JP2015218548A - Fitting structure of elasto-plastic damper to existing structural member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add an elasto-plastic damper to an existing structural member in a state the plastic deformation capacity of the existing structural member functions, which is shear-deformed when the existing structural member receives shear force in an in-plane direction.SOLUTION: Plural reinforcement members 4, 4 are disposed at a certain distance from each other in an axial direction along an existing structural member 3 in a direction perpendicular to a plane on which shear force acts to shear-deform the existing structural member 3. The reinforcement members 4, 4 positioned at both sides in the axial direction are joined to structural members 1 respectively. An elasto-plastic damper 5 having a plastic deformation part 51, which can shear-yield when shear force is applied to an in-plane direction, is disposed between the reinforcement members 4, 4 which are disposed at a certain distance in the axial direction. A part segment 31 of the existing structural member 3 is removed excluding both ends in the axial direction while leaving a part in an H-direction.

Description

  The present invention relates to a structure for attaching an elastic-plastic damper to an existing structural member by adding an elastic-plastic damper that undergoes shear deformation by receiving an in-plane shearing force to an existing structural member, and absorbing vibration energy by the elastic-plastic damper. It is.

  In order to give an existing structural member the ability to absorb vibration energy, when a shear deformation type elastic-plastic damper is added to the structural member, in order to preferentially yield the elastic-plastic damper before the structural member yields, The structural member is divided at a part in the axial direction, and an elastoplastic damper is installed between the divided structural members (see Patent Documents 1 and 2).

  In this case, for example, the beam as an existing structural member is separated into two structural members in the axial direction, and each structural member projects in a cantilever manner from a column as a main structural member to which it is connected, and an elastic-plastic damper is attached. As a result, the columns (main structural members) and the constituent members arranged in parallel form a pillar / beam frame.

  When a horizontal force acts on the frame surface and relative deformation occurs between the parallel columns, each component tries to keep a vertical connection to each column while the components are connected to each other. Since the elasto-plastic damper is trying to draw both components together, a bending moment acts on each component in the forming direction. As a result, since the bending moment of the structural member near the joint with the column is maximized, depending on the yield strength of the elastic-plastic damper, the portion of the structural member near the joint precedes the elastic-plastic damper. In such a case, the elasto-plastic damper cannot sufficiently exhibit the energy absorption capability due to the yield.

  If the cross-sectional shape (composition (height)) of each component is uniform over the entire length, the vicinity of the joint between the component and the column where the bending moment is maximized during relative deformation between the columns in parallel Since deformation and damage concentrate on the joint, and the vicinity of this joint may yield, even if the elastic-plastic damper can yield, the energy absorption capacity of the elastic-plastic damper may not be fully demonstrated. is assumed.

JP-A-1-203543 (FIGS. 2 and 3) Japanese Patent Laid-Open No. 3-156075 (FIG. 1)

  When the cross-section of the component member is uniform over the entire length as described above and the yield in the vicinity of the junction between the component member and the column occurs prior to the yield of the elastic-plastic damper, the junction with the column of the component member Since the section other than the vicinity has a surplus force with respect to the bending moment and does not yield as a result of bearing the bending moment, the constituent member does not perform the function of absorbing vibration energy together with the elastic-plastic damper. This can be said to be in a use state in which the plastic deformation ability that can be originally exhibited is lost unless the structural member is divided into constituent members.

  In view of the above background, the present invention proposes a structure for attaching an elastic-plastic damper to an existing structural member in which an elastic-plastic damper is added to the structural member in a state where the plastic deformation ability can be exhibited when the structural member is already present. .

The structure for attaching an elastic-plastic damper to an existing structural member according to claim 1 is an existing structure that is installed between parallel main structural members and is capable of undergoing shear deformation in the in-plane direction of the structural surface including the main structural members. An elastic-plastic damper mounting structure that adds an elastic-plastic damper to the member.
A plurality of reinforcing members are arranged along the existing structural member at a distance from each other in the axial direction in a direction perpendicular to the acting surface of the shearing force that shears and deforms the existing structural member, and are located on both sides in the axial direction. The reinforcing member is joined to each main structural member,
An elastic-plastic damper having a plastically deformable portion that can bear a shearing force in the in-plane direction between the reinforcing members separated from each other and can yield a shear,
It is a constituent requirement that a part of the existing structural member except for the end in the axial direction is removed leaving a part in the forming direction.

  The main structural member mainly refers to a column, a beam, and the like, and the structural surface including the main structural member refers to, for example, a structural surface of a frame including columns and beams. Since the main structural members only need to be arranged in parallel at a distance, the main structural members may be piles in addition to the columns located at the ends of the adjacent structures. When the main structural members 1 and 1 are pillars as shown in FIGS. 1 and 5- (a), the existing structural member 3 is a beam, and as shown in FIG. 5- (b), the main structural members 1 and 1 are In the case of a beam, the existing structural member 3 is a stud, a seismic wall, a brace or the like. When the main structural member 1 is a column of an adjacent structure, the existing structural member 3 is a beam protruding from a column located on the adjacent structure side of each structure. When the main structural member 1 is a pile, the existing structural member 3 is a foundation beam that connects the piles. However, the main structural member 1 and the existing structural member 3 are not limited to these.

  As shown in FIG. 5- (c), braces are erected in a frame 2 including a column or beam constituting the main structural member 1, and the braces constitute a frame 2, or the column, beam, or connection between the columns and beams. When joining to any part of the part, a bracket or the like is installed between the brace and the frame 2 so that they are joined to each other. The bracket may become the existing structural member 3. In this case, since the bracket continues across the brace and the frame 2, the brace becomes one main structural member 1 of the main structural members 1 and 1 arranged in parallel, and the frame 2 (beam or column) becomes the other. It becomes the main structural member 1.

