JP4363747B2

JP4363747B2 - Method of joining PCa beam members at column beam joints and PCa beam members therefor

Info

Publication number: JP4363747B2
Application number: JP2000165378A
Authority: JP
Inventors: 裕行長縄; 高仁柳瀬
Original assignee: Sato Kogyo Co Ltd
Current assignee: Sato Kogyo Co Ltd
Priority date: 2000-06-02
Filing date: 2000-06-02
Publication date: 2009-11-11
Anticipated expiration: 2020-06-02
Also published as: JP2001342679A

Description

【０００１】
【発明の属する技術分野】
本発明は、ＰＣａ（プレキャストコンクリート）梁部材の接合を各階毎の柱梁接合部で行うようにしたＰＣａ梁部材の接合方法およびそのためのＰＣａ梁部材に関する。
【０００２】
【従来の技術】
近年、鉄筋コンクリート造や、鉄骨鉄筋コンクリート造の建築物では、躯体工事の省力化、工期短縮、品質向上、環境問題に対する配慮等からＰＣａ梁部材が頻繁に使用されるようになってきた。
【０００３】
ＰＣａ梁部材は、各階毎に柱と一体的に接合されるが、ＰＣａ梁部材の接合形式には、図１５(A)に示されるように、ＰＣａ梁部材５１の構造を中央部が梁主筋５０，５０のみで接合された２分割構造とし、前記中央部の梁主筋５０，５０…を柱５２の頭部に位置させた状態で設置し、柱梁接合部において、配筋および型枠の後、コンクリートを流し込んで柱との一体化を図るとともに、梁の中央部においても、突出している梁主筋５０ａ，５０ａ同士を機械継手または溶接継手等によって堅固に連結した後、剪断筋などを配筋するとともに、周囲に型枠を組み、しかる後コンクリートを流し込んでＰＣａ梁部材同士を接合する梁中央接合方式と、図１５(B)に示されるように、ＰＣａ梁部材５３の両端面より梁主筋５０、５０…を柱部材５２の中心線を越えた長さ位置で上方側にＬ字状に屈曲させておき、柱間に横架させてＰＣａ梁部材５３，５３を配置した後、配筋および型枠の後、コンクリートを流し込んで柱梁接合部でＰＣａ梁部材５３，５３…同士の接合を行う柱梁接合方式とに大別される。なお、図示されていないが、柱梁接合部には柱上面から突出する主筋や剪断補強筋などが配置される。また、前記ＰＣａ梁部材５１，５３…は平面視で、柱部材を中心として十字４方向または３方向等に接合される。
【０００４】
【発明が解決しようとする課題】
前者の梁中央接合方式は、柱梁接合部で梁主筋が連続し配筋作業が簡略化されるなどの利点を有するため、比較的多く採用されている方式であるが、ＰＣａ梁部材の製造に際し、型枠作業が複雑となるためコスト高になるなどの問題がある。また、施工に際しても、ＰＣａ梁部材を梁中央部で支持するためにサポート柱の設置が必要となるとともに、柱頭部と梁中央部との２箇所でそれぞれ配筋および型枠作業を行わなければならず、しかも梁鉄筋の接合も機械継手や溶接継手といった比較的手間の掛かる鉄筋接合方法が採用されるため、施工に多くの手間と時間が掛かるなどの問題があった。
【０００５】
一方、後者の柱梁接合方式は、ＰＣａ梁部材の製造が比較的容易で、図示されるようにＬ字状に屈曲させた梁主筋による重ね継手とすれば施工も比較的容易となるなどの利点を有する。しかし、柱梁接合部内で所定の構造性能を確保するには、前記梁主筋を柱中心線を越えた長さ位置で折り曲げて定着させる必要があり、対向する相手側の梁主筋とで錯綜が問題となり、梁鉄筋の本数に制限を受けるなどの問題が生じる。その結果、梁の断面寸法を大きくしたり、鉄筋強度を上げざるを得ないなどの問題が発生していた。
【０００６】
上記梁中央接合方式と柱梁接合方式とについて、その得失を検討するに、柱梁接合部での梁主筋の錯綜さえ解決できれば、後者の柱梁接合方式の方が製作面および施工面の両方で優れていることが判る。梁主筋鉄筋の錯綜は、柱中心を越えない位置で梁鉄筋を屈曲させるようにすれば解決出来るが、この場合には梁主筋が不連続となるため、所定の付着・定着強度が確保できない、所定の剪断強度が確保されないなどの構造的問題を何らかの方法で解決する必要がある。
