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JP6095906B2 - Design method for joint structure between CFT frame and column - Google Patents
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JP6095906B2 - Design method for joint structure between CFT frame and column - Google Patents

Design method for joint structure between CFT frame and column Download PDF

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JP6095906B2
JP6095906B2 JP2012137334A JP2012137334A JP6095906B2 JP 6095906 B2 JP6095906 B2 JP 6095906B2 JP 2012137334 A JP2012137334 A JP 2012137334A JP 2012137334 A JP2012137334 A JP 2012137334A JP 6095906 B2 JP6095906 B2 JP 6095906B2
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cft
column
pillar
resistance
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JP2014001552A (en
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貴穂 河野
貴穂 河野
富男 土屋
富男 土屋
宇佐美 徹
徹 宇佐美
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Takenaka Corp
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Description

本発明は、CFT構真柱と構真台柱の接合構造の設計方法に関する。 The present invention relates to a method for designing a joint structure of a CFT frame column and a frame column.

従来の逆打ち工事においては、構真柱にはH型鋼若しくはクロスH型鋼等の鋼材が広く使用され、構真柱の構真台柱への根入れ部分には、頭付スタッドが取り付けられていた。
この結果、図11(A)〜図11(D)に示すように、構真柱70に作用する軸力(鉛直荷重)Pは、構真柱70の外周面と構真台柱72のコンクリートとの間の付着抵抗N(kN)、スタッド74と構真台柱72との間のスタッド抵抗N(kN)、及び構真柱70の下端面と構真台柱72との間の支圧抵抗N(kN)とが合計された抵抗N(kN)により支持されていた。
In conventional backlash construction, steel materials such as H-shaped steel or cross H-shaped steel are widely used for the structural pillars, and headed studs are attached to the bases of the structural pillars to the structural support pillars. .
As a result, as shown in FIGS. 11 (A) to 11 (D), the axial force (vertical load) P acting on the construction column 70 is equal to the outer peripheral surface of the construction column 70 and the concrete of the construction column 72. Adhesion resistance N f (kN) between the stud 74, the stud resistance N s (kN) between the stud 74 and the structural stand column 72, and the bearing resistance between the lower end surface of the construction post 70 and the structural stand column 72. N b (kN) and the total resistance N (kN) were supported.

また、構真台柱72に作用した構真柱70からの軸力(鉛直加重)Pは、構真台柱72と地盤との間の周面摩擦抵抗、及び構真台柱の下端面と地盤との間の支圧抵抗により地盤に伝達される。このような軸力Pの伝達経路を考慮して、構真柱70の根入れ部の設計方法が提案されている(例えば、非特許文献1、2参照)。   In addition, the axial force (vertical load) P from the structural column 70 that has acted on the structural column 72 is a frictional resistance between the circumferential surface between the structural column 72 and the ground, and the lower end surface of the structural column and the ground. It is transmitted to the ground by the bearing resistance between. In consideration of such a transmission path of the axial force P, a method for designing a base portion of the structural pillar 70 has been proposed (for example, see Non-Patent Documents 1 and 2).

近年、建物の高層化に伴う建物重量の増加に対応するため、構真柱としてコンクリート充填鋼管柱(以下、CFT柱と記す)が利用されるようになってきている。CFT柱は、従来のRC柱(鉄筋コンクリート柱)やSRC柱(鉄骨鉄筋コンクリート柱)に比べ、大きな曲げ耐力及びせん断耐力を有する大断面(例えば一辺が700mm〜1000mm程度)の柱である。   In recent years, concrete filled steel pipe columns (hereinafter referred to as CFT columns) have come to be used as construction columns in order to cope with the increase in building weight accompanying the increase in the number of buildings. The CFT column is a column having a large cross section (for example, one side of about 700 mm to 1000 mm) having a large bending strength and shear strength compared to conventional RC columns (reinforced concrete columns) and SRC columns (steel reinforced concrete columns).

一方、構真柱からの軸力を受けて地盤に伝達する構真台柱は、構真台柱に用いるコンクリートの強度の増加や、拡径率(杭軸部の径に対する杭先端の径の比)が高い拡径杭の増加等により、軸部の外径が小さくなる(例えば外径が1400mm〜3000mm程度)傾向にある。   On the other hand, the structural stand column that receives the axial force from the structural stem and transmits it to the ground increases the strength of the concrete used for the structural stand column and the expansion rate (ratio of the diameter of the pile tip to the diameter of the pile shaft) However, there is a tendency that the outer diameter of the shaft portion becomes smaller (for example, the outer diameter is about 1400 mm to 3000 mm) due to an increase in the diameter-expanded pile.

CFT柱を用いた建物を逆打ち工法により構築する場合、CFT柱をそのままCFT構真柱として利用する場合が多い(例えば、特許文献1参照)。
ここに、特許文献1は、先端部にコンクリートを充填したCFT鋼管柱を、杭穴内に建て込んだ後に、杭コンクリートを打設して構真柱としての鉛直精度を確保する。次いで、CFT鋼管の中空内部にコンクリートを充填してCFT柱とする構成である。
When a building using a CFT column is constructed by a reverse driving method, the CFT column is often used as a CFT structural column as it is (see, for example, Patent Document 1).
Here, Patent Document 1 secures the vertical accuracy as a built-up column by placing a pile concrete after a CFT steel pipe column filled with concrete at the tip is built in the pile hole. Next, concrete is filled into the hollow inside of the CFT steel pipe to form a CFT column.

しかし、従来の方法に従って構築された構真台柱で特許文献1のCFT構真柱を支持させた場合、構真台柱の軸部の外径に対してCFT構真柱の幅(又は外径)が大きくなり、構真台柱の支持力(抵抗)が不足して、CFT構真柱に作用する軸力を構真台柱へ伝達できなくなる恐れがある。   However, when the CFT built-up column of Patent Document 1 is supported by a built-up column constructed according to a conventional method, the width (or outer diameter) of the CFT built-up column with respect to the outer diameter of the shaft portion of the built-up column. As a result, the support force (resistance) of the frame pillar becomes insufficient, and the axial force acting on the CFT frame pillar may not be transmitted to the frame pillar.

特開平11−264134号公報JP-A-11-264134 若林嘉津雄:建築構造と施工の接点、学芸出版、PP.98−111、1990Kazuo Wakabayashi: The point of contact between architectural structure and construction, Gakugei Publishing, PP. 98-111, 1990 石井修, 中山信雄, 伊藤栄俊, 堀江邦彦:逆打ち工法を知る II 施工計画 構造検討事項、建築技術、NO.592、PP.112−120 、1990Osamu Ishii, Nobuo Nakayama, Eitoshi Ito, Kunihiko Horie: Knowing the Reverse Method II Construction Plan Structure Considerations, Construction Technology, NO. 592, PP. 112-120, 1990

本発明は、上記事実に鑑み、構真台柱の径に対してCFT構真柱の幅が大きくなった場合においても、CFT構真柱に作用する軸力を構真台柱へ伝達できるCFT構真柱と構真台柱の接合構造の設計方法を提供することを目的とする。 In view of the above fact, the present invention provides a CFT structure that can transmit the axial force acting on the CFT structure column to the structure column even when the width of the CFT structure column becomes larger than the diameter of the structure column. It is an object of the present invention to provide a method for designing a joint structure between a column and a structural stand column.

