JP3778733B2 - Strength estimation method for steel beam-column joint. - Google Patents

Strength estimation method for steel beam-column joint. Download PDF

Info

Publication number
JP3778733B2
JP3778733B2 JP21377199A JP21377199A JP3778733B2 JP 3778733 B2 JP3778733 B2 JP 3778733B2 JP 21377199 A JP21377199 A JP 21377199A JP 21377199 A JP21377199 A JP 21377199A JP 3778733 B2 JP3778733 B2 JP 3778733B2
Authority
JP
Japan
Prior art keywords
joint
steel pipe
yield
steel
yield strength
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP21377199A
Other languages
Japanese (ja)
Other versions
JP2001041866A (en
Inventor
直人 下野
輝夫 瀬川
達雄 岡本
博之 上田
洋文 金子
亨 平出
満 樋口
修 栄藤
公甫 多賀野
充 森崎
宏一 原田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Takenaka Corp
Kubota Corp
Original Assignee
Takenaka Corp
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Takenaka Corp, Kubota Corp filed Critical Takenaka Corp
Priority to JP21377199A priority Critical patent/JP3778733B2/en
Publication of JP2001041866A publication Critical patent/JP2001041866A/en
Application granted granted Critical
Publication of JP3778733B2 publication Critical patent/JP3778733B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Description

【0001】
【発明の属する技術分野】
本発明は、内空部にコンクリートを充填された鋼管柱と、鉄骨梁との接合部の降伏耐力を、所謂降伏線理論を用いて求める鋼管柱梁接合部の耐力推定方法に関する。
【0002】
【従来の技術】
従来、この種の鋼管柱梁接合部の耐力推定方法としては、鋼管柱と鉄骨梁との接合部の降伏メカニズムを、図10に示すような降伏線(aa、bb、b’b’、a’a’、ab、bb’、b’a’)を仮定した降伏線理論によって解析し、接合部の降伏耐力を推定する方法があった(「コンクリート充填円形鋼管柱−鉄骨梁フランジ接合部の局部引張耐力に関する研究」日本建築学会構造系論文集第504号1998年2月参照)。
この方法は、具体的には、数3の(式0)によって接合部の降伏耐力を推定するものであって、対象とする鋼管は管厚寸法が一定で、鋼管には軸力が作用していない状態での算定である。
【0003】
【数3】

