JPH08338104A - Reinforced concrete pillar and its reinforcing method - Google Patents
Reinforced concrete pillar and its reinforcing methodInfo
- Publication number
- JPH08338104A JPH08338104A JP17044195A JP17044195A JPH08338104A JP H08338104 A JPH08338104 A JP H08338104A JP 17044195 A JP17044195 A JP 17044195A JP 17044195 A JP17044195 A JP 17044195A JP H08338104 A JPH08338104 A JP H08338104A
- Authority
- JP
- Japan
- Prior art keywords
- concrete
- column
- steel material
- pillar
- stress
- 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.)
- Pending
Links
Landscapes
- Rod-Shaped Construction Members (AREA)
- Reinforcement Elements For Buildings (AREA)
- Working Measures On Existing Buildindgs (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は土木、建築構造等のコ
ンクリート柱に関し、コンクリートに事前に水平圧縮応
力を与えるＰＣ鋼材の新しい用法により、柱の鉛直方向
耐力を強化するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to concrete columns for civil engineering, building structures and the like, and enhances the vertical proof strength of the columns by a new usage of PC steel which applies horizontal compressive stress to concrete in advance.
【０００２】[0002]
【従来の技術】コンクリート柱の補強手段としては周知
の鉄筋を縦横に加えるほか、フープ筋、スパイラル筋と
呼ばれる補強筋を加えるとか、既設の柱なら周囲に鋼板
を巻き立てたり、フープ筋を配置した鉄筋コンクリート
を外周に打ち足すなどの方法がある。柱ではないが煙突
などの円筒状構造物の外周に繊維シート、繊維ロープ等
をそのままか、又は若干引張力を加えて巻き付ける補強
工法もある。これは風呂桶の「タガ」と同様、円筒の周
方向引締めにより周壁の変形を防ぐものである。2. Description of the Related Art Reinforcing bars, which are well known as reinforcing means for concrete columns, are added vertically and horizontally, and reinforcing bars called hoop and spiral bars are added. There is a method such as adding reinforced concrete to the outer circumference. There is also a reinforcing method in which a fiber sheet, a fiber rope, or the like is wound around the outer periphery of a cylindrical structure such as a chimney, which is not a pillar, or is wound with a slight tensile force. This is to prevent deformation of the peripheral wall by tightening the cylinder in the circumferential direction, similar to the "tub" of the bath tub.
【０００３】[0003]
【発明が解決しようとする課題】我が国は地震国であ
り、度々大地震に見まわれ大多数の死傷者と多くの構築
物の損害を経験している。このようなことから我が国の
耐震設計は世界で最も厳しく設定され、地震による構造
物の倒壊はあり得ないとまで言われてきた。しかし、さ
きの阪神大震災ではその地震と共に多くの構造物が損傷
し、特に構築物の柱が破壊するという問題を生じた。こ
の理由は古い耐震設計規準により施工された構築物が補
強されないまま残されていたこと、現行の設計震度をも
上回る強烈な縦揺れ、横揺れが作用したことなどによる
ものである。これらにより生ずる過大な作用力に対し
て、新たに構造物を作る場合には柱の軸方向筋と共にそ
れを囲む形で周方向に配置されるフープ筋・スパイラル
筋の量を増やすか、コンクリートの強度を上げるなどに
より強化していた。また、既設の構造物を補強する場合
には柱を巻く形で鋼板を配置し、強化していた。[Problems to be Solved by the Invention] Japan is an earthquake-prone country and is often hit by large earthquakes, and suffers the majority of casualties and many structures. For this reason, it has been said that Japan's seismic design is set to be the strictest in the world, and structures cannot be destroyed by an earthquake. However, in the previous Great Hanshin Earthquake, many structures were damaged along with the earthquake, especially the pillars of the structure were destroyed. The reason for this is that the structure constructed according to the old seismic design code was left unreinforced, and there were strong pitching and rolling that exceeded the existing design seismic intensity. In case of constructing a new structure, increase the amount of hoop muscles / spiral muscles arranged in the circumferential direction to surround the axial muscles of the pillars against the excessive action force generated by these, It was strengthened by increasing strength. In addition, when reinforcing an existing structure, a steel plate was arranged in the form of a column to strengthen it.