請求項1に記載の発明に係るCFT構真柱と構真台柱の接合構造の設計方法は、建物を支持し、根入れ部にスタッドが設けられたCFT構真柱と、前記根入れ部が挿入され、前記根入れ部を抵抗Nで支持する構真台柱と、を有するCFT構真柱と構真台柱の接合構造において下記(1)式で算出される前記抵抗Nを前記建物から前記CFT構真柱に伝達される軸力より大きくる、ことを特徴としている。



ここに、
N :N及びNで求められた構真台柱の抵抗のうち値の小さい方(kN)
:N、N及びNから求められるCFT構真柱の根入れ部における構真台柱の抵抗(kN)
:コンクリートの許容圧縮応力度から求められるCFT構真柱の根入れ部における構真台柱の抵抗(kN)
:CFT構真柱の外周面と構真台柱との間の付着抵抗(kN)
:CFT構真柱の先端面と構真台柱との間の支圧抵抗(kN)
:スタッドと構真台柱との間のスタッド抵抗(kN)
α :累加係数(通常0.5)
β :累加係数(通常0.8)
σ:構真台柱コンクリートの許容圧縮応力度(kN/m2)
:構真台柱の断面積からスタッドを含むCFT構真柱の投影断面積を差し引いた断面積(m
According to the first aspect of the present invention, there is provided a method for designing a joint structure between a CFT frame column and a frame column, which supports a building and has a stud provided at a root portion, and the root portion includes: is inserted, said a構真stand pillars to support the embedment section in resistance N, in the bonding structure of the CFT構真columns and構真table columns that have the said building the resistance N calculated by the following equation (1) it greater than the axial force transmitted to the CFT構真columns from is characterized by.



here,
N: The smaller value (kN) of the resistance of the structural pillar obtained by N 1 and N 2
N 1 : The resistance of the framing pillar (kN) at the root of the CFT framing pillar obtained from N f , N b and N s
N 2 : resistance of the pedestal column (kN) at the root of the CFT pedestal column obtained from the allowable compressive stress of concrete
N f : Adhesion resistance (kN) between the outer peripheral surface of the CFT frame column and the frame column
N b : bearing resistance (kN) between the tip surface of the CFT true pillar and the true pillar
N s : Stud resistance (kN) between the stud and the stem
α: cumulative coefficient (usually 0.5)
β: cumulative coefficient (usually 0.8)
σ c : Permissible compressive stress level of kamadai column concrete (kN / m2)
A c : cross-sectional area (m 2 ) obtained by subtracting the projected cross-sectional area of the CFT true column including the stud from the cross-sectional area of the true pillar

請求項1に記載の発明によれば、構真台柱における、CFT構真柱の根入れ部を支持する抵抗N(1)式により算出る。また、建物からCFT構真柱に伝達される軸力に対し、抵抗N大きくる。
ここに(1)式は、(2)式と(3)式で算出されたCFT構真柱の根入れ部の抵抗N、Nのうち、小さい方を選択して抵抗Nとする。
According to the invention described in claim 1, in構真stand column, we calculate the resistance N to support the embedment portion of the CFT構真column (1). Further, the axis force transmitted from the building to the CFT構真column, you resistance N increases.
Here, in the formula (1), the smaller one of the resistances N 1 and N 2 of the root portion of the CFT true column calculated by the formulas (2) and (3) is selected as the resistance N.

れにより、実際の抵抗値により近い、CFT構真柱の根入れ部における構真台柱の抵抗Nを算出することができる。建物からCFT構真柱に伝達される軸力に対し抵抗Nを大きい値に調整することで、CFT構真柱に作用する軸力を構真台柱へ伝達できるCFT構真柱と構真台柱の接合構造を提供することができる。 This ensures closer to the actual resistance value, it can be calculated resistance N of 構真Taibashira the embedment portion of the CFT構真columns. By the axial force transmitted from the building to the CFT構真pillar adjusting the resistance N to a large value, CFT構真columns capable of transmitting an axial force acting on CFT構真column to構真stand pillars and構真table column A joining structure can be provided.

請求項2に記載の発明は、請求項1に記載のCFT構真柱と構真台柱の接合構造の設計方法において、前記CFT構真柱の幅(D)に対する前記構真台柱の径(Φ)の比R(R=Φ/D)2.0以上、且つ3.0未満とすことを特徴としている。
ち、比Rが2.0以上で、且つ3.0未満の範囲において、CFT構真柱に作用する軸力を構真台柱へ伝達することができる。
According to a second aspect of the present invention, there is provided a method for designing a joint structure between a CFT true pillar and a true pillar according to claim 1, wherein the diameter (Φ) of the true pillar relative to the width (D) of the CFT true pillar ) ratio R (R = Φ / D) 2.0 or more on, shall be the and less than 3.0, it is characterized in that.
Immediately Chi, the ratio R of 2.0 or more, and in a range of less than 3.0, it is possible to transmit the axial force acting on CFT構真column to構真stand pillars.

請求項3に記載の発明に係るCFT構真柱と構真台柱の接合構造の設計方法は、建物を支持し、根入れ部にスタッドが設けられたCFT構真柱と、前記CFT構真柱が根入れされる根入れ部に補強部材が設けられている構真台柱と、を有するCFT構真柱と構真台柱の接合構造において、前記補強部材を、下記(4)式を満たす強度とする、ことを特徴としている。

ここに、
:構真台柱の面積に対する補強部材の断面積の割合(%)
σsy:補強部材の降伏強度(kN/m
σct:建物からCFT構真柱に伝達される軸力に基づいて算出される構真台柱に作用する引張応力(kN/m

請求項3に記載の発明によれば、構真台柱における、CFT構真柱が根入れされる根入れ部に設けられている補強部材を(4)式を満たす強度とする。また、CFT構真柱の根入れ部には、スタッドが設けられている。
この補強部材が、構真台柱に作用する圧縮応力を分担することにより、構真台柱の径に対してCFT構真柱の幅が大きくなった場合においても、CFT構真柱に作用する軸力を構真台柱へ伝達できる、CFT構真柱と構真台柱の接合構造の設計方法を提供することができる。
A method for designing a joint structure between a CFT frame column and a frame column according to the invention described in claim 3 is a CFT frame column that supports a building and has a stud at a root portion, and the CFT frame column strength but to meet at the junction structure of the CFT構真columns and構真stand column having a構真stand pillars reinforcement member is provided on the embedment portion being embedment, the reinforcing member, the following equation (4) that is characterized in that.

here,
P w: ratio of the cross-sectional area of the reinforcing member to the area of構真stand pillars (%)
σ sy : yield strength of reinforcing member (kN / m 2 )
σ ct : Tensile stress (kN / m 2 ) acting on the frame base calculated based on the axial force transmitted from the building to the CFT column

According to the invention described in claim 3, in構真stand column, a reinforcing member CFT構真pillar is provided embedment portion being embedment (4) shall be the intensity satisfying equation. In addition, a stud is provided at the base portion of the CFT true pillar.
This reinforcing member shares the compressive stress acting on the frame column so that the axial force acting on the CFT frame column even when the width of the CFT column is larger than the diameter of the frame column. It is possible to provide a design method for the joint structure between the CFT true pillar and the true pillar.

求項4に記載の発明は、請求項3に記載のCFT構真柱と構真台柱の接合構造の設計方法において、前記構真台柱の断面積(A)に対する前記補強部材の断面積(A)の割合P(P=A/A0.45%以上とすことを特徴としている。
この結果、補強部材により、CFT構真柱と構真台柱の接合強度を高く維持することができる。
The invention described in Motomeko 4, the cross-sectional of the reinforcing member in the design method of the joining structure of the CFT構真columns and構真stand column according to claim 3, to the cross-sectional area before Symbol構真stand pillars (A 1) area percentage of (a 2) P w (P w = a 2 / a 1) shall be the 0.45% or more, is characterized by.
As a result, it is possible to maintain a high joint strength between the CFT true column and the true stand column by the reinforcing member.

本発明は、上記構成としてあるので、構真台柱の径に対してCFT構真柱の幅が大きくなった場合においても、CFT構真柱に作用する軸力を構真台柱へ伝達させることができる。   Since the present invention is configured as described above, even when the width of the CFT true pillar is larger than the diameter of the true pillar, the axial force acting on the CFT true pillar can be transmitted to the true pillar. it can.