【０００７】
この点に関し、特開平５−２９５７９２号公報では、図１６に示されるように、梁主筋５４，５４…を柱中心線を越えない位置で上方に折り曲げ定着し、これらの折曲げ鉄筋部分を囲むように多数のフープ筋（スパイラル筋）５５，５５…を配置する定着構造が提案されている。このような定着構造を採用するものとしては、他に特開平８−４９２９２号公報および特開平５−９８６９４号公報を挙げることができる。
【０００８】
しかしながら、前記特開平５−２９５７９２号公報などに記載される補強方法の場合には、非常に多くのフープ筋を必要とするため、現実の施工を考えた場合には採用し難いなどの問題がある。また、現行の鉄筋コンクリート造および鉄骨鉄筋コンクリート造の設計では、最大級の地震に対して梁端部に降伏ヒンジ（主筋の降伏）を発生させるようにし、降伏ヒンジ域での変形性能により地震エネルギーを吸収させ建物全体が崩壊しないようにしている。この点を考えると、多数のフープ筋で梁主筋部を補強する方法では、剪断力強度の増大には効果が期待出来るが、梁主筋の定着強度の点では所望の強度が確保出来ないなどの問題があった。すなわち、最大級の地震発生時に、前記梁主筋は梁端部で降伏し、ヒンジ領域が梁端部から１．０Ｄ程度（Ｄ：梁せい）まで降伏領域が進展することになる。降伏する領域は、梁内だけでなく、反対側の柱梁接合部内にも進展する。前記梁主筋は柱梁接合部内で降伏強度以上の耐力で定着させる必要があるが、多数の補強筋で補強しても梁主筋が不連続である点に変わりはなく、柱梁接合部内で定着破壊が生じ、所定の構造性能が得られないことがあった。
【０００９】
そこで本発明の主たる課題は、ＰＣａ梁部材からの梁主筋を柱部材の中心を越えない長さ位置で上方に屈曲し接合を行う柱梁接合方式を採用することを前提に、梁主筋同士の錯綜を解消するとともに、柱梁接合部内で梁主筋を構造的に連続させることにより十分な定着強度および剪断強度を確保し得るようにした柱梁接合部におけるＰＣａ梁部材の接合方法およびそのためのＰＣａ梁部材を提供することにある。
【００１０】
【課題を解決するための手段】
前記課題を解決するための本発明は、柱部材と接合されるＰＣａ梁部材は、端面より部材内方側に向かって少なくとも所定区間の断面形状が略Ｕ字状とされるとともに、設置状態において端面から水平方向に突出する梁下側主筋が柱部材の中心線を越えない長さ位置で上方に屈曲させてあり、
前記ＰＣａ梁部材を柱部材の上面端部を座として柱部材間に横架した後、直線方向に連続されるＰＣａ梁部材間において、前記柱部材を跨ぐとともに、対向する前記略断面Ｕ字状内に亘る範囲に、前記梁下側主筋を構造的に連続させる梁端部下側補強主筋と、梁上側主筋間であってかつその内側位置に配筋される梁端部上側補強主筋とが鉛直面内でループ状になるように加工された梁端部下側補強主筋および梁端部上側補強主筋を配筋し、しかる後、柱梁接合部内にコンクリートを充填し柱部材とＰＣａ梁部材とを一体的に接合することを特徴とするものである。
【００１１】
この場合、該梁端部補強下側主筋の端部近傍位置が地震時のヒンジ発生箇所となるように配筋量を決定することが望ましい。また、前記直線方向に連続されるＰＣａ梁部材間において、断面上部側位置に前記柱部材を跨いで梁端部上側補強主筋を配筋することが望ましい。
【００１２】
他方、上記接合方法のためのＰＣａ梁部材は、端面より部材内方側に向かって所定区間の断面形状が略Ｕ字状とされるとともに、設置状態において端面より突出する梁下側主筋が柱部材の中心線を越えない長さ位置で上方に屈曲させるようにしたことを特徴とするものである。
【００１３】
本発明においては、ＰＣａ梁部材内に埋設された梁下側主筋を柱梁接合部内で柱の中心線を越えない長さ位置で上方に屈曲して定着するとともに、柱部材を跨ぐと共に、両ＰＣａ梁部材に亘る区間に梁端部下側補強主筋等を配筋する。この梁端部下側補強主筋は、端部近傍位置が地震時のヒンジ発生箇所となるように配筋量が決定される。
【００１４】
従来は、最大級の地震があった場合に梁端部で降伏ヒンジを発生させる設計思想の下、梁主筋を柱梁接合部内で柱の中心線を越えない長さ位置で上方に屈曲して定着し、前記梁下側主筋が不連続となる構造的弱点をフープ筋などで補強する方法が採られていたが、本発明では規定の設計思想にとらわれず、ヒンジ発生位置を梁端部から中央側に若干ずらす設計思想の下、ＰＣａ梁部材間に跨るように前記梁端部下側補強主筋を別途配筋するようにした。これにより、梁主筋が構造的に連続するようになるとともに、最大級の地震が発生し降伏領域が柱梁接合部側に進展しても、柱梁接合部内では梁主筋の付着劣化が軽微で済み、柱梁接合部内で定着破壊および剪断破壊が生じることが無くなる。