【０００４】これまで行なわれてきたコンクリート柱の
耐力向上工法の問題点には次のようなものがある。 強い縦揺れが生じた場合、柱構造は鉛直圧縮力の増加
と減少が繰り返されることになるが、予め拘束力を付与
しない既存の強化工法は圧縮力の増加に対して抵抗して
も、減少方向の抵抗力は小さい。 コンクリート構造物は基本的にメンテナンスフリーで
あるが、既設構造物の鋼板巻き立て等の補強では鋼板塗
装などのメンテナンスが必要になる。 既設コンクリート建築物の場合には壁・窓などが柱の
周囲に配置されているため鋼板巻き立て補強は困難であ
った。 鋼板を巻き付ける補強で、鉛直力の増力が著しい場合
に、鋼管とコンクリート柱が接着されている場合は鋼管
が座屈してぜい性的な破壊となり、鋼管とコンクリート
の付着を切ってある場合はコンクリートの変形がある程
度進行しなければ耐力向上効果を発揮しないなどの欠点
があった。 新設構造物の柱においてその耐力を上げる目的で軸方
向・周方向の鉄筋を増やせばどうしても過密配筋とな
り、コンクリート打設時にこれらが障害となって施工性
が著しく低下するか、最悪の場合にはコンクリートが充
填されないなどの問題を生じていた。[0004] The problems of the concrete column proof stress improving method that have been performed so far are as follows. When strong vertical vibration occurs, the vertical compression force of the column structure will be repeatedly increased and decreased, but the existing strengthening method that does not give a restraining force in advance will decrease even if it resists the increase of the compression force. Directional resistance is small. Although concrete structures are basically maintenance-free, maintenance such as coating of steel plates is required for reinforcing existing structures such as rolling up steel plates. In the case of an existing concrete building, it was difficult to wind up and reinforce the steel plate because walls and windows were placed around the columns. When the vertical force is remarkably increased by reinforcing the steel plate by winding, if the steel pipe and the concrete column are adhered, the steel pipe buckles and becomes a brittle fracture, and if the adhesion of the steel pipe and concrete is cut off. There was a defect that the yield strength improvement effect was not exhibited unless the deformation of concrete progressed to some extent. In the case of a pillar of a new structure, if reinforcing rods in the axial and circumferential directions are increased in order to increase its proof strength, it will inevitably become overcrowded reinforcement, which will hinder the concrete pouring and significantly reduce the workability, or in the worst case. Had problems such as not being filled with concrete.
【０００５】[0005]
【課題を解決するための手段】この発明の強化したコン
クリート柱は、内部の水平方向鉄筋のあい間に、ほぼ水
平に、多段にシース管入りＰＣ鋼材を通したコンクリー
ト柱であって、上記ＰＣ鋼材の緊張により隣接コンクリ
ートに水平圧縮応力を生じており、その水平圧縮応力
は、当該コンクリート柱に鉛直荷重が加わった時、コン
クリート内応力が三軸になって、柱の垂直耐力を所要値
まで増大する値であることを特徴とする。上記シース管
入りＰＣ鋼材は柱内をほぼ水平に横断して、両端を柱表
面に定着させてよい。あるいはまた、そのシース管入り
ＰＣ鋼材は柱の外周よりやや内側を水平にほぼ一周して
いるか、らせん状にめぐっているものも勧められる。A reinforced concrete column according to the present invention is a concrete column in which a PC steel material containing a sheath pipe is passed substantially horizontally between the horizontal reinforcing bars in the interior thereof in a multi-step manner. Due to the tension of the steel material, horizontal compressive stress is generated in the adjacent concrete, and when the vertical compressive load is applied to the concrete column, the stress in the concrete becomes triaxial and the vertical proof stress of the column reaches the required value. It is characterized by an increasing value. The PC steel material containing the sheath tube may cross the inside of the column substantially horizontally, and both ends may be fixed to the surface of the column. Alternatively, it is also recommended that the PC steel material containing the sheath tube has a substantially horizontal inner circumference from the outer circumference of the column or a spiral shape.
【０００６】この発明のコンクリート柱の強化方法は、
コンクリート柱の構築時、水平方向鉄筋のあい間にシー
ス管入りＰＣ鋼材をほぼ水平に多段に配設し、その端部
を型枠の外に出してコンクリートを打設し、コンクリー
ト硬化後、上記ＰＣ鋼材端部をけん引してコンクリート
表面に定着させることを特徴とする。The method for strengthening a concrete column according to the present invention is
When constructing a concrete column, PC steel materials with sheath tubes are arranged in multiple stages in a horizontal direction between horizontal rebars, and the ends are placed outside the formwork and concrete is poured. After hardening the concrete, the above It is characterized in that the end of PC steel material is towed and fixed on the concrete surface.
【０００７】柱が既設の場合は、既製コンクリート柱の
外周にほぼ水平に多段にＰＣ鋼材を沿わし、そのＰＣ鋼
材を緊張させて隣接コンクリートに水平圧縮応力を生ぜ
しめておき、該コンクリート柱が鉛直荷重を受けた時、
上記隣接コンクリートに三軸応力を生じて柱の鉛直耐力
を所要値まで増大するようにしておくことを特徴とす
る。柱の断面が円形か類似円形か多角形なら、そのＰＣ
鋼材は該柱外周に輪状またはらせん状に巻つけてよい。
柱の対向側面が平行していたら、上記柱の平行する両側
面に支圧梁材を当て、各梁材の両端部に通した上記ＰＣ
鋼材により、上記梁同士を締合わせてよい。あるいは
又、既製コンクリート柱に水平に横断穿孔し、その孔内
にＰＣ鋼材通して緊張させ、その両端を孔縁に定着させ
てよい。In the case where the column is already installed, PC steel material is laid along the outer periphery of the prefabricated concrete column in a substantially horizontal manner in multiple stages, and the PC steel material is tensioned to generate horizontal compressive stress in the adjoining concrete. When receiving a load,
It is characterized in that triaxial stress is generated in the adjacent concrete to increase the vertical proof stress of the column to a required value. If the cross section of the pillar is circular, similar circular or polygonal, the PC
The steel material may be wound around the column in a ring shape or a spiral shape.