(A)は、本発明の第1の実施の形態に係るCFT構真柱と構真台柱の接合構造の基本構成を示す接合部の横断面図であり、(B)は縦断面図である。(A) is a cross-sectional view of a joint portion showing the basic configuration of the joint structure of the CFT true column and the true stand column according to the first embodiment of the present invention, and (B) is a vertical cross-sectional view. . (A)は、本発明の第1の実施の形態に係るCFT構真柱と構真台柱の接合構造の模型実験の試験体1の横断面図及び縦断面図であり、(B)は試験体2の横断面図及び縦断面図であり、(C)は試験体3の横断面図及び縦断面図である。(A) is the cross-sectional view and longitudinal cross-sectional view of the test body 1 of the model experiment of the joint structure of the CFT true column and the true stand column according to the first embodiment of the present invention, and (B) is the test FIG. 2C is a transverse sectional view and a longitudinal sectional view of the body 2, and FIG. 本発明の第1の実施の形態に係るCFT構真柱と構真台柱の接合構造の模型実験の試験体1〜試験体3の代表寸法を示す図である。It is a figure which shows the representative dimension of the test body 1-the test body 3 of the model experiment of the junction structure of the CFT frame column and the frame mount based on the 1st Embodiment of this invention. 本発明の第1の実施の形態に係るCFT構真柱と構真台柱の接合構造の模型実験の実験結果を示す図であり、(A)はP−δ特性を(B)は最大鉛直加重を示している。It is a figure which shows the experimental result of the model experiment of the joint structure of the CFT frame column and frame column based on the 1st Embodiment of this invention, (A) is a P-delta characteristic, (B) is the maximum vertical load. Is shown. (A)と(B)は、いずれも本発明の第1の実施の形態に係るCFT構真柱と構真台柱の接合構造の他の展開例を示す接合部の横断面図である。(A) And (B) is a cross-sectional view of the junction part which shows the other example of expansion | deployment of the junction structure of the CFT construction true pillar and the construction stand pillar which concern on the 1st Embodiment of this invention. (A)は、本発明の第2の実施の形態に係るCFT構真柱と構真台柱の接合構造の基本構成を示す接合部の横断面図であり、(B)は縦断面図である。(A) is a cross-sectional view of a joint portion showing a basic configuration of a joint structure of a CFT true pillar and a true pillar according to a second embodiment of the present invention, and (B) is a vertical cross-sectional view. . 本発明の第2の実施の形態に係る構真台柱に作用する引張応力の算定方法を示す図である。It is a figure which shows the calculation method of the tensile stress which acts on the frame column based on the 2nd Embodiment of this invention. (A)は、本発明の第2の実施の形態に係るCFT構真柱と構真台柱の接合構造の模型実験の試験体4の横断面図及び縦断面図であり、(B)は試験体5の横断面図及び縦断面図であり、(C)は試験体6の横断面図及び縦断面図であり、(D)は試験体7の横断面図及び縦断面図である。(A) is the cross-sectional view and longitudinal cross-sectional view of the test body 4 of the model experiment of the joint structure of the CFT frame column and the frame column according to the second embodiment of the present invention, and (B) is the test FIG. 2C is a transverse sectional view and a longitudinal sectional view of the test body 6, FIG. 3C is a transverse sectional view and a longitudinal sectional view of the test body 6, and FIG. 本発明の第2の実施の形態に係るCFT構真柱と構真台柱の接合構造の模型実験の試験体4〜試験体7の代表寸法を示す図である。It is a figure which shows the representative dimension of the test body 4-the test body 7 of the model experiment of the joining structure of the CFT frame column and frame frame column based on the 2nd Embodiment of this invention. 本発明の第2の実施の形態に係るCFT構真柱と構真台柱の接合構造の模型実験の実験結果を示す図であり、(A)はP−δ特性を、(B)は最大鉛直加重を示している。It is a figure which shows the experimental result of the model experiment of the joining structure of the CFT frame column and frame column based on the 2nd Embodiment of this invention, (A) is a P-delta characteristic, (B) is maximum vertical. The weight is shown. 従来例のCFT構真柱と構真台柱の接合構造の構真柱根入れ部における荷重伝達方法を示す図である。It is a figure which shows the load transmission method in the frame column penetration part of the joining structure of the CFT frame column of a prior art example, and a frame column.

(第1の実施形態)
図1〜図5を用いて、第1の実施形態に係るCFT構真柱と構真台柱の接合構造10について説明する。
ここに、図1は、本発明の第1の実施の形態に係るCFT構真柱と構真台柱の接合構造の基本構成を示す図であり、図2は、模型実験の試験体1〜試験体3の横断面図及び縦断面図であり、図3は、試験体1〜試験体3の代表寸法を示す図であり、図4は、模型実験の実験結果を示す図であり、図5は、他の展開例を示す接合部の横断面図である。
(First embodiment)
A joint structure 10 of a CFT true pillar and a true pillar according to the first embodiment will be described with reference to FIGS.
FIG. 1 is a diagram showing a basic configuration of the joint structure of the CFT true pillar and the true pillar according to the first embodiment of the present invention, and FIG. FIG. 3 is a diagram showing representative dimensions of the test body 1 to the test body 3, and FIG. 4 is a diagram showing an experimental result of a model experiment. These are the cross-sectional views of the junction part which shows the other example of an expansion | deployment.

図1に示すように、第1の実施形態に係るCFT構真柱と構真台柱の接合構造10は、根入れ部36にスタッド16が設けられたCFT構真柱12を有している。
CFT構真柱12は、一辺がDの正方形の角形鋼管の内部に、コンクリート18が充填されたコンクリート充填鋼管である。CFT構真柱12の下部は根入れ部36とされ、構真台柱14に深さHで根入れされている。CFT構真柱12の根入れ部36の外周面には、頭付きスタッド16が複数本、所定の間隔を開けて設けられている。
As shown in FIG. 1, the joint structure 10 of the CFT true pillar and the true stand pillar according to the first embodiment has a CFT true pillar 12 in which a stud 16 is provided in a root portion 36.
The CFT true column 12 is a concrete-filled steel pipe in which concrete 18 is filled inside a square steel pipe with a square D having a side. A lower portion of the CFT frame pillar 12 is a root insertion portion 36, and is rooted at a depth H in the frame pillar 14. A plurality of studs 16 with heads 16 are provided at predetermined intervals on the outer peripheral surface of the insertion portion 36 of the CFT true pillar 12.

構真台柱14は、地中に埋設され、CFT構真柱12を支持する外径Φの鉄筋コンクリート製の柱体である。構真台柱14には、CFT構真柱12の根入れ部36が深さHで根入れされ、CFT構真柱12から伝達される鉛直荷重Pは、構真台柱14を介して周囲の地盤へ伝達される。   The structure stand pillar 14 is a reinforced concrete pillar body having an outer diameter Φ that is embedded in the ground and supports the CFT structure pillar 12. The root section 36 of the CFT structural pillar 12 is embedded at the depth H in the structural pillar 14, and the vertical load P transmitted from the CFT structural pillar 12 is transmitted to the surrounding ground via the structural pillar 14. Is transmitted to.

このような構成において、CFT構真柱12が根入れされる構真台柱14の抵抗N(kN)は、下記(1)式で算出することができる。


ここに、
N :N及びNで求められた構真台柱の抵抗のうち値の小さい方(kN)
:N、N及びNの和から求められるCFT構真柱の根入れ部における構真台柱の抵抗(kN)
:コンクリートの許容圧縮応力度から求められるCFT構真柱の根入れ部における構真台柱の抵抗(kN)
:CFT構真柱の外周面と構真台柱との間の付着抵抗(kN)
:CFT構真柱の先端面と構真台柱との間の支圧抵抗(kN)
:スタッドと構真台柱との間のスタッド抵抗(kN)
α :累加係数(通常0.5)
β :累加係数(通常0.8)
σ :構真台柱コンクリートの許容圧縮応力度(kN/m
:構真台柱の断面積からスタッドを含むCFT構真柱の投影面積を差し引いた断面積(m
In such a configuration, the resistance N (kN) of the built-up column 14 in which the CFT built-up column 12 is incorporated can be calculated by the following equation (1).


here,
N: The smaller value (kN) of the resistance of the structural pillar obtained by N 1 and N 2
N 1 : The resistance of the framing pillar (kN) at the root of the CFT framing pillar obtained from the sum of N f , N b and N s
N 2 : resistance of the pedestal column (kN) at the root of the CFT pedestal column obtained from the allowable compressive stress of concrete
N f : Adhesion resistance (kN) between the outer peripheral surface of the CFT frame column and the frame column
N b : bearing resistance (kN) between the tip surface of the CFT true pillar and the true pillar
N s : Stud resistance (kN) between the stud and the stem
α: cumulative coefficient (usually 0.5)
β: cumulative coefficient (usually 0.8)
σ c : Permissible compressive stress level of structural support column concrete (kN / m 2 )
A c : Cross-sectional area (m 2 ) obtained by subtracting the projected area of the CFT true prism including the stud from the cross-sectional area of the true pillar

次に、抵抗Nの具体的な算出方法について説明する。
先ず(2)式で構真台柱14の抵抗N(kN)を算出する。
ここに(2)式は、上述した非特許文献1、2に記載された式であり、従来から広く使用されている。(2)式を用いることで、構真柱12の外周面と構真台柱14のコンクリートとの間の付着抵抗N(kN)、スタッド16と構真台柱14との間のスタッド抵抗N(kN)、及び構真柱12の下端面と構真台柱14との間の支圧抵抗N(kN)とが合計された構真台柱14の抵抗N(kN)が算出される。
Next, a specific method for calculating the resistance N will be described.
First, the resistance N 1 (kN) of the countersunk column 14 is calculated by the equation (2).
Here, equation (2) is the equation described in Non-Patent Documents 1 and 2 described above, and has been widely used in the past. By using the expression (2), the adhesion resistance N f (kN) between the outer peripheral surface of the stem column 12 and the concrete of the stem column 14, and the stud resistance N s between the stud 16 and the stem column 14 (KN) and the resistance N 1 (kN) of the truth column 14 obtained by adding up the bearing resistance N b (kN) between the lower end surface of the truth column 12 and the truth column 14 are calculated.

次に、(3)式で構真台柱14の抵抗N(kN)を算出する。
ここに(3)式は新たに提案された式であり、(3)式を用いることで、構真台柱14を構成するコンクリートの許容圧縮応力度σと、構真台柱14の断面積からスタッド16を含むCFT構真柱12の投影面積を差し引いた断面積A(m)との積から、構真台柱14の抵抗N(kN)が算出される。
Next, the resistance N 2 (kN) of the frame base 14 is calculated by the equation (3).
Here, the expression (3) is a newly proposed expression, and by using the expression (3), the allowable compressive stress σ c of the concrete that constitutes the structural pillar 14 and the cross-sectional area of the structural pillar 14 are obtained. From the product of the cross-sectional area A c (m 2 ) obtained by subtracting the projected area of the CFT true pillar 12 including the stud 16, the resistance N 2 (kN) of the true pillar 14 is calculated.

最後に(1)式により、(2)式で算出された抵抗N(kN)と(3)式で算出された抵抗N(kN)が比較され、小さい方の値が選択され抵抗N(kN)とされる。
この抵抗N(kN)により、構真柱12から構真台柱14に作用する軸力(荷重)P(kN)が支持される。
Finally, the resistance N 1 (kN) calculated by the expression (2) and the resistance N 2 (kN) calculated by the expression (3) are compared by the expression ( 1 ), and the smaller value is selected and the resistance N (KN).
This resistance N (kN) supports the axial force (load) P (kN) that acts on the beam support column 14 from the beam support column 12.

次に、(1)式〜(3)式の適用範囲について説明する。
(1)式〜(3)式の適用範囲としては、CFT構真柱12の幅Dに対する構真台柱14の径Φの比R(R=Φ/D)が、2.0以上で、且つ3未満(2.0≦R<3.0)が望ましい。
Next, the application range of the equations (1) to (3) will be described.
As an application range of the formulas (1) to (3), the ratio R (R = Φ / D) of the diameter Φ of the scaffold base 14 to the width D of the CFT true pillar 12 is 2.0 or more, and Less than 3 is desirable (2.0 ≦ R <3.0).

上限である比Rが3.0未満という条件については、(2)式は、従来から用いられている式であり、後述すように、比Rが3.0以上の範囲では、(2)式で実際の抵抗とほぼ等しい値を算出することができるため、この範囲を除外するため比Rが3.0未満とした。
一方、下限である比Rが2.0以上という条件については、根切り部36の角部において、CFT構真柱12を囲むコンクリートの被り厚さKが絶対量が不足し(例えば、比Rが2.0ではコンクリートの最小被り厚さKが約0.3Dとなる)、構真台柱14として要求される安全率を物理的に確保できなくなるため、比Rの下限を2.0以上とした。
Regarding the condition that the upper limit ratio R is less than 3.0, the expression (2) is a conventionally used expression. As will be described later, in the range where the ratio R is 3.0 or more, (2) Since a value almost equal to the actual resistance can be calculated by the equation, the ratio R is set to less than 3.0 in order to exclude this range.
On the other hand, for the condition that the ratio R, which is the lower limit, is 2.0 or more, the absolute thickness of the concrete covering thickness K surrounding the CFT frame pillar 12 at the corner of the root cutting portion 36 is insufficient (for example, the ratio R Is 2.0, the minimum covering thickness K of the concrete is about 0.3D), and the safety factor required for the construction column 14 cannot be physically secured, so the lower limit of the ratio R is set to 2.0 or more. did.

従って、(1)式〜(3)式を用いることにより、構真台柱14の軸部の径Φに対し、CFT構真柱12の幅Dが相対的に大きくなり、(2)式では、構真台柱14の抵抗N(支持力)が過大に算出される範囲(比Rが2.0以上で且つ3未満)において、後述するように、構真台柱14の実際の抵抗とほぼ等しい抵抗Nを算出することができる。   Therefore, by using the formulas (1) to (3), the width D of the CFT frame column 12 becomes relatively large with respect to the diameter Φ of the shaft portion of the frame column 14, and in the equation (2), In a range in which the resistance N (supporting force) of the frame holder 14 is excessively calculated (the ratio R is 2.0 or more and less than 3), as will be described later, the resistance is substantially equal to the actual resistance of the beam holder 14. N can be calculated.

次に、(1)式〜(3)式の妥当性について実証実験結果を用いて説明する。
実証実験は、CFT構真柱の根入れ部の抵抗を把握するため、実際の構真柱の根入れ部の1/5程度のスケールの構造模型を用いて実施した。
試験体は図2に示す3種類(試験体1〜3)とした。試験体1〜3は、径Φの異なる3種類の構真台柱28、30、32を用いて行った。また、試験体1〜3の構真台柱28、30、32には、いずれも一辺の幅がD1のCFT構真柱26が根入れされている。
Next, the validity of the equations (1) to (3) will be described using the results of demonstration experiments.
The demonstration experiment was carried out using a structural model having a scale of about 1/5 of that of the actual framing column.
Three types of test bodies (test bodies 1 to 3) shown in FIG. 2 were used. The test bodies 1 to 3 were carried out using three kinds of structural support columns 28, 30, and 32 having different diameters Φ. In addition, the CFT construction pillars 26 having a side width D1 are all incorporated in the construction pillars 28, 30, and 32 of the test bodies 1 to 3.

実証実験は、試験体1〜3のそれぞれについて、構真柱26の上部に鉛直荷重Pを加え、鉛直荷重Pを徐々に大きくし、鉛直荷重Pに対する構真台柱28、30、32の変位量δを計測した。   In the demonstration experiment, the vertical load P is applied to the upper part of the construction column 26 for each of the test bodies 1 to 3, and the vertical load P is gradually increased, so that the displacement amount of the construction platform columns 28, 30, and 32 with respect to the vertical load P is increased. δ was measured.

図3に試験体1〜3の各部の代表寸法を示す。
構真柱26の幅D1は試験体1〜3ですべて同じ寸法(200mm)とした。構真柱26が根入れされた試験体1の構真台柱28の径Φ1は600mm、試験体2の径Φ2は500mm、試験体3の径Φ3は400mmとした。
この結果、試験体1〜3の構真柱26の幅D1に対する構真台柱28、30、32の径Φ1〜Φ3の比R(R=Φ/D)は、R=2.0〜3.0の範囲となった。また、試験体1〜3の構真柱26を囲む構真台柱28、30、32のコンクリートの最小被り厚さK1〜K3は、0.3D〜0.8Dの範囲であった。
FIG. 3 shows representative dimensions of each part of the test bodies 1 to 3.
The width D1 of the true pillar 26 was set to the same dimension (200 mm) in the test bodies 1 to 3. The diameter [Phi] 1 of the structural support column 28 of the test body 1 in which the structural pillar 26 was embedded was 600 mm, the diameter [Phi] 2 of the test body 2 was 500 mm, and the diameter [Phi] 3 of the test body 3 was 400 mm.
As a result, the ratio R (R = Φ / D) of the diameters Φ1 to Φ3 of the structural pillars 28, 30, 32 to the width D1 of the structural pillars 26 of the test bodies 1 to 3 is R = 2.0-3. The range was zero. Moreover, the minimum covering thickness K1-K3 of the concrete of the construction stand pillars 28, 30, 32 surrounding the construction pillar 26 of the test bodies 1 to 3 was in the range of 0.3D to 0.8D.

図4(A)に検証実験の結果を、図4(B)に検証結果を示す。図4(A)の横軸は構真台柱の変位量δ(mm)であり、縦軸は構真柱に加えた鉛直荷重P(kN)である。
図4(A)の特性Q1は試験体1のP-δ特性であり、特性Q2は試験体2のP-δ特性であり、特性Q3は試験体3のP-δ特性である。
FIG. 4A shows the result of the verification experiment, and FIG. 4B shows the verification result. The horizontal axis of FIG. 4 (A) is the displacement amount δ (mm) of the stem column, and the vertical axis is the vertical load P (kN) applied to the stem column.
The characteristic Q1 in FIG. 4A is the P-δ characteristic of the test body 1, the characteristic Q2 is the P-δ characteristic of the test body 2, and the characteristic Q3 is the P-δ characteristic of the test body 3.

特性Q1は、最も大きな鉛直荷重P(最大約4200kN)に耐えることができた。また、この時の変位量δは最も小さな値であった。これは、試験した3種類の試験体の中で、試験体1の構真台柱28の径Φ1が最も大きいためと思われる。
特性Q2は、次に大きな鉛直荷重P(最大約2700kN)に耐えることができた。また、この時の変位量δは、次に小さな値であった。これは、試験体2の構真台柱30の径Φ2が、試験体1に次いで大きいためと思われる。
特性Q3は、最も小さな鉛直荷重P(最大約1800kN)に耐えることができた。また、この時の変位量δは、最も大きな値であった。これは、試験した3種類の試験体の中で、試験体3の構真台柱32の径Φ3が最も小さいためと思われる。
The characteristic Q1 was able to withstand the largest vertical load P (maximum of about 4200 kN). Further, the displacement amount δ at this time was the smallest value. This is considered to be because the diameter Φ1 of the frame base 28 of the test body 1 is the largest among the three types of test bodies tested.
The characteristic Q2 was able to withstand the next largest vertical load P (maximum of about 2700 kN). The displacement amount δ at this time was the next smallest value. This is presumably because the diameter Φ2 of the frame column 30 of the test body 2 is the second largest after the test body 1.
The characteristic Q3 was able to withstand the smallest vertical load P (maximum of about 1800 kN). Further, the displacement amount δ at this time was the largest value. This is considered to be because the diameter Φ3 of the frame base 32 of the test body 3 is the smallest among the three types of test bodies tested.

図4(A)の横軸に平行な特性Uは、上述した(2)式で算出した構真台柱の抵抗Nである。すべての試験体1〜3で同じ値(約4100kN)となっている。
また、図4(A)の横軸に平行な特性S1は、(3)式で算出した試験体1の構真台柱28の抵抗Nである。抵抗Nは約4600kNであった。特性S2は、(3)式で算出した試験体2の構真台柱30の抵抗Nである。抵抗Nは約2600kNであった。特性S3は、(3)式で算出した試験体3の構真台柱32の抵抗Nである。抵抗Nは約1700kNであった。
Parallel characteristic U on the horizontal axis in FIG. 4 (A), the resistance N 1 of構真stand column calculated by the aforementioned equation (2). All the test bodies 1 to 3 have the same value (about 4100 kN).
Further, characteristics S1 parallel to the horizontal axis of FIG. 4 (A), the resistance of N 2 (3) specimens were calculated by the formula 1 of構真Taibashira 28. Resistance N 2 was about 4600KN. Characteristic S2 is the resistance of N 2 (3)構真Taibashira 30 of the calculated specimen 2 in formula. Resistance N 2 was about 2600KN. Characteristics S3 is the resistance of N 2構真Taibashira 32 of the test body 3 calculated in (3) below. Resistance N 2 was about 1700KN.

図4(B)には、最大鉛直荷重の実測値、及び(1)〜(3)式の算出結果を示している。最大鉛直荷重をCFT構真柱12の根入れ部の抵抗と考えると、これらの結果から、(1)式の算出結果は、実際に測定した実測値と試験体1〜3のいずれにおいてもよく一致しているといえる。
即ち、試験体1については(2)式の算出結果を採用し、試験体2については(3)式の算出結果を採用し、試験体3については(3)式の算出結果を採用することで、構真台柱の根入れ部の抵抗を正しく求めることができる。
FIG. 4B shows the actual measurement value of the maximum vertical load and the calculation results of the equations (1) to (3). Assuming that the maximum vertical load is the resistance of the root portion of the CFT structural column 12, from these results, the calculation result of the formula (1) may be either the actually measured value or the specimens 1 to 3. It can be said that they are in agreement.
That is, the calculation result of the formula (2) is adopted for the test specimen 1, the calculation result of the formula (3) is adopted for the test specimen 2, and the calculation result of the formula (3) is adopted for the test specimen 3. Thus, it is possible to correctly determine the resistance of the root portion of the structure stem.

ここに、試験体1の構真柱12の幅(D)に対する構真台柱14の径(Φ)の比R(R=Φ/D)は3.0であり、試験体2の比Rは2.5であり、試験体3の比Rは2.0である。
このことから、比Rが2.0〜3.0の範囲において、(1)〜(3)式でCFT構真柱の根入れ部の抵抗を評価できるといえる。
Here, the ratio R (R = Φ / D) of the diameter (Φ) of the structural column 14 to the width (D) of the structural column 12 of the test body 1 is 3.0, and the ratio R of the test body 2 is 2.5, and the ratio R of the specimen 3 is 2.0.
From this, it can be said that in the range of the ratio R of 2.0 to 3.0, it is possible to evaluate the resistance of the root portion of the CFT true column by the equations (1) to (3).

なお、比Rが3.0以上の範囲では、従来から(2)式で抵抗を評価してきた。今回の実験でも、上述したように、比Rが3.0において(2)式で抵抗を評価できることが証明された。
一方、比Rが3.0より小さい範囲では、(2)式の算出値と実測値は大きく乖離しており、(2)式では、比Rが3.0より小さい範囲では算出値は過大となり、正しく評価することはできない。
In the range where the ratio R is 3.0 or more, the resistance has been conventionally evaluated by the equation (2). In this experiment, as described above, it was proved that the resistance can be evaluated by the expression (2) when the ratio R is 3.0.
On the other hand, in the range where the ratio R is smaller than 3.0, the calculated value of the formula (2) and the measured value are greatly different from each other. In the formula (2), the calculated value is excessive in the range where the ratio R is smaller than 3.0. It cannot be evaluated correctly.

この(2)式では過大と算出される範囲においては、(3)式を用いることにより実測値とほぼ等しい抵抗を算出することができる。即ち、本実施の形態の(1)式〜(3)式を用いれば、比Rが2.0〜3.0の範囲で、CFT構真柱の根入れ部の抵抗を正しく評価することができる。   In the range in which the expression (2) is calculated to be excessive, a resistance substantially equal to the actually measured value can be calculated by using the expression (3). That is, if the formulas (1) to (3) of the present embodiment are used, the resistance of the root portion of the CFT true pillar can be correctly evaluated in the range of the ratio R of 2.0 to 3.0. it can.

次に、効果について説明する。
以上説明したように、CFT構真柱と構真台柱の接合構造10において、構真台柱14の径Φに対し、CFT構真柱12の幅Dが大きくなった場合(CFT構真柱12の幅Dに対する構真台柱14の径Φの比R(R=Φ/D)が2以上で、且つ3未満)においても、構真台柱14の抵抗Nを正しく把握することができる。この抵抗Nを用いて鉛直荷重Pを調整することで、CFT構真柱12に作用する軸力を構真台柱14へ伝達できるCFT構真柱と構真台柱の接合構造10を提供することができる。
Next, the effect will be described.
As described above, in the joint structure 10 of the CFT true pillar and the true pillar, when the width D of the CFT true pillar 12 becomes larger than the diameter Φ of the true pillar 14 (the CFT true pillar 12 Even when the ratio R (R = Φ / D) of the diameter Φ of the frame column 14 to the width D is 2 or more and less than 3, the resistance N of the frame column 14 can be correctly grasped. By adjusting the vertical load P using this resistance N, it is possible to provide a joint structure 10 between the CFT true pillar and the true pillar that can transmit the axial force acting on the CFT true pillar 12 to the true pillar 14. it can.

即ち、従来の(2)を用いた根入れ部の抵抗Nの算定方法では、根入れ部の抵抗を過大に評価する範囲(比Rが3.0未満)が存在するため、この範囲において、構真台柱14にクラック等が発生するという問題を解決できる。
更に、構真台柱14に生じたクラック等により、CFT構真柱12が予想以上に沈下し、その後の逆打ち躯体の作業に悪影響を及ぼすという問題を解決できる。
That is, in the conventional method for calculating the resistance N of the penetration portion using (2), there is a range in which the resistance of the penetration portion is excessively evaluated (the ratio R is less than 3.0). It is possible to solve the problem that cracks or the like are generated in the structural pillar 14.
Furthermore, it is possible to solve the problem that the CFT structural pillar 12 sinks more than expected due to cracks or the like generated in the structural support pillar 14 and adversely affects the subsequent work of the reverse strut body.