【００１５】
【発明の実施の形態】
〔参考第１形態例〕
以下、本発明の各実施の形態について図面を参照しながら詳述する。
【００１６】
図１および図２はそれぞれ本発明ＰＣａ梁部材１の接合方法に使用されるＰＣａ梁部材の端部斜視図、図３〜図６は施工要領手順図、図７は配筋後の平面図、図８はスラブ配筋を含む平面図である。
【００１７】
本接合方法において使用されるＰＣａ梁部材１は、図１に示されるように、全長区間に亘って断面略Ｕ字状部４が形成されたＰＣａ梁部材１Ａ、或いは図２に示されるように、端面より所定区間範囲に断面略Ｕ字状部４が形成されたＰＣａ梁部材１Ｂのように、端面より部材内方側に向かって少なくとも所定区間に亘り断面略Ｕ字状部４が形成されたＰＣａ梁部材である。
【００１８】
具体的に図１に示されるＰＣａ梁部材１Ａは、スラブ部分を現場打設施工とするために、剪断補強筋（スターラップ）２，２…が上部側部分を露出させた状態で部材長手方向に沿って所定間隔で埋設された所謂ハーフＰＣａ梁部材であり、全長に亘り断面形状を略Ｕ字状として軽量化を図ったものである。底版部には、部材長手方向に沿って複数の、図示例では３本の梁下側主筋３，３が埋設されるとともに、設置状態で端面から水平方向に突出する前記梁下側主筋３，３…が柱部材の中心線を越えない長さ位置で上方に屈曲させるようにしている。
【００１９】
一方、図２に示されるＰＣａ梁部材１Ｂは、同じくスラブ部分を現場打設施工とするために、剪断補強筋（スターラップ）２，２…が上部側部分を露出させた状態で部材長手方向に沿って所定間隔で埋設されるとともに、設置状態で端面から水平方向に突出する前記梁下側主筋３，３…が柱部材の中心線を越えない長さ位置で上方に屈曲させるようにしている点は同様であるが、断面Ｕ字状部４は端面から所定区間のみとされ、他の躯体部分は無垢となっている。
【００２０】
これらＰＣａ梁部材１は、図３に示されるように、柱部材５の上面端部を座として柱部材５，５間に横架され、図７に示されるように、平面視で柱部材５を中心に十字４方向（或いは３または２方向）に設置される。ＰＣａ梁部材１，１…を設置したならば、図４に示されるように、直線方向に連続されるＰＣａ梁部材１，１間において、前記柱部材５を跨ぐとともに、対向する前記略断面Ｕ字状部４，４内に亘る範囲に複数本の、図示例では２本の梁端部下側補強主筋６、６を配筋する。前記梁端部下側補強主筋６は、両端部をそれぞれ上方側に曲げ上げて定着させるようにしてある。
【００２１】
前記梁端部下側補強主筋６，６の配筋を終えたならば、図５に示されるように、柱主筋７，７を囲むスターラップ筋８，８…を配筋するとともに、ＰＣａ梁部材１のスターラップ筋２，２内に梁上側主筋９，９…を配筋する。また、柱梁接合部に側型枠を設置するとともに、スラブの底型枠を設置する。一方、図８に示されるように、前記柱梁接合部と共に一体的にコンクリート打設が行われるスラブ部分に、格子状にスラブ筋１０，１０…を配筋するとともに、直線方向に連続されるＰＣａ梁部材１，１間に、図８に示されるように、スラブ内であってかつ断面上部側に前記柱部材５を跨いで梁端部上側補強主筋１１，１１…を配筋する。図示の例では十字方向にＰＣａ梁部材１，１が連続されるため、梁端部上側補強主筋１１，１１…は平面視で井桁状に配筋されている。
【００２２】
上記梁端部下側補強主筋６，６および梁端部上側補強主筋１１，１１の端部近傍位置がそれぞれ設計上のヒンジ発生位置とされ、最大級の地震が発生した場合には、降伏領域が部材前後方向に進展することによって地震エネルギーを吸収するようになっている。
【００２３】
すべての配筋および型枠作業を終えたならば、スラブと共に柱梁接合部内にコンクリートを充填し、柱部材５とＰＣａ梁部材１，１…とを一体的に接合する。その後は、柱主筋を組み立てるとともに、型枠を組み、コンクリートを流し込んで上階までの柱部材５を構築するとともに、前記ＰＣａ梁部材の接合要領に従って上階の施工を行う。
【００２４】
〔参考第２形態例〕
図９および図１０に参考第２形態例として示されるＰＣａ梁部材の接合方法は、前記梁端部下側補強主筋６，６および梁端部上側補強主筋１１，１１に代えて、端部を折り曲げ加工せずに単に棒状のままの梁端部下側補強主筋６Ａ，６Ａおよび梁端部上側補強主筋１１Ａ，１１Ａを用いた場合の例を示したものである。施工要領については前記参考第１形態例のとおりであるため説明は省略する。