If the opposite sides of the pillars are parallel, the above-mentioned PCs with pressure bearing beams applied to both parallel sides of the pillars and passed through both ends of each beam
The beams may be tightened together by a steel material. Alternatively, a prefabricated concrete column may be horizontally perforated, and a PC steel material may be passed through the hole to tension it, and both ends thereof may be fixed to the edge of the hole.
【０００８】[0008]
【作用】ＰＣ鋼材を使ってコンクリート構造物にプレス
トレストを与えるということは、従来の概念では、使用
時引張り歪みを生ずる位置に予め同方向の圧縮歪みを与
えておく事であった。この発明では使用時圧縮歪みを生
ずる位置に、予め側方から圧縮歪みを与えておく。つま
り鉛直荷重を受ける柱にＰＣ鋼材による水平方向圧縮力
を加えておく。多軸応力による耐力向上作用を利用した
のである。以上は弾性限内の歪みを考えているが、弾性
限を超す歪みについては、次のように考えられる。The function of prestressing a concrete structure using a PC steel material is that, in the conventional concept, a compressive strain in the same direction is previously applied to a position where a tensile strain is generated during use. In the present invention, the compression strain is applied from the side in advance to the position where the compression strain is generated during use. That is, the horizontal compressive force of PC steel is applied to the column that receives the vertical load. This is because the proof stress improving action due to the multiaxial stress was utilized. Although the strain in the elastic limit is considered above, the strain exceeding the elastic limit is considered as follows.
【０００９】通常、コンクリート柱のような形状の物質
を上下から拘束し、荷重を加えた場合の破壊を便宜的に
圧縮破壊と呼んでいるが、厳密には内部に生じた剪断面
がずれて破壊するものであって、コンクリートの内部組
織が圧縮によって崩壊することにより破壊するものでは
ない。本発明はこのずれを押しとどめる方向の剪断力を
拘束力として予め与えておくものであり、本発明者らの
さきの発明「剪断プレストレス入りコンクリート床版合
成部材とその製法」（特公平７−３１０１）における剪
断プレストレスと同価である。図１４ａ、１４ｂにさき
の阪神大震災でみられた柱の代表的な破壊形態を示す。
図１４ａは破壊前、図１４ｂは破壊後で、１はコンクリ
ート柱、２は鉄筋である。この場合の破壊においても柱
には明らかな剪断ひびわれが生じており、コンクリート
が圧縮によって粉々に粉砕されたのではないことがわか
る。Usually, a material having a shape such as a concrete column is constrained from above and below, and the failure when a load is applied is called compression failure for the sake of convenience, but strictly speaking, the shear plane generated inside is displaced. It destroys, but not when the internal structure of concrete collapses due to compression. The present invention preliminarily gives a shearing force in the direction of restraining this deviation as a restraining force, and the invention of the inventors of the present invention, "Shealing prestressed concrete floor slab composite member and its manufacturing method" (Japanese Patent Publication No. 3101) and the shear prestress. 14a and 14b show typical rupture forms of columns observed in the Great Hanshin Earthquake.
Fig. 14a is before breaking, Fig. 14b is after breaking, 1 is a concrete column, 2 is a reinforcing bar. Even in the fracture in this case, the columns were clearly sheared and cracked, indicating that the concrete was not shattered by compression.
【００１０】柱構造が地震を受けたとき、柱には曲げと
同時に鉛直力が加わる。図に示した柱の破壊形態は明ら
かに鉛直力が作用したことを示しており、曲げだけでは
この様な破壊は生じない。過大な鉛直力Ｌが作用したと
き、柱内部の剪断力は図１５のτＬのごとくになる。在
来工法のフープ筋やスパイラル筋・鋼管などは、図１６
に示されるように、柱の破壊に伴う変位を拘束する形で
反力Ｒが生じ、その作用により生じた剪断反力τＲが図
１５のτＬに抵抗する。本発明においては図１７のごと
く、将来発生するであろうτＬに対して、予め拘束力ｐ
を与えることにより逆向きの剪断力τｐを与えておくも
ので、この拘束力は在来工法のような柱の破壊に伴う受
動的なものではない。もちろん、予め導入した剪断力τ
ｐの耐力向上効果を上回る鉛直力Ｌが作用したときに
は、荷重による剪断力τＬが卓越することになるが、予
め拘束力ｐを与えた材料が反力Ｒを生じて拘束するた
め、柱の破壊が生じた以降は在来工法と同様な耐力向上
効果がある。When the pillar structure is subjected to an earthquake, a vertical force is applied to the pillar simultaneously with bending. The failure mode of the columns shown in the figure clearly indicates that vertical force was applied, and bending alone does not cause such failure. When an excessive vertical force L acts, the shearing force inside the column becomes as shown by τL in FIG. Fig. 16 shows the hoop reinforcements, spiral reinforcements, and steel pipes of the conventional construction method.
As shown in FIG. 5, a reaction force R is generated in a form of restraining the displacement due to the breakage of the column, and the shear reaction force τR generated by the action resists τL in FIG. In the present invention, as shown in FIG. 17, the binding force p is previously set with respect to τL which will be generated in the future.