また、本実施形態によるCFT構真柱と構真台柱の接合構造10を用いる事により、構真柱12の根入れ部分の抵抗を正しく評価することができ、構真台柱14や逆打ち躯体の品質が確保され、逆打ち工事を安全に行うことができる。
更に、CFT構真柱12に作用する軸力が、構真台柱14の根入れ部分の抵抗より大きい場合、本実施形態によるCFT構真柱と構真台柱の接合構造10を用いることにより、構真台柱の径Φを大きくする、若しくは構真台柱14のコンクリート強度を増加させるなどの対策を簡易に計画することができる。
Further, by using the joint structure 10 of the CFT frame column and the frame column according to the present embodiment, the resistance of the root portion of the beam column 12 can be correctly evaluated, and the frame column 14 and the reverse strut body Quality is ensured, and backlash construction can be performed safely.
Further, when the axial force acting on the CFT structural column 12 is larger than the resistance of the root portion of the structural column 14, the construction structure 10 of the CFT structural column and the structural column according to the present embodiment is used. It is possible to easily plan measures such as increasing the diameter Φ of the main column or increasing the concrete strength of the structural column 14.

なお、CFT構真柱12は、断面が矩形の角形鋼管で説明したが、図5(B)に示す断面が円形のCFT鋼管38であっても良い。この場合には、幅DをCFT鋼管38の直径Dとすればよい。   Although the CFT true pillar 12 has been described as a rectangular steel pipe having a rectangular cross section, it may be a CFT steel pipe 38 having a circular cross section shown in FIG. In this case, the width D may be the diameter D of the CFT steel pipe 38.

また、本実施形態の適用範囲は、CFT構真柱12の幅Dに対する構真台柱14の径Φの比R(R=Φ/D)が2以上3未満と表現した。しかし、CFT構真柱12の根入れ部の最小被り厚さKで表現してもよい。
即ち、断面が矩形の、CFT構真柱12を覆う根入れ部における構真台柱14の最小被り厚さをK(図5(A)参照)、CFT構真柱12の幅をDとしたとき、最小被り厚さKは0.3D以上、0.8D未満(0.3D≦K<0.8D)と表現される。
なお、断面が円形のCFT鋼管38では、最小被り厚さK4は、0.5D以上、1.0D未満(0.5D≦K4<1.0D)と表現される(図5(B)参照)。
In addition, the application range of the present embodiment is expressed as a ratio R (R = Φ / D) of the diameter Φ of the frame column 14 to the width D of the CFT frame column 12 being 2 or more and less than 3. However, it may be expressed by the minimum covering thickness K of the root portion of the CFT true pillar 12.
That is, when the minimum covering thickness of the framing column 14 at the root portion covering the CFT framing column 12 having a rectangular cross section is K (see FIG. 5A) and the width of the CFT framing column 12 is D. The minimum covering thickness K is expressed as 0.3D or more and less than 0.8D (0.3D ≦ K <0.8D).
In the CFT steel pipe 38 having a circular cross section, the minimum covering thickness K4 is expressed as 0.5D or more and less than 1.0D (0.5D ≦ K4 <1.0D) (see FIG. 5B). .

(第2の実施形態)
図6〜図10を用いて、第2の実施形態に係るCFT構真柱と構真台柱の接合構造40について説明する。構真台柱42が補強部材としての補強鉄筋48を有している点において、第1の実施形態と相違する。相違点を中心に説明する。
(Second Embodiment)
The joint structure 40 of the CFT true pillar and the true pillar according to the second embodiment will be described with reference to FIGS. The frame holder 42 is different from the first embodiment in that it has a reinforcing bar 48 as a reinforcing member. The difference will be mainly described.

ここに、図6は第2の実施形態に係るCFT構真柱と構真台柱の接合構造の基本構成を示す図であり、図7は構真台柱に作用する引張応力の算定方法を示す図であり、図8は模型実験の試験体4〜試験体7の構成を示す図であり、図9は模型実験の試験体4〜試験体7の代表寸法を示す図であり、図10は模型実験の実験結果を示す図である。   FIG. 6 is a diagram showing the basic configuration of the joint structure of the CFT true column and the true column according to the second embodiment, and FIG. 7 is a diagram showing a method for calculating the tensile stress acting on the true column. FIG. 8 is a diagram showing the configuration of the test bodies 4 to 7 of the model experiment, FIG. 9 is a diagram showing the representative dimensions of the test bodies 4 to 7 of the model experiment, and FIG. 10 is the model. It is a figure which shows the experimental result of experiment.

図6に示すように、第2の実施の形態に係るCFT構真柱と構真台柱の接合構造40は、根入れ部にスタッド16が設けられたCFT構真柱12を有し、CFT構真柱12は、構真台柱42に深さHで根入れされている。
ここに、CFT構真柱12とスタッド16は、第1の実施の形態で既に説明したCFT構真柱12及びスタッド16と同じ寸法、同じ構成であり説明は省略する。
As shown in FIG. 6, the joint structure 40 of the CFT structure true pillar and the structure support pillar according to the second embodiment has a CFT structure pillar 12 in which a stud 16 is provided at the root portion, and has a CFT structure. The true pillar 12 is embedded in the structural stand pillar 42 at a depth H.
Here, the CFT structure true pillar 12 and the stud 16 have the same dimensions and the same configuration as those of the CFT structure true pillar 12 and the stud 16 already described in the first embodiment, and the description thereof will be omitted.

構真台柱42は、主筋44と帯筋46からなる補強部材としての補強鉄筋48を有している。補強鉄筋48は、構真台柱42の外周に、CFT構真柱12を囲んで所定の被り厚さで設けられている。更に、補強鉄筋48は、構真台柱42の長さ方向の全長に渡り配筋されている。   The structural support column 42 has a reinforcing bar 48 as a reinforcing member composed of a main bar 44 and a band bar 46. The reinforcing steel bars 48 are provided on the outer periphery of the beam support column 42 so as to surround the CFT beam frame 12 with a predetermined covering thickness. Further, the reinforcing reinforcing bars 48 are arranged over the entire length of the structural support column 42 in the length direction.

補強鉄筋48は、下記(4)式〜(6)式を満たす強度を有している。


ここに、
:構真台柱の断面積に対する補強部材の断面積の割合(%)
σsy :補強部材の降伏強度(kN/m
σct :構真台柱に作用する引張応力(kN/m
σcc :構真台柱に作用する圧縮応力(kN/m
Φ :構真台柱の径(m)
D :構真柱の幅(m)
x :構真柱根入れ先端深度からの距離(m)
β :形状係数(−)
The reinforcing steel bars 48 have a strength that satisfies the following formulas (4) to (6).


here,
P w : Ratio of the cross-sectional area of the reinforcing member to the cross-sectional area of the structural pillar (%)
σ sy : yield strength of reinforcing member (kN / m 2 )
σ ct : Tensile stress (kN / m 2 ) acting on the structural stand column
σ cc : Compressive stress (kN / m 2 ) acting on the stem
Φ: Diameter of the stem pillar (m)
D: width of the structural pillar (m)
x: Distance (m) from the depth of the tip of the timber pillar
β: Shape factor (-)

上式において、補強鉄筋48の量は(4)式により算出される。なお、構真台柱42に作用する引張り応力σctは、非特許文献1に記されている割裂引張り応力の算定方法に基づいて図7、(5)式及び(6)式により算定される。
図7は、横軸に構真柱根入れ先端深度からの距離x(m)と構真台柱の径Φ(m)の比(x/Φ)をとり、縦軸に構真台柱42に作用する引張応力σct(kN/m)と圧縮応力σcc(kN/m)の比(σct/σcc)をとっている。図7を用いることで、形状係数βごとの縦軸と横軸の関係を求めることができる。
In the above equation, the amount of reinforcing bars 48 is calculated by equation (4). It should be noted that the tensile stress σ ct acting on the structural stand column 42 is calculated according to the split tensile stress calculation method described in Non-Patent Document 1 according to equations (5) and (6).
FIG. 7 shows the ratio (x / Φ) between the distance x (m) from the depth of the root of the root of the true column and the diameter Φ (m) of the true column to the horizontal axis and the vertical axis acting on the true column 42. The ratio (σ ct / σ cc ) between the tensile stress σ ct (kN / m 2 ) and the compressive stress σ cc (kN / m 2 ) is taken. By using FIG. 7, the relationship between the vertical axis and the horizontal axis for each shape factor β can be obtained.

また、CFT構真柱と構真台柱の接合構造40において、補強鉄筋48は、構真台柱42の断面積(A)に対する補強鉄筋48の断面積(A)の割合P(P=A/A)が0.45%以上とされている。
これにより、補強鉄筋48に要求される強度が確保される。
Further, in the joint structure 40 between the CFT true column and the true stand column, the reinforcing reinforcing bar 48 has a ratio P w (P w ) of the cross sectional area (A 2 ) of the reinforcing reinforcing bar 48 to the cross sectional area (A 1 ) of the true supporting column 42. = A 2 / A 1 ) is 0.45% or more.
Thereby, the strength required for the reinforcing steel bars 48 is ensured.