【００２５】
〔参考第３形態例〕
また、図１１および図１２に参考第３形態例として示されるＰＣａ梁部材の接合方法は、梁端部下側補強主筋および梁端部上側補強主筋として、端部を折り曲げ加工せずに単に棒状のままの梁端部下側補強主筋６Ａ，６Ａおよび梁端部上側補強主筋１１Ａ，１１Ａを使用するが、梁端部上側補強主筋１１Ａ、１１Ａを、梁上側主筋９、９間であってかつその内側位置に２段配筋とした態様を示したものである。
【００２６】
〔本発明に係る形態例〕
さらに、図１３および図１４に本発明に係る形態例として示されるＰＣａ梁部材の接合方法は、前記梁端部下側補強主筋および梁端部上側補強主筋として、鉛直面内でループ状になるように加工された梁端部下側補強主筋６Ｂ、６Ｂおよび梁端部上側補強主筋１１Ｂ、１１Ｂの態様を示したものである。
【００２７】
以上のように、梁端部下側補強主筋および梁端部上側補強主筋は、構造性能を満たす限りにおいて任意の形状を採ることができるが、いずれにしても柱部材５を跨ぐとともに、対向する前記略断面Ｕ字状部４，４内に亘る範囲に配筋することにより、梁主筋が構造的に連続するようになり、柱梁接合部内で定着破壊や剪断破壊が生じるのを防止する。
【００２８】
【発明の効果】
以上詳説のとおり本発明によれば、ＰＣａ梁部材からの梁下側主筋を柱部材の中心を越えない長さ位置で上方に屈曲し接合を行う柱梁接合方式を採用することで、梁主筋同士の錯綜が解消されるようになるとともに、直線方向に連続されるＰＣａ梁部材間において、前記柱部材を跨ぐとともに、対向する前記略断面Ｕ字状内に亘る範囲に梁下側主筋を構造的に連続させる梁端部下側補強主筋を配筋するようにしたため、柱梁接合部内で十分な定着強度および剪断強度を確保し得るようになる。
【図面の簡単な説明】
【図１】本発明ＰＣａ梁部材１の接合方法に使用されるＰＣａ梁部材１Ａの端部斜視図である。
【図２】本発明ＰＣａ梁部材１の接合方法に使用される他のＰＣａ梁部材１Ｂの端部斜視図である。
【図３】本発明ＰＣａ梁部材１の接合要領を示す手順図（その１）である。
【図４】本発明ＰＣａ梁部材１の接合要領を示す手順図（その２）である。
【図５】本発明ＰＣａ梁部材１の接合要領を示す手順図（その３）である。
【図６】本発明ＰＣａ梁部材１の接合要領を示す手順図（その４）である。
【図７】配筋後の平面図である。
【図８】スラブ配筋を含む平面図である。
【図９】梁端部補強主筋の参考第２態様を示す縦断面図である。
【図１０】その平面図である。
【図１１】梁端部補強主筋の参考第３態様を示す縦断面図である。
【図１２】その平面図である。
【図１３】梁端部補強主筋の本発明に係る形態例を示す縦断面図である。
【図１４】その平面図である。
【図１５】 (A)および(B)はそれぞれ従来のＰＣａ梁部材の接合方式を示す図である。
【図１６】従来の柱梁接合部におけるＰＣａ梁部材の接合構造を示す要部拡大縦断面図である。
【符号の説明】
１・１Ａ・１Ｂ…ＰＣａ梁部材、２…剪断補強筋、３…梁下側主筋、４…断面略Ｕ字状部、５…柱部材、６・６Ａ・６Ｂ…梁端部下側補強主筋、７…柱主筋、８…スターラップ筋、９…梁上側主筋、１０…スラブ筋、１１・１１Ａ・１１Ｂ…梁端部上側補強主筋[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a PCa beam member joining method in which PCa (precast concrete) beam members are joined at column beam joints on each floor, and a PCa beam member therefor.
[0002]
[Prior art]
In recent years, in a reinforced concrete structure or a steel reinforced concrete structure, a PCa beam member has been frequently used in order to save labor of the frame construction, shorten the construction period, improve quality, and consider environmental issues.
