JP2020094478A - Earthquake proof repair method of existing structure - Google Patents
Earthquake proof repair method of existing structure Download PDFInfo
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Abstract
Description
本発明は、冷間成形角形鋼管からなる柱本体を有する柱部材を備えた既存構造物の耐震改修方法に関する。 The present invention relates to a seismic retrofitting method for an existing structure including a column member having a column body made of cold-formed rectangular steel pipe.
従来の冷間成形角形鋼管を用いた柱部材では、鋼管角部が強い冷間加工を受けることにより、この鋼管角部とベースプレートやダイヤフラムとの溶接部が脆性破断して塑性変形性能が低下することが懸念される。脆性破断は、引張応力の高さ、靱性の低さ、部材の形状や切欠き等による応力集中の三条件が揃う場合に発生する。 In the column member using the conventional cold-formed rectangular steel pipe, when the steel pipe corner is subjected to strong cold working, the welded portion of this steel pipe corner and the base plate or diaphragm is brittlely fractured and the plastic deformation performance deteriorates. Is concerned. Brittle fracture occurs when the three conditions of high tensile stress, low toughness, stress concentration due to the shape and notch of the member, and the like are met.
そこで、例えば非特許文献１に示される方法に従って、柱部材に作用する応力を割り増して構造物の設計を行うなどの対応をとる必要がある。 Therefore, for example, according to the method described in Non-Patent Document 1, it is necessary to take measures such as designing a structure by increasing the stress acting on the column member.
しかし、過去に建設された既存構造物には、非特許文献１に示されるような対応がとられていない構造物も存在する。このような既存構造物の耐震改修を行う場合、ブレース等の補強部材を取り付けることによる既存構造物の耐力向上や、既存構造物の一部を取り除く減築を行うことによる外力入力低減といった通常の耐震改修方法では、必ずしも十分な耐震改修効果が得られない場合がある。具体的には、上記のような通常の耐震改修方法に加えて、冷間成形角形鋼管を用いた柱部材の脆性破断が発生しないよう、冷間成形角形鋼管を用いた柱部材の応力状態の詳細な検討、およびこの冷間成形角形鋼管を用いた柱部材の補強が必要となる場合がある。 However, existing structures constructed in the past include structures that are not dealt with as shown in Non-Patent Document 1. When carrying out seismic retrofitting of such existing structures, the usual methods such as improving the proof stress of existing structures by attaching reinforcing members such as braces and reducing external force input by removing some existing structures The seismic retrofitting method may not always provide sufficient seismic retrofitting effects. Specifically, in addition to the usual seismic retrofitting method as described above, in order to prevent brittle fracture of the column member using the cold-formed square steel pipe, the stress state of the column member using the cold-formed square steel pipe should be prevented. Detailed examination and reinforcement of the column member using this cold forming square steel pipe may be needed.
非特許文献２には、冷間成形角形鋼管を用いた柱部材の補強方法の具体例が複数示されている。これら補強方法の概要を、図３４（ａ）〜（ｄ）に示す。 Non-Patent Document 2 shows a plurality of specific examples of a method of reinforcing a column member using a cold-formed rectangular steel pipe. An outline of these reinforcing methods is shown in FIGS. 34(a) to 34(d).
図３４（ａ）、（ｂ）の補強方法は、既存構造物の冷間成形角形鋼管を用いた柱部材９の柱脚部および柱頭部に、平鋼板や山形鋼からなる補強材９１、９２を側面隅肉溶接により取り付けるものである。これらの補強方法では、柱端部断面において補強材に作用する垂直応力を適切に伝達させるために、補強材９１、９２をダイヤフラム（やベースプレート）に完全溶込み溶接しなければならない。通常、既存構造物の柱部材の柱脚部には床スラブが設置されているので、図３４（ａ）、（ｂ）の補強方法を適用するには、柱部材９周辺の床スラブを除去する必要がある。 34(a) and 34(b), the reinforcement members 91, 92 made of flat steel plates or angle steel are used for the column base and column head of the column member 9 using the cold-formed rectangular steel pipe of the existing structure. Is attached by side fillet welding. In these reinforcing methods, the reinforcing members 91 and 92 must be completely penetration-welded to the diaphragm (or the base plate) in order to properly transmit the vertical stress acting on the reinforcing member in the cross section of the column end portion. Since the floor slab is usually installed on the column base of the column member of the existing structure, the floor slab around the column member 9 is removed in order to apply the reinforcement method of FIGS. 34(a) and (b). There is a need to.
図３４（ｃ）の補強方法は、既存構造物の冷間成形角形鋼管を用いた柱部材９の柱脚部および柱頭部に、平鋼板からなる補強板９３を側面隅肉溶接により取り付けたうえで、これら柱脚部の床スラブ上面および柱頭部の梁下面に、平鋼板からなる定着板９４を配置して、この定着板に設けられた補強リブ９４ａにより上記補強板９３を押さえつけるようにし、この状態で柱脚部側および柱頭部側の両定着板９４、９４を、床スラブごとＰＣ鋼棒９５で締結するものである。 The reinforcing method of FIG. 34(c) is such that the reinforcing plate 93 made of a flat steel plate is attached to the column base and column head of the column member 9 using the cold-formed rectangular steel pipe of the existing structure by side face fillet welding. Then, the fixing plate 94 made of a flat steel plate is arranged on the floor slab upper surface of the column base and the beam lower surface of the column head, and the reinforcing plate 93 is pressed by the reinforcing ribs 94a provided on the fixing plate. In this state, the fixing plates 94, 94 on the column base side and the column head side are fastened together with the floor slab by the PC steel rod 95.
図３４（ｄ）の補強方法は、既存構造物の冷間成形角形鋼管を用いた柱部材９の柱脚部に、シヤーコッター９６を溶接により取り付けたうえで、この柱脚部を鋼板型枠９７で取り囲み、柱部材９の柱脚部と鋼板型枠９７の間に無収縮モルタル９８を充填して、柱部材の柱脚部を根巻き補強するものである。 34(d), the shear cotter 96 is attached to the column base portion of the column member 9 using the cold-formed rectangular steel pipe of the existing structure by welding, and the column base portion is attached to the steel plate form 97. The non-shrink mortar 98 is filled between the column base of the column member 9 and the steel plate form 97 to reinforce the column base of the column member.
これら図３４（ｃ）、（ｄ）の補強方法では、必ずしも柱周辺の床スラブを除去する必要は無いが、補強構造を構成する補強部材の点数が多く、複雑である。 In the reinforcing methods shown in FIGS. 34(c) and 34(d), it is not always necessary to remove the floor slab around the columns, but the number of reinforcing members constituting the reinforcing structure is large and complicated.
このように、非特許文献２に示される方法では、冷間成形角形鋼管を用いた柱部材を補強するために、床スラブを一旦除去したり、複雑な構造の補強部材を取り付けたりする必要があり、大がかりな工事が必要となる問題がある。 As described above, in the method disclosed in Non-Patent Document 2, in order to reinforce the column member using the cold-formed rectangular steel pipe, it is necessary to remove the floor slab once or attach a reinforcing member having a complicated structure. Yes, there is a problem that large-scale construction is required.
本発明は、冷間成形角形鋼管を用いた柱部材を備えた既存構造物において、冷間成形角形鋼管を用いた柱部材の鋼管角部とベースプレートやダイヤフラムとの溶接部の脆性破断を防止すべく、柱部材に作用する応力を割り増す対応が設計時に取られていない場合にも、簡単な方法により、上記溶接部が脆性破断することを抑制し、柱部材の柱脚部や柱梁接合部における塑性変形性能を高めて、既存構造物の十分な耐震改修効果を得ることのできる、既存構造物の耐震改修方法を提供することを目的とする。 The present invention, in an existing structure provided with a column member using a cold-formed rectangular steel pipe, prevents brittle fracture of a welded portion of a steel pipe corner portion of a column member using a cold-formed rectangular steel pipe and a base plate or a diaphragm. Therefore, even if the measure to increase the stress acting on the column member is not taken at the time of design, it is possible to suppress brittle fracture of the welded portion by a simple method, and to join the column base portion and the beam-column joint of the column member. An object of the present invention is to provide a seismic retrofitting method for an existing structure, which can improve the plastic deformation performance of a part to obtain a sufficient seismic retrofitting effect for the existing structure.
上記課題を解決するため、本発明は以下の特徴を有する。 In order to solve the above problems, the present invention has the following features.