Is applied to give a reverse shearing force τp, and this restraining force is not a passive force due to the destruction of the column unlike the conventional construction method. Of course, the shear force introduced in advance τ
When the vertical force L exceeds the proof stress improving effect of p, the shearing force τL due to the load is predominant, but the material to which the restraining force p is given in advance causes the reaction force R to restrain, so that the column is destroyed. After the occurrence of the above, it has the same proof stress improving effect as the conventional method.
【００１１】[0011]
【実施例】図１８、１９はこの発明の用途の例として、
橋の橋脚８と高層建築の柱９を示す。図２０は従来工法
による鉄筋コンクリート柱の例で、１はコンクリート
柱、２は軸方向鉄筋（縦筋）、３はいわゆるフープ筋、
スパイラル筋等の周方向鉄筋（横筋）で、矢印Ａは鉛直
荷重を示す。この従来の構造では荷重Ａによりコンクリ
ート１に生ずる縦方向圧縮応力が弾性限内の時は縦横の
鉄筋２、３はほとんど働かず、荷重Ａがさらに大きくな
ってコンクリートが降伏し、ダイレタンシーにより膨れ
はじめると横筋３がこれを拘束する。さらに大きな力が
加わると、縦筋２が座屈により折れ曲ってコンクリート
から飛び出そうとするが、横筋３はそれを拘束する。つ
まり従来の横筋３はコンクリートが鉛直荷重で降伏し膨
れはじめてから働くものであった。図２１は既設のコン
クリート柱１に、モルタル、樹脂等の充填材をはさんで
鋼板１１を巻きつけ補強した従来技術を示す。この工法
は図２０の横筋３が不足する場合に施工するもので、鋼
板１１の作用は図２０の横筋３と同様である。18 and 19 show examples of applications of the present invention.
Shown are the piers 8 of the bridge and the columns 9 of the skyscraper. FIG. 20 shows an example of a reinforced concrete column manufactured by the conventional method. 1 is a concrete column, 2 is an axial reinforcing bar (vertical bar), 3 is a so-called hoop bar,
A circumferential reinforcing bar (horizontal bar) such as a spiral bar, an arrow A indicates a vertical load. In this conventional structure, when the longitudinal compressive stress generated in the concrete 1 due to the load A is within the elastic limit, the vertical and horizontal reinforcing bars 2 and 3 hardly act, the load A becomes larger and the concrete yields and begins to swell due to dilatancy. And the horizontal stripe 3 restrains this. When a larger force is applied, the vertical bar 2 bends due to buckling and tries to jump out of the concrete, but the horizontal bar 3 restrains it. That is, the conventional horizontal bar 3 works after the concrete begins to yield and expand under the vertical load. FIG. 21 shows a conventional technique in which a steel plate 11 is wrapped around an existing concrete column 1 with a filler such as mortar or resin interposed therebetween for reinforcement. This construction method is applied when the horizontal bar 3 in FIG. 20 is insufficient, and the action of the steel plate 11 is the same as that of the horizontal bar 3 in FIG.
【００１２】図１〜１３にこの発明の実施例を示す。そ
の１はコンクリート柱、２は縦筋、３は横筋で、部分拡
大図を添えた４はシース管、５はその中に通して緊張さ
せたＰＣ鋼材である。このＰＣ鋼材５は緊張により、隣
接コンクリートを求心方向へ締付けて水平圧縮応力を生
ぜしめている。従って柱１に鉛直荷重Ａが加わって垂直
圧縮応力が生ずると三軸応力になり、従来の垂直応力だ
けの場合より鉛直耐力を大きく強める。1 to 13 show an embodiment of the present invention. Part 1 is a concrete column, 2 is a vertical bar, 3 is a horizontal bar, 4 is a sheath tube with a partially enlarged view, and 5 is a PC steel material that is passed through it and tensioned. Due to the tension, the PC steel material 5 tightens the adjacent concrete in the centripetal direction to generate horizontal compressive stress. Therefore, when the vertical load A is applied to the column 1 and vertical compressive stress is generated, it becomes triaxial stress, and the vertical proof stress is greatly strengthened as compared with the case of the conventional vertical stress alone.
【００１３】機械工学便覧の「多軸応力下の静的強度」
の項には、最大剪断応力説によれば σ1-σ3=σf 但しσ1、σ2、σ3 は主応力（σ1 ＞σ2 ＞σ3 ）で、σ
f は単軸応力下の静的強度である。となっている。従っ
てσ1=σf+σ3 となる。これを柱の鉛直耐力に当てはめ
ると、三軸応力下の鉛直耐力σ1 は、単軸応力下の鉛直
耐力σf に最も弱い水平圧縮応力σ3 を加えた値に向上
するということである。つまり所要の鉛直耐力と単軸応
力下の鉛直耐力との差以上の水平圧縮応力を生ぜしめる
ようＰＣ鋼材で締付ければよいのである。この簡素な理
論がコンクリート柱にはよく適合することを実験で確か
めている。"Static strength under multiaxial stress" in Mechanical Engineering Handbook
According to the theory of maximum shear stress, σ 1 -σ 3 = σ f, where σ 1 , σ 2 and σ 3 are principal stresses (σ 1 > σ 2 > σ 3 ),
f is the static strength under uniaxial stress. Has become. Therefore, σ 1 = σ f + σ 3 . When this is applied to the vertical proof stress of the column, the vertical proof stress σ 1 under triaxial stress is improved to the value obtained by adding the weakest horizontal compressive stress σ 3 to the vertical proof stress σ f under uniaxial stress. In other words, it is sufficient to fasten with the PC steel material so as to generate a horizontal compressive stress that is greater than the difference between the required vertical proof stress and the vertical proof stress under uniaxial stress. Experiments have confirmed that this simple theory fits well with concrete columns.
