JP4559996B2 - Building reinforcement structure and method using iron-based shape memory alloy. - Google Patents

Description

The present invention relates to a reinforcing structure that utilizes the shape restoring action of an iron-based shape memory alloy member when reinforcing a building.

Conventionally, as a reinforcement structure which does not use a shape memory alloy member in a reinforcement structure of an existing building, for example, the structures disclosed in Patent Documents 1 to 3 are known.
Moreover, as an example of the conventional general reinforcement structure, the structure as shown in FIGS. 11-13 is known. FIG. 11 shows an example of small-scale reinforcement, and FIGS. 12 and 13 both show examples of large-scale reinforcement.

  First, in the small-scale reinforcing structure example shown in FIG. 11, a new facility 40 is added in addition to the existing facility 36 placed on the beam member 41 disposed between the left and right column members 35, 35. In connection with this, the case where the reinforcement member 41a is additionally attached to the existing beam member 41 and it respond | corresponds is shown. In the case of such small-scale reinforcement, that is, when the simple reinforcement method can be adopted, the degree of influence on the operation such as temporary suspension of the operation due to the reinforcement work is small, and the cost of the reinforcement work does not become a big problem.

  On the other hand, in the large-scale reinforcement work performed in the same building as in FIG. 11 described above, it may be necessary to release the stress of the beam member 41. In this case, as shown in FIG. 12, the central portion of the beam member 41 is pushed up by a temporary bundle pillar 37, a hydraulic pump 42, a hydraulic jack 43, etc. as shown in the figure to release the stress of the beam member 41, The reinforcing member 41 b is attached over the entire length of 41. And the procedure which removes temporary members, such as the hydraulic jack 43, is newly installed and installed. In the case of such a large-scale reinforcement work, the temporary cost of the hydraulic jack 43 and the like is high, a space for temporary installation must be secured, and there is a demerit that there is an influence on the operation such as temporary interruption of the operation. Occurs.

In another example of large-scale reinforcement shown in FIG. 13, the existing equipment 36 is temporarily removed to release the stress of the beam member 41, and the reinforcement member 41c is attached. After that, the procedure for installing the existing equipment 36 and the new equipment 45 is taken. In this case, there is a cost for removing and restoring the existing equipment 36, and if it is difficult to remove the existing equipment 36 temporarily, this reinforcing method cannot be adopted.
JP 2000-257270 A Japanese Patent Laid-Open No. 10-30364 Japanese Patent Laid-Open No. 9-144049

As described above, in the case of a large-scale reinforcement work that requires stress release of the beam member, it is a problem to minimize the influence on the operation and keep the reinforcement work cost low. An object of this invention is to provide the reinforcement structure and reinforcement method of a building using the iron-type shape memory alloy which can eliminate such a subject.

In order to solve the above problems, in the building reinforcement structure using the iron-based shape memory alloy of the first invention, a support member is provided under the beam member in the building, and between the support member and the beam member, vertically arranged to elongated member having to extend the iron-based shape memory alloy member is compressed occurs a given strain in the vertical direction is provided in the vertical direction of the shape recovery of the iron-based shape memory alloy member The extension of the extension member accompanying the above causes the beam member to be pushed up to release or reduce the stress of the beam member .

According to a second invention, in the building reinforcement structure using the iron-based shape memory alloy according to the first invention, the support member provided under the beam member is a bundle column.
According to a third aspect of the present invention, in the building reinforcement structure using the iron-based shape memory alloy of the first aspect, the support member provided under the beam member is a brace.
According to a fourth aspect of the invention, in the building reinforcement structure using the iron-based shape memory alloy according to the first aspect of the present invention, the support member provided under the beam member includes a tensile lower chord member whose both ends are fixed to the beam member, and the beam It is a bundle material composed of an elongated member interposed between the member and the tension lower chord material, and the beam member, the tension lower chord material and the bundle material constitute a tension string beam.
In the fifth invention, in the building reinforcing structure using the iron-based shape memory alloy according to any one of the first to fourth inventions, the iron-based shape memory alloy member is friction-bonded, bearing-bonded, It is arranged in any form of clamping.
In the method for reinforcing a building using the iron-based shape memory alloy of the sixth invention, the building is reinforced by the reinforcing structure using the iron-based shape memory alloy of any one of the first to fifth inventions.

  According to the present invention, in large-scale reinforcement work that requires stress release, it is possible to minimize the impact on operations compared to a method of jacking up or a method of temporarily removing existing equipment, and to reduce the cost of reinforcement work. It is possible to keep the cost low, and it is possible to significantly reduce the load on the middle part of the beam where the bending stress is high, particularly the central part of the beam.

