JP4401808B2 - Beam reinforcement structure - Google Patents

Description

  The present invention relates to a beam reinforcing structure in a wooden building.

  In homes, there is a need to secure a large space on the lower floor by changing the floor plan at the time of new construction due to changes in family structure and changes in lifestyle.

  In order to meet such needs, renovation work will be performed to remove the pillars standing near the center of the living room or at the boundary of the adjacent living room. In this case, the pillar is supported only by removing the pillar. The beam that had been bent bends downward. For this reason, it is indispensable to simultaneously perform reinforcement work for increasing the rigidity of the beam.

JP-A-6-99412

  Here, as a method of increasing the rigidity of the beam, for example, when there is a problem that the floor of the upper floor is squeezed, there is a method of attaching a beam to an existing beam and fastening it with a bolt or the like.

  However, this method not only increases the cost of the renovation work, but also raises the problem that vibration of the upper floor cannot be suppressed.

  In particular, when the accessory beam is a lightweight steel frame, there is a problem that workability is poor due to its large weight.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a beam reinforcing structure that has good workability and can sufficiently increase the bending rigidity of an existing beam.

In order to achieve the above-mentioned object, the beam reinforcing structure according to the present invention includes a beam that is provided below the existing beam so that a predetermined clearance is formed between the beam and the lower surface of the existing beam. And by adhering a pair of auxiliary plates to each side of the existing beam and the auxiliary beam so that the existing beam and the auxiliary beam are sandwiched from both sides (the existing beam is bridged) Except for the case where the accessory plate is joined to a pair of columns), the existing beam and the accessory beam are composite beams joined to each other via the pair of accessory plates .

  In order to expand the living room space on the lower floor, the present applicant, when performing the renovation work to remove the pillars standing in the living room space, how to reinforce the beams accompanying the removal of the pillars, First, we focused on whether or not floor vibrations can be suppressed, and as a result of various research and experiments under such attention, mechanical fastening such as bolts, lag screws, and dowels is not compatible with existing beams. Ascertain that there is a limit to the degree of integration with the beam, and as an alternative method, if the existing beam and the accessory beam are bonded together in a specified way, both rigidity improvement and integration are realized. I found new knowledge that I could do it.

  That is, in the reinforcing structure of a beam according to claim 1, the upper and lower two-stage structure in which a supplementary beam is arranged below the existing beam so that a predetermined clearance is formed between the lower surface of the existing beam. Since it is a beam, the beam formation of the composite beam is increased, and the cross-sectional secondary moment I is significantly increased. Along with this, the bending rigidity EI of the composite beam is also greatly increased.

  In addition, as described above, by using bonding using an adhesive instead of mechanical bonding such as bolts, the existing beam and the beam are composite beams that are firmly bonded via a pair of plates. Thus, integration without backlash is possible, and floor vibration can be suppressed.

  In addition, by arranging the accessory beam below the existing beam so that a predetermined clearance is formed between the lower surface of the existing beam, the clearance of the existing beam, for example, expansion and contraction due to temperature change, is absorbed by the clearance. It is also possible to do.

  Further, in the beam reinforcing structure according to claim 2, as in the case of claim 1, an auxiliary beam is arranged below the existing beam so that a predetermined clearance is formed between the lower surface of the existing beam. Since it is a composite beam having an upper and lower two-stage structure, the beam formation of the composite beam is increased, and the cross-sectional secondary moment I is significantly increased. Along with this, the bending rigidity EI of the composite beam is also greatly increased.

  In addition, by adopting bonding using an adhesive instead of mechanical bonding such as bolts as described above, the existing beam and the accessory beam become a composite beam that is firmly bonded to each other via the bonding plate, thus. Further, integration without backlash is possible, and floor vibration can be suppressed.

  In addition, by arranging the accessory beam below the existing beam so that a predetermined clearance is formed between the lower surface of the existing beam, the clearance of the existing beam, for example, expansion and contraction due to temperature change, is absorbed by the clearance. It is also possible to do.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a beam reinforcing structure according to the present invention will be described with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.