[0003]
The PCa beam member is integrally joined to the column for each floor. As shown in FIG. 15A, the PCa beam member has a structure in which the central portion of the PCa beam member 51 has a beam main bar as shown in FIG. It is set as the 2 division structure joined only by 50 and 50, and it has installed in the state where beam main reinforcement 50,50 ... of the above-mentioned center part was located in the head of column 52, and at the column beam junction, reinforcement and formwork After that, concrete is poured into the column to be integrated with the pillar, and at the center of the beam, the protruding beam main bars 50a, 50a are firmly connected to each other by a mechanical joint or a welded joint, and then shear bars are arranged. A beam center joint method in which a formwork is built around the concrete, and then concrete is poured into the PCa beam members to join each other, as shown in FIG. 15 (B), and the beam from both ends of the PCa beam member 53 as shown in FIG. The main bars 50, 50. Bend in an L shape upward at a position beyond the core, place the PCa beam members 53, 53 horizontally between the columns, and then pour concrete after reinforcement and formwork Are roughly divided into column beam joining methods in which the PCa beam members 53, 53... Although not shown in the figure, a main reinforcing bar, a shear reinforcing bar, and the like that protrude from the upper surface of the column are arranged at the column beam joint. In addition, the PCa beam members 51, 53,...
[0004]
[Problems to be solved by the invention]
The former beam center joint method has the advantage that the beam main bar is continuous at the column beam joint and simplifies the bar arrangement work. Therefore, it is a relatively popular method. At this time, there is a problem that the formwork work becomes complicated and the cost becomes high. In addition, it is necessary to install a support column to support the PCa beam member at the center of the beam at the time of construction, and the reinforcement and formwork work must be performed at two locations, the column head and the beam center, respectively. In addition, since the rebar joining method, such as a mechanical joint or a welded joint, is used for joining the beam reinforcing bars, there is a problem that the construction takes a lot of labor and time.
[0005]
On the other hand, the latter column beam connection method is relatively easy to manufacture the PCa beam member, and if it is a lap joint with a beam main bar bent in an L shape as shown in the drawing, the construction is also relatively easy. Have advantages. However, in order to secure a predetermined structural performance within the beam-column joint, it is necessary to bend and fix the beam main bar at a length position beyond the column center line, and there is a complication with the beam main bar on the opposite side. It becomes a problem, and there arises a problem that the number of beam reinforcing bars is limited. As a result, there have been problems such as increasing the cross-sectional dimensions of the beam and increasing the strength of the reinforcing bars.
[0006]
To examine the advantages and disadvantages of the beam center joint method and the column beam joint method described above, if the complexity of the main beam of the beam at the column beam joint can be solved, the latter column beam joint method is both the production surface and the construction surface. It turns out that it is excellent. The complexity of the beam reinforcement can be solved by bending the beam reinforcement at a position that does not exceed the center of the column, but in this case the beam reinforcement is discontinuous, so the prescribed adhesion / fixing strength cannot be secured. It is necessary to solve a structural problem such as that a predetermined shear strength is not ensured by some method.
[0007]
In this regard, in Japanese Patent Laid-Open No. 5-295922, as shown in FIG. 16, the beam main bars 54, 54... Are bent and fixed upward at a position not exceeding the column center line, and these bent reinforcing bar portions are surrounded. A fixing structure in which a large number of hoop muscles (spiral muscles) 55, 55. Other examples that employ such a fixing structure include JP-A-8-49292 and JP-A-5-98694.
[0008]
However, in the case of the reinforcing method described in the above-mentioned Japanese Patent Application Laid-Open No. 5-295922 and the like, a very large number of hoops are required, and thus there is a problem that it is difficult to adopt when considering actual construction. is there. Also, in the current design of reinforced concrete and steel-framed reinforced concrete, a yield hinge (yield of the main reinforcement) is generated at the beam end for the largest earthquake, and the seismic energy is absorbed by the deformation performance in the yield hinge area. Let the entire building not collapse. Considering this point, the method of reinforcing the beam main bar with a large number of hoop bars can be expected to increase the shear force strength, but the desired strength cannot be secured in terms of the fixing strength of the beam main bar. There was a problem. In other words, when the largest earthquake occurs, the beam main bar yields at the beam end, and the yield region extends from the beam end to about 1.0D (D: beam). The yielding area develops not only in the beam but also in the opposite beam-column joint. The beam reinforcement must be fixed in the beam-column joint with a yield strength greater than the yield strength, but even if it is reinforced with a number of reinforcement bars, the beam main reinforcement is not discontinuous, and is fixed in the beam-column joint. Breakage occurred, and the predetermined structural performance could not be obtained.
[0009]
Therefore, the main problem of the present invention is that it is assumed that a beam main bar from a PCa beam member is bent upward at a length position not exceeding the center of the column member, and a column beam connection method is used. A method of joining a PCa beam member in a beam-to-column joint that eliminates the complications and ensures sufficient fixing strength and shear strength by structurally continuing the beam main bars in the beam-to-column joint, and PCa therefor It is to provide a beam member.