According to the first invention, the extension member provided between the beam member and the support member can be pushed up by the shape restoration of the iron-based shape memory alloy member to push up the beam member and release the stress of the beam member. The advance preparation does not require time and effort for the work on the construction site, and the effect that the reinforcement work is easy and inexpensive can be obtained. In addition, since the support member and the extension member are not removed after reinforcement, the removal cost is unnecessary, and further, the installation space for the hydraulic pump or the like is not required as in the conventional case, so that the work space can be made compact. An effect is also obtained.
According to the second invention, when there are existing facilities that cannot be removed in the vicinity of the pillar material and there are restrictions on the floor and space, construction is possible if there is a small floor space for standing the bundle pillars. Is obtained.
According to the third invention, when there is existing equipment that cannot be removed below the center of the beam member and there are restrictions on the floor and space, it is possible to configure the stress relief structure of the beam member by using braces and remove it. The effect that the work can be omitted is obtained.
According to the fourth aspect of the present invention, the stress relief structure of the beam member can be configured by configuring the stringed beam even under adverse conditions where there are existing facilities that cannot be removed in the entire lower part of the beam member.
According to the fifth aspect of the invention, there is an effect that it is possible to appropriately select the arrangement structure of the iron-based shape memory alloy member in the elongated member according to the stress release structure to be employed.
According to the sixth invention, an appropriate reinforcing method can be selected by the support member having the iron-based shape memory alloy member according to the construction environment conditions in the building to be reinforced, and therefore according to any one of the first to fifth inventions. An effect is obtained.

    Next, the present invention will be described in detail based on the illustrated embodiment.

  FIG. 1 is an explanatory view showing a reinforcing method of the building 1 and should also be referred to as a bundle pillar type reinforcing method. First, the outline of the reinforcing method will be described with reference to this drawing, and then the details of the reinforcing structure will be described with reference to FIGS.

Fig.1 (a) shows the structure of the building 1 before reinforcement. The building 1 includes a pair of left and right column members 3 and a beam member 2 whose ends are joined to the upper ends thereof. An existing facility 4 is installed at the center of the beam member 2. FIG.1 (b) shows distribution of the bending moment 7 which both the members 2 and 3 receive in this state (before reinforcement).

  When the building 1 is reinforced to cope with the addition of new equipment (not shown) on the beam member 2, a bundle column 5 as a support member is placed at the center of the beam member 2 as shown in FIG. The extension member 8 provided with the shape memory alloy 9 (see FIG. 5) is fixed to the top of the bundle pillar 5 (see FIG. 5). A broken line 10 shown in FIG. 1C indicates the existing equipment 6 that restricts the reinforcing method (reinforcing structure). When there is a restriction such as the existing equipment 6 at such a position, a bundle pillar type reinforcing structure is adopted.

  The elongating member 8 is composed of four shape memory alloy members 9 and mounting plates 11 and 11 disposed so as to sandwich them from above and below (see FIG. 5). When the bundle column 5 and the extending member 8 are erected below the beam member 2, a predetermined slight gap 12 is provided between the upper mounting plate 11 of the extending member 8 and the beam member 2.

  The shape memory alloy member 9 is previously processed at a certain critical temperature or less, and has a property of returning to its original shape when a certain critical temperature is exceeded by a heating operation. In order to utilize this property, after the above-mentioned bundle column 5 and the extending member 8 are erected, the shape memory alloy member 9 is heated to a predetermined temperature equal to or higher than a certain critical temperature. When the shape memory alloy member 9 that has been heated reaches a certain critical temperature or more, it expands in the vertical direction and recovers its shape. And the expansion | extension member 8 also expand | extends according to the shape recovery (restoration expansion | extension to an up-down direction) (refer FIG. 1 d).

  Thus, by the shape recovery of the shape memory alloy member 9, the gap 12 provided between the elongating member 8 and the beam member 2 thereon is filled, and the beam member 2 is further pushed upward. In this pushed-up state, the upper mounting plate 11 of the extending member 8 is finally bolted to the beam member 2. The bundle pillar 5 and the extending member 8 constitute a push-up member 13 of the beam member 2.

  In addition, you may take the method of pushing the expansion | extension member 8 under the beam member 2, without providing the clearance gap 12 on the expansion | extension member 8 at the time of attachment before said heating operation.