  The elastoplastic damper 5 is a shear deformation type damper that undergoes shear deformation in response to a shear force in the in-plane direction, or that undergoes shear deformation with bending deformation, and is a plate or rod located in the center of the entire damper. The plastic deformation part 51 which is a region such as (linear) undergoes shear deformation. In the drawing, the plastic deformation portion 51 is formed in a shape corresponding to the bending moment distribution due to the shearing force when the shearing force is applied, but the shape of the plastic deformation portion 51 is arbitrary.

  The elastoplastic damper 5 is rigidly joined to the reinforcing members 4 and 4 separated from each other at both side portions (joint portions 52 and 52) in the direction perpendicular to the shearing force acting direction in the plane, so The intermediate plastic deformation portion 51 sandwiched is subjected to shear deformation when it receives a shearing force in the in-plane direction along with the relative displacement between the reinforcing members 4 and 4, or shear deformation accompanied by bending deformation, and shear yielding. Or, vibration energy is absorbed by bending yielding.

  The plurality of reinforcing members 4, 4 are arranged in a state where the material axes are parallel to the material axes of the existing structural member 3, while being spaced apart from each other in the axial direction along the existing structural member 3 as shown in FIGS. The reinforcing members 4, 4 that are arranged and located on both sides in the axial direction are rigidly joined to the main structural member 1 at the ends of the main structural member 1, 1 side. The reinforcing members 4 and 4 which are adjacent to each other at a distance in the axial direction are installed by being connected by joining an elastic-plastic damper 5 therebetween, and are continuous between the main structural members 1 and 1. The elastic-plastic damper 5 is disposed on one side of the reinforcing members 4 and 4 in the width direction, or on both sides as shown in FIG.

  1 to 3 show an example in which there are two reinforcing members 4, 4 arranged between adjacent main structural members 1, 1. In the case of two reinforcing members 4, each reinforcing member 4 is a main structural member. It is joined to the main structural member 1 at the end on one side and is connected to the adjacent reinforcing member 4 at the end on the opposite (reinforcing member 4) side through an elastic-plastic damper 5. A distance corresponding to the installation of the elastic-plastic damper 5 is secured between the reinforcing members 4 and 4 adjacent in the axial direction. Since the elastic-plastic damper 5 is joined to the reinforcing member 4 at the joint 52, the distance secured between the adjacent reinforcing members 4, 4 is the axial direction of the plastic deforming portion 51 of the elastic-plastic damper 5 in the axial direction of the reinforcing member 4. It will be about the size of the length when viewed. The number of the plurality of reinforcing members 4 arranged along the existing structural member 3 may be three or more as shown in FIG.

  When three or more reinforcing members 4 are installed between the main structural members 1 and 1, the end of the reinforcing member 4 positioned on the intermediate side in the axial direction and the end of the reinforcing member 4 adjacent to the end An elastic-plastic damper 5 is straddled between them. The “direction perpendicular to the acting surface of the shearing force that shears and deforms the existing structural member” in claim 1 refers to a direction perpendicular to the surface including the acting direction of the shearing force. The direction is the out-of-plane direction of the frame 2 including, for example, the width direction of the beam.

  Further, in the first aspect, “arranged along the existing structural member” means that the reinforcing member 4 is in the width direction perpendicular to the direction (height direction) of the existing structural member 3 in which the shearing force and the bending moment are applied. The width direction of the existing structural member 3 is also “a direction perpendicular to the acting surface of the shearing force that shears and deforms the existing structural member”. Hereinafter, the reinforcement member 4 being arranged along the existing structural member 3 is referred to as a side view.

  The reinforcing member 4 is disposed on at least one side in the width direction of the existing structural member 3. When the elastoplastic dampers 5 are evenly arranged with respect to the web of the existing structural member 3, the reinforcing members 4 are arranged on both sides of the existing structural member 3 in the width direction. “The direction in which the existing structural member is formed” is the direction in which the shearing force acts on the existing structural member 3, and is also the in-plane direction of the structural surface (frame 2) including the main structural members 1 and 1 arranged in parallel. The width direction of 3 is the out-of-plane direction.

  An elastic-plastic damper 5 is installed across the ends of the plurality of reinforcing members 4, 4 that are arranged with a distance in the axial direction facing each other, and directly or indirectly to the ends of each reinforcing member 4. Are joined together. “Indirect joining” means that a dedicated member for joining the joint 52 of the elastic-plastic damper 5 to the reinforcing member 4 is interposed between the two. The reinforcing members 4 and 4 are connected to each other by the joining of the elastic-plastic damper 5 to each reinforcing member 4 and are continuous. The elasto-plastic damper 5 is joined to each reinforcing member 4 at joints 52 located on both sides in the direction perpendicular to the shearing force acting direction of the plastic deformation part 51. Each joint is mainly by bolts or welding.

  Of the plurality of reinforcing members 4, 4, the reinforcing member 4 positioned closer to the main structural member 1 is rigidly joined to the main structural member 1 at the end on the main structural member 1 side. When relative deformation occurs between the two main structural members 1 and 1 within the composition plane of the frame 2 to be included, an attempt is made to follow the main structural member 1. The reinforcing members 4 and 4 joined to the main structural members 1 and 1 arranged in parallel follow the deformation of each main structural member 1 so that the elastic-plastic damper 5 between the adjacent reinforcing members 4 and 4 bears a shearing force. Then, the plastic deformation portion 51 of the elastic-plastic damper 5 is subjected to shear deformation.

  Since the existing structural member 3 is removed while leaving a part in the forming direction in the partial section 31 except for the end portion in the axial direction, the yield strength of the partial section 31 is reduced. In this case, the remaining portion of the existing structural member 3 except the removed portion 32 at the time of relative deformation between the two main structural members 1 and 1 can yield as a plastic deformation portion 33 by receiving a shearing force, and can exhibit the plastic deformation capability. . In the following, “partial section 31” refers to a section excluding an end portion in the axial direction.

  A steel material (steel frame) is mainly used for the existing structural member 3 in order to make the existing structural member 3 exhibit plastic deformation ability, but it is not necessarily limited to the steel material. In principle, the partial section 31 from which a part of the forming direction is removed is matched with a section having a large bending stress in the entire length of the existing structural member 3 as described later so as to yield in preference to the other sections. (Claim 3), it is not always necessary to coincide with a section where the degree of bending stress is large.

  The reinforcing member 4 is provided side by side in the width direction of the existing structural member 3, and the elastic plastic damper 5 is straddled between the reinforcing members 4 and 4 that are spaced apart in the axial direction, so that the existing structural member 3 is not divided, It can be used as a single structural member that is continuous in the axial direction. That is, as described above, the partial section 31 in the axial direction of the existing structural member 3 is yielded, and the existing structural member 3 can exhibit the plastic deformation ability.

  Yield occurs in a portion where the bending stress degree σ is large in the axial direction in the entire length of the existing structural member 3, and therefore, the total M of the bending moment at the long-term load and the bending moment at the short-term load is calculated as It becomes a section where the size (M / Z = σ) divided by the section modulus Z of each section becomes large. The part where the degree of bending stress σ is large is located in the partial section 31, and in principle, the partial section 31 corresponds to the installation position of the elastic-plastic damper 5 straddling between the reinforcing members 4 and 4 adjacent in the axial direction. (Claim 3), depending on the number of reinforcing members 4 installed between the main structural members 1 and 1, that is, the number of installed elastic-plastic dampers 5, a plurality of locations within the total length of the existing structural members 3. Sometimes it is. A portion where the bending stress degree σ is large is not necessarily a portion where the bending stress degree σ is maximum within the entire length of the existing structural member 3.

  Therefore, by adjusting the section modulus Z (secondary moment of section) of any section of the existing structural member 3, it becomes possible to freely set the location where the yield occurs, and the bending moment is reduced during short-term loading. It is avoided that stress and deformation are concentrated at the end of the existing structural member 3 that is maximized near the main structural member 1. “Adjusting the section modulus” means the size (width and height) of the area (area) of the removed portion 32 in the axial section when the existing structural member 3 is viewed in the width direction as shown in FIG. ) Is adjusted to adjust the size of the cross-sectional area in the direction of shearing force. In FIG. 4, the removal portion 32 is indicated by hatching.

  The fact that the partial section 31 in the axial direction of the existing structural member 3 is removed leaving a part in the forming direction is that the secondary moment of inertia (sectional modulus) of the partial section 31 having the removed portion 32 is the main structural member 1. When the existing structural member 3 bears the bending moment at the long-term load and the bending moment at the short-term load, the bending stress degree of the partial section 31 when the existing structural member 3 bears the bending moment at the short-term load becomes smaller at the end portion. It is meaningful to be larger than the bending stress. As a result, stress and deformation do not concentrate at the end of the existing structural member 3 in the axial direction, and the possibility of breakage at the end decreases, while the section closer to the middle (partial section 31) has a bending moment. Therefore, the existing structural member 3 can exhibit the plastic deformation ability and the energy absorption ability independently of or in synchronism with the yield of the elastic-plastic damper 5.

  “A part of the existing structural member excluding the end portion in the axial direction is removed leaving a part in the forming direction” means that the secondary moment of the cross section of the existing structural member 3 is reduced. This means that the section is a partial section near the intermediate section excluding the section at the end in the axial direction, and that a part of the forming direction is removed in the partial section. By removing a part of the forming direction, the cross-sectional secondary moment (section modulus Z) of the partial section 31 including the removed part (removed part 32) is lower than the cross-sectional secondary moment of the other sections. Since the degree of bending stress σ increases, it becomes possible to yield before other sections.

  The removed portion 32 in the partial section 31 may be formed from either the upper end side or the lower end side of the existing structural member 3 or in the intermediate portion in the forming direction. However, as shown in FIG. In the case of a beam, in order to give the existing structural member 3 the ability to support the slab 7, the removal portion 32 is formed from the lower end side, and the upper end (flange) of the existing structural member 3 is kept flat. Since the upper end of the existing structural member 3 is kept flat in the partial section 31, the existing structural member 3 has the ability to support the slab 7 together with the existing structural member 3 being continuous over the entire length. Have.

  In this case, unlike the structural members of Patent Documents 1 and 2, the existing structural member 3 is continuous in the axial direction, so that the partial section 31 including the removal portion 32 yields due to shearing force and is plastically deformed. Even if this happens, the amount of deformation does not reach as much as when it is divided, so that the slab 7 supported by the existing structural member 3 is prevented from being damaged.

  The removal portion 32 is formed in a partial section 31 in the axial direction of the existing structural member 3, and the cross-sectional secondary moment of the intermediate portion other than the end portion in the axial direction is reduced, so that the main structural members 1, 1 are arranged in parallel. When the relative deformation occurs, the bending stress degree σ of the partial section 31 (intermediate portion) where the removed portion 32 is located, rather than the end portion of the existing structural member 3 near the main structural member 3, becomes large, and is likely to yield. become. Here, when the yield strength of the elastic-plastic damper 5 straddled between the reinforcing members 4 and 4 provided alongside the existing structural member 3 is set lower than the yield strength of the partial section 31 of the existing structural member 3. Will yield the elastic-plastic damper 5 prior to the yielding of the partial section 31 of the existing structural member 3.

  However, since the yield strength of the elastic-plastic damper 5 does not have to be set lower than the yield strength of the partial section 31 of the existing structural member 3, The plastic damper 5 does not always yield. Therefore, when the partial section 31 of the existing structural member 3 yields, it yields at the same time other than the yield before the yield of the elastic-plastic damper 5 and the yield after the yield of the elastic-plastic damper 5. There is a case. In addition, the reinforcing member 4 and the existing structural member 3 share the shearing force and bending moment in the forming direction, and in yielding the elastic plastic damper 5 and the partial section 31 of the existing structural member 3 according to the respective sharing, Although they are independent from each other and separated from each other, they are not necessarily required and may be partially connected.

  The existing structural member 3 and the reinforcing member 4 are mainly made of steel having an open cross-sectional shape having a flange as a resistance element against a bending moment and a web as a resistance element against a shearing force, such as H-shaped steel. Since a cross-sectional shape having a web can bear a bending moment and a shearing force, a steel material having a closed cross-sectional shape can also be used. In that case, at least a part may have an open cross section in order to adjust the yield strength in each section.

  The plurality of reinforcing members 4, 4 provided alongside the existing structural member 3 are installed between the main structural members 1, 1 that are parallel to each other with a distance in the axial direction. At the time of deformation, the joint of the reinforcing member 4 near the main structural member 1 to the main structural member 1 tries to follow the deformation of the main structural member 1 while maintaining the angle formed with the main structural member 1 as described above. However, since the elastic-plastic damper 5 is stretched between the adjacent reinforcing members 4, 4, the end of the reinforcing member 4 on the elastic-plastic damper 5 side tends to be attracted to the elastic-plastic damper 5. The reinforcing member 4 near the structural member 1 receives a concentrated load from the elastic-plastic damper 5 as a cantilever, and the entire length bears a bending moment and a shearing force. The reinforcing members 4 other than the reinforcing member 4 near the main structural member 1 receive shearing force and bending moment from the elastic-plastic damper 5 at both ends in the axial direction as fixed beams at both ends.

  In this relationship, the bending moment generated near the joint portion with the main structural member 1 tends to be maximized in the axial direction of the reinforcing member 4, and the reinforcing member 4 has a uniform cross-sectional shape in the axial direction. Since the section modulus is constant in the axial direction, the degree of bending stress at the end of the reinforcing member 4 near the main structural member 1 is maximized, and it cannot be said that there is no possibility of yielding at this end. . If the yielding of the end of the reinforcing member 4 near the main structural member 1 precedes the yielding of the elastic-plastic damper 5, the function of the elastic-plastic damper 5 may not be fully utilized. Therefore, in order to prevent yielding from occurring at the end of the reinforcing member 4, the reinforcing member located on the main structural member 1 side among the plurality of reinforcing members 4, 4 arranged at a distance from each other in the axial direction. It is appropriate that the cross-sectional secondary moment of the end portion of the member 4 near the main structural member 1 is set to be larger than the cross-sectional secondary moment of the end portion close to the intermediate portion in the axial direction.

  The “reinforcing member positioned on the main structural member 1 side” is stretched from the main structural member 1 in a cantilevered state when the number of the reinforcing members 4 installed between the adjacent main structural members 1 and 2 is two. Each of the reinforcing members 4 to be ejected is indicated, and in the case of three or more, the two reinforcing members 4 and 4 which are located on the main structural member 1 side and become cantilever beams are indicated. The “end near the main structural member 1” and the “end near the intermediate portion in the axial direction” in claim 2 indicate end portions on both sides of the same reinforcing member 4 located on the main structural member 1 side.

  “The cross-sectional secondary moment of the end portion of the reinforcing member located on the main structural member side near the main structural member is larger than the cross-sectional secondary moment of the end portion close to the intermediate portion in the axial direction” It means that the reinforcing member 4 to be formed is formed into an elevational shape corresponding to the bending moment distribution, like a beam of equal strength. However, it is only necessary that the cross-sectional secondary moment at the end of the reinforcing member 4 near the main structural member 1 is larger than the cross-sectional secondary moment at the end near the axially intermediate portion, and as shown in FIG. Since the cross-sectional secondary moment other than the end near the intermediate portion excluding the end may be equivalent to the cross-sectional secondary moment at the end near the intermediate portion, the entire reinforcing member 4 does not have to be a beam of equal strength. .

  When the number of the reinforcing members 4 is three or more, the reinforcing member 4 located on the intermediate side receives the bending moment from the elastic-plastic dampers 5 and 5 between both ends in the axial direction. It becomes a state. Therefore, the distribution of the bending moment is different from that of the reinforcing member 4 on the main structural member 1 side, which is a cantilever beam, but it is bent like a beam of equal strength like the reinforcing member 4 located on the main structural member 1 side. By forming an elevational surface shape corresponding to the moment distribution, the possibility of occurrence of yield in any part in the axial direction is eliminated. The “elevation shape corresponding to the bending moment distribution” is a case where the formation (height) of the reinforcing member 4 is changed in the axial direction, and the cross-section is obtained by changing the width of the reinforcing member 4 or the width of the reinforcing member 4 in the axial direction. The secondary moment may be changed in the axial direction.

  Eventually, regardless of the number of main structural members 1, 1, the total reinforcing member 4 is an elevational shape corresponding to a bending moment distribution generated in the axial direction of each reinforcing member 4, or a cross-sectional shape that changes in the axial direction. As a result, a situation in which yielding occurs in any of the axial directions of all the reinforcing members 4 is avoided. “The cross-sectional shape changes in the axial direction” means that the width or the width of the reinforcing member 4 changes in the axial direction as described above, and the reinforcing member 4 corresponds to the bending moment distribution. Will do.

  According to the second aspect of the present invention, the sectional secondary moment (section modulus) at the end of the reinforcing member 4 located on the main structural member 1 side near the main structural member 1 is the sectional secondary moment (section modulus) at the end near the axially intermediate portion. ) Is larger, the bending stress degree of the end portion of the reinforcing member 4 near the main structural member 1 is lowered, and this end portion is less likely to yield depending on the bending moment received from the elastic-plastic damper 5. The bending stress degree at the end portion near the main structural member 1 of the reinforcing member 4 located on the main structural member 1 side is reduced, so that the bending stress degree at the end portion near the intermediate portion in the axial direction is the end near the main structural member 1. Therefore, the shearing force is easily concentrated between the joint portions 52 and 52 of the elastic-plastic damper 5 straddled between the reinforcing members 4 and 4. It is possible to reliably yield before the reinforcing member 4.

  The “second moment of cross section” referred to in claim 2 is an expression including the case where the cross-sectional shape of the reinforcing member 4 is not uniform in the forming direction, but when the reinforcing member 4 has a uniform cross-sectional shape in the forming direction. In other words, claim 2 can be rephrased as, for example, “the end portion of the reinforcing member 4 located on the main structural member 1 side near the main structural member 1 is larger than the end portion near the intermediate portion in the axial direction”. “Completion” is the height in the direction of shear deformation. “It is not a uniform cross-sectional shape in the forming direction” means that, for example, when the reinforcing member is an H-shaped steel, ribs protrude from the web.

  The reinforcing member 4 is provided side by side in the width direction of the existing structural member 3, so that the main structural member regardless of whether the existing structural member 3 and the reinforcing member 4 are joined to the main structural member 1 in an independent state. The existing structural member 3 and the reinforcing member 4 can be paired to resist the horizontal force even when a horizontal force is applied in the direction outside the surface of the frame 2 including 1 (the width direction of the existing structural member 3). In this case, the flanges of the existing structural member 3 and the reinforcing member 4 bear the shearing force due to the horizontal force in the direction outside the surface, and the web of the existing structural member 3 and the reinforcing member 4 bears the bending moment.

  In the section where the elastic-plastic damper 5 is straddled between the adjacent reinforcing members 4 and 4 as described above, a plurality of reinforcing members 4 are continuously installed between the adjacent main structural members 1 and 1. The cross-sectional secondary moment of the reinforcing member 4 is adjusted so that the bending stress is increased within the entire length when 4 is continuous. On the other hand, the partial section 31 in which the removal portion 32 in the existing structural member 3 is formed is a section in which the yield is caused to precede other sections within the entire length of the existing structural member 3. The position of the elasto-plastic damper 5 connecting the reinforcing member 4 and a partial section of the existing structural member 3 when viewed from the vertical surface of the frame 2 or when the existing structural member 3 and the reinforcing member 4 are overlapped in the width direction. If the position of 31 is different in the axial direction, sections of the existing structural member 3 other than the partial section 31 that does not yield yield resistance when the elastic-plastic damper 5 tries to yield, There is a possibility of hindering the yield of the plastic damper 5.

  In view of this, the existing structural member 3 provided alongside the reinforcing member 4 does not hinder the yield of the elastic-plastic damper 5 connecting the adjacent reinforcing members 4, 4. The partial section 31 of the existing structural member 3 corresponds to the installation position of the elastic-plastic damper 5 straddling between the reinforcing members 4 and 4 adjacent in the axial direction on the elevation surface of the main structural members 1 and 1 It is reasonable (Claim 3). “Corresponding” means that the number of elastic plastic dampers 5 installed in the section between adjacent main structural members 1 and 1 is the same as the number of partial sections 31 of the existing structural member 3, It means that the arrangement position of the elastoplastic damper 5 in the axial direction and the formation position of the partial section 31 of the existing structural member 3 are coincident with each other on the elevation surface. However, the length of the elastic-plastic damper 5 in the axial direction of the reinforcing member 4 and the length of the partial section 31 of the existing structural member 3 do not need to match.

  The partial section 31 of the existing structural member 3 corresponds to the installation position of the elastic-plastic damper 5 straddling between the reinforcing members 4 and 4 adjacent in the axial direction, so that the elastic-plastic damper 5 is intended to yield. Since the possibility that the existing structural member 3 exerts a resistance force when the bending moment acting on the ends of the reinforcing members 4 and 4 is reduced, the yield of the elastic-plastic damper 5 is not hindered, and the elastic-plastic It is possible to induce the yielding of the damper 5 and to make the elastic-plastic damper 5 efficiently exhibit the energy absorption capability.

  Along the existing structural member in the direction perpendicular to the surface of the shear force acting on the existing structural member, several reinforcing members are placed at a distance from each other and joined to each main structural member, and the reinforcement is placed at a distance. Since the elastic-plastic damper that can yield shear between the members is installed, it is not necessary to divide the existing structural member as in the case where the elastic-plastic damper is incorporated into a part of the existing structural member. Therefore, since the existing structural member can be used as one structural member that is continuous in the axial direction, a part of the existing structural member having a reduced yield strength is formed in a part of the axial direction of the existing structural member. It is possible to cause the existing structural member to exhibit plastic deformation ability by yielding the section.

  As a result, by adjusting the section modulus according to the magnitude of the bending stress in any section of the existing structural member, it is possible to freely set the location where yield occurs, and the bending moment during short-term loading It is possible to avoid stress and deformation from concentrating on the end portion of the existing structural member that is maximized near the main structural member.

It is the elevation which showed a mode that the reinforcement member was provided side by side in the width direction one side of the existing structural member, and the elastic-plastic damper was straddled between adjacent reinforcement members. It is the xx sectional view taken on the line of FIG. FIG. 3 is a sectional view taken along line yy of FIG. 2. It is the elevation which showed the removal part in the existing structural member shown in FIG. (A) is an elevation view showing the installation state of a reinforcing member and an elasto-plastic damper when the existing structural member is a beam erected between adjacent columns, and (b) is an erection between the adjacent beams of the existing structural member (C) is an elevation view showing the installed state of the reinforcing member and the elasto-plastic damper in the case of the formed stud, and (c) is a brace installed between adjacent beams and a bracket installed between the beams. It is the elevation which showed the installation state of the reinforcement member and elastic-plastic damper in a certain case. (A) is a beam in which an existing structural member is installed between adjacent columns, and an elevation view showing an installation state of the reinforcing member and the elastic-plastic damper when the reinforcing member is divided into three in the axial direction; (B) is an intermediate column in which an existing structural member is installed between adjacent beams, and an elevation view showing the installation state of the reinforcing member and the elastic-plastic damper when the reinforcing member is divided into three in the axial direction. c) is an elevational view showing an installed state of the reinforcing member and the elastic-plastic damper when the existing structural member is spanned between adjacent beams and the reinforcing member is divided into four in the axial direction.

  1 to 3 show an existing structural member 3 that can be shear-deformed in the in-plane direction of a structural surface (frame 2) including the main structural members 1 and 1 that is installed between the main structural members 1 and 1 such as parallel columns. A plurality of reinforcing members 4, 4 for installing the elastoplastic damper 5 in the width direction are arranged at a distance from each other in the axial direction, and elastoplasticity is provided between the reinforcing members 4, 4 at a distance in the axial direction. A state where the damper 5 is straddled is shown. The “width direction of the existing structural member 3” is the out-of-plane direction of the structural surface including the main structural members 1, 1, and the existing structural member 3 when the main structural members 1, 1 undergo relative deformation in the in-plane direction. The direction perpendicular to the acting direction of the shearing force acting on. 1 to 3 show an example in which the main structural member 1 is a column and the existing structural member 3 is a beam.

  In the drawing, a square steel pipe is used for the main structural member 1 and an H-shaped steel is used for the existing structural member 3 and the reinforcing member 4, but the structural types of the main structural member 1, the existing structural member 3 and the reinforcing member 4 are as follows. Regardless, the cross-sectional shape is not questioned. Among the plurality of reinforcing members 4, the reinforcing members 4 and 4 positioned on both sides in the axial direction are joined to the main structural members 1 and 1 positioned on the respective sides. In the figure, 7 indicates a slab supported by the existing structural member 3.

  The existing structural member 3 is originally rigidly joined to the main structural members 1 and 1 at both ends in the axial direction, so that the intermediate structural members 1 and 1 except for both ends are relatively deformed in the composition plane. Attempts to shear deformation at the part. The direction of shear deformation of the existing structural member 3 is the direction in which the existing structural member 3 is formed, that is, the direction in which the shearing force and the bending moment are applied.

  The reinforcing member 4 is arranged in parallel to the existing structural member 3 on at least one side in the width direction, which is a direction orthogonal to the direction of shear deformation of the existing structural member 3. At least two reinforcing members 4 form a set and are laid between adjacent main structural members 1 and 1 and are rigidly joined to the main structural member 1 at the end on the main structural member 1 side. A distance for installation of the elastic-plastic damper 5 is secured between the reinforcing members 4 and 4 adjacent in the axial direction, and the elastic-plastic damper 5 is straddled between the reinforcing members 4 and 4 facing each other at this distance. Each reinforcing member 4 is rigidly joined by bolts 6 or welding.

  The elasto-plastic damper 5 bears a shearing force or a shearing force and a bending moment when a relative deformation occurs between the main structural members 1 and 1 in the in-plane direction of the frame 2. In the case of having at least the plastic deformation portion 51 that is plastically deformed by the bolt and being joined to the reinforcing member 4 by the bolt 6, the plastic deformation portion 51 is joined to the reinforcing member 4 on both sides in the direction perpendicular to the shearing force acting direction. Joints 52, 52 are formed.

  When the elastic-plastic damper 5 is welded directly or indirectly to the reinforcing member 4, it is welded to the reinforcing member 4 on both sides of the plastic deformation portion 51 in the direction orthogonal to the shearing force acting direction. In addition, since a welding allowance is secured on both sides of the plastic deformation portion 51, the welding allowance corresponds to the joint portion 52. When the joint portion 52 is joined to the reinforcing member 4 by the bolt 6, a plurality of insertion holes for the bolt 6 are formed in the joint portion 52.

  1 and 5, when the plastic deformation portion 51 of the elastic-plastic damper 5 has an elevational shape corresponding to the bending moment distribution generated when concentrated loads are alternately applied to both sides of the both ends fixed beam in the shearing force acting direction. However, the shape of the plastic deformation portion 51 is arbitrary, and may be a polygonal shape, a square shape, or a shape that partially includes a curve.

  FIG. 4 shows a relative deformation of the main structural members 1 and 1 in a partial section 31 which is an intermediate portion excluding an axial end of the existing structural member 3 existing on the back side of the reinforcing members 4 and 4 shown in FIG. In order to sometimes yield, a procedure for forming the plastic deformation portion 33 in the partial section 31 of the existing structural member 3 is shown. In the partial section 31, a part of the forming direction is left, and the remaining part becomes the plastic deformation part 33 by removing the other part. In FIG. 4, the hatched area indicates the removed portion 32. FIG. 4 shows an example in which the reinforcing member 4 is an H-shaped steel. In this case, the lower flange and a part of the web continuous to the lower flange are removed.

