allowance at the time of large deformation can be earned and the plastic deformation ability can be improved.

  FIG. 4A is a schematic diagram of a cross member 3 provided with both ends of the shear yield inducing hole 5 (here, one example of the hole 5), and a plastic hinge formed in that case. Is shown. FIG. 4B shows a cross member 3 in which the shear yield-inducing hole 5 is provided in the center, and a schematic view of a plastic hinge formed in that case. As can be seen from these drawings, in the case of FIG. 4A in which the holes 5 are provided at both ends of the cross member 3, plastic hinges are formed at both ends of the cross member 3, so that the deformation allowance at the time of large deformation is large. Can earn. In the case of FIG. 4 (B) in which the hole 5 is provided in the center of the cross member 3, the plastic deformation region is limited, and the plastic deformation ability is inferior to that in the case of FIG. 4 (A).

  FIG. 5 shows another embodiment of the present invention. In this ladder-shaped bearing wall 1, in the previous embodiment shown in FIGS. 1 to 4, the vertical member 2 is perpendicular to the wall of the bearing wall as the stiffening member 4 </ b> A for stiffening the cross member 3. An L-shaped member is used that includes a plate portion 4Aa that is in surface contact with the surface 2b and a plate portion 4Ab that is in surface contact with the outer surface of the web portion 3a that is the side surface of the cross member 3. The stiffening member 4A may be an angle member or a bent product of a steel plate. FIGS. 5A to 5D show a front view, a plan view, a side view, and a rear view of the joint portion of the end of the cross member 3 to the vertical member 2 in this case. Other configurations, for example, the steel material used as the vertical member 2 and the cross member 3, the posture of the cross member 3, and the like are the same as those in the previous embodiment. As for the action, in this embodiment, the effect of preventing out-of-plane deformation of the longitudinal member 2 is lower than that of the previous embodiment, and the stiffening member 4A does not protrude from the surface parallel to the wall surface of the longitudinal member 2. Although the effect that the accommodation is improved is obtained, other functions and effects are obtained in the same manner as in the previous embodiment.

DESCRIPTION OF SYMBOLS 1 ... Ladder-shaped load-bearing wall frame 2 ... Vertical member 2a, 2b ... Surface 3 ... Cross member 3a ... Web part 4, 4A ... Stiffening member 4a, 4b, 4Aa, 4Ab ... Plate part 5 ... Hole for shear yield induction

Claims (5)

In a ladder-shaped load-bearing wall frame comprising two parallel metal vertical members, and a plurality of metal cross members laid side by side between the vertical members,
Plate opposite ends of the cross member is being respectively joined to the transverse member to the both longitudinal member via a stiffening member for stiffening the stiffening member is in surface contact with and joined to the surface of the longitudinal member parts and the crosspiece side in contact over surface throughout the height direction of the side surface of possess a plate portion joined, the plate portion joined in contact with a side surface of the lateral member, the lateral A ladder-shaped load-bearing wall frame having a length in the longitudinal direction of the transverse member that can form a rigid region at the end of the member and reduce the shear span ratio of the transverse member .   The ladder-type bearing wall frame according to claim 1, wherein the stiffening member has a flat plate shape, the two plate portions continue in the same plane, and are parallel to the wall surface of the bearing wall in the longitudinal member. Ladder-type load-bearing wall frames that are respectively joined to the side surfaces of the cross member that are flush with the surface.   2. The ladder-type bearing wall frame according to claim 1, wherein the stiffening member faces a surface of the vertical member in contact with a surface perpendicular to a wall surface of the bearing wall, and faces the side surface of the transverse member. A ladder-shaped load-bearing wall frame that is L-shaped with a plate part in contact. In ladder bearing walls frame according to any one of claims 1 to 3, that put the two ends of the crosspiece, the junction a portion deviating from the junction of the front Symbol stiffening member in the vicinity of only ladder bearing wall frame holes are provided for shear yield induced. The ladder-type bearing wall frame according to claim 4, wherein there are a plurality of shear yield-inducing holes provided at both ends of the cross member.

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