Figure 0003778733
【0004】
ここで、ct:鋼管の管厚、csσy:鋼管の周方向の降伏応力度、θ:梁フラ ンジ端部と鋼管軸心とを結ぶ直線と、梁フランジ材軸芯との交角、Xp:面外曲げ降伏線aa(a’a’)とbb(b’b’)との間隔寸法、rt:接合部と梁 フランジとの溶接余盛りを含んだ接合高さ寸法、sD:鋼管の外径寸法、cMp:鋼管の壁の単位長さあたりの面外曲げ全塑性耐力。
【0005】
【発明が解決しようとする課題】
前述した一つ目の鋼管柱梁接合部の耐力推定方法によれば、耐力の推定そのものは、前記(式0)に代入するだけであるから、極めて簡単に実施でき、設計条件を色々と変化させて、それらの多数の検討を実施した結果から手軽に且つ短時間に接合部耐力の推定を行うことが可能である。しかし、その反面、算定対象とする鋼管が、梁との接合部を増厚してあるような場合であったり、鋼管に軸力が作用しているような場合は、算定条件にそれらのパラメータが加味されてないから、推定した算定結果は、図11に示すように、実験値に比べて全体的にバラツキが見られ、解析精度が低いという問題点がある。
この問題点を解決するには、精度の高い解析結果を得られるFEM解析によって接合部の降伏耐力を推定する方法があるが、この場合には、解析のための前処理や、解析そのものに手間がかかり、時間とコストとがかさむという別の問題点がある。
従って、本発明の目的は、上記問題点を解消し、鋼管柱梁接合部の耐力推定を、より精度よく、且つ、より手間を掛けずに簡単に実施できるようにするところにある。
【0006】
【課題を解決するための手段】
請求項1の発明の特徴構成は、図1〜4に例示するごとく、内空部にコンクリート2を充填された鋼管柱Cと、鉄骨梁Bとの接合部K2の崩壊機構を、降伏線とそれに囲まれた平板部分とで規定し、前記降伏線での断面降伏条件から前記接合部K2の降伏耐力(cPy)を導く降伏線理論を用いて、前記接合部K2の降伏耐力(cPy)を求める鋼管柱梁接合部の耐力推定方法において、前記鋼管柱Cを、管厚寸法を厚肉に形成した前記接合部K2と、それの上下に連なる一般部K1とに分けて考え、前記接合部K2の管厚寸法tp と、前記一般部K1の管厚寸法tc を別々に設定し、前記接合部K2の降伏耐力(cPy)を求めるにあたり、前記接合部K2の上端部と前記鉄骨梁Bの上端部との距離(Lp)、及び、前記鋼管柱Cに作用する軸力(N)を前記降伏線理論に反映させて前記降伏耐力(cPy)を下記の(式1)で求めるところにある。
一般的に鋼管柱と鉄骨梁との接合部は、他の部分よりも応力が集中しやすい部分であるから、特に、その接合部について鋼管の管厚寸法を他の部分より増加させておくことで、無駄のない状態での接合部の補剛を図ることができ、このような接合部構造を採用することが増えている。しかし、このように鋼管の接合部のみを厚肉に形成してある構造と、鋼管全体を厚肉に形成してある構造とでは、降伏耐力に差を生じることが解った。また、鋼管柱には、軸方向の力が作用しているのがごく普通の状況であるが、この軸力の作用によっても接合部の降伏耐力に変化があることが解った。
請求項1の発明の特徴構成によれば、従来の降伏線理論による鋼管柱梁接合部の耐力推定の過程に、鋼管の前記一般部と前記接合部との鋼管の管厚寸法に差がある条件下の補正や、鋼管に軸力が作用する条件下の補正を盛り込むことができ、より、精度の高い降伏耐力評価を行うことが可能となった。
具体的には、前記接合部の上端部と前記鉄骨梁の上端部との距離、及び、前記鋼管柱に作用する軸力を、それぞれ新しいパラメータとして組み込むことによって、現実により近づき、肌理細かで精度の高い推定結果を得られるようになった。このことは、図5に示すように、鋼管柱梁接合部の降伏耐力の実験結果と、当該推定式で求められた降伏耐力との関係に示すとおりである。
【0008】
【数4】
Figure 0003778733
【0009】
【数5】
Figure 0003778733
【0010】
また、前記(式1)に、各パラメータの値を代入するだけで、極めて簡単に鋼管柱梁接合部の降伏耐力(cPy)を算出することができる。従って、各部材の寸法や材質等の設計条件を変化させて多数の算定を実施するような作業を、短時間に実施することが可能となり、設計業務の効率化を図ることが可能となる。
また、前記(式1)によって求められた鋼管柱梁接合部の降伏応力(以後、単に算定値という)は、図5・7に示すように、求められる降伏応力の大きい領域から小さい領域にわたる広い範囲において、実験値に近似しており、バラツキが少なく、且つ、精度の高い算定を実現することが可能となる。
即ち、設計業務に対する対応性が向上して鋼管柱梁接合部の評価を迅速に行えるようになると共に、鋼管柱梁接合部の経済設計を叶えることが可能となる。
尚、上述のように、図面との対照を便利にするために符号を記したが、該記入により本発明は添付図面の構成に限定されるものではない。
【0011】
【発明の実施の形態】
以下に本発明の実施の形態を図面に基づいて説明する。尚、図面において従来例と同一の符号で表示した部分は、同一又は相当の部分を示している。
図1、図2、図3に示すように、鋼管コンクリート柱・梁接合部は、鋼管コンクリート柱Cに鉄骨梁Bを接合させて構成されている。
前記鋼管コンクリート柱(鋼管柱に相当)Cは、鋼管1にコンクリート2を充填した構造のものである。
前記鉄骨梁Bは、上下のフランジBFをウエブBWで連結固着した構造のH形鋼(又は、I形鋼)によって構成してある。そして、鉄骨梁Bの端部は、前記鋼管コンクリート柱Cの外周に沿う凹形状に加工してある。そして、鋼管1へは、溶接によって連結してある。溶接余盛りの寸法は、フランジBFの外側余盛り寸法がS3、フランジBFの内側余盛り寸法がS2、フランジBFの左右側余盛り寸法が夫々S1に設定してある。また、Bfは、フランジ幅寸法を表し、tfは 、フランジ厚みを表す。従って、接合部の溶接余盛りを含んだ接合高さrtは、 (S2+S3+tf)で求められる。
前記鋼管1は、遠心力鋳鋼管であり、この鋼管1のうち、前記鉄骨梁Bが固定される仕口部1Aを含んだ縦所定範囲間の接合部K2は、図に示すように、それの上下に連なる一般部K1の管厚tcよりも大なる管厚tpに形成して補剛してある。
前記接合部K2は、接合部K2の内径を前記一般部K1の内径と等しくした状態で、接合部K2の外径Dpを一般部K1の外径Dcよりも大きくして管厚tp を一般部K1の管厚tcよりも大にしてある。つまり、鋼管コンクリート柱Cは 、内部のコンクリート軸部断面が一定のものである。前記接合部K2と一般部K1との段部は、そこに応力集中が発生することを防止するように漸次管厚を変化させるアール形状に構成されている。
接合部K2の上端部と鉄骨梁Bの上端部との距離は、Lpで表す。
そして、この鋼管コンクリート柱・梁接合部の降伏耐力(cPy)を評価するに、下記数6、数7の推定式(式1)に基づいて算定し評価するものである。
【0012】
【数6】
Figure 0003778733
【0013】
【数7】
Figure 0003778733
【0014】
複数の算定モデルを想定し、それらに対応する各数値(図6参照)を前記(式1)に代入して各モデル毎の鋼管柱梁接合部の降伏耐力を推定した結果を図5・7に示す。但し、図中のDcは一般部の外径、tcは一般部の管厚、Bfは鉄骨 梁のフランジ幅、tfは鉄骨梁のフランジ厚み寸法、S1は溶接余盛りの左右側 余盛り寸法、S2は溶接余盛りの内側余盛り寸法、S3は溶接余盛りの外側余盛り寸法、hpは接合部の外側への増厚寸法、Lpは鋼管柱における接合部と鉄骨 梁の上端部との距離、npは鋼管の軸応力比、pσyは鋼管の接合部での降伏応力 度、cσyは鋼管の一般部での降伏応力度、fσyは鉄骨梁の降伏応力度をそれぞれ示す。
また、同様の算定モデルについての実験値と、従来の降伏線理論によって算出した鋼管柱梁接合部の降伏耐力とについてもそれぞれ記載した。
これから見られるように、前記(式1)によれば、極めて「実験値」に近似した推定値が得られていると同時に、従来の「降伏線理論」の結果に比べて、鋼管柱梁接合部の降伏耐力評価をより精度よく実施することができるものである。
従って本実施形態の耐力推定式によれば、従来の鋼管柱梁接合部の降伏耐力評価法よりも、鋼管コンクリート柱・梁接合部の耐力を適正に評価することが可能となり、その結果、鋼管コンクリート柱の設計を、より経済的に且つ安全に行うことができるようになる。
次に、前記(式1)を導いた経過について説明する。
発明者は、鋼管柱梁接合部の降伏メカニズムの設定にあたり、図4に示すように降伏線AA’、BB’、CC’、DD’、AB、A’B’、BC、B’C’、CD、C’D’をそれぞれ仮定し、前記AA’、BB’、CC’、DD’の降伏線は、鋼管壁の曲げによって降伏し、前記AB、A’B’、BC、B’C’、CD、C’D’の降伏線は、引張によって降伏するものとした。
また、当該推定式の導出にあたっては、圧縮及び曲げに伴う座屈は生じないものと仮定すると共に、式の展開において引張応力を正と定義すると共に、鋼材の圧縮降伏応力度、曲げ降伏応力度はともに引張降伏応力度と同じとした。
そして、各降伏線の内部仕事の合計値Eiを求め、この内部仕事Eiが、梁フランジに作用する荷重Pがなす外部仕事Exと等しくなるとして数8のとおり当該推定式(式1)を導いた。
【0015】
【数8】
Figure 0003778733
【0016】
次に、当該推定式(式1)による鋼管梁接合部の降伏耐力と対比させた実験値は、図7に示したが、その実験について簡単に説明する。
〈試験体〉
図8に示すように、試験体は、実物の約二分の一の大きさの柱・梁接合部の十字型骨組であり、鋼管コンクリート柱Cの鋼管1には、JIS規格がSMK490の遠心力鋳鋼管を用い、鉄骨梁Bには、JIS規格がSM490Aの梁材料からなるものを用いるとともに、鋼管1の仕口部1Aが鉄骨梁Bよりも先行して崩壊するように十分な強度を与えた。各試験体は横断面形状が円形のものである。鉄骨梁Bの上下端から前記接合部K2の上下端の出寸法Lpは50mm(一定)とした(図6参照)。
〈加力装置〉
載荷試験に用いる加力装置として、図8に示すものを用意した。加力装置の概要を説明すると、加力装置は、試験体の鋼管コンクリート柱Cの下端を載荷する載荷台3と、試験体の鋼管コンクリート柱Cの上端に荷重を掛ける1000トン載荷試験機4と、試験体を鉛直姿勢に保持するように試験体の鋼管コンクリート柱Cのうち1600mmを隔てた上端近くと下端近くとを拘束する反力ビーム5の群と、試験体の梁Bの端部にロードセル6を介して荷重Qbを載荷するオイルジャッキ7とからなる。
〈加力形式〉
試験体への加力(載荷)形式は、鉛直載荷形式とした。鉛直載荷形式は、図9に示すように、両鉄骨梁Bの端部に荷重Qb1,Qb2を同方向に単調載荷する鉛直‐単調載荷形式である。そして、鋼管コンクリート柱Cの最大耐力に対する比としての軸力比として、0.0と0.3とを設定した。つまり、鋼管コンクリート柱Cに対して最大耐力の30%の軸力を作用させる、或いは、軸力を作用させないかのいずれかに設定した。