  Of the entire length of the existing structural member 3, the axial position of the partial section 31 where the plastic deformation portion 33 is formed is a plurality of sections other than the partial section 31 of the existing structural member 3 as shown in FIGS. It is made to correspond to the installation position of the elasto-plastic damper 5 between the reinforcing members 4 and 4 so as not to hinder the yield that is likely to occur in the elasto-plastic damper 5 straddled between the reinforcing members 4 and 4 of the book. That is, when the existing structural member 3 and the reinforcing member 4 are viewed in the width direction, a partial section 31 (plastic deformation portion 33) of the existing structural member 3 is interposed between the reinforcing members 4 and 4 provided alongside the existing structural member 3. The length of the partial section 31, the length of the reinforcing member 4 and the like are set so as to be disposed at a position corresponding to the position of the elastic plastic damper 5 that is laid. 1 to 4, the axial length of the partial section 31 of the existing structural member 3 and the length of the elastic-plastic damper 5 are the same, but this is not always necessary.

  Sections other than the partial section 31 have rigidity in the forming direction (in-plane direction) of the remaining part (plastic deformation portion 33) by removing a part of the forming direction in the partial section 31 of the existing structural member 3 Therefore, when the remaining portion of the partial section 31 is subjected to a shearing force and a bending moment in the forming direction, it is in a state of being easily sheared and becomes a plastically deformable portion 33 that can be plastically deformed by shear deformation. As shown in FIG. 4, the partial section 31 is a section connecting both ends of the removal portion 32 in the axial direction of the existing structural member 3. When the removal portion 32 is formed, the corner portion of the removal portion 32 is removed in a curved line so that stress concentration does not occur in the remaining portion around the removal portion 32.

  A plurality of reinforcing members 4, 4 installed at a distance from each other between the adjacent main structural members 1, 1 are rigidly joined to the main structural member 1 at the end on the main structural member 1 side. Adjacent reinforcing members 4, 4 are also stretched between them and joined together via an elastic-plastic damper 5 that is rigidly joined, so that the plurality of reinforcing members 4, 4 are one continuous member. As a result, the main structural members 1 and 1 are installed.

  When there are two reinforcing members 4 installed between the main structural members 1 and 1 as shown in FIGS. 1 and 5, each reinforcing member 4 is a cantilever projecting from the main structural member 1, and FIG. As shown, also in the case of three or more, the reinforcing member 4 located on the main structural member 1 side is a cantilever beam. When the number of installations between the main structural members 1 and 1 is 3 or more, the reinforcing member 4 (other than the main structural member 1 side) located on the axially intermediate portion side is rigid on both axial sides (both ends). Since it receives a bending moment in a direction orthogonal to the material axis from the elastic-plastic dampers 5 and 5 to be joined, it behaves as a both-end fixed beam.

  In this relationship, at the time of relative deformation between the main structural members 1 and 1 due to the action of a horizontal force on the frame 2 (short-term load), the end of the reinforcing member 4 located on the main structural member 1 side on the main structural member 1 side The bending moment is maximized. If the end on the main structural member 1 side of the reinforcing member 4 at this time yields due to a bending moment, the yielding of the elastic-plastic damper 5 cannot be preceded, so the reinforcing member before the yielding of the elastic-plastic damper 5 It is necessary to prevent yielding in any part of 4.

  Therefore, among the plurality of reinforcing members 4, 4 arranged at a distance from each other in the axial direction, the cross-sectional secondary moment of the end portion of the reinforcing member 4 located on the main structural member 1 side near the main structural member 1 is The elevation shape and the cross-sectional shape of the reinforcing member 4 are set so as to be larger than the cross-sectional secondary moment of the end portion of the same reinforcing member 4 near the intermediate portion in the axial direction. This also means that the reinforcing member 4 is formed in an elevational shape corresponding to the bending moment distribution generated in the axial direction.

  When there are three or more reinforcing members 4 installed between the main structural members 1 and 1, the reinforcing members 4 other than the main structural member 1 behave as fixed beams at both ends as described above. Corresponding to the bending moment distribution generated in the axial direction in the same manner as the reinforcing member 4 located on the main structural member 1 side, the vertical surface shape in which the cross-sectional secondary moment at both ends in the axial direction is larger than the cross-sectional secondary moment at the central portion, etc. Formed. Thus, regardless of the number of reinforcing members 4 installed between the adjacent main structural members 1, 1, all the reinforcing members 4 are formed in an elevational shape corresponding to the bending moment distribution generated in the axial direction. The possibility of yielding in any part in the axial direction is eliminated.

  1 and FIGS. 5 (a) to 5 (c), two reinforcing members 4, 4 are laid between the main structural members 1, 1, and an elastic-plastic damper 5 is straddled between the reinforcing members 4, 4. An example is shown. In these cases, each reinforcing member 4 behaves as a cantilever beam against the shearing force and bending moment received from the elastic-plastic damper 5 by being rigidly joined to the main structural member 1 at the end on the main structural member 1 side. Therefore, the vertical shape or cross section of the reinforcing member 4 is such that the secondary moment of section of the end of each reinforcing member 4 on the main structural member 1 side is greater than the sectional moment of inertia of the end of the elastic plastic damper 5 side. The shape is adjusted. In FIG. 1, the total length of the reinforcing member 4 is divided into three sections in the axial direction, the section (height) of the section on the elasto-plastic damper 5 side is made constant, and each of the sections closer to the main structural member 1 and the intermediate section is formed. Is gradually expanded from the elastoplastic damper 5 side to the main structural member 1 side, and the reinforcing member 4 is formed in an elevational shape so that the section near the main structural member 1 is equal to or greater than the section near the elastoplastic damper 5. doing.