[0010]
[Means for Solving the Problems]
In the present invention for solving the above-mentioned problems, the PCa beam member joined to the column member has a substantially U-shaped cross section at least in a predetermined section from the end surface toward the inner side of the member. The lower main bar of the beam protruding in the horizontal direction from the end face is bent upward at a length position not exceeding the center line of the column member,
After the PCa beam member is horizontally mounted between the column members with the upper end portion of the column member as a seat, the PCa beam members straddle the column member and are opposed to each other between the PCa beam members continuous in a linear direction. the range over within a beam-lower side reinforcing main reinforcements to the beam lower main reinforcement structurally continuous, with beam-part upper reinforcing main reinforcement which is Haisuji to be in and its inner position in between beams upper main reinforcement in the vertical The beam reinforcement at the lower end of the beam end and the reinforcement reinforcement at the upper end of the beam end, which have been processed to form a loop in the plane, are arranged, and then the concrete is filled in the beam-column joint to connect the column member and the PCa beam member. It is characterized by being integrally joined.
[0011]
In this case, it is desirable to determine the bar arrangement amount so that the position in the vicinity of the end of the lower end reinforcement of the beam end becomes the hinge occurrence location at the time of the earthquake. In addition, between the PCa beam members that are continuous in the linear direction, it is preferable that the beam end upper reinforcing main bar is arranged across the column member at a position on the upper side of the cross section.
[0012]
On the other hand, the PCa beam member for the joining method has a substantially U-shaped cross section in a predetermined section from the end surface toward the inside of the member, and the beam lower main bar protruding from the end surface in the installed state is a column. It is characterized in that it is bent upward at a length position not exceeding the center line of the member.
[0013]
In the present invention, the lower main bar of the beam embedded in the PCa beam member is bent and fixed upward at a position not exceeding the center line of the column in the column beam joint portion. A beam end lower reinforcement main bar is arranged in a section extending over the PCa beam member. The reinforcement amount of the reinforcement at the lower end of the beam end is determined so that the position in the vicinity of the end becomes the hinge occurrence location at the time of the earthquake.
[0014]
Conventionally, under the design philosophy of generating a yield hinge at the beam end in the event of the largest earthquake, the beam main bar is bent upward at a length that does not exceed the column center line in the column beam joint. A method has been adopted in which the structural weak point where the lower main bar of the beam becomes discontinuous is reinforced with a hoop bar or the like, but in the present invention, the hinge generation position is determined from the beam end without being bound by the prescribed design concept. Under the design philosophy of slightly shifting to the center side, the beam reinforcement lower reinforcement main bar is separately arranged so as to straddle between the PCa beam members. As a result, the main bars of the beam become structurally continuous, and even if the largest earthquake occurs and the yield region progresses toward the beam-column joint side, the deterioration of the adhesion of the beam main bars is minimal within the beam-column joint. In other words, fixing fracture and shear fracture do not occur in the beam-column joint.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
[ Reference Example 1]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
1 and 2 are perspective views of end portions of a PCa beam member used in the joining method of the PCa beam member 1 of the present invention, FIGS. 3 to 6 are construction procedure procedures, and FIG. 7 is a plan view after bar arrangement, FIG. 8 is a plan view including slab reinforcement.
[0017]
As shown in FIG. 1, the PCa beam member 1 used in this joining method is a PCa beam member 1A in which a substantially U-shaped section 4 is formed over the entire length section, or as shown in FIG. Like the PCa beam member 1B in which the substantially U-shaped section 4 is formed in the predetermined section range from the end face, the substantially U-shaped section 4 is formed over at least the predetermined section from the end face toward the inside of the member. PCa beam member.
[0018]
Specifically, the PCa beam member 1A shown in FIG. 1 has a longitudinal direction in which the shear reinforcement bars (stirrup) 2, 2... Is a so-called half-PCa beam member embedded at a predetermined interval along the cross section, and the weight is reduced by making the cross-sectional shape substantially U-shaped over the entire length. A plurality of, in the illustrated example, three beam lower main bars 3, 3 are embedded in the bottom plate portion along the longitudinal direction of the member, and the beam lower main bars 3 project in the horizontal direction from the end face in the installed state. 3 is bent upward at a length position not exceeding the center line of the column member.
[0019]
On the other hand, the PCa beam member 1B shown in FIG. 2 has a longitudinal direction in which the shear reinforcement bars (stirrup) 2, 2. The beam lower main bars 3, 3... Projecting in the horizontal direction from the end face in the installed state are bent upward at a length position not exceeding the center line of the column member. However, the U-shaped section 4 has only a predetermined section from the end face, and the other housing part is innocuous.
[0020]
As shown in FIG. 3, these PCa beam members 1 are horizontally mounted between the column members 5 and 5 with the upper end portion of the column member 5 as a seat, and as shown in FIG. Is installed in four cross directions (or three or two directions). When the PCa beam members 1, 1... Are installed, as shown in FIG. 4, the substantially cross-section U that straddles the column member 5 and faces each other between the PCa beam members 1, 1 continuous in a linear direction. A plurality of (in the illustrated example) two beam end lower reinforcing main bars 6 and 6 are arranged in a range extending within the character-shaped parts 4 and 4. The beam reinforcement lower reinforcing bars 6 are fixed by bending both ends upward.