〈載荷試験〉
当該載荷試験では、図9に示すように、両梁端への荷重Qb1,Qb2の単調載荷に伴う梁端部の上下方向の変形(たわみ)量δb(δb1,δb2)と仕口部1Aの径方向の変形量δp(δp1,δp2)とをダイヤルゲージを用いて測定した。
【0017】
〔別実施形態〕
以下に他の実施の形態を説明する。
〈1〉 前記接合部K2は、先の実施形態では、鋼管1の径方向外側に増厚した形状のものを説明したが、その構成に限るものではなく、例えば、鋼管1の径方向内側にのみ増厚した形状のもの、又は、鋼管1の径方向内外両側に増厚した形状のものであってもよく、何れの場合にも鋼管柱梁接合部の耐力推定値に大きな変動が無いことが確認されている。
〈2〉 先の実施形態における算定モデルは、接合部K2の上端部と鉄骨梁Bの上端部との距離Lpが50mm、軸力比(鋼管コンクリート柱の軸方向に加わる力(軸力)と、鋼管コンクリート柱の軸方向の降伏耐力との比)ncが、0.3 以か0のものを使用しているが、Lpやncが他の値であってもよく、本発明に よれば、幅の広い範囲の算定に対応することが可能で、より精度よく降伏耐力cPyを推定することができる。
〈3〉 前述の実施形態では、接合部K2のみを厚肉化した鋼管柱梁接合部を耐力の評価対象としたが、本発明は、鋼管1の全体を厚肉化する状態で接合部K2を補剛した鋼管柱梁接合部の耐力評価にも適用できる。
〈4〉 降伏線は、先の実施形態による形状に限らず、変形して考えることも可能である。
【図面の簡単な説明】
【図1】鋼管柱梁接合部を示す側面視説明図
【図2】鋼管柱梁接合部を示す上面視説明図
【図3】鋼管柱梁接合部を示す鉄骨梁軸芯方向視断面図
【図4】降伏線の設定を示す説明図
【図5】実験値と耐力推定値とを示す説明図
【図6】算定モデルの各数値を示す説明図
【図7】算定結果を示す説明図
【図8】実験装置を示す側面視説明図
【図9】実験方法を示す説明図
【図10】従来の降伏線設定状況を示す説明図
【図11】従来の耐力推定値と実験値とを示す説明図
【符号の説明】
cPy 接合部の降伏耐力
2 コンクリート
B 鉄骨梁
C 鋼管柱
K2 接合部
Lp 鋼管柱における接合部と鉄骨梁の上端部との距離
N 鋼管に作用する軸力
p 鋼管柱の接合部の管厚
c 鋼管柱の一般部の管厚[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for estimating the yield strength of a steel tube-column-beam joint that uses a so-called yield line theory to determine the yield strength of the joint between a steel tube column filled with concrete in the inner space and a steel beam.
[0002]
[Prior art]
Conventionally, as a method for estimating the yield strength of this type of steel pipe column-to-beam joint, the yield mechanism of the joint between the steel pipe column and the steel beam is represented by a yield line (aa, bb, b′b ′, a 'a', ab, bb ', b'a') was analyzed by the yield line theory, and there was a method for estimating the yield strength of the joint ("concrete-filled circular steel pipe column-steel beam flange joint “Research on local tensile strength” (see Architectural Institute of Japan, No. 504, February 1998).
Specifically, this method estimates the yield strength of the joint by Equation 3 (Equation 0). The steel pipe of interest has a constant thickness, and an axial force acts on the steel pipe. It is a calculation in the state that is not.
[0003]
[Equation 3]
Figure 0003778733
[0004]
Here, ct: pipe thickness of steel pipe, cs σ y : circumferential yield stress of steel pipe, θ: intersection angle between beam flange end and steel pipe axis, and beam flange material axis, Xp : distance dimension 'and bb (B'B plane bending yield line aa (A'A)' and), r t: bonding height including the welding surplus prime the junction and the beam flange, sD: steel pipe CMp: out-of-plane bending total plastic yield strength per unit length of steel pipe wall.
[0005]
[Problems to be solved by the invention]
According to the method for estimating the yield strength of the first steel pipe column beam joint described above, the estimation of the yield strength itself can be performed simply by substituting it into (Equation 0), and the design conditions can be changed in various ways. Thus, it is possible to estimate the joint strength easily and in a short time from the results of many studies. However, on the other hand, if the steel pipe to be calculated has a thickened joint with the beam, or if axial force is acting on the steel pipe, these parameters must be included in the calculation conditions. Therefore, there is a problem in that the estimated calculation result has a variation as a whole as compared with the experimental value and the analysis accuracy is low, as shown in FIG.
In order to solve this problem, there is a method of estimating the yield strength of the joint by FEM analysis that can obtain highly accurate analysis results. In this case, however, preprocessing for analysis and analysis itself are troublesome. There is another problem that it takes a lot of time and costs.
Accordingly, an object of the present invention is to solve the above-mentioned problems and to easily carry out the estimation of the proof stress of the steel pipe column beam joint with higher accuracy and less effort.
[0006]
[Means for Solving the Problems]
The characteristic configuration of the invention of claim 1 is, as illustrated in FIGS. 1 to 4, the collapse mechanism of the joint K2 between the steel pipe column C filled with the concrete 2 in the inner space and the steel beam B, and the yield line. The yield strength (cPy) of the joint K2 is defined by using a yield line theory that derives the yield strength (cPy) of the joint K2 from the cross-sectional yield condition at the yield line. In the method for estimating the yield strength of the steel pipe column-beam joint to be obtained, the steel pipe column C is considered as being divided into the joint K2 having a thick tube thickness and the general part K1 continuous above and below the joint K2. In setting the pipe thickness dimension tp of K2 and the pipe thickness dimension tc of the general part K1 separately, and determining the yield strength (cPy) of the joint part K2, the upper end part of the joint part K2 and the steel beam B Acts on the distance (Lp) from the upper end and the steel pipe column C The yield strength (cPy) is obtained by the following (formula 1) by reflecting the axial force (N) in the yield line theory.