【００１４】図１のＰＣ鋼材５は図２のように環状のも
のを多段に入れても、また図３のようにらせん状に入れ
てもよい。いずれにしろＰＣ鋼材５の端部はコンクリー
トから露出させておき、打設したコンクリートが硬化し
てから油圧ジャッキ等により緊張させ、コンクリート表
面で定着する。定着方法は図４のように、コンクリート
表面に出たＰＣ鋼材５の両端を、周知のように油圧ジャ
ッキでけん引して、一体化した二本の鋼管１２に、定着
具１３を介して定着するとか、図５のように、コンクリ
ート柱１内に輪状に通したシース管４内のＰＣ鋼材５の
両端を、上下に食い違わせて図のように、コンクリート
柱１の周面の垂直***部１ａから外へ引き出して油圧ジ
ャッキでけん引し、支圧板６と定着具１３とでコンクリ
ート外面に定着するなど自由である。The PC steel material 5 shown in FIG. 1 may be annularly arranged in multiple stages as shown in FIG. 2 or may be spirally inserted as shown in FIG. In any case, the end portion of the PC steel material 5 is exposed from the concrete, and after the placed concrete is hardened, it is tensioned by a hydraulic jack or the like and fixed on the concrete surface. As for the fixing method, as shown in FIG. 4, both ends of the PC steel material 5 exposed on the concrete surface are towed by hydraulic jacks as is well known, and fixed to the two integrated steel pipes 12 via the fixing tool 13. Or, as shown in FIG. 5, the both ends of the PC steel material 5 in the sheath pipe 4 which is passed through the concrete pillar 1 in a ring shape are vertically misaligned, and as shown in the figure, a vertical ridge on the peripheral surface of the concrete pillar 1 It can be freely drawn out from 1a and towed by a hydraulic jack, and fixed on the outer surface of concrete by the pressure bearing plate 6 and the fixing tool 13.
【００１５】円柱にくらべて角柱の場合、ＰＣ鋼材５の
端部処理が簡単である。すなわち図６ａ、６ｂの角柱の
場合、縦横のシース管４内ＰＣ鋼材５が柱を横断し、両
端を柱表面の凹みに嵌めた支圧板６により定着してい
る。シース管４に通したＰＣ鋼材５は、コンクリート投
入前からのアンボンドＰＣ鋼材にするか、またはシース
管４だけでコンクリート投入し、その硬化後に挿入する
か、どちらでもよい。いずれにしろ従来のＰＣコンクリ
ートへのプレストレス導入工法をそのまま利用するの
で、詳細説明は略す。In the case of a prism, as compared with a cylinder, the end treatment of the PC steel material 5 is easier. That is, in the case of the prism shown in FIGS. 6a and 6b, the PC steel material 5 in the sheath tube 4 in the vertical and horizontal directions crosses the column and is fixed by the bearing plates 6 fitted into the recesses on the column surface at both ends. The PC steel material 5 passed through the sheath tube 4 may be an unbonded PC steel material before the concrete is poured, or the concrete may be poured only by the sheath tube 4 and then inserted, and then inserted. In any case, the conventional method of introducing prestress into PC concrete is used as it is, and therefore the detailed description is omitted.
【００１６】図６ａ、６ｂのコンクリート柱は断面が正
方形ゆえ、シース管４、ＰＣ鋼材５を水平方向縦横に通
したが、図７のコンクリート柱１（又は壁）は長方形断
面ゆえ、短辺方向のみに強化を施した例である。短辺方
向にのみ多くのＰＣ鋼材５を通し緊張させたが、長辺方
向にはポアソン比で短辺方向の三分の一程度の圧縮応力
が生ずる。なお図７はシース管を略している。Since the concrete columns shown in FIGS. 6a and 6b have a square cross section, the sheath tube 4 and the PC steel material 5 are passed horizontally and vertically, but the concrete column 1 (or wall) shown in FIG. 7 has a rectangular cross section. This is an example of strengthening only. Although many PC steel materials 5 were tensioned only in the short side direction, a compressive stress of about one third in the short side direction due to Poisson's ratio is generated in the long side direction. Note that FIG. 7 omits the sheath tube.