  5A is the same as FIG. 1, when the main structural members 1 and 1 are columns and the existing structural member 3 is a beam, the reinforcement member 4 is formed from the elastic-plastic damper 5 side to the main structural member 1 side. This is a case where the reinforcing member 4 is formed in an upright shape that gradually expands. (B) shows that when the main structural members 1 and 1 are beams and the existing structural members 3 are studs erected between the beams, the formation of the reinforcing members 4 gradually expands from the elastic-plastic damper 5 side to the main structural member 1 side. When the reinforcing member 4 is formed in an upright shape, (c) shows that one main structural member 1 is a brace, the other main structural member 1 is a beam, and an existing structural member 3 is straddled between the brace and the beam. This is a case where the reinforcing member 4 is formed in an elevational shape in which the reinforcement member 4 gradually expands from the elastic-plastic damper 5 side to the main structural member 1 side.

  In FIG. 5- (a), as in the example shown in FIGS. 1 to 4, a partial section 31 (removal portion 32, the intermediate portion in the axial direction of the existing structural member 3 is located at a position corresponding to the installation position of the elastic-plastic damper 5. Alternatively, a plastic deformation portion 33) is arranged. In FIGS. 5B and 5C, the existing structural member 3 is different from the existing structural member 3 in FIG. 5A, but also in these, the installation position of the elastic-plastic damper 5 in the intermediate portion in the axial direction of the existing structural member 3 A partial section 31 is arranged at a position corresponding to. However, unlike the case of (a), the existing structural member 3 does not need to support the slab 7, and therefore, in some sections 31, removal portions 32 and 32 are formed on both sides of the existing structural member 3 in the forming direction. A plastic deformation portion 33 is formed in the middle portion in the direction. When the existing structural member 3 has an H-shaped cross section in FIGS. 5B and 5C, the removed portions 32 are formed from both sides in the forming direction including the flange and a part of the web. The portion 33 is formed on the web.

  6A to 6C show examples of the shape of the reinforcing member 4 and the plasticity to the existing structural member 3 when there are three or more reinforcing members 4 installed between the adjacent main structural members 1 and 1. An example of forming the deformable portion 33 is shown. (A) is a case where three reinforcing members 4 are installed between the main structural members 1 and 1 when the main structural members 1 and 1 are pillars and the existing structural member 3 is a beam. (B) and (c), when the main structural members 1 and 1 are beams and the existing structural member 3 is a stud, three or four reinforcing members 4 are installed between the main structural members 1 and 1. Is the case. In FIG. 6, the elasto-plastic damper 5 is shown in a simplified rectangular shape. 6 (b) and 6 (c), the existing structural member 3 is a stud, and is common to FIG. 5 (b). Therefore, the existing structural member 3 is formed with removal portions 32 from both sides in the forming direction. The web left in the partial section 31 becomes the plastic deformation portion 33.

  When three or more reinforcing members 4 are installed between the main structural members 1 and 1, the reinforcing members 4 located on both sides in the axial direction of the reinforcing member 4 are rigidly joined to the main structural member 1 to be cantilevered. Become. For this reason, like the reinforcing member 4 in the example shown in FIG. 5, the sectional secondary moment at the end of the reinforcing member 4 on the main structural member 1 side is larger than the sectional secondary moment at the end on the elastic-plastic damper 5 side. Thus, the elevation shape of the reinforcing member 4 or the three-dimensional shape including the cross-sectional shape is adjusted.

  The reinforcing member 4 positioned in the axial intermediate portion is rigidly joined to the elastic-plastic dampers 5 and 5 at both axial end portions so as to behave as both-end fixed beams. Corresponding to the bending moment distribution generated in the axial direction, for example, as shown in the figure, the cross-sectional secondary moment (composition) at both ends in the axial direction is adjusted to be larger than the cross-sectional secondary moment (composition) at the central portion. . 6 (a) to 6 (c), both ends of the reinforcing member 4 positioned at the intermediate portion in the axial direction are equal to the ends of the reinforcing member 4 positioned on both sides in the axial direction. It may be larger or smaller than both ends of the reinforcing members 4 on both sides.

1 ... Main structural member, 2 ... Frame,
3 ... Existing structural member, 31 ... Partial section, 32 ... Removal part, 33 ... Plastic deformation part,
4 …… Reinforcing member,
5 ... Elastic-plastic damper, 51 ... Plastic deformation part, 52 ... Joint part, 6 ... Bolt,
7 …… Slab.

Claims (3)

An elastic-plastic damper mounting structure that is laid between parallel main structural members and adds an elastic-plastic damper to an existing structural member that can be shear-deformed in the in-plane direction of the structural surface including the main structural member,
A plurality of reinforcing members are arranged along the existing structural member at a distance from each other in the axial direction in a direction perpendicular to the acting surface of the shearing force that shears and deforms the existing structural member, and are located on both sides in the axial direction. The reinforcing member is joined to each main structural member,
An elastic-plastic damper having a plastically deformable portion that can bear a shearing force in the in-plane direction between the reinforcing members spaced apart in the axial direction and can yield a shear yield,
A structure for attaching an elastic-plastic damper to an existing structural member, wherein a part of the existing structural member excluding an end portion in the axial direction is removed leaving a part in a forming direction.   Of the plurality of reinforcing members arranged at a distance from each other in the axial direction, the secondary moment at the end of the reinforcing member located on the main structural member side near the main structural member is close to the intermediate portion in the axial direction. The structure for mounting an elastic-plastic damper to an existing structural member according to claim 1, wherein the structure is larger than the moment of inertia of the cross section at the end of the structure. On the elevational surface of the main structural members arranged in parallel, the partial section of the existing structural member corresponds to an installation position of the elastic-plastic damper straddled between the reinforcing members adjacent in the axial direction. A structure for attaching an elastic-plastic damper to the existing structural member according to claim 1 or 2.

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