In general, a joint between a steel pipe column and a steel beam is a part where stress is more likely to concentrate than other parts, so in particular, the thickness of the steel pipe should be increased more than other parts for that joint. Thus, it is possible to stiffen the joint in a lean state, and the use of such a joint structure is increasing. However, it has been found that there is a difference in yield strength between the structure in which only the joint portion of the steel pipe is formed thick and the structure in which the entire steel pipe is formed thick. In addition, although it is an ordinary situation that axial force is applied to the steel pipe column, it has been found that the yield strength of the joint is also changed by the action of this axial force.
According to the characteristic configuration of the invention of claim 1, there is a difference in the tube thickness dimension of the steel pipe between the general part of the steel pipe and the joint in the process of estimating the proof stress of the steel pipe column beam joint by the conventional yield line theory. It was possible to incorporate corrections under conditions and conditions under which axial force acts on the steel pipe, making it possible to perform a more accurate yield strength evaluation.
Specifically, the distance between the upper end portion of the joint and the upper end portion of the steel beam and the axial force acting on the steel pipe column are incorporated as new parameters, respectively. A high estimation result can be obtained. As shown in FIG. 5, this is as shown in the relationship between the yield strength experimental result of the steel pipe column beam joint and the yield strength determined by the estimation formula.
[0008]
[Expression 4]
Figure 0003778733
[0009]
[Equation 5]
Figure 0003778733
[0010]
Also, before Symbol (Equation 1), simply by substituting the value of each parameter can be calculated quite easily steel beam-column joints of yield strength (cpy). Accordingly, it is possible to perform a large number of calculations by changing design conditions such as dimensions and materials of each member in a short time, and it is possible to improve the efficiency of design work.
Further, the yield stress (hereinafter simply referred to as a calculated value) of the steel pipe column beam joint determined by the above (Equation 1) is wide from a region where the required yield stress is large to a small region as shown in FIGS. In the range, it is approximate to the experimental value, and it is possible to realize a highly accurate calculation with little variation.
That is, the compatibility with the design work is improved, and the steel pipe column beam joint can be quickly evaluated, and the economic design of the steel pipe column beam joint can be realized.
In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the parts denoted by the same reference numerals as those in the conventional example indicate the same or corresponding parts.
As shown in FIGS. 1, 2, and 3, the steel pipe concrete column / beam joint is formed by joining a steel beam B to a steel pipe concrete column C.
The steel pipe concrete column (corresponding to a steel tube column) C has a structure in which a steel pipe 1 is filled with concrete 2.
The steel beam B is composed of H-shaped steel (or I-shaped steel) having a structure in which upper and lower flanges BF are connected and fixed by a web BW. And the edge part of the steel beam B is processed into the concave shape along the outer periphery of the said steel pipe concrete pillar C. As shown in FIG. And it connects with the steel pipe 1 by welding. As for the dimensions of the welding surplus, the outer surplus dimension of the flange BF is set to S3, the inner surplus dimension of the flange BF is set to S2, and the left and right surplus dimensions of the flange BF are respectively set to S1. Further, Bf denotes a flange width, t f represents the flange thickness. Accordingly, the joint height r t including the weld surplus of the joint is obtained by (S2 + S3 + t f ).
The steel pipe 1 is a centrifugal cast steel pipe, and a joint portion K2 between the longitudinal predetermined ranges including the joint portion 1A to which the steel beam B is fixed is as shown in the figure. Are formed and stiffened to a pipe thickness t p larger than the pipe thickness t c of the general portion K1 extending vertically.