本構成とすることにより、補強鉄筋48が、構真台柱42に作用する圧縮応力を分担することができる。この結果、構真台柱42の径Φに対してCFT構真柱12の幅Dが大きくなった場合においても、補強鉄筋48により、CFT構真柱12に作用する軸力を構真台柱42へ伝達できるCFT構真柱と構真台柱の接合構造を提供することができる。   By adopting this configuration, the reinforcing reinforcing bars 48 can share the compressive stress acting on the frame base 42. As a result, even when the width D of the CFT true column 12 is larger than the diameter Φ of the true stand column 42, the axial force acting on the CFT true column 12 is applied to the true stand column 42 by the reinforcing bars 48. It is possible to provide a joint structure of a CFT frame pillar and a frame pillar that can be transmitted.

次に、補強鉄筋の強度検証実験について説明する。
CFT構真台柱42の根入れ部に設けられた補強鉄筋48による効果を把握するため、実際の構真柱の1/5程度のスケールの構造模型を用いて強度検証実験を実施した。
Next, the strength verification experiment of the reinforcing steel bars will be described.
In order to grasp the effect of the reinforcing reinforcing bar 48 provided at the base portion of the CFT frame column 42, a strength verification experiment was performed using a structural model having a scale of about 1/5 of the actual beam column.

図8(A)〜(D)に示すように、模型実験は、4種類の試験体(試験体4〜7)を用いて行った。
図8(A)に示す試験体4は、既述の試験体3と同じ寸法、構成であり、CFT構真柱26の根入れ部が構真台柱32に根入れされている。CFT構真柱26の径はD(mm)であり、構真台柱32の径はΦ(mm)である。構真台柱32には、補強鉄筋48は設けられていない。
As shown in FIGS. 8A to 8D, the model experiment was performed using four types of test bodies (test bodies 4 to 7).
The specimen 4 shown in FIG. 8A has the same dimensions and configuration as the specimen 3 described above, and the root portion of the CFT true pillar 26 is rooted in the true pillar 32. The diameter of the CFT true pillar 26 is D (mm), and the diameter of the true pillar 32 is Φ (mm). The structural support pillar 32 is not provided with the reinforcing reinforcing bars 48.

図8(B)に示す試験体5は、試験体4と同じ基本的に寸法、構成とされている。試験体5の構真台柱58には、鉄筋量比0.2%の補強鉄筋48が、CFT構真柱26を囲んで設けられている。
図8(C)に示す試験体6は、試験体4と同じ基本的に寸法、構成とされている。試験体6の構真台柱60には、鉄筋量比0.45%の補強鉄筋48が、CFT構真柱26を囲んで設けられている。
図8(D)に示す試験体7は、試験体4と同じ基本的に寸法、構成とされている。試験体7の構真台柱62には、鉄筋量比0.7%の補強鉄筋48が、CFT構真柱26を囲んで設けられている。
The test body 5 shown in FIG. 8B is basically the same size and configuration as the test body 4. The structural support column 58 of the test body 5 is provided with a reinforcing steel bar 48 having a reinforcing bar amount ratio of 0.2% so as to surround the CFT structural column 26.
The test body 6 shown in FIG. 8C has basically the same dimensions and configuration as the test body 4. The structural support column 60 of the test body 6 is provided with a reinforcing steel bar 48 having a reinforcing bar amount ratio of 0.45% so as to surround the CFT structural column 26.
The specimen 7 shown in FIG. 8D is basically the same size and configuration as the specimen 4. A reinforcing steel bar 48 having a reinforcing bar amount ratio of 0.7% is provided on the structural base column 62 of the test body 7 so as to surround the CFT structural pillar 26.

強度検証実験は、試験体4〜7に、それぞれ鉛直荷重P(kN)を加え、鉛直荷重P(kN)に対する構真台柱32、58、60、62の変位量δ(mm)を計測した。
図9に試験体4〜7の代表寸法を示す。
In the strength verification experiment, the vertical load P (kN) was applied to each of the test bodies 4 to 7, and the displacement amount δ (mm) of the framing pillars 32, 58, 60, and 62 with respect to the vertical load P (kN) was measured.
FIG. 9 shows representative dimensions of the test bodies 4 to 7.

図9に示すように、試験体4〜7において、CFT構真柱26の幅Dはいずれも同一寸法200mmであり、構真台柱32、58、60、62の直径Φも、いずれも同一寸法400mmである。これから、構真柱の幅Dに対する構真台柱の直径Φの比Rは、いずれも2.0となっている。また、最小被り厚さKは、いずれも0.3Dとなっている。   As shown in FIG. 9, in the test bodies 4 to 7, the width D of the CFT frame column 26 has the same dimension of 200 mm, and the diameters Φ of the frame columns 32, 58, 60, and 62 all have the same size. 400 mm. From this, the ratio R of the diameter Φ of the structural pillar to the width D of the structural pillar is 2.0. Further, the minimum covering thickness K is 0.3D in all cases.

図10に強度検証実験の結果を示す。図10の横軸は構真台柱の変位量δ(mm)であり、縦軸は構真柱に加えた鉛直荷重P(kN)である。
図10(A)の特性Q4は試験体4のP-δ特性であり、特性Q5は試験体5のP-δ特性であり、特性Q6は試験体6のP-δ特性であり、特性Q7は試験体7のP-δ特性である。
FIG. 10 shows the result of the strength verification experiment. The horizontal axis in FIG. 10 is the displacement amount δ (mm) of the stem column, and the vertical axis is the vertical load P (kN) applied to the stem column.
The characteristic Q4 in FIG. 10A is the P-δ characteristic of the test body 4, the characteristic Q5 is the P-δ characteristic of the test body 5, the characteristic Q6 is the P-δ characteristic of the test body 6, and the characteristic Q7 Is the P-δ characteristic of the specimen 7.

特性Q4は、最も小さな最大鉛直荷重P(最大約1500(kN))しか耐えることができず、変位量δも大きい。これは、試験体4の構真台柱32には、補強鉄筋48が設けられていない(Pが0.0%)ためと考えられる。
特性Q5は、次に小さな最大鉛直荷重P(最大約3200(kN))にしか耐えることができない。また変位量δは特性Q4より小さい。これは、試験体5の構真台柱58には、補強鉄筋48(Pが0.2%)が設けられているものの、鉄筋量が少ない(Pが0.2%)ためと思われる。
The characteristic Q4 can withstand only the smallest maximum vertical load P (up to about 1500 (kN)), and the displacement amount δ is also large. This in構真Taibashira 32 of the specimen 4, the reinforcing rebar 48 are not provided is considered (P w is 0.0%) for.
The characteristic Q5 can withstand only the next smallest vertical load P (maximum of about 3200 (kN)). Further, the displacement amount δ is smaller than the characteristic Q4. This in構真Taibashira 58 of the test sample 5, although reinforcing rebar 48 (P w 0.2%) is provided, the amount of reinforcing steel is less seems (P w 0.2%) for .

特性Q6は、大きな最大鉛直荷重P(最大約4000(kN))に耐えることができた。また、変位量δは特性Q4より小さい。これは、試験体6の構真台柱60には、十分な量の補強鉄筋48(Pが0.45%)が配筋されているためと思われる。
特性Q7は、最も大きな最大鉛直荷重P(最大約4100(kN))に耐えることができた。また、変位量δは特性Q4より小さい。これは、試験体7の構真台柱62には、十分な量の補強鉄筋48(Pが0.7%)が配筋されているためと思われる。
The characteristic Q6 was able to withstand a large maximum vertical load P (maximum of about 4000 (kN)). Further, the displacement amount δ is smaller than the characteristic Q4. This in構真Taibashira 60 of the test body 6, a sufficient amount of reinforcing rebar 48 (P w is 0.45%) is believed to be due to being Haisuji.
The characteristic Q7 was able to withstand the largest maximum vertical load P (maximum of about 4100 (kN)). Further, the displacement amount δ is smaller than the characteristic Q4. This in構真Taibashira 62 of the specimen 7, a sufficient amount of reinforcing rebar 48 (P w 0.7%) is likely due to being Haisuji.

更に、図10(A)に示す横軸に平行な特性Uは、既述した(2)式で求めた、構真台柱32の根入れ部の抵抗である。特性Q4と特性Q5は、この特性Uの値に到達していないが、特性Q6と特性Q7の最大抵抗Nは、この値とほぼ等しい値に到達している。   Furthermore, the characteristic U parallel to the horizontal axis shown in FIG. 10A is the resistance of the root portion of the beam support 32 obtained by the above-described equation (2). The characteristic Q4 and the characteristic Q5 do not reach the value of the characteristic U, but the maximum resistance N of the characteristic Q6 and the characteristic Q7 reaches a value substantially equal to this value.