[0021]
When the reinforcement of the lower reinforcement main bars 6 and 6 is finished, the stirrup bars 8, 8... Surrounding the column main bars 7 and 7 are arranged and the PCa beam member as shown in FIG. The beam upper main bars 9, 9,... Are arranged in the stirrup bars 2, 2. In addition, a side mold is installed at the column beam joint and a bottom mold of the slab is installed. On the other hand, as shown in FIG. 8, slab bars 10, 10... Are arranged in a lattice pattern on the slab part where the concrete placement is performed together with the beam-column joints and is continued in the linear direction. As shown in FIG. 8, between the PCa beam members 1 and 1, the beam end upper reinforcement main reinforcing bars 11, 11,... Are arranged in the slab and across the column member 5 on the upper side of the cross section. In the illustrated example, since the PCa beam members 1 and 1 are continuous in the cross direction, the beam end upper reinforcing main bars 11, 11...
[0022]
The positions near the ends of the beam end lower reinforcement main bars 6 and 6 and the beam end upper reinforcement main bars 11 and 11 are designed to be hinge generation positions, respectively. Seismic energy is absorbed by advancing in the longitudinal direction of the member.
[0023]
When all the bar arrangement and formwork operations are completed, concrete is filled into the column beam joints together with the slab, and the column member 5 and the PCa beam members 1, 1. After that, the column main reinforcement is assembled, the formwork is assembled, concrete is poured into the column member 5 up to the upper floor, and the upper floor is constructed according to the joining procedure of the PCa beam member.
[0024]
[ Reference Example 2]
9 and 10, the PCa beam member joining method shown as a reference second embodiment is such that the beam end lower reinforcing main bars 6, 6 and the beam end upper reinforcing main bars 11, 11 are bent at the ends. This shows an example in which the beam end lower reinforcing main bars 6A and 6A and the beam end upper reinforcing main bars 11A and 11A are used without being processed. Since the construction procedure is the same as in the first reference embodiment, the description is omitted.
[0025]
[ Reference Example 3]
11 and FIG. 12 shows a method of joining PCa beam members as a reference third embodiment. The beam end lower reinforcing main bar and the beam end upper reinforcing main bar are simply rod-shaped without bending the end. The beam end lower reinforcement main bars 6A and 6A and the beam end upper reinforcement main bars 11A and 11A are used, and the beam end upper reinforcement main bars 11A and 11A are arranged between the beam upper main bars 9 and 9 and inside thereof. A mode in which two-stage bar arrangement is used at the position is shown.
[0026]
[ Embodiments according to the present invention ]
Further, the PCa beam member joining method shown in FIGS. 13 and 14 as an embodiment according to the present invention has a loop shape in the vertical plane as the beam end lower reinforcing bar and the beam end upper reinforcing bar. The aspect of the beam end lower reinforcement main reinforcing bars 6B and 6B and the beam end upper reinforcement main reinforcing bars 11B and 11B processed into the above is shown.
[0027]
As described above, the beam end lower reinforcement main bar and the beam end upper reinforcement main bar can take any shape as long as they satisfy the structural performance, but in any case, straddle the column member 5 and face each other. By arranging the bars in a range extending over the substantially U-shaped portions 4 and 4, the beam main bars become structurally continuous, and it is possible to prevent fixing fracture and shear fracture from occurring in the column beam joint.
[0028]
【The invention's effect】
As described above in detail, according to the present invention, by adopting a column beam joining method in which the beam lower principal bar from the PCa beam member is bent upward at a length position not exceeding the center of the column member and joined, The complexities between each other are resolved, and the beam lower main bars are structured in a range that spans the column members and spans the opposing substantially cross-sectional U-shapes between the PCa beam members that are continuous in the linear direction. Since the lower reinforcement main reinforcement of the beam end that is continuously connected is arranged, sufficient fixing strength and shear strength can be secured in the column beam joint.
[Brief description of the drawings]
FIG. 1 is an end perspective view of a PCa beam member 1A used in a method for joining PCa beam members 1 of the present invention.
FIG. 2 is an end perspective view of another PCa beam member 1B used in the method for joining PCa beam members 1 of the present invention.
FIG. 3 is a procedure diagram (part 1) showing a joining procedure of the PCa beam member 1 of the present invention.
FIG. 4 is a procedure diagram (part 2) showing a joining procedure of the PCa beam member 1 of the present invention.
FIG. 5 is a procedure diagram (No. 3) showing the joining procedure of the PCa beam member 1 of the present invention.
FIG. 6 is a procedure diagram (part 4) showing the joining procedure of the PCa beam member 1 of the present invention.
FIG. 7 is a plan view after bar arrangement.
FIG. 8 is a plan view including slab reinforcement.