The joint K2 is the inner diameter of the joint portion K2 while equal to the inner diameter of the general part K1, generally a pipe thickness t p of the outer diameter Dp of the junction K2 is made larger than the outer diameter Dc of the general portion K1 It is larger than the tube thickness t c of the portion K1. That is, the steel pipe concrete column C has a constant internal concrete shaft section. The step portion of the joint portion K2 and the general portion K1 is formed in a round shape that gradually changes the tube thickness so as to prevent stress concentration from occurring therein.
The distance between the upper end of the joint K2 and the upper end of the steel beam B is represented by Lp.
Then, in order to evaluate the yield strength (cPy) of this steel pipe concrete column / beam joint, it is calculated and evaluated based on the following formulas (6) and (7).
[0012]
[Formula 6]
Figure 0003778733
[0013]
[Expression 7]
Figure 0003778733
[0014]
Assuming multiple calculation models and substituting each numerical value (see Fig. 6) corresponding to them into the above (Equation 1), the results of estimating the yield strength of the steel pipe column beam joint for each model are shown in Figs. Shown in However, the outer diameter of Dc is generally part of FIG, t c is the pipe thickness of the general portion, Bf is the flange thickness of the flange width, t f is the steel beam of the steel beam, the left and right side excess prime welding extra prime S1 is dimensions, the inner excess prime dimensions of the welding extra prime is S2, S3 outer extra prime dimension of welding excess prime, h p is the thickness increasing dimensions of the outer joint portion, Lp upper end of the junction and the steel beams in steel column , N p is the axial stress ratio of the steel pipe, p σ y is the yield stress at the joint of the steel pipe, c σ y is the yield stress at the general part of the steel pipe, and f σ y is the yield stress of the steel beam Degrees each.
Moreover, the experimental value about the same calculation model and the yield strength of the steel pipe column beam joint calculated by the conventional yield line theory were also described, respectively.
As can be seen from the above, according to the above (Equation 1), an estimated value very close to the “experimental value” is obtained, and at the same time, compared with the result of the conventional “yield line theory”, the steel pipe column beam connection It is possible to carry out the yield strength evaluation of the part more accurately.
Therefore, according to the yield strength estimation formula of the present embodiment, it is possible to appropriately evaluate the yield strength of the steel pipe concrete column / beam joint than the conventional yield strength evaluation method of the steel pipe / column joint. The concrete column can be designed more economically and safely.
Next, the process of deriving the above (Formula 1) will be described.
The inventors set the yield mechanism of the steel pipe column beam joint, as shown in FIG. 4, yield lines AA ′, BB ′, CC ′, DD ′, AB, A′B ′, BC, B′C ′, Assuming CD and C′D ′ respectively, the yield lines of AA ′, BB ′, CC ′, and DD ′ are yielded by bending the steel pipe wall, and AB, A′B ′, BC, and B′C ′. , CD and C′D ′ yield lines were yielded by tension.
Also, in deriving the estimation formula, it is assumed that buckling due to compression and bending does not occur, the tensile stress is defined as positive in the development of the formula, and the compressive yield stress level and bending yield stress level of the steel material are defined. Are the same as the tensile yield stress.
And the total value Ei of the internal work of each yield line is calculated | required, and this estimation formula (Formula 1) is derived | led-out as several 8 as this internal work Ei becomes equal to the external work Ex which the load P which acts on a beam flange makes. It was.
[0015]
[Equation 8]
Figure 0003778733
[0016]
Next, although the experimental value compared with the yield strength of the steel pipe beam joint part by the said estimation formula (Formula 1) was shown in FIG. 7, the experiment is demonstrated easily.
<Test body>
As shown in FIG. 8, the test specimen is a cross-shaped frame with a column / beam joint of about half the size of the actual one. The steel pipe 1 of the steel pipe concrete column C has a JIS standard SMK490 centrifugal force. A cast steel pipe is used, and the steel beam B is made of a beam material of JIS standard SM490A, and sufficient strength is given so that the joint 1A of the steel pipe 1 collapses ahead of the steel beam B. It was. Each specimen has a circular cross-sectional shape. The protruding dimension Lp from the upper and lower ends of the steel beam B to the upper and lower ends of the joint portion K2 was 50 mm (constant) (see FIG. 6).