即ち、適正な鉄筋量比Pが確保されれば、補強鉄筋48の作用により、補強鉄筋48が鉛直荷重Pを分担して支持する。この結果、CFT構真柱の幅Dに比して構真台柱の径Φが十分に大きい場合の値4100(kN)の抵抗が確保される。ここに、適正な鉄筋量比Pは、試験体6、7のPが0.45%以上であることから、Pが0.45%以上ということができる。
なお、今回の試験体4〜7において、(5)式により算定される構真台柱に発生する引張り応力σt=2.0N/mm2程度であった。
That is, if an appropriate reinforcing bar amount ratio Pw is secured, the reinforcing reinforcing bar 48 shares and supports the vertical load P by the action of the reinforcing reinforcing bar 48. As a result, a resistance of 4100 (kN) is secured when the diameter Φ of the stem is sufficiently larger than the width D of the CFT true pillar. Here, a proper reinforcement weight ratio P w, since P w of the specimen 6 and 7 is 0.45% or more, P w can be said that 0.45% or more.
In the test specimens 4 to 7 of this time, the tensile stress σ t = 2.0 N / mm 2 generated in the frame base calculated by the equation (5) was about.

上述したように、補強鉄筋48による補強を行なえば、CFT構真柱26に作用する軸力が構真柱根入れ部の抵抗より大きい場合、構真台柱の抵抗を同じ寸法のまま増加させ、構真台柱にCFT構真柱26を支持させることができる。
また、本補強方法では、構真台柱の径Φを大きくする、若しくは構真台柱のコンクリート強度を増加させる等の方法で対応する必要がないため、構真台柱を構築するための掘削量の削減、コンクリート量の削減、更にはセメント量の削減が可能となる。
As described above, if the reinforcement by the reinforcing reinforcing bars 48 is performed, if the axial force acting on the CFT structural column 26 is larger than the resistance of the structural column base, the resistance of the structural column is increased with the same dimensions, The CFT frame pillar 26 can be supported on the frame pillar.
In addition, this reinforcement method does not require measures such as increasing the diameter Φ of the pedestal column or increasing the concrete strength of the pedestal column, thus reducing the amount of excavation for constructing the pedestal column It is possible to reduce the amount of concrete and further the amount of cement.

また、本実施の形態による補強鉄筋量の算定方法を用いることにより、構真柱根入れ部の抵抗を増加させる対策を、簡易に計画することができる。
なお、図示は省略するが、補強鉄筋48の代わりに、構真台柱の外周部の補強鉄筋48の位置に鋼管を埋め込んでも、補強鉄筋48と同等の効果を得ることができる。
他は、第1の実施形態と同じであり説明は省略する。
In addition, by using the method for calculating the amount of reinforcing steel bars according to the present embodiment, it is possible to easily plan a measure for increasing the resistance of the structural column base.
In addition, although illustration is abbreviate | omitted, even if it embeds a steel pipe in the position of the reinforcement reinforcement 48 of the outer peripheral part of a construction stand pillar instead of the reinforcement reinforcement 48, the effect equivalent to the reinforcement reinforcement 48 can be acquired.
Others are the same as those in the first embodiment, and a description thereof will be omitted.

10 CFT構真柱と構真台柱の接合構造
12 CFT構真柱
14 構真台柱
16 スタッド
36 根入れ部
44 主筋(補強部材)
46 帯筋(補強部材)
48 補強鉄筋(補強部材)
10 Joint structure of CFT structural column and structural column 12 CFT structural column 14 Structural column 16 Stud 36 Rooting part 44 Main reinforcement (reinforcing member)
46 Band reinforcement (reinforcement member)
48 Reinforcing bars (reinforcing members)

Claims (4)

建物を支持し、根入れ部にスタッドが設けられたCFT構真柱と、
前記根入れ部が挿入され、前記根入れ部を抵抗Nで支持する構真台柱と、
を有するCFT構真柱と構真台柱の接合構造において
下記(1)式で算出される前記抵抗Nを前記建物から前記CFT構真柱に伝達される軸力より大きくる、
CFT構真柱と構真台柱の接合構造の設計方法



ここに、
N :N及びNで求められた構真台柱の抵抗のうち値の小さい方(kN)
:N、N及びNから求められるCFT構真柱の根入れ部における構真台柱の抵抗(kN)
:コンクリートの許容圧縮応力度から求められるCFT構真柱の根入れ部における構真台柱の抵抗(kN)
:CFT構真柱の外周面と構真台柱との間の付着抵抗(kN)
:CFT構真柱の下端面と構真台柱との間の支圧抵抗(kN)
:スタッドと構真台柱との間のスタッド抵抗(kN)
α :累加係数(通常0.5)
β :累加係数(通常0.8)
σ:構真台柱コンクリートの許容圧縮応力度(kN/m
:構真台柱の断面積からスタッドを含むCFT構真柱の投影断面積を差し引いた断面積(m
CFT structure pillars that support the building and have studs at the base,
The embedment section is inserted, and構真stand pillars to support the embedment section in resistance N,
In the joint structure of the CFT構真columns and構真table columns that have a,
Below (1) you greater than the axial force transmitted to the CFT構真Column the resistance N calculated from the building by the formula,
A method for designing a joint structure between a CFT frame and a column.



here,
N: The smaller value (kN) of the resistance of the structural pillar obtained by N 1 and N 2
N 1 : The resistance of the framing pillar (kN) at the root of the CFT framing pillar obtained from N f , N b and N s
N 2 : resistance of the pedestal column (kN) at the root of the CFT pedestal column obtained from the allowable compressive stress of concrete
N f : Adhesion resistance (kN) between the outer peripheral surface of the CFT frame column and the frame column
N b : bearing resistance (kN) between the lower end face of the CFT true pillar and the true pillar
N s : Stud resistance (kN) between the stud and the stem
α: cumulative coefficient (usually 0.5)
β: cumulative coefficient (usually 0.8)
σ c : Permissible compressive stress level of structural support column concrete (kN / m 2 )
A c : cross-sectional area (m 2 ) obtained by subtracting the projected cross-sectional area of the CFT true column including the stud from the cross-sectional area of the true pillar
前記CFT構真柱の幅(D)に対する前記構真台柱の径(Φ)の比R(R=Φ/D)2.0以上、且つ3.0未満とす請求項1に記載のCFT構真柱と構真台柱の接合構造の設計方法The CFT構真Columns width diameter of the構真table column for (D) (Φ) of the ratio R (R = Φ / D) 2.0 or more on, shall be the and less than 3.0, in claim 1 A method for designing a joint structure of the described CFT column and column. 建物を支持し、根入れ部にスタッドが設けられたCFT構真柱と、
記CFT構真柱が根入れされる根入れ部に補強部材が設けられている構真台柱と、
を有するCFT構真柱と構真台柱の接合構造において、
前記補強部材を、下記(4)式を満たす強度とする、
CFT構真柱と構真台柱の接合構造の設計方法

ここに、
:構真台柱の面積に対する補強部材の断面積の割合(%)
σsy:補強部材の降伏強度(kN/m
σct:建物からCFT構真柱に伝達される軸力に基づいて算出される構真台柱に作用する引張応力(kN/m
CFT structure pillars that support the building and have studs at the base,
And構真stand pillar reinforcement member is provided on the embedment section before Symbol CFT構真pillar is embedment,
In the joint structure of CFT structural pillar and structural pillar with
The reinforcing member has a strength satisfying the following expression (4):
A method for designing a joint structure between a CFT frame and a column.

here,
P w: ratio of the cross-sectional area of the reinforcing member to the area of構真stand pillars (%)
σ sy : yield strength of reinforcing member (kN / m 2 )
σ ct : Tensile stress (kN / m 2 ) acting on the frame base calculated based on the axial force transmitted from the building to the CFT column
記構真台柱の断面積(A)に対する前記補強部材の断面積(A)の割合P(P=A/A0.45%以上とす請求項3に記載のCFT構真柱と構真台柱の接合構造の設計方法It shall be the previous SL cross-sectional area of構真stand pillars (A 1) the cross-sectional area of the reinforcing member (A 2) the ratio P w (P w = A 2 / A 1) 0.45% or more with respect to claim 3 A method for designing a joint structure of a CFT structural column and a structural column as described in 1 .
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