【００１７】図８は既製コンクリート円柱１を強化する
ため、その外周にＰＣ鋼材５を巻付け緊張させて、内部
コンクリートに求心方向圧縮応力をプレストレスとして
付与した例である。外周に巻付けるＰＣ鋼材５は外気に
さらされるため、防錆処理が施されたもの（シース管入
りアンボンドＰＣ鋼材、樹脂塗装ＰＣ鋼材等）を用い
る。ＰＣ鋼材５の配置は前述の新設柱の工法と同様に、
一巻き毎、あるいはらせん状にする。ＰＣ鋼材５の端部
の定着方法は一巻き毎の場合、図４の要領でよいが、ら
せん巻きした場合のＰＣ鋼材５の両端は、既製コンクリ
ート柱の周面に図５の***部１ａのようなアンカーを作
って定着すればよい。FIG. 8 shows an example in which, in order to strengthen the ready-made concrete cylinder 1, a PC steel material 5 is wound around its outer periphery and tensioned, and centripetal compressive stress is applied as prestress to the internal concrete. Since the PC steel material 5 wound around the outer periphery is exposed to the outside air, an anti-corrosion-treated material (unbonded PC steel material with a sheath tube, resin-coated PC steel material, etc.) is used. The arrangement of the PC steel material 5 is the same as the construction method of the above-mentioned new pillar,
Each time, or make a spiral. The method of fixing the end portion of the PC steel material 5 may be the procedure of FIG. 4 in the case of every winding, but the both ends of the PC steel material 5 in the case of spiral winding are shown in FIG. You can make an anchor like this and fix it.
【００１８】図９ａ、９ｂの実施例のコンクリート柱１
は既製の角柱で、その強化のため縦横に水平貫通孔７を
コアボーリングマシンで削孔し、これにＰＣ鋼材５を通
して緊張させ、支圧板６に両端を定着している。その部
分の防錆処理が必要である。支圧板６の形状、寸法はコ
ンクリート柱１の寸法・強度によって定められるが、柱
に対して、できるだけ平均した拘束力が加わるようにす
る。Concrete pillar 1 of the embodiment of FIGS. 9a and 9b
Is a ready-made prism, and in order to strengthen it, horizontal through holes 7 are drilled vertically and horizontally by a core boring machine, and PC steel material 5 is tensioned through this to fix both ends to the bearing plate 6. Corrosion-proofing of that part is necessary. The shape and size of the pressure bearing plate 6 are determined by the size and strength of the concrete column 1. However, an average binding force is applied to the column as much as possible.
【００１９】図１０の実施例も既製角柱を対象にしたも
ので、柱１の平行する両側面に支圧梁材１４を当て、そ
の梁材１４の両端部に通したＰＣ鋼材５により、梁材１
４同士を締合わせている。ＰＣ鋼材５の締付力の向きが
各段毎に９０°ずつ変わるようにして、柱内コンクリー
トに生ずる水平圧縮応力が縦横均等になるようにする。
支圧梁材１４は締付力を均等に分散するため、撓まない
剛性が必要である。The embodiment shown in FIG. 10 is also intended for a ready-made prism, and a bearing beam member 14 is applied to both side surfaces of the column 1 which are parallel to each other, and a beam is formed by a PC steel material 5 passed through both ends of the beam member 14. Material 1
The four are tightened together. The direction of the tightening force of the PC steel material 5 is changed by 90 ° for each step so that the horizontal compressive stress generated in the concrete in the column becomes uniform in the vertical and horizontal directions.
Since the support beam member 14 evenly distributes the tightening force, it is required to have rigidity that does not bend.
【００２０】以上、少数の実施例について説明したが、
この発明はその要旨を変えることなく、実施条件に応じ
て多様に変化、応用し得るもので、円柱、角柱以外の柱
にも適用できること言うまでもない。ＰＣ鋼材５の使い
方も図１１、１２、１３のように多様になる。すなわち
図１１は角柱に対し輪形又はらせん状ＰＣ鋼材５を入
れ、柱１の側面に支圧板６により定着している。図１２
は円柱１にＰＣ鋼材５を直径方向に通した例である。図
１３は長円形の柱１に相似形にＰＣ鋼材５を通した例で
ある。この種の応用方法は極めて多様である。Although a few examples have been described above,
Needless to say, the present invention can be variously changed and applied according to the implementation conditions without changing the gist thereof, and can be applied to columns other than the column and the prism. There are various ways to use the PC steel material 5, as shown in FIGS. That is, in FIG. 11, a ring-shaped or spiral PC steel material 5 is put in a prism and is fixed to a side surface of the pillar 1 by a pressure plate 6. 12
Is an example in which the PC steel material 5 is passed through the cylinder 1 in the diameter direction. FIG. 13 shows an example in which the PC steel material 5 is passed through the oblong pillar 1 in a similar shape. The applications of this kind are extremely diverse.
【００２１】[0021]
【発明の効果】この発明はコンクリート構造物に対する
プレストレス付与方法に新しい分野を開いた。それは従
来のように外力で引張応力を生ずる位置に予め圧縮応力
を生ぜしめておくのではない。外力で圧縮応力が生ずる
位置に、外力とは直角方向の圧縮応力をプレストレスと
して与えておく。従って外力がかかると三軸応力にな
り、外力方向の耐力が高まるという仕組みである。この
原理をコンクリート柱の鉛直耐力強化に使ったのであ
る。この発明は新設のコンクリート柱は無論のこと、既
設の柱に対しても容易に適用できるので、その効果は大
きい。INDUSTRIAL APPLICABILITY The present invention has opened a new field to a method of prestressing a concrete structure. It does not generate a compressive stress in advance at a position where a tensile stress is generated by an external force as in the conventional case. A compressive stress in a direction perpendicular to the external force is applied as a prestress to a position where the compressive stress is generated by the external force. Therefore, when an external force is applied, it becomes a triaxial stress, and the yield strength in the direction of the external force increases. This principle was used to strengthen the vertical resistance of concrete columns. The present invention can be applied to existing concrete columns not to mention new concrete columns, so that the effect is great.