<Applying device>
As a force application device used for the loading test, the one shown in FIG. 8 was prepared. The outline of the force applying device will be described. The force applying device includes a loading table 3 for loading the lower end of the steel pipe concrete column C of the test specimen, and a 1000 ton loading test machine 4 for applying a load to the upper end of the steel pipe concrete column C of the test specimen. And a group of reaction force beams 5 for restraining the vicinity of the upper end and the vicinity of the lower end of the steel pipe concrete column C of the test body separated by 1600 mm so as to hold the test body in a vertical posture, and an end portion of the beam B of the test body And an oil jack 7 for loading a load Qb via a load cell 6.
<Force type>
The type of loading (loading) on the test body was a vertical loading type. As shown in FIG. 9, the vertical loading format is a vertical-monotonic loading format in which loads Qb1 and Qb2 are monotonously loaded in the same direction on the ends of both steel beams B. And 0.0 and 0.3 were set as an axial force ratio as a ratio with respect to the maximum proof stress of the steel pipe concrete pillar C. FIG. That is, the axial force of 30% of the maximum proof stress is applied to the steel pipe concrete column C or the axial force is not applied.
<Load test>
In the loading test, as shown in FIG. 9, the vertical deformation (deflection) amount δb (δb1, δb2) of the beam end accompanying the monotonous loading of the loads Qb1, Qb2 to both beam ends and the joint 1A The amount of deformation δp (δp1, δp2) in the radial direction was measured using a dial gauge.
[0017]
[Another embodiment]
Other embodiments will be described below.
<1> In the previous embodiment, the joint portion K2 has been described as having a shape that is thickened radially outward of the steel pipe 1, but is not limited to that configuration, for example, the radially inner side of the steel pipe 1 Only the thickened shape or the thickened shape on both the inside and outside in the radial direction of the steel pipe 1 may be used, and in any case, there is no great variation in the estimated strength of the steel pipe column beam joint Has been confirmed.
<2> In the calculation model in the previous embodiment, the distance Lp between the upper end of the joint K2 and the upper end of the steel beam B is 50 mm, the axial force ratio (force (axial force) applied in the axial direction of the steel pipe concrete column) ratio) n c of the axial yield strength of the steel pipe concrete pillars, but with the existing 0.3 following or 0, may be an Lp and n c is other values, the present invention According to this, it is possible to correspond to calculation in a wide range, and it is possible to estimate the yield strength cPy with higher accuracy.
<3> In the above-described embodiment, the steel pipe column beam joint portion in which only the joint portion K2 is thickened is the object of evaluation of the proof stress, but the present invention provides the joint portion K2 in a state where the entire steel pipe 1 is thickened. It can also be applied to the strength evaluation of steel beam-column joints with stiffening.
<4> The yield line is not limited to the shape according to the previous embodiment, and can be considered as being deformed.
[Brief description of the drawings]
FIG. 1 is a side view showing a steel pipe column beam joint. FIG. 2 is a top side view showing a steel pipe column beam joint. FIG. Fig. 4 is an explanatory diagram showing the setting of the yield line. Fig. 5 is an explanatory diagram showing experimental values and estimated strength values. Fig. 6 is an explanatory diagram showing numerical values of the calculation model. Fig. 7 is an explanatory diagram showing calculation results. FIG. 8 is an explanatory diagram showing a side view of an experimental apparatus. FIG. 9 is an explanatory diagram illustrating an experimental method. FIG. 10 is an explanatory diagram illustrating a conventional yield line setting state. Illustration [Explanation of symbols]
cPy junction Yield Strength 2 Concrete B steel beam C steel column K2 junction Lp steel pipe thickness of the joint portion of the axial force t p steel column acting on the distance N steel pipe and the upper end portion of the joint portion and the steel beams in column t c Tube thickness of general part of steel pipe column