［１］ 冷間成形角形鋼管からなる柱本体と、前記柱本体の柱脚部に溶接接合されたベースプレートとを有する柱部材を備えた既存構造物の耐震改修方法であって、前記冷間成形角形鋼管の四つの角部の各々に、前記ベースプレートとの溶接部止端部に近接するようにして、少なくとも一つの孔を設けることを特徴とする既存構造物の耐震改修方法。 [1] A seismic retrofitting method for an existing structure including a column member having a column body made of cold-formed rectangular steel pipe and a base plate welded to the column base of the column body, the cold-forming method comprising: A method for seismic retrofitting an existing structure, characterized in that at least one hole is provided in each of the four corners of the rectangular steel pipe so as to be close to the toe of the welded portion with the base plate.
［２］ 前記柱部材は、前記柱本体の梁取付部に溶接接合されたダイヤフラムをさらに有し、前記冷間成形角形鋼管の四つの角部の各々に、前記ダイヤフラムとの溶接部止端部に近接するようにして、少なくとも一つの孔を設けることを特徴とする［１］に記載の既存構造物の耐震改修方法。 [2] The pillar member further has a diaphragm welded to a beam attachment portion of the pillar body, and a welded toe portion with the diaphragm is provided at each of four corner portions of the cold-formed rectangular steel pipe. The seismic retrofitting method for an existing structure according to [1], characterized in that at least one hole is provided so as to be close to the location.
［３］ 冷間成形角形鋼管からなる柱本体と、前記柱本体の梁取付部に溶接接合されたダイヤフラムとを有する柱部材を備えた既存構造物の耐震改修方法であって、前記冷間成形角形鋼管の四つの角部の各々に、前記ダイヤフラムとの溶接部止端部に近接するようにして、少なくとも一つの孔を設けることを特徴とする既存構造物の耐震改修方法。 [3] A seismic retrofitting method for an existing structure, comprising a column member having a column body made of cold-formed rectangular steel pipe and a diaphragm welded to a beam attachment portion of the column body, the method being the cold-forming. A method for seismic retrofitting an existing structure, characterized in that at least one hole is provided in each of the four corners of a rectangular steel pipe so as to be close to the toe of the welded portion with the diaphragm.
ここで、［１］〜［３］における「角部」は、曲率を有する部分だけでなく、この曲率を有する部分の両側近傍の部分も含むものとする。 Here, “corners” in [1] to [3] include not only a portion having a curvature but also portions on both sides of the portion having this curvature.
［４］ 前記孔は、前記柱部材に外力が作用した際に、前記溶接部に発生する応力を低減する形状を有することを特徴とする［１］〜［３］のいずれかに記載の既存構造物の耐震改修方法。 [4] The existing hole according to any one of [1] to [3], wherein the hole has a shape that reduces a stress generated in the welded portion when an external force acts on the pillar member. Seismic retrofitting method for structures.
［５］ 前記孔は、前記柱部材に外力が作用した際に、これら孔の断面欠損に起因する前記柱本体の局部座屈の発生を抑制する形状を有することを特徴とする［１］〜［４］のいずれかに記載の既存構造物の耐震改修方法。 [5] The hole has a shape that suppresses the occurrence of local buckling of the column body due to a cross-sectional defect of the column when an external force acts on the column member [1] to The method for earthquake-proofing an existing structure according to any one of [4].
ここで、［４］および［５］における「形状」は、孔の輪郭の形だけでなく、孔の大きさ、孔の個数、孔の位置も含む概念である。 Here, the “shape” in [4] and [5] is a concept that includes not only the shape of the contour of the hole but also the size of the hole, the number of holes, and the position of the hole.
［６］ 前記孔に近接する前記溶接部止端部と前記孔の縁の離間距離が、前記孔の直径の１倍以上５倍以下であることを特徴とする［１］〜［５］のいずれかに記載の既存構造物の耐震改修方法。 [6] The separation distance between the weld toe and the edge of the hole, which are close to the hole, is not less than 1 time and not more than 5 times the diameter of the hole. [1] to [5] Seismic retrofitting method for existing structures described in either.
［７］ 前記孔は複数であり、前記冷間成形角形鋼管の四つの角部の各々の稜線の両側に対称に配置されることを特徴とする［１］〜［６］のいずれかに記載の既存構造物の耐震改修方法。 [7] The hole is plural, and is arranged symmetrically on both sides of each ridgeline of each of the four corners of the cold-formed rectangular steel pipe. [1] to [6] Seismic retrofitting method for existing structures.
［８］ 前記孔の各々の縁は滑らかに加工されていることを特徴とする［１］〜［７］のいずれかに記載の既存構造物の耐震改修方法。 [8] The seismic retrofitting method for an existing structure according to any one of [1] to [7], wherein each edge of the holes is smoothly processed.
［９］ 前記既存構造物の耐力を増加させる補強部材を取り付けることを特徴とする［１］〜［８］のいずれかに記載の既存構造物の耐震改修方法。 [9] The method for seismic retrofitting an existing structure according to any one of [1] to [8], wherein a reinforcing member that increases the proof stress of the existing structure is attached.
ここで、［９］における「補強部材」は、ブレースやダンパーなど、既存構造物の耐力を増加させることが可能なあらゆる補強部材を含む。 Here, the "reinforcing member" in [9] includes all reinforcing members such as braces and dampers that can increase the proof stress of the existing structure.
［１０］ 前記既存構造物の一部を取り除く減築を行い、減築後の前記既存構造物に入力する外力を低減させることを特徴とする［１］〜［９］のいずれかに記載の既存構造物の耐震改修方法。 [10] A reduction is performed by removing a part of the existing structure, and an external force input to the existing structure after the reduction is reduced, according to any one of [1] to [9]. Seismic retrofitting method for existing structures.
［１１］ 前記既存構造物と構造的に一体となる増築部を設ける増築を行い、前記既存構造物と前記増築部が一体となった構造物全体の耐力が、前記既存構造物の耐力よりも大きくなるようにすることを特徴とする［１］〜［１０］のいずれかに記載の既存構造物の耐震改修方法。 [11] An extension is provided by providing an extension that is structurally integrated with the existing structure, and the yield strength of the entire structure in which the existing structure and the extension are integrated is greater than the yield strength of the existing structure. The method for seismic retrofitting an existing structure according to any one of [1] to [10], characterized in that the method is enlarged.
本発明によれば、冷間成形角形鋼管を用いた柱部材を備えた既存構造物において、冷間成形角形鋼管の四つの角部の各々に、ベースプレートまたはダイヤフラムとの溶接部止端部に近接するようにして、孔を設けることにより、地震時などに耐震改修後の前記柱本体に外力が作用する場合に前記溶接部に生じる引張応力を拡散、低減して、溶接部が脆性破断することを抑制できる。 According to the present invention, in the existing structure including the column member using the cold-formed rectangular steel pipe, each of the four corners of the cold-formed rectangular steel pipe is close to the base plate or the weld toe of the diaphragm. By providing holes, the tensile stress generated in the welded portion when an external force acts on the column body after seismic retrofitting during an earthquake etc. is diffused and reduced, and the welded portion breaks brittlely. Can be suppressed.
よって、既存構造物の設計時に、冷間成形角形鋼管を用いた柱部材の鋼管角部とベースプレートやダイヤフラムとの溶接部が脆性破断して塑性変形性能が低下することを防止すべく、柱部材に作用する応力を割り増す対応が取られていなくても、既存構造物の十分な耐震改修効果が得られる。 Therefore, at the time of designing an existing structure, in order to prevent the welded portion of the steel pipe corner portion of the column member using the cold-formed rectangular steel pipe and the base plate or the diaphragm from brittle fracture and to reduce the plastic deformation performance, the column member is prevented. Even if no measures are taken to increase the stress acting on the existing structure, sufficient seismic retrofitting effects on existing structures can be obtained.
また、柱本体の角部に孔を設ける簡単な方法により、床スラブを一旦除去したり、複雑な構造の補強部材を取り付けたりする大がかりな工事を必要とせずに、溶接部が脆性破断することを抑制し、既存構造物の十分な耐震改修効果が得られる。したがって、経済性に優れた耐震改修方法となる。 In addition, a simple method of forming holes in the corners of the pillar body will not cause the welded part to break brittlely without the need for large-scale work such as once removing the floor slab or installing a reinforcing member with a complicated structure. Sufficient seismic retrofit effect of existing structures can be obtained. Therefore, the seismic retrofitting method has excellent economical efficiency.
さらに、上記孔の大きさが比較的小さくても、溶接部の脆性破断の抑制効果が十分得られるため、孔の断面欠損による柱部材の耐力低下はわずかである。また、孔の断面欠損による柱部材の耐力低下に対しては、既存構造物の耐力を増加させる補強部材を取り付けたり、既存構造物の一部を取り除く減築を行ったり、既存構造物と構造的に一体となる増築部を設ける増築を行ったりする方法を併用して、耐震改修後の構造物全体の保有耐力を必要耐力以上とし、耐震性能を確保できるため、既存構造物の耐震改修効果が確実に得られる。 Further, even if the size of the hole is relatively small, the effect of suppressing brittle fracture of the welded portion can be sufficiently obtained, so that the proof stress of the column member due to the cross-sectional defect of the hole is slightly reduced. In addition, in order to reduce the strength of the column member due to the loss of the cross section of the hole, a reinforcement member that increases the yield strength of the existing structure may be attached, or some of the existing structure may be removed to reduce the strength of the existing structure. In addition to the method of constructing an extension that is integrated as a unit, it is possible to secure the seismic performance by making the total strength of the structure after seismic retrofitting higher than the required strength by using the method of extension and so on. Is definitely obtained.
加えて、柱部材の柱脚部や柱梁接合部における塑性変形性能や低サイクル疲労特性が向上し、既存構造物の耐震改修効果がさらに高められる。 In addition, the plastic deformation performance and low cycle fatigue characteristics of the column base and column-beam joints of the column members are improved, and the seismic retrofit effect of the existing structure is further enhanced.
以下、図面を参照して、本発明の既存構造物の耐震改修方法の実施形態を詳細に説明する。 Hereinafter, an embodiment of a seismic retrofitting method of an existing structure of the present invention will be described in detail with reference to the drawings.
図１〜図６に、本発明の第１〜第６の実施形態の既存構造物の耐震改修方法をそれぞれ示す。 1 to 6 show seismic retrofitting methods for existing structures according to first to sixth embodiments of the present invention, respectively.
第１〜第６の実施形態の既存構造物の耐震改修方法が適用される既存構造物の柱部材１は、冷間成形角形鋼管からなる柱本体１０と、柱本体１０の柱脚部に溶接接合されたベースプレート１５とを有する。 The pillar member 1 of the existing structure to which the seismic retrofitting method of the existing structure of the first to sixth embodiments is applied is a pillar body 10 made of cold-formed rectangular steel pipe and a pillar leg portion of the pillar body 10. It has the joined base plate 15.
図１に示す第１の実施形態の既存構造物の耐震改修方法では、柱本体（角形鋼管）１０の四つの角部の各々に、ベースプレート１５との溶接部止端部（溶接部と柱本体１０との境界位置）に近接するようにして、孔１１を一つずつ設ける。四つの角部に設けられる孔１１は、溶接部止端部からの高さが同じとなるように配置する。 In the seismic retrofitting method of the existing structure of the first embodiment shown in FIG. 1, each of the four corners of the column body (square steel pipe) 10 has a welded toe (a welded part and a column body) with the base plate 15. The holes 11 are provided one by one so as to be close to the boundary position (10). The holes 11 provided at the four corners are arranged so that they have the same height from the weld toe.
ここで、上記「近接して」とは、構造物の自重による鉛直力や地震力等の水平力が柱部材１に入力するとき、柱本体１０とベースプレート１５との溶接部のうち、角形鋼管角部に隣接する部位に発生する応力を低減することができる位置を意味する。具体的には、孔１１の縁と溶接部止端部との離間距離が、例えば数ｍｍから孔の直径の５倍程度となるような位置に孔１１を設けることをいう。また、上記「角部」は、曲率を有する部分だけでなく、この曲率を有する部分の両側の近傍の部分も含む。 Here, the term “in close proximity” means that when a horizontal force such as a vertical force or seismic force due to the weight of the structure is input to the column member 1, a square steel pipe is included in the welded portion of the column body 10 and the base plate 15. It means a position where the stress generated in the portion adjacent to the corner can be reduced. Specifically, it means that the hole 11 is provided at a position where the distance between the edge of the hole 11 and the toe of the welded portion is, for example, several mm to about 5 times the diameter of the hole. Further, the "corner" includes not only a portion having a curvature, but also portions in the vicinity of both sides of the portion having the curvature.
孔１１は、この孔１１が設けられた柱部材１に地震力等による外力が作用した際に、上記溶接部に発生する引張応力が、この溶接部の各位置において低減されるような形状に形成する。 The hole 11 has a shape such that the tensile stress generated in the welded portion is reduced at each position of the welded portion when an external force such as an earthquake force acts on the pillar member 1 provided with the hole 11. Form.
本実施の形態では、孔１１の輪郭の形は、正円形とする。これに代えて、孔の輪郭の形を、楕円形、長円形などとすることも可能である。 In the present embodiment, the shape of the outline of the hole 11 is a perfect circle. Alternatively, the shape of the outline of the hole may be an elliptical shape, an oval shape, or the like.
孔１１の直径は、柱部材１に要求される耐力、塑性変形性能や柱本体（角形鋼管）１０の寸法とのバランスで決定される。孔の輪郭の形が正円形でない場合も、孔の大きさは、上記に相当する寸法とすることが好ましい。 The diameter of the hole 11 is determined in balance with the proof stress required for the column member 1, the plastic deformation performance, and the dimensions of the column body (square steel pipe) 10. Even when the contour of the hole is not a perfect circle, the size of the hole is preferably set to a dimension corresponding to the above.
第１の実施形態の既存構造物の耐震改修方法によれば、冷間成形角形鋼管を用いた柱部材１を備えた既存構造物において、柱本体（角形鋼管）１０の四つの角部の各々に、ベースプレート１５の溶接部止端部に近接するようにして孔１１を設けることにより、地震時などに耐震改修後の柱本体１０に作用する外力によって孔１１の下側の鋼管角部溶接部付近に生じる引張応力が拡散、低減され、この溶接部が脆性破断することを抑制できる。 According to the seismic retrofitting method of the existing structure of the first embodiment, each of the four corners of the column body (square steel pipe) 10 in the existing structure including the column member 1 using the cold-formed rectangular steel pipe. By providing the hole 11 close to the toe of the welded portion of the base plate 15, the welded portion of the steel pipe corner portion below the hole 11 is applied by the external force acting on the column body 10 after the seismic retrofitting in the event of an earthquake. The tensile stress generated in the vicinity is diffused and reduced, and brittle fracture of the welded portion can be suppressed.
よって、既存構造物の設計時に、冷間成形角形鋼管を用いた柱部材１の鋼管角部とベースプレート１５との溶接部が脆性破断して塑性変形性能が低下することを防止すべく、柱部材１に作用する応力を割り増す対応が取られていなくても、既存構造物の十分な耐震改修効果が得られる。 Therefore, at the time of designing an existing structure, in order to prevent the welded portion between the corner portion of the steel pipe of the column member 1 using the cold-formed rectangular steel pipe and the base plate 15 from brittle fracture and deterioration of plastic deformation performance, the column member is prevented. Even if no measures have been taken to increase the stress acting on No. 1, sufficient seismic retrofitting effects on existing structures can be obtained.
また、柱本体１０の角部に孔１１を設ける簡単な方法により、床スラブを一旦除去したり、複雑な構造の補強部材を取り付けたりする大がかりな工事を必要とせずに、溶接部が脆性破断することを抑制し、既存構造物の十分な耐震改修効果が得られる。したがって、経済性に優れた耐震改修方法となる。 In addition, by a simple method of forming the holes 11 at the corners of the pillar body 10, the welded portion is fragile and broken without requiring large-scale work such as once removing the floor slab or attaching a reinforcing member having a complicated structure. Therefore, it is possible to obtain sufficient seismic retrofitting effects on existing structures. Therefore, the seismic retrofitting method has excellent economical efficiency.
さらに、孔１１の大きさが比較的小さくても、溶接部の脆性破断の抑制効果が十分得られるため、孔１１の断面欠損による柱部材の耐力低下はわずかである。また、孔１１の断面欠損による柱部材の耐力低下に対しては、後述の第１〜第５の変形例で説明するように、既存構造物の耐力を増加させる補強部材を取り付けたり、既存構造物の一部を取り除く減築を行ったり、既存構造物と構造的に一体となる増築部を設ける増築を行ったりする方法を併用して、耐震改修後の構造物全体の保有耐力を必要耐力以上とし、耐震性能を確保できるため、既存構造物の耐震改修効果が確実に得られる。 Further, even if the size of the hole 11 is relatively small, the effect of suppressing brittle fracture of the welded portion can be sufficiently obtained, so that the decrease in the yield strength of the column member due to the cross-sectional defect of the hole 11 is slight. In addition, as to the decrease in the yield strength of the column member due to the lack of the cross section of the hole 11, a reinforcing member that increases the yield strength of the existing structure is attached, or the existing structure is increased, as described in the first to fifth modified examples described below. Combined with the method of removing a part of an object or adding an extension part that is structurally integrated with the existing structure, the required strength of the entire structure after seismic retrofitting is required. As mentioned above, since the seismic performance can be secured, the seismic retrofit effect of the existing structure can be surely obtained.
加えて、柱部材１の柱脚部や柱梁接合部における塑性変形性能や低サイクル疲労特性を向上させ、既存構造物の耐震改修効果を高めることができる。 In addition, it is possible to improve the plastic deformation performance and low cycle fatigue characteristics of the column base portion and the column-beam joint portion of the column member 1 and enhance the seismic retrofit effect of the existing structure.
図２〜図６に示す第２〜第６の実施形態の既存構造物の耐震改修方法は、第１の実施形態の既存構造物の耐震改修方法から、孔の数や位置を変更したものである。これら第２〜第６の実施形態の既存構造物の耐震改修方法では、柱本体（角形鋼管）１０の四つの角部の各々に、二つ〜四つの孔が、ベースプレートとの溶接部止端部に近接するようにして設けられている。 The seismic retrofitting method of the existing structure of the second to sixth embodiments shown in FIGS. 2 to 6 is obtained by changing the number and positions of holes from the seismic retrofitting method of the existing structure of the first embodiment. is there. In the seismic retrofitting method of the existing structures of the second to sixth embodiments, two to four holes are formed in each of the four corners of the column main body (square steel pipe) 10, and the weld end of the base plate is welded. It is provided so as to be close to the section.
図２に示す第２の実施形態の既存構造物の耐震改修方法では、柱本体（角形鋼管）１０の四つの角部の各々において、二つの孔２１、２２を、角形鋼管角部の稜線の両側に対称に設ける。 In the seismic retrofitting method for the existing structure of the second embodiment shown in FIG. 2, two holes 21 and 22 are formed in each of the four corners of the column main body (square steel pipe) 10 to form a ridgeline of the corner of the square steel pipe. Install symmetrically on both sides.
第２の実施形態の既存構造物の耐震改修方法では、地震力などの外力により耐震改修後の柱本体１０に曲げが発生したときに角形鋼管角部に生じる材軸方向引張応力が、孔２１、２２の下側の鋼管角部溶接部付近において拡散され、この部位における引張応力が低減される。 In the seismic retrofitting method of the existing structure of the second embodiment, when the bending occurs in the column main body 10 after the seismic retrofitting due to an external force such as seismic force, the tensile stress in the axial direction of the square steel pipe occurs in the hole 21. , 22 is diffused in the vicinity of the corner welded portion of the steel pipe, and the tensile stress in this portion is reduced.
図３、図４に示す第３、第４の実施形態の既存構造物の耐震改修方法では、柱部材１の在軸方向に孔３１、３２、４１〜４４を設ける。 In the seismic retrofitting method for existing structures of the third and fourth embodiments shown in FIGS. 3 and 4, the holes 31, 32, 41 to 44 are provided in the axial direction of the pillar member 1.
図３に示す第３の実施形態の既存構造物の耐震改修方法では、柱本体（角形鋼管）１０の四つの角部の各々において、二つの孔３１、３２を、角形鋼管角部の稜線上に沿って並ぶように設ける。 In the seismic retrofitting method of the existing structure of the third embodiment shown in FIG. 3, two holes 31 and 32 are formed in each of the four corners of the column body (square steel pipe) 10 on the ridgeline of the corner of the square steel pipe. It is provided so as to line up along the line.
図４に示す第４の実施形態の既存構造物の耐震改修方法では、柱本体（角形鋼管）１０の四つの角部の各々において、四つの孔４１〜４４を、角形鋼管角部の稜線の両側に二つずつ対称に設ける。 In the seismic retrofitting method of the existing structure of the fourth embodiment shown in FIG. 4, in each of the four corners of the column body (square steel pipe) 10, four holes 41 to 44 are formed in the ridge line of the corner of the square steel pipe. Install two symmetrically on each side.
第３、第４の実施形態の既存構造物の耐震改修方法では、柱部材１の材軸方向に複数設けた孔３１、３２、４１〜４４近傍において、耐震改修後の柱本体３０、４０の塑性変形が促進され、柱部材１の塑性変形性能や低サイクル疲労特性がさらに向上して、既存構造物の耐震改修効果がさらに高められる。 In the seismic retrofitting method for the existing structure of the third and fourth embodiments, in the vicinity of the holes 31, 32, 41 to 44 provided in the axial direction of the pillar member 1, the pillar main bodies 30, 40 after the seismic retrofitting are installed. Plastic deformation is promoted, the plastic deformation performance and low cycle fatigue characteristics of the column member 1 are further improved, and the seismic retrofit effect of the existing structure is further enhanced.
図５、図６に示す第５、第６の実施形態の既存構造物の耐震改修方法では、孔５１〜５３、６１〜６３を千鳥状に配置するように設ける。 In the seismic retrofitting method for existing structures of the fifth and sixth embodiments shown in FIGS. 5 and 6, the holes 51 to 53 and 61 to 63 are provided so as to be arranged in a staggered pattern.
図５に示す第５の実施形態の既存構造物の耐震改修方法では、柱本体（角形鋼管）１０の四つの角部の各々において、孔５１を、溶接部止端部に近接するようにして、角形鋼管角部の稜線上に設けるとともに、孔５２、５３を、上記孔５１よりも溶接部止端部からの高さが大きい位置に、角形鋼管角部の稜線の両側に対称に設ける。 In the seismic retrofitting method for the existing structure of the fifth embodiment shown in FIG. 5, in each of the four corners of the column body (square steel pipe) 10, the holes 51 are made to be close to the weld toe. The holes 52 and 53 are provided symmetrically on both sides of the ridge line of the corner of the square steel pipe at a position where the height from the toe of the weld is larger than that of the hole 51.
図６に示す第６の実施形態の既存構造物の耐震改修方法では、柱本体（角形鋼管）１０の四つの角部の各々において、孔６１、６２を、溶接部止端部に近接するようにして、角形鋼管角部の稜線の両側に対称に設けるとともに、孔６３を、上記孔６１、６２よりも溶接部止端部からの高さが大きい位置に、角形鋼管角部の稜線上に設ける。 In the seismic retrofitting method of the existing structure of the sixth embodiment shown in FIG. 6, the holes 61, 62 are formed so as to be close to the weld toe at each of the four corners of the column body (square steel pipe) 10. And the holes 63 are provided symmetrically on both sides of the ridgeline of the square steel pipe corner, and the holes 63 are provided on the ridgeline of the square steel pipe corner at a position where the height from the weld toe is larger than that of the holes 61 and 62. Set up.
第１〜第６の実施形態の既存構造物の耐震改修方法のいずれにおいても、上記孔１１、２１、２２、３１、３２、４１〜４４、５１〜５３、６１〜６３は、耐震改修後の柱部材１に外力が作用した際に、これら孔の断面欠損に起因する柱本体１０の局部座屈の発生を抑制するような大きさや位置に配列される。「局部座屈の発生を抑制」とは、孔を設けることによる局部座屈強度の低下が、孔を設けない場合の局部座屈強度に対して一定の割合以内に抑えられていることを指すものとする。 In any of the seismic retrofitting methods of the existing structures of the first to sixth embodiments, the holes 11, 21, 22, 31, 32, 41 to 44, 51 to 53, 61 to 63 are the ones after the seismic retrofitting. When the external force acts on the pillar member 1, the pillar members 1 are arranged in such a size and position as to suppress the occurrence of local buckling of the pillar main body 10 due to the cross-section loss of these holes. "Suppressing the occurrence of local buckling" means that the decrease in local buckling strength due to the provision of holes is suppressed within a certain ratio with respect to the local buckling strength without the provision of holes. I shall.
上記孔１１、２１、２２、３１、３２、４１〜４４、５１〜５３、６１〜６３は、この孔に近接する溶接部止端部と、孔の縁の離間距離が、孔の直径の１倍以上５倍以下となるように設けられることが好ましい。このようにすることで、孔を設けることによって得られる溶接部止端部の応力低減効果が高められる。 In the holes 11, 21, 22, 31, 32, 41 to 44, 51 to 53, 61 to 63, the distance between the weld toe near the hole and the edge of the hole is 1 of the diameter of the hole. It is preferable that they are provided so as to be not less than twice and not more than five times. By doing so, the stress reducing effect of the weld toe portion obtained by providing the hole is enhanced.
上記孔１１、２１、２２、３１、３２、４１〜４４、５１〜５３、６１〜６３の縁は滑らかに加工することが好ましい。具体的には、ガス溶断による孔加工ではなくドリル加工によるキリ孔加工とし、孔の縁に面取り加工や丸み付け加工を施すことが好ましい。このようにすることで、孔の縁における応力集中の発生を抑制して、溶接部が脆性破断することを確実に抑制できる。 The edges of the holes 11, 21, 22, 31, 32, 32, 41 to 44, 51 to 53, 61 to 63 are preferably processed smoothly. Specifically, it is preferable to perform drilling instead of drilling by gas fusing, and chamfering or rounding the edges of the holes. By doing so, it is possible to suppress the occurrence of stress concentration at the edge of the hole and reliably suppress brittle fracture of the welded portion.
なお、上記第１〜第６の実施形態では、柱本体１０の柱脚部にベースプレート１５が溶接接合されてなる柱部材１に対して、本発明の既存構造物の耐震改修方法が適用される場合について説明したが、本発明は、ベースプレート１５に代えて、あるいはベースプレート１５に加えて、柱本体の梁取付部にダイヤフラムが溶接されてなる柱部材に対しても同様に適用可能である。具体的には、角形鋼管の四つの角部の各々において、ダイヤフラムの溶接部止端部に近接するようにして、少なくとも一つの孔を設けるようにすれば良い。 In addition, in the said 1st-6th embodiment, the seismic retrofitting method of the existing structure of this invention is applied with respect to the pillar member 1 which the base plate 15 is weld-joined to the pillar base part of the pillar main body 10. Although the case has been described, the present invention can be similarly applied to a column member in which a diaphragm is welded to a beam attachment portion of a column body instead of the base plate 15 or in addition to the base plate 15. Specifically, at least one hole may be provided in each of the four corners of the square steel pipe so as to be close to the weld toe of the diaphragm.
本発明の既存構造物の耐震改修方法の変形例を、図２８〜図３３を参照して説明する。 A modified example of the seismic retrofitting method of the existing structure of the present invention will be described with reference to FIGS. 28 to 33.
図２８は、本発明の既存構造物の耐震改修方法を適用する前の、既存構造物１００の構面を示す。 FIG. 28 shows a structure surface of the existing structure 100 before the seismic retrofitting method for the existing structure of the present invention is applied.
図２９に、本発明の既存構造物の耐震改修方法の第１の変形例を示す。この第１の変形例では、既存構造物１００に対し、冷間成形角形鋼管からなる柱本体１０を有する柱部材１の柱脚部に溶接接合されたベースプレートの溶接部止端部、および上記柱本体１０の梁取付部に溶接接合されたダイヤフラムの溶接部止端部に近接するようにして、冷間成形角形鋼管の四つの角部の各々に、少なくとも一つの孔を設けている。この孔は、必ずしも柱脚部のベースプレートの溶接部止端部近傍、梁取付部のダイヤフラムの溶接部止端部近傍の全てに設ける必要はない。具体的には、既存構造物１００のうち柱部材１の耐力や柱梁耐力比に余裕のある部位には孔を設けなくとも、既存構造物の十分な耐震改修効果が得られる。 FIG. 29 shows a first modification of the seismic retrofitting method for existing structures of the present invention. In the first modification, a welded toe portion of a base plate welded to a column base portion of a column member 1 having a column body 10 made of a cold-formed rectangular steel pipe with respect to the existing structure 100, and the column. At least one hole is provided in each of the four corners of the cold-formed rectangular steel pipe so as to be close to the weld toe of the diaphragm welded to the beam attachment portion of the main body 10. This hole does not necessarily have to be provided in the vicinity of the weld toe of the base plate of the column base and near the weld toe of the diaphragm of the beam attachment. Specifically, a sufficient seismic retrofit effect of the existing structure can be obtained without providing a hole in a portion of the existing structure 100 where the column member 1 has a proof strength or a beam-column strength ratio.
図３０に、本発明の既存構造物の耐震改修方法の第２の変形例を示す。この第２の変形例では、図２９に示す第１の変形例に加えて、既存構造物１００の耐力を増加させる補強部材１２１（ブレースやダンパーなど）を、既存構造物１００の構面に取り付ける。 FIG. 30 shows a second modified example of the seismic retrofitting method for an existing structure of the present invention. In this second modified example, in addition to the first modified example shown in FIG. 29, a reinforcing member 121 (a brace, a damper, etc.) that increases the proof stress of the existing structure 100 is attached to the construction surface of the existing structure 100. ..
この第２の変形例によれば、補強部材１２１により既存構造物１００の耐力が増加することで、既存構造物１００の柱部材１に設けた孔の断面欠損による柱部材１の耐力低下が補われる。よって、耐震改修後の構造物全体の保有耐力を必要耐力以上とし、耐震性能を確保できる。 According to the second modification, the strength of the existing structure 100 is increased by the reinforcing member 121, so that the decrease in the yield strength of the pillar member 1 due to the lack of the cross section of the hole provided in the pillar member 1 of the existing structure 100 is compensated. Be seen. Therefore, the possession capacity of the entire structure after the seismic retrofitting can be made more than the required capacity, and seismic performance can be secured.
図３１に、本発明の既存構造物の耐震改修方法の第３の変形例を示す。この第３の変形例では、図２９に示す第１の変形例に加えて、既存構造物１００の耐力を増加させる補強部材１２２（ブレースやダンパーなど）を、既存構造物１００の構面に取り付ける。また、既存構造物１００の上に、この既存構造物１００と構造的に一体となるように、一層分の増築部１０１を設ける増築を行う。 FIG. 31 shows a third modified example of the method for retrofitting an existing structure against earthquakes of the present invention. In the third modified example, in addition to the first modified example shown in FIG. 29, a reinforcing member 122 (a brace, a damper, etc.) that increases the proof stress of the existing structure 100 is attached to the construction surface of the existing structure 100. .. Further, the extension is provided on the existing structure 100 by providing the extension portion 101 for one layer so as to be structurally integrated with the existing structure 100.
この第３の変形例によれば、補強部材１２２により既存構造物１００の耐力が増加することで、既存構造物１００の柱部材１に設けた孔の断面欠損による耐力低下が補われる。よって、既存構造物１００の上に増築部１０１を設けることによる外力入力増加を加味しても、耐震改修後の構造物全体の保有耐力を必要耐力以上とし、耐震性能を確保できる。 According to the third modification, the reinforcing member 122 increases the proof stress of the existing structure 100, thereby compensating for the proof stress decrease due to the cross-sectional defect of the hole provided in the pillar member 1 of the existing structure 100. Therefore, even if the increase in external force input by providing the extension portion 101 on the existing structure 100 is taken into consideration, the seismic resistance performance of the entire structure after seismic retrofitting can be made greater than or equal to the necessary strength, and seismic performance can be secured.
図３２に、本発明の既存構造物の耐震改修方法の第４の変形例を示す。この第４の変形例では、図２９に示す第１の変形例に加えて、既存構造物１００の横に、この既存構造物１００と構造的に一体となるように、３スパン分の増築部１０２を設ける増築を行う。また、既存構造物１００と増築部１０２が一体となった構造物全体の耐力を増加させるよう、補強部材１２３（ブレースやダンパーなど）を、増築部１０２の構面に取り付ける。 FIG. 32 shows a fourth modified example of the seismic retrofitting method for an existing structure of the present invention. In the fourth modification, in addition to the first modification shown in FIG. 29, an extension part for three spans is provided next to the existing structure 100 so as to be structurally integrated with the existing structure 100. The addition of 102 is performed. Further, a reinforcing member 123 (a brace, a damper, etc.) is attached to the construction surface of the extension section 102 so as to increase the yield strength of the entire structure in which the existing structure 100 and the extension section 102 are integrated.
この第４の変形例によれば、既存構造物１００の横に、この既存構造物１００と構造的に一体となる増築部１０２を設ける増築を行うことで、既存構造物１００と増築部１０２が一体となった構造物全体の耐力が増加する。また、補強部材１２３により、既存構造物１００と増築部１０２が一体となった構造物全体の耐力がさらに増加する。よって、既存構造物１００の柱部材１に設けた孔の断面欠損による耐力低下が補われ、耐震改修後の構造物全体の保有耐力を必要耐力以上とし、耐震性能を確保できる。なお、補強部材１２３を、増築部１０２でなく既存構造物１００の構面に取り付けても、同様の効果が得られる。 According to this 4th modification, the existing structure 100 and the additional part 102 are provided by adding the additional part 102 which is structurally integrated with this existing structure 100 next to the existing structure 100. The yield strength of the entire integrated structure is increased. Further, the reinforcing member 123 further increases the proof stress of the entire structure in which the existing structure 100 and the extension portion 102 are integrated. Therefore, the decrease in the proof strength due to the cross-section loss of the hole provided in the pillar member 1 of the existing structure 100 is compensated, and the proof strength of the entire structure after the seismic retrofitting is set to the necessary proof strength or more, and the aseismic performance can be secured. Even if the reinforcing member 123 is attached to the construction surface of the existing structure 100 instead of the extension portion 102, the same effect can be obtained.
図３３に、本発明の既存構造物の耐震改修方法の第５の変形例を示す。この第５の変形例では、図２８に示される既存構造物１００の最上層を取り除く減築を行い、減築後の既存構造物に入力する外力を低減させる。 FIG. 33 shows a fifth modified example of the earthquake-resistant repair method for existing structures of the present invention. In the fifth modification, the top layer of the existing structure 100 shown in FIG. 28 is removed so as to reduce the external force input to the existing structure after the reduction.
この第５の変形例によれば、既存構造物１００の最上層を取り除く減築を行い、減築後の既存構造物に入力する外力を低減させることで、既存構造物１００の柱部材１に設けた孔の断面欠損による耐力低下が補われ、耐震改修後の構造物全体の保有耐力を必要耐力以上とし、耐震性能を確保できる。 According to the fifth modified example, the pillar member 1 of the existing structure 100 is reduced by reducing the outermost layer of the existing structure 100 and reducing the external force applied to the existing structure after the reduction. The reduction in proof strength due to the lack of cross-section of the holes provided is compensated for, and the proof strength of the entire structure after seismic retrofitting is made greater than or equal to the required proof strength, thus ensuring seismic performance.
冷間成形角形鋼管からなる柱本体と、前記柱本体の梁取付部に溶接接合されたダイヤフラムとを有する柱部材に対して、耐震改修前のもの、本発明の既存構造物の耐震改修方法により改修されたものの各々について、地震等による水平外力が作用した場合に、柱部材とダイヤフラムとの溶接部に生じる相当塑性ひずみについて、孔の有無、孔の直径をパラメータとして、有限要素法による数値解析を行った。 For a column member having a column main body made of cold-formed rectangular steel pipe and a diaphragm welded to the beam attachment portion of the column main body, before the seismic retrofitting, by the seismic retrofitting method of the existing structure of the present invention For each of the repaired ones, the numerical analysis by the finite element method with or without holes and the diameter of the holes as a parameter for the equivalent plastic strain that occurs in the weld between the column member and the diaphragm when a horizontal external force such as an earthquake is applied. I went.
本数値解析においては、冷間成形角形鋼管からなる柱本体の形状を、外寸４００ｍｍ角、板厚２２ｍｍ、角部の曲率半径（外周側）２５ｍｍ、柱本体の長さ１９８２ｍｍとした。また、柱本体の柱脚部とダイヤフラムとの間の溶接部の形状を、ルートギャップ７ｍｍ、開先角度３５度、柱側フランク角度１４０度、ダイヤフラム側余盛８ｍｍ、裏当て金９ｍｍ×２５ｍｍとした。溶接部の溶け込みは考慮しないものとした。 In this numerical analysis, the shape of the column main body made of cold-formed rectangular steel pipe was 400 mm square in outer dimension, 22 mm in plate thickness, 25 mm in radius of curvature (outer peripheral side) of the corner portion, and 1982 mm in length of column main body. In addition, the shape of the welded portion between the column base of the column body and the diaphragm is set to have a root gap of 7 mm, a groove angle of 35 degrees, a column side flank angle of 140 degrees, a diaphragm side extra area of 8 mm, and a backing plate of 9 mm x 25 mm. did. Melting of the weld was not considered.
パラメータとなる孔の有無および孔の直径については、耐震改修前の例として孔を設けていない場合、本発明例１として直径が３９ｍｍの孔を設けた場合、本発明例２として直径が７８ｍｍの孔を設けた場合の三例とした。孔の縁と溶接部止端部（溶接部と柱本体との境界位置）との離間距離は１０ｍｍとした。 Regarding the presence/absence of holes as parameters and the diameter of holes, as an example before earthquake-proof repair, no holes were provided, when a hole having a diameter of 39 mm was provided as Example 1 of the present invention, and a diameter of 78 mm was provided as Example 2 of the present invention. Three cases are shown where holes are provided. The distance between the edge of the hole and the weld toe (boundary position between the weld and the column body) was 10 mm.
上記従来例および本発明例１、２において、各柱部材の柱脚部のダイヤフラム側を固定端、反対側の柱頭部を自由端とし、この自由端に４５度方向（角形鋼管からなる柱本体の断面係数が最大となる方向）に水平力（せん断力）を入力する条件で、数値解析を行った。 In the above-mentioned conventional example and the present invention examples 1 and 2, the diaphragm side of the column base of each column member is the fixed end, and the column head on the opposite side is the free end, and the free end has a direction of 45 degrees (column main body made of square steel pipe. Numerical analysis was carried out under the condition that horizontal force (shear force) was input in the direction in which the section modulus of was maximum.
図７〜図９に、従来例において、柱部材の変形角（自由端の変位／柱本体の長さ）が、０．００６ｒａｄ、０．０１ｒａｄ、０．０２ｒａｄとなった各時点での、柱本体のダイヤフラム近傍に発生する相当塑性ひずみの数値解析結果を、コンター図で示す。 7 to 9, in the conventional example, the deformation angle of the pillar member (displacement of free end/length of pillar body) is 0.006 rad, 0.01 rad, 0.02 rad The results of numerical analysis of the equivalent plastic strain generated near the diaphragm of the main body are shown in the contour diagram.
同様に、図１０〜図１２に、本発明例１において、柱部材の変形角が、０．００６ｒａｄ、０．０１ｒａｄ、０．０２ｒａｄとなった各時点での、柱本体のダイヤフラム近傍に発生する相当塑性ひずみの数値解析結果を、コンター図で示す。 Similarly, in FIGS. 10 to 12, in Example 1 of the present invention, the deformation angle of the column member occurs near the diaphragm of the column main body at each time when the deformation angle is 0.006 rad, 0.01 rad, and 0.02 rad. The results of numerical analysis of equivalent plastic strain are shown in contour diagrams.
また、図１３〜図１５に、本発明例２において、柱部材の変形角が、０．００６ｒａｄ、０．０１ｒａｄ、０．０２ｒａｄとなった各時点での、柱本体のダイヤフラム近傍に発生する相当塑性ひずみの数値解析結果を、コンター図で示す。 Moreover, in FIG. 13 to FIG. 15, in Example 2 of the present invention, the deformation angle of the pillar member is 0.006 rad, 0.01 rad, and 0.02 rad. The results of numerical analysis of plastic strain are shown in contour diagrams.
図１６に、従来例において、柱部材が、０．００６ｒａｄ、０．０１ｒａｄ、０．０２ｒａｄとなった各時点での、この柱部材に発生する上記相当塑性ひずみ（図７〜図９にも図示）の溶接部止端部位置における値と、角形鋼管（柱本体）の角部からの距離との関係を、グラフで示す。図１６のグラフにおいて、横軸の止端部座標は、角形鋼管（柱本体）を水平４５°方向（上記水平力の入力方向）から見たときの、角部からの距離を投影した長さ（角部位置を０とする）である。 In FIG. 16, in the conventional example, the column member has 0.006 rad, 0.01 rad, and 0.02 rad at each time point, the above-mentioned equivalent plastic strain generated in this column member (also shown in FIGS. 7 to 9 ). ) Is a graph showing the relationship between the value at the weld toe position and the distance from the corner of the square steel pipe (column body). In the graph of FIG. 16, the coordinates of the toe of the abscissa are the lengths obtained by projecting the distance from the corner when the rectangular steel pipe (column body) is viewed from the horizontal 45° direction (the input direction of the horizontal force). (The corner position is 0).
同様に、図１７に、本発明例１において、柱部材が、０．００６ｒａｄ、０．０１ｒａｄ、０．０２ｒａｄとなった各時点での、この柱部材に発生する上記相当塑性ひずみ（図１０〜図１２にも図示）の溶接部止端部位置における値と、角形鋼管（柱本体）の角部からの距離との関係を、グラフで示す。 Similarly, in FIG. 17, in Example 1 of the present invention, the column member has 0.006 rad, 0.01 rad, and 0.02 rad at each time point, and the equivalent plastic strain generated in the column member (FIGS. 10 to 10). The relationship between the value at the weld toe position (also shown in FIG. 12) and the distance from the corner of the rectangular steel pipe (column body) is shown in a graph.