FIG. 9 is a longitudinal sectional view showing a second reference embodiment of a beam end reinforcing main reinforcing bar.
FIG. 10 is a plan view thereof.
FIG. 11 is a longitudinal sectional view showing a third reference embodiment of the beam end reinforcing main reinforcement.
FIG. 12 is a plan view thereof.
FIG. 13 is a longitudinal sectional view showing a form example according to the present invention of a beam end reinforcing main bar.
FIG. 14 is a plan view thereof.
FIGS. 15A and 15B are diagrams showing a conventional joining method of PCa beam members, respectively.
FIG. 16 is an enlarged vertical cross-sectional view of a main part showing a joint structure of PCa beam members in a conventional column beam joint.
[Explanation of symbols]
1 · 1A · 1B ... PCa beam member, 2 ... shear reinforcement, 3 ... beam lower main reinforcement, 4 ... substantially U-shaped section, 5 ... column member, 6 · 6A · 6B ... beam end lower reinforcement reinforcement, 7 ... Column main bars, 8 ... Stirrup bars, 9 ... Beam upper main bars, 10 ... Slab bars, 11, 11A, 11B ... Beam end upper reinforcement bars

Claims

柱部材と接合されるＰＣａ梁部材は、端面より部材内方側に向かって少なくとも所定区間の断面形状が略Ｕ字状とされるとともに、設置状態において端面から水平方向に突出する梁下側主筋が柱部材の中心線を越えない長さ位置で上方に屈曲させてあり、
前記ＰＣａ梁部材を柱部材の上面端部を座として柱部材間に横架した後、直線方向に連続されるＰＣａ梁部材間において、前記柱部材を跨ぐとともに、対向する前記略断面Ｕ字状内に亘る範囲に、前記梁下側主筋を構造的に連続させる梁端部下側補強主筋と、梁上側主筋間であってかつその内側位置に配筋される梁端部上側補強主筋とが鉛直面内でループ状になるように加工された梁端部下側補強主筋および梁端部上側補強主筋を配筋し、しかる後、柱梁接合部内にコンクリートを充填し柱部材とＰＣａ梁部材とを一体的に接合することを特徴とする柱梁接合部におけるＰＣａ梁部材の接合方法。The PCa beam member joined to the column member has a substantially U-shaped cross section at least in a predetermined section from the end surface toward the inner side of the member, and has a beam lower main bar that protrudes horizontally from the end surface in the installed state. Is bent upward at a position that does not exceed the center line of the column member,
After the PCa beam member is horizontally mounted between the column members with the upper end portion of the column member as a seat, the PCa beam members straddle the column member and are opposed to each other between the PCa beam members continuous in a linear direction. the range over within a beam-lower side reinforcing main reinforcements to the beam lower main reinforcement structurally continuous, with beam-part upper reinforcing main reinforcement which is Haisuji to be in and its inner position in between beams upper main reinforcement in the vertical The beam reinforcement at the lower end of the beam end and the reinforcement reinforcement at the upper end of the beam end, which have been processed to form a loop in the plane, are arranged, and then the concrete is filled in the beam-column joint to connect the column member and the PCa beam member. A method of joining PCa beam members in a column beam joint, characterized by being integrally joined.

該梁端部補強下側主筋の端部近傍位置が地震時のヒンジ発生箇所となるように配筋量を決定してある請求項１記載の柱梁接合部におけるＰＣａ梁部材の接合方法。2. The method of joining PCa beam members at a beam-to-column joint according to claim 1, wherein the amount of bar arrangement is determined so that the position near the end of the lower end reinforcement of the beam end becomes a hinge occurrence location at the time of an earthquake.

前記直線方向に連続されるＰＣａ梁部材間において、断面上部側位置に前記柱部材を跨いで梁端部上側補強主筋を配筋してある請求項１、２いずれかに記載の柱梁接合部におけるＰＣａ梁部材の接合方法。The beam-column joint according to any one of claims 1 and 2, wherein a beam end upper reinforcement main bar is arranged across the column member at a position on the upper side of the cross section between the PCa beam members continuous in the linear direction. Joining method of PCa beam members.

端面より部材内方側に向かって所定区間の断面形状が略Ｕ字状とされるとともに、設置状態において端面より突出する梁下側主筋が柱部材の中心線を越えない長さ位置で上方に屈曲させるようにしたことを特徴とする請求項１〜３いずれかに記載の柱梁接合部におけるＰＣａ梁部材の接合方法に使用されるＰＣａ梁部材。The cross-sectional shape of the predetermined section is substantially U-shaped from the end surface toward the inner side of the member, and the beam lower main bar protruding from the end surface in the installed state is at a position that does not exceed the center line of the column member. The PCa beam member used in the method for joining a PCa beam member at a column beam joint according to any one of claims 1 to 3, wherein the PCa beam member is bent.