【図１】この発明の一実施例説明図である。FIG. 1 is an explanatory view of an embodiment of the present invention.
【図２】輪形多段に柱に入れたＰＣ鋼材の説明図であ
る。FIG. 2 is an explanatory view of a PC steel material put in a pillar in a ring-shaped multi-stage.
【図３】らせん状ＰＣ鋼材の説明図である。FIG. 3 is an explanatory view of a spiral PC steel material.
【図４】ＰＣ鋼材の両端結合部の一例説明図である。FIG. 4 is an explanatory diagram of an example of a both-end joint portion of a PC steel material.
【図５】円柱内の輪形ＰＣ鋼材の両端定着部実施例説明
図である。FIG. 5 is an explanatory diagram of an embodiment of both ends fixing portion of a ring-shaped PC steel material in a cylinder.
【図６】ａは角柱に縦横ＰＣ鋼材を通した実施例の立面
説明図である。ｂは図６ａの平面説明図である。FIG. 6a is an elevational view of an embodiment in which a vertical and horizontal PC steel material is passed through a prism. 6b is an explanatory plan view of FIG. 6a.
【図７】扁平な柱に適用した実施例説明図である。FIG. 7 is an explanatory diagram of an example applied to a flat column.
【図８】既製コンクリート円柱の実施例説明図である。FIG. 8 is an explanatory view of an example of a ready-made concrete column.
【図９】ａは既製の角柱の実施例の立面説明図である。
ｂは図９ａの平面説明図である。FIG. 9a is an elevational view of an embodiment of a ready-made prism.
9b is a plan view of FIG. 9a. FIG.
【図１０】角柱の他の実施例説明図である。FIG. 10 is an explanatory view of another embodiment of the prism.
【図１１】角柱に輪形ＰＣ鋼材を使った実施例の平面説
明図である。FIG. 11 is an explanatory plan view of an example in which a ring-shaped PC steel material is used for a prism.
【図１２】円柱に直線ＰＣ鋼材を使った実施例の平面説
明図である。FIG. 12 is an explanatory plan view of an example in which a straight PC steel material is used for a cylinder.
【図１３】長円形柱の実施例の平面説明図である。FIG. 13 is an explanatory plan view of an example of an elliptical column.
【図１４】ａはコンクリート柱の圧縮破壊前の説明図で
ある。ｂは図１４ａの破壊後の説明図である。FIG. 14A is an explanatory diagram before a compressive failure of a concrete column. FIG. 14b is an explanatory diagram after the destruction of FIG. 14a.
【図１５】圧縮破壊時の剪断力説明図である。FIG. 15 is an explanatory diagram of shearing force at the time of compressive failure.
【図１６】図１５の反力Ｒの状態説明図である。16 is a state explanatory view of the reaction force R of FIG.
【図１７】この発明の拘束力Ｐの説明図である。FIG. 17 is an explanatory view of the binding force P of the present invention.
【図１８】この発明の用途の一例の橋脚説明図である。FIG. 18 is an explanatory view of a pier as an example of the application of the present invention.
【図１９】他の用途の一例の建築物の柱説明図である。FIG. 19 is a diagram illustrating a pillar of a building which is an example of another application.
【図２０】従来の鉄筋コンクリート柱の説明図である。FIG. 20 is an explanatory diagram of a conventional reinforced concrete column.
【図２１】既設コンクリート柱強化のため鋼板を巻き立
てた従来技術説明図である。FIG. 21 is a diagram illustrating a conventional technique in which a steel plate is wound up to strengthen an existing concrete column.
４ シース管 ５ ＰＣ鋼材 ６ 支圧板 4 Sheath tube 5 PC steel 6 Bearing plate
Claims (9)
平に、多段にシース管入りＰＣ鋼材を通したコンクリー
ト柱であって、上記ＰＣ鋼材の緊張により隣接コンクリ
ートに水平圧縮応力を生じており、その水平圧縮応力
は、当該コンクリート柱に鉛直荷重が加わった時、コン
クリート内応力が三軸になって、柱の垂直耐力を所要値
まで増大する値であることを特徴とする強化したコンク
リート柱。1. A concrete column in which a PC steel material containing a sheath pipe is passed substantially horizontally between the horizontal reinforcing bars inside, and a horizontal compressive stress is generated in the adjacent concrete due to the tension of the PC steel material. The horizontal compressive stress is a value that increases the vertical proof stress of the column to the required value when the internal stress of the concrete becomes triaxial when the vertical load is applied to the concrete column. Pillar.
て、 そのシース管入りＰＣ鋼材は柱内をほぼ水平に横断し
て、両端を柱表面に定着させたものであることを特徴と
する強化したコンクリート柱。2. The concrete pillar according to claim 1, wherein the sheathed PC steel material has a structure in which the inside of the pillar traverses substantially horizontally and both ends are fixed to the surface of the pillar. Concrete pillars.