Claims (1)

内空部にコンクリートを充填された鋼管柱と、鉄骨梁との接合部の崩壊機構を、降伏線とそれに囲まれた平板部分とで規定し、前記降伏線での断面降伏条件から前記接合部の降伏耐力(cPy)を導く降伏線理論を用いて、前記接合部の降伏耐力(cPy)を求める鋼管柱梁接合部の耐力推定方法であって、
前記鋼管柱を、管厚寸法を厚肉に形成した前記接合部と、それの上下に連なる一般部とに分けて考え、前記接合部の管厚寸法と、前記一般部の管厚寸法を別々に設定し、前記接合部の降伏耐力(cPy)を求めるにあたり、前記接合部の上端部と前記鉄骨梁の上端部との距離(Lp)、及び、前記鋼管柱に作用する軸力(N)を前記降伏線理論に反映させて前記降伏耐力(cPy)を下記の(式1)で求める鋼管柱梁接合部の耐力推定方法。
Figure 0003778733
Figure 0003778733
The collapse mechanism of the joint between the steel pipe column filled with concrete in the inner space and the steel beam is defined by the yield line and the flat plate part surrounded by it, and the joint is determined from the cross-sectional yield condition at the yield line. The yield strength (cPy) of the steel pipe column beam joint part which calculates | requires the yield strength (cPy) of the said joint part using the yield line theory which derives | leads-out yield strength (cPy),
The steel pipe column is considered to be divided into the joint portion in which the tube thickness dimension is formed thick and the general portion connected to the upper and lower sides thereof, and the tube thickness dimension of the joint portion and the pipe thickness dimension of the general portion are separated. In determining the yield strength (cPy) of the joint, the distance (Lp) between the upper end of the joint and the upper end of the steel beam, and the axial force (N) acting on the steel pipe column The yield strength (cPy) is estimated by the following (Formula 1) by reflecting the above in the yield line theory.
Figure 0003778733
Figure 0003778733
JP21377199A 1999-07-28 1999-07-28 Strength estimation method for steel beam-column joint. Expired - Fee Related JP3778733B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP21377199A JP3778733B2 (en) 1999-07-28 1999-07-28 Strength estimation method for steel beam-column joint.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP21377199A JP3778733B2 (en) 1999-07-28 1999-07-28 Strength estimation method for steel beam-column joint.