また、図１８に、本発明例２において、柱部材が、０．００６ｒａｄ、０．０１ｒａｄ、０．０２ｒａｄとなった各時点での、この柱部材に発生する上記相当塑性ひずみ（図１０〜図１２にも図示）の溶接部止端部位置における値と、角形鋼管（柱本体）の角部からの距離との関係を、グラフで示す。 In addition, in FIG. 18, in Example 2 of the present invention, the column member has 0.006 rad, 0.01 rad, and 0.02 rad at each time point, and the equivalent plastic strain generated in the column member (FIGS. 10 to 10). 12 also shows the relationship between the value at the weld toe position of the welded portion and the distance from the corner of the square steel pipe (column body) in a graph.
通常は、冷間成形角形鋼管からなる柱本体の溶接部に発生する脆性破断は、溶接部止端部が起点となるから、この溶接部止端部に発生する相当塑性ひずみが小さい程、柱部材の溶接部が脆性破断するリスクが小さいと評価できる。 Usually, the brittle fracture that occurs in the weld of the column body made of cold-formed rectangular steel pipe starts at the weld toe, so the smaller the equivalent plastic strain that occurs at the weld toe, It can be evaluated that the risk of brittle fracture of the welded parts is low.
図７〜図９、図１０〜図１２、図１３〜図１５を比較すると、孔の縁に近接する溶接部止端部に発生する相当塑性ひずみが、本発明例１では従来例よりも小さくなっており、本発明例２ではさらに本発明例１よりも小さくなっていることが分かる。 Comparing FIG. 7 to FIG. 9, FIG. 10 to FIG. 12, and FIG. 13 to FIG. 15, the equivalent plastic strain generated in the weld toe near the edge of the hole is smaller in Example 1 of the present invention than in the conventional example. It can be seen that Example 2 of the present invention is smaller than Example 1 of the present invention.
また、図１６〜図１８を見ると、柱部材の変形角０．０２ｒａｄ時点での相当塑性ひずみの最大値が、従来例では０．０８２５であるのに対し、本発明例１では０．０２７６（従来例に対し６７％減）、本発明例２では０．０１３８（従来例に対し８３％減）となっている。 16 to 18, the maximum value of the equivalent plastic strain at the time of the deformation angle of 0.02 rad of the column member is 0.0825 in the conventional example, whereas it is 0.0276 in the first example of the present invention. (67% reduction from the conventional example) and 0.0138 (83% reduction from the conventional example) in the present invention example 2.
したがって、本発明のように、柱本体とダイヤフラムとの溶接部止端部に近接するようにして、角形鋼管角部に孔を設けることで、溶接部が脆性破断することを抑制する効果が得られることが分かる。 Therefore, as in the present invention, by providing a hole in the corner of the square steel pipe so as to be close to the weld toe of the column body and the diaphragm, the effect of suppressing brittle fracture of the weld is obtained. You can see that.
図１９のグラフに、従来例および本発明例１、２の各々における、柱部材の自由端の変位と荷重（入力する水平力）との関係を、比較して示す。本発明例１、２では、孔の断面欠損により、柱部材の耐力低下が生じている。しかし、この柱部材の耐力低下を、柱部材の変形角０．０２ｒａｄ時点において比較すると、本発明例１では従来例に対し６％減、本発明例２では従来例に対し１９％減にとどまっており、孔の断面欠損による影響は小さく、柱部材に必要な耐力が確保されていることが分かる。 The graph of FIG. 19 shows a comparison between the displacement of the free end of the column member and the load (horizontal force to be input) in each of the conventional example and the present invention examples 1 and 2. In Examples 1 and 2 of the present invention, the proof stress of the column member is reduced due to the lack of the cross section of the hole. However, when comparing the reduction of the proof stress of the column member at the time of the deformation angle of the column member of 0.02 rad, Example 1 of the present invention decreased by 6% from the conventional example, and Example 2 of the present invention decreased by 19% from the conventional example. Therefore, it can be seen that the influence of the cross-section loss of the hole is small and the proof stress required for the column member is secured.
冷間成形角形鋼管からなる柱本体と、前記柱本体の梁取付部に溶接接合されたダイヤフラムとを有する柱部材であって、本発明の既存構造物の耐震改修方法により改修されたものについて、地震等による水平外力が作用した場合に、柱部材とダイヤフラムとの溶接部に生じる相当塑性ひずみについて、冷間成形角形鋼管の四つの角部に設ける孔の縁と、この孔に近接する前記ダイヤフラムの溶接部止端部との離間距離をパラメータとして、有限要素法による数値解析を行った。 A column member having a column body made of cold-formed rectangular steel pipe and a diaphragm welded to the beam attachment portion of the column body, which is repaired by the seismic retrofitting method of the existing structure of the present invention, Regarding the equivalent plastic strain generated in the welded portion of the column member and the diaphragm when a horizontal external force due to an earthquake etc. acts, the edges of the holes provided at the four corners of the cold-formed rectangular steel pipe and the diaphragm close to this hole. Numerical analysis was carried out by the finite element method using the distance from the weld toe of the weld as a parameter.
本数値解析においては、図２に示す第２の実施形態のように、冷間成形角形鋼管の四つの角部の各々に、角部の稜線の両側に対称に一対の孔が設けられた柱部材を解析対象とした。孔の直径は３９ｍｍとし、各孔の縁が角部の稜線の曲率を有する部分から１４ｍｍ離れるようにして、各孔が設けられるものとした。 In this numerical analysis, as in the second embodiment shown in FIG. 2, a column in which a pair of holes are symmetrically provided on both sides of the ridgeline of the corner at each of the four corners of the cold-formed rectangular steel pipe. The member was used as an analysis target. The diameter of each hole was 39 mm, and each hole was provided so that the edge of each hole was separated from the portion having the curvature of the ridgeline of the corner by 14 mm.
冷間成形角形鋼管からなる柱本体の形状は、実施例１と同様に、外寸４００ｍｍ角、板厚２２ｍｍ、角部の曲率半径（外周側）２５ｍｍ、柱本体の長さ１９８２ｍｍとした。また、柱本体の柱脚部とダイヤフラムとの間の溶接部の形状も、実施例１と同様に、ルートギャップ７ｍｍ、開先角度３５度、柱側フランク角度１４０度、ダイヤフラム側余盛８ｍｍ、裏当て金９ｍｍ×２５ｍｍとし、溶接部の溶け込みは考慮しないものとした。 As in Example 1, the shape of the column body made of cold-formed rectangular steel pipe was 400 mm square in outer dimensions, 22 mm in plate thickness, 25 mm in radius of curvature (outer peripheral side) of the corner, and 1982 mm in column body length. Further, the shape of the welded portion between the column base of the column main body and the diaphragm is also the same as in Example 1, with a root gap of 7 mm, a groove angle of 35 degrees, a column side flank angle of 140 degrees, and a diaphragm side extra protrusion of 8 mm. The backing metal was 9 mm×25 mm, and the melting of the weld was not considered.
本実施例の数値解析のパラメータとなる、ダイヤフラムの溶接部止端部（溶接部と柱本体との境界位置）と孔の縁との離間距離は、孔の直径の１倍である３９ｍｍ（本発明例Ａ）、２倍である７８ｍｍ（本発明例Ｂ）、３．８倍である１５０ｍｍ（本発明例Ｃ）、０．２６倍である１０ｍｍ（本発明例Ｄ）の四例とした。 The distance between the weld toe of the diaphragm (the boundary position between the weld and the column body) and the edge of the hole, which is a parameter of the numerical analysis of the present embodiment, is 39 mm (one of the diameter of the hole). Inventive Example A) Four examples were used, namely, doubled 78 mm (Inventive Example B), 3.8 times 150 mm (Inventive Example C), and 0.26 times 10 mm (Inventive Example D).
上記本発明例Ａ〜Ｄにおいて、各柱部材の柱脚部のダイヤフラム側を固定端、反対側の柱頭部を自由端とし、この自由端に４５度方向（角形鋼管からなる柱本体の断面係数が最大となる方向）に水平力（せん断力）を入力する条件で、数値解析を行った。 In Examples A to D of the present invention, the diaphragm side of the column base of each column member is the fixed end and the column head on the opposite side is the free end, and the free end has a direction of 45 degrees (the cross-section coefficient of the column main body made of square steel pipe. Numerical analysis was carried out under the condition that horizontal force (shear force) was input in the direction in which was maximum.
図２０〜図２３に、本発明例Ａ〜Ｄにおいて、柱部材の変形角（自由端の変位／柱本体の長さ）が０．０２ｒａｄとなった各時点での、柱本体のダイヤフラム近傍に発生する相当塑性ひずみの数値解析結果を、コンター図で示す。 20 to 23, in each of Examples A to D of the present invention, in the vicinity of the diaphragm of the column main body at each time when the deformation angle of the column member (displacement of free end/length of column main body) was 0.02 rad. The numerical analysis result of the equivalent plastic strain that occurs is shown in a contour diagram.