て、 そのシース管入りＰＣ鋼材は柱の外周よりやや内側を水
平にほぼ一周していることを特徴とする強化したコンク
リート柱。3. The reinforced concrete column according to claim 1, wherein the PC steel material with a sheath pipe extends substantially inward from the outer periphery of the column substantially horizontally.
て、 そのシース管入りＰＣ鋼材は柱の外周よりやや内側をら
せん状にめぐっていることを特徴とする強化したコンク
リート柱。4. The reinforced concrete column according to claim 1, wherein the sheathed PC steel material spirally extends inward from the outer periphery of the column.
のあい間にシース管入りＰＣ鋼材をほぼ水平に多段に配
設し、その端部を型枠の外に出してコンクリートを打設
し、コンクリート硬化後、上記ＰＣ鋼材端部をけん引し
てコンクリート表面に定着させることを特徴とするコン
クリート柱の強化方法。5. When constructing a concrete pillar, PC steel material with a sheath tube is arranged substantially horizontally in multiple stages between horizontal rebars, and the end portion thereof is taken out of the formwork and concrete is poured, A method for strengthening a concrete column, comprising the steps of pulling the PC steel material edge and fixing it on the concrete surface after hardening the concrete.
多段にＰＣ鋼材を沿わし、そのＰＣ鋼材を緊張させて隣
接コンクリートに水平圧縮応力を生ぜしめておき、該コ
ンクリート柱が鉛直荷重を受けた時、上記隣接コンクリ
ートに三軸応力を生じて柱の鉛直耐力を所要値まで増大
するようにしておくことを特徴とするコンクリート柱の
強化方法。6. When a pre-cast concrete column is provided with PC steel material in a multi-step manner substantially horizontally on the outer periphery thereof and the PC steel material is tensioned to generate horizontal compressive stress in adjacent concrete, and the concrete pillar is subjected to a vertical load. , A method for strengthening a concrete column, characterized in that triaxial stress is generated in the adjacent concrete to increase the vertical proof stress of the column to a required value.
ることを特徴とするコンクリート柱の強化方法。7. The method for strengthening a concrete column according to claim 6, wherein the PC steel material is wound around the column in a ring shape or a spiral shape.
端部に通した上記ＰＣ鋼材により、上記梁材同士を締合
わすことを特徴とするコンクリート柱の強化方法。8. The strengthening method according to claim 6, wherein supporting beam members are applied to both parallel side surfaces of the column, and the beam members are fastened to each other by the PC steel material passed through both ends of each beam member. A method for strengthening concrete columns, characterized by combining.
し、その孔内にＰＣ鋼材を通して緊張させ、その両端を
孔縁に定着させることを特徴とするコンクリート柱の強
化方法。9. A method for strengthening a concrete column, which comprises transversely perforating a prefabricated concrete column, passing a PC steel material through the hole to tension the ends, and fixing both ends to the hole edges.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17044195A JPH08338104A (en) | 1995-06-14 | 1995-06-14 | Reinforced concrete pillar and its reinforcing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17044195A JPH08338104A (en) | 1995-06-14 | 1995-06-14 | Reinforced concrete pillar and its reinforcing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08338104A true JPH08338104A (en) | 1996-12-24 |
Family
ID=15904985
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17044195A Pending JPH08338104A (en) | 1995-06-14 | 1995-06-14 | Reinforced concrete pillar and its reinforcing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08338104A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008133725A (en) * | 2008-03-06 | 2008-06-12 | Public Works Research Institute | Reinforced concrete pier |
| JP2013053412A (en) * | 2011-09-01 | 2013-03-21 | Kajima Corp | Structure made of reinforced concrete |
| CN103575597A (en) * | 2013-10-24 | 2014-02-12 | 湖南工业大学 | Axial compression column non-loading reinforcement test device |
| JP6186640B1 (en) * | 2017-02-27 | 2017-08-30 | 株式会社神島組 | Reinforcement structure of reinforced concrete structure |
| CN114893012A (en) * | 2022-05-07 | 2022-08-12 | 浙江翰达工程检测有限公司 | Reinforced concrete column resetting method |
-
1995
- 1995-06-14 JP JP17044195A patent/JPH08338104A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008133725A (en) * | 2008-03-06 | 2008-06-12 | Public Works Research Institute | Reinforced concrete pier |
| JP2013053412A (en) * | 2011-09-01 | 2013-03-21 | Kajima Corp | Structure made of reinforced concrete |
| CN103575597A (en) * | 2013-10-24 | 2014-02-12 | 湖南工业大学 | Axial compression column non-loading reinforcement test device |
| JP6186640B1 (en) * | 2017-02-27 | 2017-08-30 | 株式会社神島組 | Reinforcement structure of reinforced concrete structure |
| CN114893012A (en) * | 2022-05-07 | 2022-08-12 | 浙江翰达工程检测有限公司 | Reinforced concrete column resetting method |
| CN114893012B (en) * | 2022-05-07 | 2023-07-18 | 浙江翰达工程检测有限公司 | Reset method for reinforced concrete column |
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