(First embodiment)
FIG. 1 is a view showing a beam reinforcing structure according to the present embodiment, where FIG. 1 (a) is a side view, FIG. 1 (b) is an exploded perspective view, and FIG. 1 (c) is an AA line. FIG. As can be seen from these drawings, the beam reinforcing structure 1 according to the present embodiment is applied to a wooden existing beam 3 spanned between a pair of opposing columns 2 and 2, and the lower surface of the existing beam. A wooden support beam 4 is arranged below the existing beam 3 so that a predetermined clearance δ is formed between the existing beam 3 and the pair of additional beams so that the existing beam 3 and the support beam 4 are sandwiched from both sides. The plates 5 and 5 are bonded to the side surfaces of the existing beam and the auxiliary beam, respectively.

  Here, the clearance δ is preferably 10 to 50 mm and more preferably about 15 to 30 mm so as to absorb the flare of the existing beam 3. The reason for this range is that if it is 50 mm or more, there is a concern of lateral buckling.

  Incidentally, the composite beam obtained by bonding the existing beam 3 and the accessory beam 4 up and down without providing the clearance δ can ensure bending rigidity that can be regarded as a single beam. That is, when the integration rate is defined with respect to the measured value with respect to the theoretical value, the integration rate of the above-mentioned composite beam without clearance is 88.8%, and there is a plate (thickness 12 mm, size 300 × 800 mm) on both sides. Of structural plywood) reaches 93.2%.

  However, if a clearance is not provided, when stress that causes warping or twisting occurs in the existing beam 3 due to humidity or the like, the stress of expansion and contraction is constrained and cannot escape as deformation, There is a great concern that an internal stress is generated and a crack or a crack is generated in the existing beam 3.

  On the other hand, in the case of the composite beam according to this embodiment when using the same accessory plate, the integration rate is 74.5%, which does not reach the above-mentioned value, but the existing beam and the accessory beam are arranged up and down, and the bolt 27.4% when fastened with a dowel, 31.6% when fastened with a dowel, 33% when fastened with a lag screw, and a pair of plywood as plywood. Compared to mechanical reinforcement, it shows a much higher value, such as 35-42% when nailed by contact. Above all, the slight decrease in the integration rate described above can be compensated for by increasing the beam rigidity and the bending rigidity EI by the clearance δ.

  The accessory plate 5 may be appropriately selected from various plate materials including a wood-based plate material such as a structural plywood, an OSB plywood (orientated strand board, or a wood chip formed into a plate together with a synthetic resin). .

  For the beam 4, for example, a laminated material can be used.

  In the beam reinforcing structure 1 according to the present embodiment, an upper and lower two-stage structure in which a beam 4 is arranged below the existing beam so that a predetermined clearance δ is formed between the lower surface of the existing beam 3. Therefore, the composite beam D of the composite beam is increased, and the cross-sectional secondary moment I is significantly increased. Along with this, the bending rigidity EI of the composite beam is also greatly increased.

  In addition, as described above, instead of mechanical bonding such as bolts, bonding using an adhesive is employed, so that the existing beam 3 and the beam 4 are firmly bonded to each other via the pair of plates 5 and 5. The resulting composite beam.

  In order to perform the beam reinforcement structure 1 according to the present embodiment as a renovation work, first, pillars that hinder the formation of a wide space on the lower floor are removed. Here, description will be made assuming that the column to be removed is erected between the pair of columns 2 and 2 and the column head is joined to the existing beam 3.

  If it is necessary to temporarily receive the upper floor load when removing the obstructing column, it may be appropriately performed using a known technique so as not to hinder the attachment of the beam 4 and the plate 5.

  Next, when it is judged that the unevenness of the side surface of the existing beam 3 is large and the adhesive is not compatible, planarization (canna) is performed as necessary to smooth the side surface, and the beam 4 Is installed.

  When installing the beam 4, a spacer (not shown) having a thickness corresponding to the clearance δ is interposed between the lower surface of the existing beam 3 and the existing beam 3 is screwed from below the beam 4 in such a state. 3 is temporarily fixed.

  Next, the pair of auxiliary plates 5 and 5 are bonded to the side surfaces of the existing beam and the auxiliary beam so as to sandwich the existing beam 3 and the auxiliary beam 4 from both sides. When the splicing plate 5 is bonded, it may be performed while avoiding the small beam 6 hanging on the existing beam so as to be orthogonal to the existing beam 3.

  As an adhesive to be used, it is possible to appropriately select from any commercially available adhesive. For example, a two-component mixed epoxy resin adhesive marketed under the trade name “Sea Cadure 30” from Nippon Sika Co., Ltd. Agents can be used. Such an adhesive has high viscosity and does not spill, so it has good workability. If it is not in winter, it will develop strength up to about 90% of the final strength in 3 days. There are advantages such as not.

  As described above, according to the beam reinforcing structure 1 according to the present embodiment, the auxiliary beam 4 is arranged below the existing beam so that a predetermined clearance δ is formed between the lower surface of the existing beam 3. Since the composite beam having the upper and lower two-stage structure is formed, the composite beam D of the composite beam is increased, and the cross-sectional secondary moment I can be greatly increased. It becomes possible to greatly improve the bending rigidity of the existing beam 3 bridged between them.

  Therefore, even if the column erected between the columns 2 and 2 is pulled out, the reinforcement of the existing beam 3 makes it possible to suppress the downward deflection amount to a desired size, and a large space without columns. Can be formed on the lower floor.

  In addition, according to the beam reinforcing structure 1 according to the present embodiment, since bonding using an adhesive is employed instead of mechanical bonding such as bolts, the existing beam 3 and the beam 4 are connected to a pair of beam 5. , 5 can be used as a composite beam firmly joined together. Therefore, integration without backlash is possible, and floor vibration can be suppressed.

  In addition, according to the beam reinforcing structure 1 according to the present embodiment, since the beam 4 is arranged below the existing beam so that a predetermined clearance δ is formed between the lower surface of the existing beam 3, The clearance of the beam 3, for example, the expansion and contraction due to the temperature change can be absorbed by the clearance.

  Although not specifically mentioned in the present embodiment, the existing beam 3 between the columns 2 and 2 is not a single object, and is composed of an existing beam 3a having a large beam and an existing beam 3b having a small beam as shown in FIG. In the same manner as in the above-described embodiment, the accessory beam 4 is arranged under the existing beam 3b having a small beam structure, and a pair of accessory plates 5 and 5 are attached to the place where the accessory beam 4 is arranged and bonded. do it.

Incidentally, in this case, the Young's modulus of the composite beam is 9.76 kN / mm ² , which is not inferior to that of a single pine beam, and therefore the existing beam spanned between the columns 2 and 2 is Even if the existing beam 3b is succeeded, it is not necessary to reinforce it with a steel beam as in the prior art, and it has been found that it can be sufficiently reinforced with wooden beams and plates.

(Second Embodiment)
Next, a second embodiment will be described. Note that components that are substantially the same as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 3 is a view showing a beam reinforcing structure according to the present embodiment. FIG. 3A is a side view, FIG. 3B is an exploded perspective view, and FIG. 3C is a BB line. FIG. As can be seen from these drawings, the beam reinforcing structure 21 according to the present embodiment is applied to the existing wood-based beam 3 spanned between a pair of opposing columns 2 and 2 as in the first embodiment. The wooden beam 4 is arranged below the existing beam so that a predetermined clearance δ is formed between the lower surface of the existing beam 3. In this embodiment, the lower surface of the existing beam 3 is arranged. The joining plate 24 is fitted and bonded to the existing beam-side fitting groove 22 formed on the beam and the beam-side fitting groove 23 formed on the upper surface of the beam 4.

  Here, the clearance δ is preferably 10 to 50 mm and more preferably about 15 to 30 mm so as to absorb the flare of the existing beam 3. The reason for this range is that if it is 50 mm or more, there is a concern of lateral buckling.

  Incidentally, the advantages and disadvantages when the clearance δ is not provided are as described in the first embodiment, and in the composite beam according to this embodiment, the integration rate is 75.8% (thickness 12 mm, size 300 × 800 mm). Although the structural plywood of the above was used as the joining plate), although not reaching the above-mentioned value, the numerical value is much higher than that of the mechanical reinforcement as in the first embodiment. Above all, the slight decrease in the integration rate described above can be compensated for by increasing the beam rigidity and the bending rigidity EI by the clearance δ.

  The joining plate 24 may be appropriately selected from various plate materials including a wood-based plate material such as a structural plywood, an OSB plywood (orientated strand board, or a wood chip formed with a synthetic resin into a plate material). .

  In the beam reinforcing structure 21 according to the present embodiment, an upper and lower two-stage structure in which the beam 4 is arranged below the existing beam so that a predetermined clearance δ is formed between the lower surface of the existing beam 3 and the beam. Therefore, the composite beam D of the composite beam is increased, and the cross-sectional secondary moment I is significantly increased. Along with this, the bending rigidity EI of the composite beam is also greatly increased.

  In addition, as described above, instead of mechanical bonding such as bolts, bonding using an adhesive is adopted, so that the existing beam 3 and the accessory beam 4 are firmly bonded to each other via the bonding plate 24. It becomes.

  In order to perform the beam reinforcement structure 21 according to the present embodiment as a renovation work, first, pillars that hinder the formation of a wide space on the lower floor are removed. Here, description will be made assuming that the column to be removed is erected between the pair of columns 2 and 2 and the column head is joined to the existing beam 3.

  If it is necessary to temporarily receive the upper floor load when removing the obstructing column, it may be appropriately performed using a known technique so as not to hinder the attachment of the beam 4 and the joining plate 24.

  Next, the existing beam side fitting groove 22 is formed and processed on the lower surface of the existing beam 3 by using a circular saw or the like, and similarly, the auxiliary beam side fitting groove 23 is formed and processed on the upper surface of the auxiliary beam 4.

  Next, one edge of the joining plate 24 is fitted and bonded to the existing beam-side fitting groove 22 formed on the lower surface of the existing beam 3, and the other edge of the joining plate is attached to the upper surface of the beam 4. Are fitted into the beam-side fitting groove 23 formed in the above, and are similarly bonded.

  The adhesive used is the same as in the first embodiment, and the description thereof is omitted here.

  As described above, according to the beam reinforcing structure 21 according to the present embodiment, the auxiliary beam 4 is arranged below the existing beam so that a predetermined clearance δ is formed between the lower surface of the existing beam 3. Since the composite beam having the upper and lower two-stage structure is formed, the composite beam D of the composite beam is increased, and the cross-sectional secondary moment I can be greatly increased. It becomes possible to greatly improve the bending rigidity of the existing beam 3 bridged between them.

  Therefore, even if the column erected between the columns 2 and 2 is pulled out, the reinforcement of the existing beam 3 makes it possible to suppress the downward deflection amount to a desired size, and a large space without columns. Can be formed on the lower floor.

  Further, according to the beam reinforcing structure 21 according to the present embodiment, since the bonding using an adhesive is adopted instead of the mechanical bonding such as a bolt, the existing beam 3 and the accessory beam 4 are connected via the bonding plate 24. It is possible to make a composite beam that is firmly joined to each other. Therefore, integration without backlash is possible, and floor vibration can be suppressed.

  Further, according to the beam reinforcing structure 21 according to the present embodiment, the beam 4 is arranged below the existing beam so that a predetermined clearance δ is formed between the lower surface of the existing beam 3 and the existing beam 3. The clearance of the beam 3, for example, the expansion and contraction due to the temperature change can be absorbed by the clearance.

It is a figure of the reinforcing structure of a beam concerning a 1st embodiment, (a) is a side view, (b) is an exploded perspective view, and (c) is a sectional view which meets an AA line. The side view of the reinforcement structure of the beam which concerns on a modification. It is a figure of the reinforcement structure of the beam which concerns on 1st Embodiment, (a) is a side view, (b) is a disassembled perspective view, (c) is sectional drawing which follows a BB line.

Explanation of symbols

1, 21 Beam reinforcement structure 2 Column 3 Existing beam 4 Beam 5 Plate 22 Existing beam side fitting groove 23 Beam side fitting groove 24 Joint plate

Claims (1)

The auxiliary beam is arranged below the existing beam so that a predetermined clearance is formed between the lower surface of the existing beam and a pair of auxiliary plates are provided so as to sandwich the existing beam and the auxiliary beam from both sides. By adhering to each side surface of the existing beam and the auxiliary beam (except when the auxiliary plate is joined to a pair of pillars spanning the existing beam), the existing beam and the auxiliary beam are A beam reinforcing structure characterized in that it is a composite beam joined to each other via the pair of accessory plates .

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