図２４〜図２７に、本発明例Ａ〜Ｄにおいて、柱部材が０．００６ｒａｄ、０．０１ｒａｄ、０．０２ｒａｄとなった各時点での、この柱部材に発生する上記相当塑性ひずみ（図２０〜図２３にも図示）の溶接部止端部位置における値と、角形鋼管（柱本体）の角部からの距離との関係を、グラフで示す。図２４〜図２７のグラフにおいて、横軸の止端部座標は、角形鋼管（柱本体）を水平４５°方向（上記水平力の入力方向）から見たときの、角部からの距離を投影した長さ（角部位置を０とする）である。 24 to 27, in Examples A to D of the present invention, the equivalent plastic strain generated in the column member at each time when the column member became 0.006 rad, 0.01 rad, 0.02 rad (FIG. 20). ~ FIG. 23 also shows) the relationship between the value at the weld toe position and the distance from the corner of the square steel pipe (column body) in a graph. In the graphs of FIGS. 24 to 27, the coordinates of the toe of the horizontal axis are projections of the distance from the corner when the rectangular steel pipe (column body) is viewed in the horizontal 45° direction (the input direction of the horizontal force). It is the length (the corner position is 0).
通常は、冷間成形角形鋼管からなる柱本体の溶接部に発生する脆性破断は、溶接部止端部が起点となるから、この溶接部止端部に発生する相当塑性ひずみが小さい程、柱部材の溶接部が脆性破断するリスクが小さいと評価できる。 Usually, the brittle fracture that occurs in the weld of the column body made of cold-formed rectangular steel pipe starts at the weld toe, so the smaller the equivalent plastic strain that occurs at the weld toe, It can be evaluated that the risk of brittle fracture of the welded parts is low.
図２０〜図２３を比較すると、孔の縁と溶接部止端部との離間距離が大きくなるにつれて、孔の周辺に発生する部分的な応力集中箇所も溶接部止端部から離れていき、孔を設けることによって得られる溶接部止端部の応力低減効果が確実に確保されることがわかる。 Comparing FIGS. 20 to 23, as the distance between the edge of the hole and the weld toe increases, the partial stress concentration points that occur around the hole also move away from the weld toe. It can be seen that the stress reducing effect of the weld toe portion obtained by providing the hole is surely secured.
また、図２４〜図２７を見ると、孔の縁から溶接部止端部までの離間距離が１０ｍｍ（孔の直径の０．２６倍）の本発明例Ｄでは、角形鋼管角部における溶接部止端部の相当塑性ひずみが抑えられていないのに対し、離間距離が３９ｍｍ〜１５０ｍｍ（孔の直径の１〜３．８倍）の本発明例Ａ〜Ｃでは、角形鋼管角部における溶接部止端部の相当塑性ひずみが抑えられている。このように、孔に近接する溶接部止端部と孔の縁の離間距離を、孔の直径の１倍以上５倍以下とすれば、孔を設けることによって得られる溶接部止端部の応力低減効果が高められることがわかる。 24 to 27, in Example D of the present invention in which the distance from the edge of the hole to the weld toe was 10 mm (0.26 times the diameter of the hole), the weld at the corner of the square steel pipe While the equivalent plastic strain of the toe portion is not suppressed, in the invention examples A to C in which the separation distance is 39 mm to 150 mm (1 to 3.8 times the diameter of the hole), the welded portion in the corner portion of the square steel pipe is used. Equivalent plastic strain at the toe is suppressed. Thus, if the distance between the weld toe near the hole and the edge of the hole is not less than 1 time and not more than 5 times the diameter of the hole, the stress at the weld toe obtained by providing the hole is increased. It can be seen that the reduction effect is enhanced.
１ 柱部材
１０ 柱本体
１１、２１、２２、３１、３２、４１〜４４、５１〜５３、６１〜６３ 孔
１５ ベースプレート
１００ 既存構造物
１０１、１０２ 増築部
１１１ 減築部
１２１、１２２、１２３ 補強部材
1 pillar member 10 pillar main body 11, 21, 22, 31, 32, 41-44, 51-53, 61-63 hole 15 base plate 100 existing structure 101, 102 extension section 111 reduction section 121, 122, 123 reinforcement member
Claims (11)
前記柱本体の柱脚部に溶接接合されたベースプレートと
を有する柱部材を備えた既存構造物の耐震改修方法であって、
前記冷間成形角形鋼管の四つの角部の各々に、前記ベースプレートとの溶接部止端部に近接するようにして、少なくとも一つの孔を設けることを特徴とする既存構造物の耐震改修方法。 A column body made of cold-formed rectangular steel pipe,
A method for seismic retrofitting an existing structure comprising a column member having a base plate welded to a column base of the column body,
A method for seismic retrofitting an existing structure, characterized in that at least one hole is provided in each of the four corners of the cold-formed rectangular steel pipe so as to be close to the toe of the welded portion with the base plate.
前記冷間成形角形鋼管の四つの角部の各々に、前記ダイヤフラムとの溶接部止端部に近接するようにして、少なくとも一つの孔を設けることを特徴とする請求項１に記載の既存構造物の耐震改修方法。 The pillar member further has a diaphragm welded to the beam attachment portion of the pillar body,
The existing structure according to claim 1, wherein at least one hole is provided in each of the four corners of the cold-formed rectangular steel pipe so as to be close to a toe of a welded portion with the diaphragm. Seismic retrofitting method.
前記柱本体の梁取付部に溶接接合されたダイヤフラムと
を有する柱部材を備えた既存構造物の耐震改修方法であって、
前記冷間成形角形鋼管の四つの角部の各々に、前記ダイヤフラムとの溶接部止端部に近接するようにして、少なくとも一つの孔を設けることを特徴とする既存構造物の耐震改修方法。 A column body made of cold-formed rectangular steel pipe,
A method for seismic retrofitting an existing structure comprising a column member having a diaphragm welded to a beam attachment portion of the column body,
A method for seismic retrofitting an existing structure, characterized in that at least one hole is provided in each of the four corners of the cold-formed rectangular steel pipe so as to be close to the toe of the welded portion with the diaphragm.
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| Publication number | Priority date | Publication date | Assignee | Title |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09235885A (en) * | 1996-03-04 | 1997-09-09 | Shimizu Corp | Earthquake resisting reinforced structure of existing building |
| JP3845804B2 (en) * | 1995-09-01 | 2006-11-15 | サイズミック・ストラクチュラル・デザイン・アソシエイツ・インコーポレイテッド | Stress reduction connection of steel frame |
| JP2011127408A (en) * | 2009-12-21 | 2011-06-30 | Nippon Steel & Sumikin Metal Products Co Ltd | Support for guard fence |
| JP2015190120A (en) * | 2014-03-27 | 2015-11-02 | 株式会社竹中工務店 | Aseismatic repair method of building |
| CN105332422A (en) * | 2015-11-03 | 2016-02-17 | 北京工业大学 | Vertical outer rib beam-column joint connector applicable to prefabricated steel structural systems |
| JP2018071253A (en) * | 2016-11-01 | 2018-05-10 | Ｊｆｅスチール株式会社 | Cold-formed square steel pipe and column beam joint |
-
2019
- 2019-11-28 JP JP2019215211A patent/JP6996544B2/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3845804B2 (en) * | 1995-09-01 | 2006-11-15 | サイズミック・ストラクチュラル・デザイン・アソシエイツ・インコーポレイテッド | Stress reduction connection of steel frame |
| JPH09235885A (en) * | 1996-03-04 | 1997-09-09 | Shimizu Corp | Earthquake resisting reinforced structure of existing building |
| JP2011127408A (en) * | 2009-12-21 | 2011-06-30 | Nippon Steel & Sumikin Metal Products Co Ltd | Support for guard fence |
| JP2015190120A (en) * | 2014-03-27 | 2015-11-02 | 株式会社竹中工務店 | Aseismatic repair method of building |
| CN105332422A (en) * | 2015-11-03 | 2016-02-17 | 北京工业大学 | Vertical outer rib beam-column joint connector applicable to prefabricated steel structural systems |
| JP2018071253A (en) * | 2016-11-01 | 2018-05-10 | Ｊｆｅスチール株式会社 | Cold-formed square steel pipe and column beam joint |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114856237A (en) * | 2022-04-29 | 2022-08-05 | 重庆科技学院 | Combined steel pipe-wrapped reinforced concrete column |
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