  FIG. 1E shows the distribution of the bending moment after the shape memory alloy member 9 recovers its shape after the heating operation and pushes the beam member 2 upward. By the reinforcement, the distribution of the bending moment 7 is changed to a convex shape upward at the center of the beam member 2, and the stress of the beam member 2 is released or reduced. The bundle pillar 5 and the elongated member 8 including the shape memory alloy member 9 are continuously used as they are. FIG. 10A shows an enlarged view of the relationship between the bundle column 5, the extension member 8, and the beam member 1 in the bundle column type reinforcing structure.

  FIG. 2 is an explanatory diagram when a brace-type reinforcing structure using a brace 14 as a support member is employed in accordance with the constraints of the existing equipment 6 shown in the drawing. Further, FIG. 3 is an explanatory diagram when a truss-type reinforcing structure in which a stringed beam (truss) 15 as a supporting member is configured to avoid the existing equipment 6 installed over the entire range between the column members 3 and 3 is adopted. It is. The extension member 8 in the reinforcing structure of FIGS. 2 and 3 may be the same as or similar to the extension member 8 of the bundle pillar type (FIG. 1) shown below.

In FIG. 3, the supporting member provided under the beam member 2 includes a tension lower chord material 15a whose both ends are fixed to the beam member 2, and a shape memory interposed between the beam member 2 and the tension lower chord material 15a. and the alloy member 9 is including extension length member 8 and Tabazai 8a, constitute a Chotsuruhari 15 by a the beam member 2 and tensile lower chord member 15a elongated member 8 and Tabazai 8a. As the tension lower chord material 15a, a general steel material such as a wire shape or a rod shape may be used. PC cables or PC steel materials may be used. Both end portions of the tension lower chord member 15a are fixed to each end portion of the beam member 2 in a tensioned state by fixing metal fittings (not shown).

  4 (a) and 4 (b) are explanatory views showing the reinforcing effect in the case where the stress of the beam member 2 is released by the above-described pushing-up, in comparison with the reinforcing effect at the time of simple reinforcement in the background art.

  FIG. 4A is a bar graph showing the stress (load) of the beam member 2 during simple reinforcement (no stress release). The lower horizontal dashed line 16 in the figure indicates the strength level of the beam member 2, and the upper horizontal dashed line 17 indicates the improved strength level after simple reinforcement. The stress of the beam member 2 before reinforcement is in a state close to the proof stress (lower horizontal alternate long and short dash line 16) as shown by the left bar graph 18, and has a small remaining power. Since it is necessary to bear a part of the load of the additional equipment with this small surplus portion, there is a limit to the response by reinforcement, and the right bar graph 19 (the stress of the beam member 2 after reinforcement does not change from that before reinforcement) As shown by the upper horizontal alternate long and short dash line 17 in FIG.

  On the other hand, if the reinforcement method of this embodiment is performed, the stress of the beam member 2 is remarkably released (reduced) as shown by the bar graph 20 in the center of FIG. As a result, as shown by the bar graph 21 on the right side, it is possible to add a reinforcing material equivalent to that before reinforcement to the beam member 2 in a stress state with reduced release, so that the total proof stress is greatly improved (significant reinforcement). Is possible.

  FIGS. 5A and 5B show the detailed structure of the elongating member 8 constituting the push-up member 13. (A) is a side view, (b) is AA sectional drawing of (a). As shown in FIG. 5, two parallel brackets 22 are erected and fixed to each of the four rectangular brackets 22 at four positions in front and rear, right and left at equiangular intervals on the rectangular mounting plate 11. The shape memory alloy member 9 is inserted between the gaps without any gap and is firmly tightened by the bolts and nuts 29. Accordingly, each shape memory alloy member 9 is friction bonded to the mounting plate 11 via the parallel bracket 22. The shape memory alloy member 9 and the bracket 22 are integrated by bolts and nuts 29 via the friction surfaces. In other words, in this embodiment, both end portions of the shape memory alloy member 9 are respectively disposed between the brackets 22, and both side surfaces thereof are interposed between the brackets 22 and contacted and firmly tightened by the bolts and nuts 29. This is a configuration in which the tightening force of the bolt / nut 29 and the friction between the side surface of the bracket 22 and the both side surfaces of the shape memory alloy member 9 (friction joining using the tightening force of the bolt) are used. .

  It should be noted that a gap 23 as shown in FIG. 6 may be present at the joint between the shape memory alloy member 9 and the bracket 22 parallel to the bolt / nut 29, in which case the shear strength of the bolt shaft portion is utilized. A bearing connection structure is adopted, and the inner surface of the mounting hole 25 of the shape memory alloy member 9 is used as a bearing surface (bearing surface), and is supported by the outer peripheral side surface of the bolt 29 inserted therethrough, and the shear strength of the bolt 29 is utilized. In such a form, the bolt shaft cross section may be enlarged. Such upper and lower mounting plates 11 and 11 are opposed to each other in the vertical direction with the shape memory alloy member 9 interposed therebetween. The lower mounting plate 11 is fixed to the upper end portion of the bundle pillar 5 with four mounting holes 24 by bolts / nuts 30 or the like, and the upper mounting plate 11 is similarly fixed to the beam member 2 by bolts / nuts 30 or the like. In order to be fixed, a horizontal flange 31 having a bolt insertion hole may be provided at the upper end of the bundle pillar 5. In the case of the support bearing as described above, a pin may be used instead of the bolt 29.

FIG. 7 is a perspective view of a single shape memory alloy member 9 processed into a plate shape. The four shape memory alloy members 9 are cut and formed into a thick plate shape as shown in the figure. Bolts are fastened to the parallel brackets 22 by two mounting holes 25 on the upper and lower sides, and the fixed portion does not recover its shape (a portion that does not change even when heated by a gas burner or the like). Only the intermediate portion 9a is in a range where the shape is recovered by the heating operation.
For example, the shape memory alloy member 9 has a tensile strength of 680 to 1000 MPa, a transformation temperature of 300 to 350 ° C., a shape recovery force of 180 MPa, and a shape recovery strain of 2.5 to 4.0%. It is preferable to use an iron-based shape memory alloy such as 16% Mn-5% Si-12% Cr-5% Ni-Fe or 20% Mn-5% Si-8% Cr-5% Ni-Fe.

  FIGS. 8A to 8C are explanatory views for explaining the state of shape recovery of the shape memory alloy member 9 that is generally processed into a plate shape, separately from the above-described one. The shape memory alloy member 9 processed into a plate shape shown in (a) is compressed in the vertical direction as shown in (b) at a predetermined temperature of 300 ° C. or lower to cause strain in the plate thickness direction. A broken line 9b in the drawing indicates a plate thickness state before compression. At this time, since the volume is substantially constant, the shape memory alloy member 9 also changes in the plate width direction (direction perpendicular to the plate thickness). Then, after being attached under the beam member 2 in the state shown in FIG. 5, the intermediate portion 9a is heated. The intermediate portion 9 a of the shape memory alloy member 9 recovers its shape in the vertical direction at 300 to 350 ° C., and pushes up the beam member 2. Thereby, the stress of the beam member 2 is released or reduced. In addition, it is preferable that the joint portion by the bolt is made thick so that the strain is not given, and the strain is given only to the intermediate portion.

  FIG. 9 shows the configuration of the elongated member 28 in the second embodiment. The elongated member 28 can be used in a bundle pillar type or a stringed beam type, but is applied to a brace type reinforcing structure in the illustrated embodiment. Then, the shape memory alloy member 26 constituting the elongated member 28 is formed in a square block shape as shown in FIGS. 9A and 9B, and is below a predetermined critical temperature in advance as shown in FIG. 9C. In the state in which the strain is generated by compressing in the vertical direction under the conditions (shown in the center diagram of (c), the broken line indicates the shape before compression), It is clamped (pinched and supported) and arranged. At this time, the shape memory alloy member 26 is disposed so as to be prevented from being displaced in the four L-shaped guides 27a arranged so as to stand and be fixed to both the mounting plates 27 so as to face each other. In this embodiment, the shape memory alloy member 26 is supported by being sandwiched between mounting plates 27 and 27 that are vertically opposed to each other. Although the four L-shaped guides 27a are provided on the mounting plate 27, two L-shaped guides 27a may be provided on the mounting plate 27 in the diagonal direction of the shape memory alloy member 26. Besides, a form in which a flat guide is provided on the mounting plate 27 in the vicinity of each side surface of the shape memory alloy member 26 may be employed. That is, the shape memory alloy member 26 may be supported by being sandwiched between two members (attachment plates 27 and 27). A support part for supporting the upper or lower part of the shape memory alloy member 26 corresponding to the mounting plate 27 and a support part for supporting the shape memory alloy member 26 so as not to be displaced laterally are provided in the beam member 2 or the bundle column in advance. If it is, the mounting plate 27 can be omitted. That is, the shape memory alloy member 26 may be sandwiched and supported (a sandwiched configuration).

  In attaching the extension member 28 onto the brace 14 as a support member, as shown in FIG. 10B, a bracket 27 b erected downward is attached to the lower attachment plate 27 of the extension member 28. It fixes to the top part 14a with a bolt, a nut, etc. via a joint plate etc. Then, a predetermined slight gap 12 is provided between the beam member 2 or the upper mounting plate 27 is attached to the beam member 2 without a gap, and then the shape memory alloy material 26 is heated. As described above, the shape memory alloy member 26 recovers its shape in the vertical direction at 300 to 350 ° C. and pushes up the beam member 2. In this way, the stress of the beam member 2 is released by the brace type reinforcement structure as in the case of the bundle column type reinforcement.

  When implementing this invention, you may make it reinforce a building by reinforcing a steel beam member, a reinforced concrete beam member, and the beam member of the composite structure made from steel and concrete as a beam member.

(A) is a front view showing a building before reinforcement, (b) is a distribution diagram of bending moment before reinforcement, (c) is a front view showing a state in which a push-up member is erected below a beam member, (d) These are distribution diagrams of the bending moment after reinforcement. It is explanatory drawing which shows a brace type reinforcement structure. It is explanatory drawing which shows the truss type reinforcement structure. (A) is explanatory drawing which shows an example of the prior art which simply reinforces a beam member, (b) is explanatory drawing which shows the reinforcement example of this invention which releases the stress of a beam member. (A) is a side view of the extending | stretching member in a bundle pillar type reinforcement structure, (b) is AA sectional drawing of (a). (A) is a side view of the example of a design change of the extending member in the reinforcing structure of the bundle pillar type, and (b) is a BB cross-sectional view of (a). It is a perspective view of a plate-shaped shape memory alloy member. (A)-(c) is explanatory drawing explaining the mode of the shape recovery of the shape memory alloy member processed into plate shape. (A) is a side view of an example of the extending | stretching member provided with a square block-shaped shape memory alloy member, (b) is BB sectional drawing of (a). (A) is an enlarged view showing the relationship between a bundle column, an elongated member, and a beam member in a bundle column type reinforcement structure, and (b) is a brace type reinforcement structure including an elongated block shape memory alloy member. It is a side view of Embodiment 2 used for. It is explanatory drawing of an example of the simple reinforcement structure by a prior art. It is explanatory drawing of an example of the reinforcement structure using the hydraulic jack etc. by a prior art. It is explanatory drawing of an example of the reinforcement structure which removes the existing installation by a prior art once.

1 Building 2, 41 Beam member 3, 35 Column material 4, 6, 36 Existing equipment 5, 37 Bunch column (support member)
7 Bending moment 8, 28 Elongating member 8a Bundle material 9, 26 Shape memory alloy member 9a Intermediate part 10, 9b Broken line 11, 27 Mounting plate 12, 23 Gap 13 Push-up member 14 Brace (supporting member)
15a Tensile lower chord material 15 Truss (support member, tension string beam)
16 Lower horizontal alternate long and short dash line 17 Upper horizontal alternate long and short dash line 18, 19, 20, 21 Bar graph 22 Parallel bracket 24 Mounting hole 25 Mounting hole 27 Mounting plate 27a Guide 27b Bracket 29 Bolt / nut 30 Bolt / nut 31 Bolt / nut 40 New equipment 41a, 41b, 41c Reinforcing member 42 Hydraulic pump 43 Hydraulic jack 44, 45 New equipment

Claims (6)

A support member is provided under the beam member in the building, and an iron-based shape memory alloy member that is compressed in the vertical direction and causes strain is arranged between the support member and the beam member so as to extend in the vertical direction. extending member having is provided, that the stress in the vertical direction of the beam member the beam member is pushed up by extension of the elongated member with the shape recovery of the iron-based shape memory alloy member is released or reduced Reinforcement structure of the building using the characteristic iron-based shape memory alloy. The reinforcing structure for a building using an iron-based shape memory alloy according to claim 1, wherein the support member provided under the beam member is a bundle column. The reinforcing structure for a building using an iron-based shape memory alloy according to claim 1, wherein the support member provided under the beam member is a brace. The support member provided under the beam member is a bundle member composed of a tension lower chord material whose both ends are fixed to the beam member, and an extending member interposed between the beam member and the tension lower chord material, 2. The building reinforcement structure using an iron-based shape memory alloy according to claim 1, wherein a tension string beam is constituted by a tension lower chord material and a bundle material. Iron-based shape memory alloy member in the elongated member, friction bonding, Bearing bonding, iron according to any one of claims 1 to 4, characterized in that it is arranged by any form of clamping Reinforcement structure of buildings using system shape memory alloy. A building reinforcing method using an iron-based shape memory alloy, wherein the building is reinforced by a reinforcing structure of the building using the iron-based shape memory alloy according to any one of claims 1 to 5.

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