Publications (2)

Publication Number Publication Date
JP2001041866A JP2001041866A (en) 2001-02-16
JP3778733B2 true JP3778733B2 (en) 2006-05-24

Family

ID=16644773

Family Applications (1)

Application Number Title Priority Date Filing Date
JP21377199A Expired - Fee Related JP3778733B2 (en) 1999-07-28 1999-07-28 Strength estimation method for steel beam-column joint.

Country Status (1)

Country Link
JP (1) JP3778733B2 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5946613B2 (en) * 2011-07-29 2016-07-06 大和ハウス工業株式会社 Strength prediction method for steel column beam joint with different diameters of upper and lower columns
CN108426765B (en) * 2018-03-30 2024-04-26 西南交通大学 Fatigue test device for steel bridge deck test piece
KR101942939B1 (en) * 2018-07-27 2019-01-28 목포대학교산학협력단 Use of the broken coupler testing device on the scaffold and the breaking test method of the scaffold
JP7356109B2 (en) 2020-04-23 2023-10-04 株式会社神戸製鋼所 Evaluation method for deformation performance of square steel pipes

Also Published As

Publication number Publication date
JP2001041866A (en) 2001-02-16

Similar Documents

Publication Publication Date Title
US11821806B2 (en) Calculation method of ultimate moment resistance and moment-rotation curve for steel beam to concrete-filled steel tube column connections with bidirectional bolts
Cheng et al. Seismic performance of steel beams to concrete-filled steel tubular column connections
JP3778733B2 (en) Strength estimation method for steel beam-column joint.
CN105806572A (en) Single-layer latticed shell structure node semi-rigid measuring method
JP2020200751A (en) Model of restoring force characteristic of concrete pile with double steel pipe, and method for modeling restoring force characteristic
JP3456479B2 (en) Concrete filled circular steel tubular column
JP5946613B2 (en) Strength prediction method for steel column beam joint with different diameters of upper and lower columns
JP4898374B2 (en) Strength evaluation method of steel pipe concrete column / beam joint
CN206571413U (en) A kind of section construction engineering creeping ladder
JP6827278B2 (en) How to design a beam-column joint structure
JP2019007172A (en) Column beam joining structure
JP5160258B2 (en) Beam-column joint structure and structure
JPH11200489A (en) Steel pipe column having joining metallic materials and annular joining metallic material
JP2007169930A (en) Lap joint for connecting concrete members or the like, and method of designing the same
JP3861961B2 (en) Method for obtaining the strength of beam-column joints in steel pipe columns.
JP7116269B1 (en) Non-diaphragm brace structure
JPH0835923A (en) Estimation method of proof stress of steel-pipe-pillar-beam jointed part
JP2018162654A (en) Pile head joint part design method, construction method, design drawing, specification for pile head anchor reinforcement, and pile head anchor reinforcement attachment position checking device
JP3434427B2 (en) Through-hole reinforcement for reinforced concrete structures
JP2010047941A (en) Joint structure of column and beam
JPS62268422A (en) Friction pile
JP2570578Y2 (en) Concrete filled steel pipe column
JP2024027801A (en) Method for calculating shear strength of pile cap
JPH0711732A (en) Steel frame perforated beam and building
CN116305405A (en) External inhaul cable ultimate stress and external inhaul cable stiffening beam section strength analysis method

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20040723

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20051024

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20051027

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20051219

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20060216

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20060228

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20090310

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100310

Year of fee payment: 4

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110310

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110310

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120310

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130310

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140310

Year of fee payment: 8

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees