JP3971637B2

JP3971637B2 - Wall fixing structure and wall panel fixing structure

Info

Publication number: JP3971637B2
Application number: JP2002107682A
Authority: JP
Inventors: 久廣平石; 正人越路
Original assignee: Kajima Corp; Obayashi Corp; Takenaka Corp; Penta Ocean Construction Co Ltd; Okumura Corp; Toda Corp; Shimizu Corp; Ohmoto Gumi Co Ltd
Current assignee: Kajima Corp; Obayashi Corp; Takenaka Corp; Penta Ocean Construction Co Ltd; Okumura Corp; Toda Corp; Shimizu Corp; Ohmoto Gumi Co Ltd
Priority date: 2002-04-10
Filing date: 2002-04-10
Publication date: 2007-09-05
Anticipated expiration: 2022-04-10
Also published as: JP2003301522A

Description

【０００１】
【発明の属する技術分野】
本発明は、壁または壁パネルの固定構造に関する。
【０００２】
【従来の技術】
図１６を参照しながら、鉄筋コンクリート建造物における壁１と基礎２の従来の固定構造について説明する。壁１は垂直に延びる複数の鉄筋３（図示例では４本）を有している。これら鉄筋３は、壁１の幅方向（すなわち水平長手方向，図中左右方向）に間隔をおいて配置されるとともに、下方に垂直に延びて基礎２のコンクリート２ａに埋め込まれている。コンクリート２ａを打設して基礎２を構築した後、壁１のコンクリート１ａが打設される。このように、連続した共通の鉄筋３を埋め込み、コンクリート１ａ，２ａを連ねることにより、壁１の下端縁が基礎２に固定される。
【０００３】
上記固定構造において、壁１は基礎２の曲げ剛性より小さい。この曲げ剛性の急変する位置が、壁１の壁下端縁Ｅとなる。また、上記鉄筋３において、壁１に埋め込まれた部分が主筋部３ａとなり、基礎２に埋め込まれた部分がアンカー筋部３ｂとなる。
【０００４】
【発明が解決しようとする課題】
大きな地震の際に、上記建造物が水平方向に揺れると、壁１の下端縁近傍には曲げモーメントが働く。この曲げモーメントにより、鉄筋３は引張，圧縮の交番荷重を受ける。図１７に示すように壁１が右方向に傾くと左側の鉄筋３に引張り荷重が付与される。この際、主筋部３ａにおいて、壁下端縁Ｅに最も近い領域で降伏が開始される。この主筋部３ａの降伏すなわち伸びは、壁１のコンクリート１ａのひび割れＨをもたらす。その後で、壁１が左方向に傾くと、一旦伸びた鉄筋３に圧縮荷重が付与されるが、この際、ひび割れたコンクリート１ａにおいて主筋部３ａの外側にかぶっている部位（かぶりコンクリート）の剥落等の損傷が生じる。またこの損傷によってコンクリートの圧縮に対する抵抗力が減少する。さらに、場合によっては主筋部３ａが外側にはみ出すのを阻止できず、その座屈をもたらす。このようにして、壁１の破損が生じる。
【０００５】
他方、工業化住宅（プレハブ式家屋）では、プレキャスト壁パネルは、コンクリート基礎に埋設されたアンカー筋（アンカー）の上端部に溶接により固定される。上記地震の際にこのアンカー筋に引張り荷重が加わると、アンカー筋と壁パネルとの溶接部で破断が生じてしまう。これを防ぐために、壁パネルをアンカー筋に強固に固定すると、アンカー筋の上端部の一点に歪みが集中し破断してします。
【０００６】
【課題を解決するための手段】
本願の第１の発明は、壁の幅方向に間隔をおいて配置され壁内において垂直をなす複数の主筋部を、基礎内の複数のアンカー筋部にそれぞれ連ねることにより、壁の下端縁を基礎に固定する構造において、
上記アンカー筋部の壁下端縁近傍領域には、主筋部の壁下端縁近傍領域より降伏荷重が小さく地震の際に優先的に降伏する降伏予定部が、所定長さにわたり形成されていることを特徴とする。
この構成によれば、大きな地震の際に基礎のアンカー筋部で優先的に降伏が生じ、主筋部の壁下端縁近傍領域での降伏を回避でき、ひいては壁の破損を著しく軽減できる。
【０００７】
好ましくは、上記アンカー筋部において、上記降伏予定部が上記壁下端縁から離れており、壁下端縁から降伏予定部までの領域が、降伏予定部より大きな降伏荷重を有する非降伏部として提供される。この構成によれば、地震の際に降伏予定部が延びた時には、非降伏部と基礎のコンクリートとの間の抵抗により、降伏予定部に付与される剪断荷重を軽減できる。そのため、降伏予定部は引張，圧縮の交番荷重を良好に受け持つことができ、地震エネルギーを良好に吸収できる。
【０００８】
一態様として、上記主筋部とアンカー筋部が連続した鉄筋により形成され、上記主筋部の壁下端縁近傍領域が大径をなして形成されている。これによれば、連続した鉄筋の断面積を変えるだけで、降伏予定部を提供することができる。
好ましくは、上記大径部が上記基礎へと突出し、この突出部が上記降伏予定部より降伏荷重が大きい非降伏部となる。これにより、降伏予定部に付与される剪断荷重を軽減するための非降伏部を、簡易に形成することができる。
他の態様として、上記主筋部とアンカー筋部が連続した鉄筋により形成され、上記主筋部の壁下端縁近傍領域の外周には補強筒が固定される。これにより、補強筒だけの簡単な構造で、主筋部の壁下端縁近傍領域とアンカー筋部の降伏予定部との降伏荷重の差を得ることができる。
【０００９】
好ましくは、上記補強筒が上記基礎へと突出し、この突出部が上記降伏予定部より降伏荷重が大きい非降伏部として提供される。これにより、降伏予定部に付与される剪断荷重を軽減するための非降伏部を、簡易に形成することができる。好ましくは、上記アンカー筋部の降伏予定部のコンクリートへの付着強度を実質的にゼロにする。これにより、アンカー筋部の降伏予定部での優先的な降伏をより一層確実なものとすることができる。
【００１０】
本願の他の発明は、壁の幅方向に間隔をおいて配置され壁内において垂直をなす第１鉄筋を、基礎内の複数の第２鉄筋にそれぞれ連ねることにより、壁の下端縁を基礎に固定する構造において、
上記壁の下端縁近傍領域には補強筒が配されており、上記第１鉄筋は上記壁の下端縁に達せずその端部が補強筒内に収容されて付着されており、上記第２鉄筋は壁下端縁を超えて壁内に入り込むとともにその端部が補強筒内に収容されており、第２鉄筋の補強筒内の端部は、その上端から所定長さにわたる第１領域と、補強筒の下端から所定長さにわたる第２領域とを有し、第１領域が補強筒に付着され、第２領域と補強筒との付着強度が上記第１領域より低いか実質的にゼロであり、この第２領域が地震の際に降伏する降伏予定部として提供されることを特徴とする。
この構成によれば、大きな地震の際に補強筒内の鉄筋の降伏予定部で降伏が生じる。降伏予定部が伸びても、降伏予定部が補強筒に囲まれているので、構成材のコンクリートにひび割れ等の悪影響を及ぼさない。また、補強筒自体によって構成材の強度を高めることができる。その結果、地震の際の構成材の破損を著しく軽減できる。さらに、鉄筋の降伏が補強筒の上端から上方に及ぶのを防止でき、この点からも壁のコンクートの損傷を回避できる。しかも、構造は補強筒を鉄筋に装着しただけであるから構造も簡単である。
【００１１】
本願のさらに他の発明は、壁の下端縁を基礎に固定するために、壁内の主筋部と基礎内のアンカー筋部とを連続した鉄筋により構成し、この鉄筋を壁の幅方向に複数本配置してなる壁の固定構造において、
上記壁の下端縁近傍領域には補強筒が配され、上記鉄筋はこの補強筒を挿通しており、この補強筒内において、補強筒の上端から所定長さにわたる第１領域と、補強筒の下端から所定長さにわたる第２領域とを有し、第１領域が補強筒に付着され、第２領域と補強筒との付着強度が上記第１領域より低いか実質的にゼロであり、この第２領域が地震の際に降伏する降伏予定部として提供されることを特徴とする。
この構成によれば、連続した鉄筋を用いた場合において、上記発明と同等の作用効果が得られる。
【００１２】
本願のさらに他の発明は、壁の下端縁を基礎に固定するために、壁内の主筋部と基礎内のアンカー筋部とを連続した鉄筋により構成し、この鉄筋を壁の幅方向に複数本配置してなる壁の固定構造において、
上記壁の下端縁近傍領域の外周には補強筒が配され、上記鉄筋はこの補強筒を挿通しており、鉄筋と補強筒の全長にわたる付着強度が、鉄筋の他の部分とコンクリートとの付着強度より低いか実質的にゼロであり、この補強筒内の鉄筋が地震の際に降伏する降伏予定部として提供されることを特徴とする。
この構成によれば、これによれば、地震の際の降伏領域を長くすることができる。
【００１３】
好ましくは、上記補強筒が上記壁下端縁から上記基礎へと突出している。この構成によれば、地震の際に降伏予定部が延びた時には、補強筒の下端部と基礎のコンクリートとの間の抵抗により、降伏予定部に付与される剪断荷重を軽減できる。そのため、降伏予定部は引張，圧縮の交番荷重を良好に受け持つことができ、地震エネルギーを良好に吸収できる。また、構成も簡単である。
【００１４】
本願のさらに他の発明は、壁の幅方向に間隔をおいて配置された垂直をなす複数の鉄筋を、壁と基礎とに連続して通すことにより、壁の下端縁を基礎に固定する構造において、
上記鉄筋の壁下端縁近傍の所定長さにわたる領域が、他の領域に比べて弱いか実質的にゼロであり、この領域が地震の際に優先的に降伏する降伏予定部として提供されることを特徴とする。
この構成よれば、鉄筋の降伏予定部と壁または基礎のコンクリートとの付着が弱いので、地震の際に降伏予定部で降伏が優先的に行われ、壁の損傷を軽減できる。
【００１５】
本願のさらに他の発明は、壁パネルの幅方向に間隔をおいて配置され、壁パネルの下端縁をコンクリート基礎に固定する構造において、
壁パネルの下端縁に設けられた取付部材と、コンクリート基礎に垂直に埋め込まれ、その上端部が上記取付部材に固定されたアンカーとを備え、上記アンカーは、上記基礎内において壁パネルの下端縁近傍の所定長さにわたる領域が、その上端部より降伏荷重が小さく、地震時に降伏する降伏予定部として提供されることを特徴とする。
この構成では、地震の際にアンカーの所定長さにわたる降伏予定部で降伏が生じるので、アンカーと壁パネルとの溶接箇所が破断したり、アンカーの上端部が局所的に破断するのを防止できる。また、降伏予定部は、アンカーに付与される引張と圧縮の交番荷重に応答して塑性変形を繰り返すことができ、地震エネルギーを有効に吸収することができる。
【００１６】
好ましくは、上記降伏予定部が、上記壁パネルの下端縁から離れてそれより下方に位置する。これにより、地震の際に降伏予定部が延びた時には、アンカーの上端部と基礎のコンクリートとの間の抵抗により、降伏予定部に付与される剪断荷重を軽減できる。
【００１７】
この発明の一態様では、更に連結部材を備え、この連結部材の上部が上記コンクリート基礎の上面から突出して上記取付部材に固定され、この連結部材の下部が上記コンクリート基礎に埋め込まれて上記アンカーの上端部に固定され、上記アンカーにおいて上記連結部材より下方の部位が上記降伏予定部として提供される。他の態様では、上記アンカーの上端部が直接に上記取付部材に固定される。
【００１８】
好ましくは、上記アンカーが全長にわたって同材質により形成され、上記アンカーの降伏予定部の断面積が、アンカーの上端部の断面積より小さい。これにより、降伏予定部を簡単に形成することができる。
好ましくは、上記アンカーの降伏予定部とコンクリートとの付着強度は、アンカーの他の部位とコンクリートとの付着強度より低いか実質的にゼロである。これにより、地震の際に降伏予定部の降伏をより一層確実にすることができる。
【００１９】
【発明の実施の形態】
以下、本発明の第１実施形態について図１，図２を参照しながら説明する。本実施形態は、鉄筋コンクリート建造物において、壁１を基礎２に固定するための構造である。壁１と基礎２は、打ち継いで連続させたコンクリート１ａ，２ａを有している。なお、壁１と基礎２の鉄筋の配置は前述した従来構造と同様である。壁１と基礎２のコンクリート１ａ，２ａには、複数の連続した鉄筋１０が垂直に埋め込まれている。鉄筋１０において、壁１の壁下端縁Ｅより上側が壁１の主筋部１１となり、壁下端縁Ｅより下側がアンカー筋部１２となる。
【００２０】
上記鉄筋１０は、全長にわたって同材質をなし、壁下端縁Ｅの近傍領域が大径をなしている。この大径部１３は、壁下端縁Ｅから所定長さにわたって上方に延びていて主筋部１１の下端部をなしている。また、壁下端縁Ｅから所定長さにわたって下方に延びてアンカー筋部１２の上端部をなし、後述する非降伏部Ｎとなっている。
【００２１】
上記アンカー筋部１２において、中間部の径（断面積）は、上端部（非降伏部Ｎ）および下端部より小さく、この中間部において非降伏部Ｎ近傍の領域が後述する降伏予定部Ｙとなっている。径の大きな下端部は基礎２のコンクリート２ａへの定着部１４となっている。
【００２２】
アンカー筋部１２の壁下端縁Ｅの近傍に、降伏予定部Ｙが設けられ、この降伏予定部Ｙの断面積が主筋部１１の壁下端縁近傍領域より小さく、それ故に降伏荷重も小さくなっている。
上記鉄筋１０は後述する全ての実施形態で用いられる鉄筋と同様に異形鉄筋（ネジ鉄筋を含む）であり、その外周にはフシが形成されており、コンクリート１ａ，２ａとの付着性を確保している。ただし、アンカー筋部１２の降伏予定部Ｙの外周にはテープが巻かれたり、粘土やエポキシ樹脂が塗布されているため、降伏予定部Ｙのコンクリートへの付着強度は鉄筋１０の他の部位と比較すれば非常に小さいか実質的にゼロ（アンボンド状態）となっている。本実施形態では、非降伏部Ｎの外周にも同様にしてアンボンド材料を設けることにより非降伏部Ｎの付着強度をも実質的にゼロにしてもよい。アンボンド状態は、鉄筋１０のフシをなくして丸棒部を形成することにより得てもよい。
【００２３】
上記壁１の固定構造において、鉄筋コンクリート造の建造物が地震によって横揺れした時には、従来構造と同様に壁１に大きな曲げモーメントが付与される。この際、コンクリート１ａ，２ａ間に割れが生じる点は、従来構造と似ているが、鉄筋１０の主筋部１１ではなく、アンカー筋部１２が優先的に降伏する点が従来構造と大きく異なる。
【００２４】
詳述すると、図２に示すように、壁１が右側に傾くようにモーメントが働いた場合には、左側の鉄筋１０に引張荷重が付与される。この際、鉄筋１０の壁下端縁近傍領域に大きな引張荷重が付与されるが、アンカー筋部１２の降伏予定部Ｙの降伏荷重が小さいので、この部位で優先的に降伏が生じる。その結果、主筋部１１の壁下端縁近傍領域での降伏や座屈を軽減できるとともに、壁１のコンクリート１ａのひび割れや破損を軽減できる。上記降伏予定部Ｙはアンボンド状態であるので、降伏予定部Ｙでの優先的な降伏をより一層確実なものとすることができる。
【００２５】
なお、アンカー筋部１２では、降伏予定部Ｙで降伏がなされるが、これより降伏荷重が大きい非降伏部Ｎでは降伏が生じない。また、降伏予定部Ｙより下側でも、コンクリート２ａとの付着により引張り荷重が減少するので、降伏は生じない。
【００２６】
壁１が右から左への傾きに移行する過程では、左側の鉄筋１０の壁下端縁近傍領域に圧縮荷重が付与される（押し込み力が働く）。この圧縮荷重により、アンカー筋部１１の降伏予定部Ｙが圧縮変形し、元の長さに戻る。このように、建造物の横揺れに伴い、アンカー筋部１１の降伏予定部Ｙでは、引張荷重と圧縮荷重を受け持ちながら塑性変形を繰り返すことできる。その結果、地震エネルギーを吸収することができ、建造物の耐震性を向上できる。
【００２７】
図２に戻って説明するが、上記アンカー筋部１２の降伏予定部Ｙでの降伏に伴う伸びにより、アンカー筋部１２の非降伏部Ｎが基礎２のコンクリート２ａから一部抜き出されるが、上記降伏予定部Ｙはコンクリート２ａ内にとどまる。この状態では、非降伏部Ｎとコンクリート２ａとの間の抵抗により、降伏予定部Ｙへ付与される剪断荷重を軽減することができる。したがって、降伏予定部Ｙは引張，圧縮の交番荷重を良好に受け持つことができ、地震エネルギーを良好に吸収できる。なお、上記非降伏部Ｎの軸方向長さが建築基準法で定められた最大規模の地震動の際に生じる降伏予定部Ｙの伸び量（最大伸び量）より長くなっているので、非降伏部Ｎの完全抜け出しを確実に防止でき、上記作用を確保することができる。
【００２８】
なお、上記第１実施形態において、鉄筋１０の主筋部１１は全長にわたって非降伏部Ｎと同じ径にしてもよい。また、鉄筋１０の全長にわたって同じ径にし、降伏予定部を空洞に形成してもよい。
【００２９】
次に、本発明の他の実施形態について説明する。これら実施形態において、先行して説明する実施形態と共通の特徴については説明を省略する。図３（Ａ）に示す第２実施形態では、全長にわたって同一材質，同一径の鉄筋２０が用いられる。この鉄筋２０の壁下端縁近傍領域の外周には補強筒２３が圧着，螺合（ネジ鉄筋の場合），モルタル充填等の手段で全長にわたって固定されている。補強筒２３は壁下端縁Ｅより上側の方が下側の方より長い。壁１の主筋部２１は、壁下端縁近傍領域が鉄筋２０と補強筒２３により構成され、それより上方が鉄筋２０のみから構成されている。基礎２のアンカー筋部２２は、壁下端縁Ｅ近傍した領域が鉄筋２０と補強筒２３により構成されて非降伏部Ｎとなり、その下方に鉄筋２０のみからなる降伏予定部Ｙが構成されている。
【００３０】
上記第２実施形態では、補強筒２３を鉄筋２０に固定しただけの簡単な構造で、アンカー筋部２２の降伏予定部Ｙの降伏荷重を、主筋部２１の壁下端縁近傍領域およびアンカー部２２の非降伏部Ｎの降伏荷重より小さくすることができる。本実施形態の作用は、第１実施形態と同様であるので説明を省略する。なお、本実施形態では、鉄筋２０の下端部に定着筒２４が固定されている。
【００３１】
図３（Ｂ）に示す第３実施形態では、第１，第２実施形態と同様に連続した鉄筋３０により、壁１の主筋部３１と基礎２のアンカー筋部３２が構成されている。ただし、鉄筋３０において、壁下端縁Ｅより所定距離下方の位置Ｐを堺にして材質，材料が異なり、この位置Ｐの下側の部位の降伏点が上側の部位の降伏点より低い。その結果、アンカー筋部３２において、壁下端縁Ｅと位置Ｐとの間に非降伏部Ｎが形成され、位置Ｐの下側に降伏予定部Ｙが形成されている。なお、アンカー筋部３２において、降伏予定部Ｙだけを降伏点の低い材質，材料にしてもよい。
【００３２】
図４（Ａ），（Ｂ），（Ｃ）は本発明の第４〜第６実施形態を示す。これら実施形態では、壁１側の第１鉄筋４０ａと基礎２側の第２鉄筋４０ｂとを備えている。第１鉄筋４０ａは主筋部４１の大部分を占めるが、その下端が壁下端縁Ｅに達していない。第２鉄筋４０ｂは、基礎２のアンカー筋部４２の全長を占め、一部が壁下端縁Ｅを超えて壁１のコンクリート１ａに入り込んでいる。第２鉄筋４０ｂの上端部と下端部は大径部４０ｘ，４０ｙとなっている。大径部４０ｘにおいて壁下端縁Ｅより上側が下側より長くなっており、この上側の部位が主筋部４１の壁下端縁近傍領域を構成し、下側の部位がアンカー筋部４２の非降伏部Ｎとなっている。下側の大径部４０ｙは、コンクリート２ａへの定着部となっている。第２鉄筋４０ｂの中間部は、上記大径部４０ｘより断面積が小さく降伏荷重が小さい。この大径部４０ｘの下側が降伏予定部Ｙとなっている。
【００３３】
上記第４〜第６実施形態は、第１鉄筋４０ａと第２鉄筋４０ｂの連結の仕方が互いに異なっているので、簡単に説明する。図４（Ａ）の第４実施形態では、第２鉄筋４０ｂの大径部４０ｘに連結穴が形成されており、この連結穴に第１鉄筋４０ａの下端が挿入されて固定されている。図４（Ｂ），図４（Ｃ）の第５，第６実施形態では、それぞれ連結筒４８，４９により、第２鉄筋４０ｂの上端部と第１鉄筋４０ａの下端部とが連結されている。
【００３４】
図５（Ａ）に示す第７実施形態は、図１に示す第１実施形態と似た構成であるが、鉄筋１０の大径部１３の下端が壁下端縁Ｅとほぼ一致しており、アンカー筋部１２に非降伏部Ｎが形成されず、降伏予定部Ｙが、壁下端縁Ｅから下方に延びている。他の構成は図１と同様であるので、説明を省略する。
【００３５】
図５（Ｂ）に示す第８実施形態は、図３（Ａ）に示す第２実施形態と似た構成であるが、補強筒２３の下端が壁下端縁Ｅとほぼ一致しており、アンカー筋部２２に非降伏部Ｎが形成されず、降伏予定部Ｙが、壁下端縁Ｅから下方に延びている。他の構成は図１と同様であるので、説明を省略する。
【００３６】
上記第７，第８実施形態では非降伏部を設けないので、第１，第２実施形態のように降伏予定部Ｙへの剪断荷重を軽減するという作用は期待できないが、壁１の破損回避では同等の作用効果が得られる。なお、アンカー筋部において、降伏予定部Ｙと壁下端縁Ｅとの間に非降伏部を設けない構成は、上述した他の全ての実施形態に適用することができる。
【００３７】
次に、本発明の第９実施形態について図６を参照しながら説明する。本実施形態では、図３に示す第２実施形態と同様に連続した鉄筋２０と鋳鉄等の金属製の補強筒２３とを備えている。鉄筋２０の下端部は折り曲げられて定着部２５となっている。上記補強筒２３は、鉄筋２０の壁下端縁近傍領域の外周に装着されている。鉄筋２０は補強筒２３内において、第１領域Ｆと第２領域Ｙとを有している。上側の第１領域Ｆは補強筒２３の上端から所定長さにわたり、下側の第２領域Ｙは補強筒２３の下端から所定長さにわたる。
【００３８】
上記第１領域Ｆでは鉄筋２０と補強筒２３がモルタルにより付着されており、付着強度が十分に確保される。これに対して第２領域Ｙでは、鉄筋２０の外周にテープが巻かれたり粘度や樹脂が塗布されており、この状態で補強筒２３と鉄筋２０との間にモルタルが充填固化されることにより、両者の付着がなされている。このため、第２領域Ｙでの鉄筋２０と補強筒２３との付着強度は第１領域Ｆ非常に低く、実質的にゼロ（アンボンド状態）である。さらに第２領域Ｙでの鉄筋２０と補強筒２３の付着強度は、鉄筋２０と壁１,基礎２のコンクリート１ａ,２ａとの付着強度よりはるかに低い。この第２領域Ｙは後述の作用をなす降伏予定部として提供される。
【００３９】
なお、アンボンド状態は、鉄筋２０のフシをなくして丸棒部を形成することにより得てもよい。補強筒２３は、第１領域Ｆでのみ鉄筋２０に圧着，螺合させてもよい。本明細書では、これら圧着,螺合も付着の範囲に入る。
【００４０】
上記補強筒２３の壁下端縁Ｅより上方の長さは、後述する地震の際の作用を考慮して所定長さとなっている。さらに補強筒２３は、壁下端縁Ｅから下方へと突出しており、この突出した領域Ｔは、基礎２のコンクリート２ａに埋め込まれている。この突出量は、壁下端縁Ｅより上方の長さより短いが、建築基準法で定められた最大規模の地震動の際に生じる降伏予定部Ｙの伸び量（最大伸び量）より長くなっている。
【００４１】
上記壁１の固定構造において、鉄筋コンクリート造の建造物が地震によって横揺れした時には、壁１に大きな曲げモーメントが付与される。図６（Ｂ）に示すように、壁１が右側に傾くように曲げモーメントが働いた場合には、左側の鉄筋２０に引張荷重が付与される。この際、鉄筋２０の主筋部２１の壁下端縁近傍領域に大きな引張荷重が付与されるが、鉄筋２０は補強筒２３内の降伏予定部Ｙがアンボンド状態なので、この部位で優先的に降伏が生じる。この降伏予定部Ｙが補強筒２３内にあるので、降伏予定部Ｙでの降伏は、その周囲のコンクリート１ａに影響を与えず、そのひび割れを回避ないしは軽減できる。しかも、鉄筋２０は補強筒２３内の第１領域Ｆで補強筒２３との付着を確保しているので、鉄筋２０の降伏が補強筒２３より上方に及ばず、その周囲のコンクリート１ａのひび割れも回避ないしは軽減できる。また、補強筒２３自体も壁１の下端部を強化することができる。その結果、壁１の破損を回避ないしは軽減できる。
【００４２】
壁１が右から左への傾きに移行する過程では、左側の鉄筋２０の主筋部２１の壁下端縁近傍領域に圧縮荷重が付与される（押し込み力が働く）。この圧縮荷重により、伸びていた降伏予定部Ｙが圧縮変形され、元の長さに戻る。このように、建造物の横揺れに伴い、アンカー筋部１１の降伏予定部Ｙでは、引張荷重と圧縮荷重を受け持ちながら塑性変形を繰り返すことできる。その結果、地震エネルギーを吸収することができ、建造物の耐震性を向上できる。また、鉄筋２０の降伏予定部Ｙの大部分は、補強筒２３に守られているため圧縮荷重を受けても座屈が防止される。
【００４３】
図６（Ｂ）に戻って説明するが、上記鉄筋２０の降伏予定部Ｙが伸びた時に、補強筒２３が基礎２のコンクリート２ａから一部抜き出る。この抜き出し量は、上記降伏予定部Ｙの補強筒２３からの抜き出し量（降伏予定部Ｙの伸び量）とほぼ等しい。この状態では、補強筒２３の下端部とコンクリート２ａ（詳しくは補強筒２０の下端部が収容されていた穴２ｘの周縁）との間の抵抗により、降伏予定部Ｙへ付与される剪断荷重を軽減することができる。したがって、降伏予定部Ｙは引張，圧縮の交番荷重を良好に受け持つことができ、地震エネルギーを良好に吸収できる。なお、上記補強筒２３の壁下端縁Ｅから基礎２への突出量が最大規模の地震動の際に生じる降伏予定部Ｙの伸び量（最大伸び量）より長くなっているので、補強筒２３の完全抜け出しを確実に防止でき、上記作用を確保することができる。
【００４４】
次に、図７を参照しながら本発明の第１０実施形態を説明する。この実施形態では、補強筒２３の全長にわたって鉄筋２０は補強筒２３とアンボンド状態となっており（両者の付着強度が鉄筋２０とコンクリート１ａ，２ａとの付着強度より低い）、この補強筒２３の領域が地震の際に伸縮を繰り返す降伏予定部Ｙとして提供される。この構成では、補強筒２３の上方において鉄筋２０の若干の降伏が予想されるが、補強筒２３の周囲のコンクリート１ａの損傷軽減に関しては、第１実施形態と同様である。
【００４５】
次に、図８を参照しながら本発明の第１１実施形態を説明する。この実施形態では、壁１の第１鉄筋２１Ａ（主筋または主筋部）と基礎２の第２鉄筋２２Ａ（アンカー筋またはアンカー筋部）とは、別の鉄筋で構成されており、これら端部が補強筒２３（継手）によって連結されている。補強筒２３の配置位置は、第１０実施形態と同じである。
【００４６】
上記第１鉄筋２１Ａは壁下端縁Ｅに達せず、その端部が補強筒２３内に収容されモルタル等により補強筒２３に付着されている。上記第２鉄筋２２Ａは壁下端縁Ｅを超えて壁１内に入り込むとともにその端部が補強筒２３内に収容されている。第２鉄筋２２Ａの補強筒２３内の端部は、その上端から所定長さにわたる第１領域Ｆ’と、補強筒２３の下端（基礎２側端）から所定長さにわたる第２領域Ｙ’とを有している。第１領域Ｆ’はモルタル等により補強筒２３に付着されているが、第２領域Ｙ’は第１０実施形態と同様に補強筒２３に対してアンボンド状態となっており、降伏予定部として提供される。（第２領域Ｙ’と補強筒２３との付着強度は、上記第１領域Ｆ’，第１鉄筋２１Ａと補強筒２３の付着強度より低く、鉄筋２１Ａ，２２Ａとコンクリート１ａ，２ａとの付着強度より低い。
【００４７】
上記第１１実施形態の地震時の作用は第９実施形態と同様であるので、説明を省略する。
上記第１１実施形態において、降伏予定部Ｙ’を第２鉄筋の他の部位より細くしてもよい。
【００４８】
上記第９〜１１実施形態において、鉄筋は、補強筒の下端から所定長さにわたって基部のコンクリートとアンボンド状態にし（基部内の他の領域に比べて基部のコンクリートとの付着強度を低くし）、この領域をも降伏予定部としてもよい。この領域が補強筒内の降伏予定部と連続するため、降伏予定部を長くすることができる。
【００４９】
上記第９〜第１１実施形態において、補強筒の下端が壁下端縁Ｅとほぼ一致して、基部側に突出していなくてもよい。この場合、降伏予定部への剪断荷重を軽減するという作用は期待できないが、壁の破損回避に関しては上記実施形態と同等の作用効果が得られる。
補強筒内において鉄筋の降伏予定部はアンボンド状態でなくてもよく、例えば付着力の弱いモルタルで両者を直接付着してもよい。
モルタル充填に先立ち補強筒の内周面に樹脂等を塗布して内周面を平滑にしたり、あるいは内周面が平滑な補強筒を用いることにより、鉄筋と補強筒との間のアンボンド状態を得てもよい。
【００５０】
次に、図９を参照しながら、本発明の第１２実施形態について説明する。本実施形態は、壁１の固定のために連続した鉄筋２０を用いる点で第９実施形態と同じであるが、補強筒２３を用いない。この実施形態では、鉄筋２０の主筋部２１の壁下端縁近傍領域Ｙ”がコンクリート１ａに対してアンボンド状態となっている（壁下端縁近傍領域Ｙ”とコンクリート１ａとの付着強度が、主筋部２１の他の領域とコンクリート１ａとの付着強度を低い）。その結果、この壁下端縁近傍領域Ｙ”が地震の際に降伏する降伏予定部として提供される。この実施形態によれば、補強筒による効果は得られないが、鉄筋２０の降伏予定部Ｙ”での降伏に伴うコンクリート１ａの損傷を軽減できる。
【００５１】
なお、上記鉄筋２０は、アンカー筋部１２の壁下端縁近傍領域をもアンボンド状態にして（アンカー筋部の他の領域より基礎２のコンクリートとの付着強度を低くして）、降伏予定部を構成してもよい。この場合、この降伏予定部が主筋部の降伏予定部と連続して、鉄筋２０の降伏予定部を長くすることができる。
さらに、第１２実施形態において、アンカー筋部１２の上端部をアンボンド状態にすることにより、上記降伏予定部Ｙ”をアンカー筋部１２のみに形成してもよい。
【００５２】
次に、本発明の第１３実施形態を図１０〜図１２を参照しながら説明する。図１０に示すように、プレハブ家屋のプレキャスト壁パネル１’（壁）は、コンクリート基礎２’に載っている。この壁パネル１’の下端縁は、その幅方向（水平長手方向，図１において左右方向）に間隔をおいて配置された複数の固定構造５０により、コンクリート基礎２’に固定されている。
【００５３】
各固定構造５０は、壁パネル１’の下端縁の両側面に設けられた２枚の取付プレート５１（平板形状の取付部材）を備えている。図１０〜図１２では１枚のみ示す。この取付プレート５１は、高い剛性を有し、図示しない複数の壁内のアンカーを介して壁パネル１’に強固に固定されている。さらに各固定構造５０は、各取付プレート５１毎に、一枚の高い剛性を有する連結プレート５２（平板形状の連結部材）と、複数のアンカー５３とを備えている。
【００５４】
上記アンカー５３は、鉄筋等により全長にわたって同材質で形成されていて断面円形の棒状をなし、コンクリート基礎２’に垂直に埋め込まれている。アンカー５３は、上から順に第１部位５３ａ（上端部），第２部位５３ｂ（中間部），第３部位５３ｃ（下端部）を有している。第２部位５３ｂは、第１部位５３ａ，第３部位５３ｃより長いが径が小さく（断面積が小さく）、降伏荷重が小さくなっている。
【００５５】
本実施形態では、上記アンカー５３の上端すなわち第１部位５３ａの上端は、図示のようにコンクリート基礎２’の上面と同一高さか、これより高い方が好ましい。上記連結プレート５２は、下部がコンクリート基礎２’に埋め込まれ、上記複数のアンカー５３の第１部位５３ａに溶接により固定されている。上記連結プレート５２の上部は、コンクリート基礎２’の上面から突出しており、取付プレート５１に面接触状態で溶接により固定されている。このようにして、壁パネル１’は、取付プレート５１，連結プレート５２を介してアンカー５３に固定されている。
【００５６】
上記第２部位５３ｂにおいて、上記第１部位５３ａの近傍部（連結プレート５２の近傍部）は、後述する降伏予定部Ｙとして提供される。第２部位５２ｂより径の大きな第３部位５２ｃは、コンクリート基礎２’への定着部として提供される。この降伏予定部Ｙとコンクリート基礎２’の間は、アンボンド状態かまたは非常に小さな付着力となっている。
【００５７】
上記壁パネル１’の固定構造５０において、家屋が地震により揺れると、壁パネル１’にモーメントが加わる。この際、壁パネル１’とアンカー５３との溶接部が破断したりアンカー５３の上端近傍に局所的に歪みが集中して破断する可能性がある。しかし、本実施形態では、アンカー５３の所定長さにわたる降伏予定部Ｙが優先的に降伏することにより、このような破断を回避できる。
【００５８】
以下、詳述する。壁パネル１’から取付プレート５１，連結プレート５２を介して、アンカー５３に引張荷重が作用すると、アンカー５３の第２部位５３ｂの降伏予定部Ｙで降伏が生じる。これは、第２部位５３ｂの降伏荷重が、連結プレート５２とアンカー５３の第１部位５３ａ（非降伏部）の合計降伏荷重に比べて小さいからである。なお、第２部位５３ｂにおいて第１部位５３ｂの近傍が降伏予定部Ｙとなるのは、それより下の部位がコンクリートの抵抗を受けて降伏しないからである。
【００５９】
上記アンカー５３の第２部位５３ｂの降伏予定部Ｙが降伏に伴い伸びることにより、アンカー５３の第１部位５３ａの一部および連結プレート５２の下部（取付プレートに溶接されていない下部）の一部がコンクリート基礎２から抜け出るが、上記降伏予定部Ａはコンクリート基礎２内にとどまる。これは降伏予定部Ａの元の位置が、コンクリート基礎２の上面より下方に位置しているからである。
【００６０】
壁パネル１’が上記とは逆のモーメントを付与されてコンクリート基礎２’に向かって変位した場合には、アンカー５３には圧縮荷重が働く。この圧縮荷重によりアンカー５３の降伏予定部Ｙが圧縮変形され、元の長さに戻る。なお、降伏予定部Ｙがコンクリート基礎２内にあり、このコンクリートに支えられるため、降伏予定部Ｙは座屈することなく確実に元に戻る。
【００６１】
上記のように、アンカー５３の降伏予定部Ｙは、引張荷重と圧縮荷重を受け持ちながら、塑性変形を繰り返すことができ、地震による振動エネルギーを吸収することができる。
【００６２】
以下、本発明の第１４〜１６実施形態について図面を参照しながら説明する。これら実施形態において第１３実施形態に対応する構成部には同番号を付してその詳細な説明を省略する。
図１３は本発明の第１４実施形態を示す。この実施形態では、コンクリート基礎２’に垂直に埋め込まれるアンカー６３は板形状をなし、上から順に第１部位６３ａ（上端部，非降伏部），第２部位６３ｂ（中間部），第３部位６３ｃ（下端部）を有している。第２部位６３ｂは、第１部位６３ａ，第３部位６３ｃに比べて長いが幅が狭く（断面積が小さく）、降伏荷重が小さくなっている。第２部位６３ｂにおいて、第１部位６３ａ，連結プレート５２の近傍が降伏予定部Ｙとなっている。第１部位６３ａは連結プレート５２に面接触状態で溶接により固定されている。幅広の第３部位６３ｃは、コンクリート基礎２’への定着部となっている。
【００６３】
図１４は本発明の第１５実施形態を示す。この実施形態の固定構造では、連結プレートを用いず、第１３実施形態と同様の棒状のアンカー５３を用いている。アンカー５３の第１部位５３ａ（非降伏部）は、第１３実施形態より長く、その上部がコンクリート基礎２’の上面から突出し、取付プレート５１に溶接で直接固定されている。第１部位５３ａの下部はコンクリート基礎２’に埋め込まれている。したがって、第２部位５３ｂの降伏予定部Ｙは、コンクリート基礎２’の上面（壁パネルの下端縁）から離れ、その下方に位置している。そのため、第１３実施形態と同様の作用効果が得られる。
【００６４】
図１５は本発明の第１６実施形態を示す。この実施形態の固定構造では、連結プレートを用いず、第１４実施形態と同様の平板形状のアンカー６３を用いている。アンカーボルト６３の第１部位６３ａは、第１４実施形態より長く、その上部がコンクリート基礎２の上面から突出し、取付プレート５１に面接触状態で溶接により直接固定されている。第１部位６３ａの下部はコンクリート基礎２に埋め込まれている。したがって、第２部位６３ｂの降伏予定部Ｙは、コンクリート基礎２’の上面から離れ、その下方に位置している。そのため、第１４実施形態と同様の作用効果が得られる。
【００６５】
上記第１３〜第１６の実施形態において、降伏予定部Ｙの上端が壁下端縁と同一高さでもよい。また、アンカーは、第１部位とこれより下の第２部位の断面積が同じでもよい。この場合、第２部位の降伏点が第１部位の降伏点より低くなるように材料を選択する。
第１３〜第１６の実施形態において、アンカーとして断面半円形，Ｔ字形，Ｌ字形，三角形のものを用いて、その上端部の平坦面をプレートに溶接するようにしてもよい。
本発明のアンカーでは、定着部を設けずコンクリート基礎内の骨組みに固定してもよい。
【００６６】
【発明の効果】
以上説明したように本発明の壁の固定構造によれば、地震の際の壁の破損を軽減でき、本発明の壁パネルの固定構造によれば、壁パネルを固定するアンカーの破断を防止できる。
【図面の簡単な説明】
【図１】本発明の第１実施形態をなす壁固定構造の通常状態を示し、（Ａ）は断面にして示す正面図であり、（Ｂ）は断面にして示す側面図である。
【図２】同壁固定構造の地震時の状態を断面にして示す正面図である。
【図３】（Ａ），（Ｂ）は、本発明の第２，第３実施形態をなす壁固定構造の一部をそれぞれ断面にして示す正面図である。
【図４】（Ａ）〜（Ｃ）は、本発明の第４〜第６実施形態をなす壁固定構造の一部をそれぞれ断面にして示す正面図である。
【図５】（Ａ），（Ｂ）は、本発明の第７，第８実施形態をなす壁固定構造の一部をそれぞれ断面にして示す正面図である。
【図６】本発明の第９実施形態をなす壁固定構造を断面にして示す正面図であり、（Ａ）は通常時の状態、（Ｂ）は地震時の状態をそれぞれ示す。
【図７】本発明の第１０実施形態をなす壁固定構造を断面にして示す正面図である。
【図８】本発明の第１１実施形態をなす壁固定構造を断面にして示す正面図である。
【図９】本発明の第１２実施形態をなす壁固定構造を断面にして示す正面図である。
【図１０】本発明の第１３実施形態をなす壁パネル固定構造を断面にして示す正面図である。
【図１１】同固定構造の拡大正面図である。
【図１２】同固定構造の縦断面図である。
【図１３】本発明の第１４実施形態をなす壁パネル固定構造を示す拡大正面図である。
【図１４】本発明の第１５実施形態をなす壁パネル固定構造を示す拡大正面図である。
【図１５】本発明の第１６実施形態をなす壁パネル固定構造を示す拡大正面図である。
【図１６】従来の壁固定構造の通常状態を断面にして示す正面図である。
【図１７】同従来の壁固定構造の地震時の状態を断面にして示す正面図である。
【符号の説明】
Ｙ，Ｙ” 降伏予定部
Ｎ非降伏部
Ｅ壁下端縁
１壁
１’ 壁パネル
２，２’ 基礎
１０、２０、３０鉄筋
１１，２１，３１，４１主筋部
１２、２２、３２，４２アンカー筋部
１３大径部
２３補強筒
４０ａ第１鉄筋
４０ｂ第２鉄筋
４０ｘ大径部
５０固定構造
５１取付プレート（取付部材）
５２連結プレート（連結部材）
５３，６３アンカー
５３ａ，５３ａ第１部位
５３ｂ，５３ｂ第２部位
５３ｃ，６３ｃ第３部位[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wall or wall panel fixing structure.
[0002]
[Prior art]
The conventional fixing structure of the wall 1 and the foundation 2 in the reinforced concrete building will be described with reference to FIG. The wall 1 has a plurality of reinforcing bars 3 (four in the illustrated example) extending vertically. These reinforcing bars 3 are arranged at intervals in the width direction of the wall 1 (that is, the horizontal longitudinal direction, the left-right direction in the figure), and extend vertically downward and are embedded in the concrete 2 a of the foundation 2. After the concrete 2a is placed and the foundation 2 is constructed, the concrete 1a of the wall 1 is placed. Thus, the lower end edge of the wall 1 is fixed to the foundation 2 by embedding a continuous common rebar 3 and connecting the concrete 1a and 2a.
[0003]
In the fixed structure, the wall 1 is smaller than the bending rigidity of the foundation 2. The position where the bending rigidity changes suddenly becomes the wall lower edge E of the wall 1. Further, in the reinforcing bar 3, the part embedded in the wall 1 becomes the main reinforcing part 3 a, and the part embedded in the foundation 2 becomes the anchor reinforcing part 3 b.
[0004]
[Problems to be solved by the invention]
If the building shakes in the horizontal direction during a large earthquake, a bending moment acts near the lower edge of the wall 1. Due to this bending moment, the reinforcing bar 3 receives alternating loads of tension and compression. As shown in FIG. 17, when the wall 1 is tilted rightward, a tensile load is applied to the left reinforcing bar 3. At this time, yielding starts in the region closest to the wall lower edge E in the main muscle portion 3a. The yielding, that is, the elongation of the main reinforcement 3a causes a crack H in the concrete 1a of the wall 1. Thereafter, when the wall 1 is tilted to the left, a compressive load is applied to the rebar 3 that has once been stretched. At this time, a portion of the cracked concrete 1a that covers the outer side of the main reinforcement 3a (cover concrete) is peeled off. Such damage will occur. This damage also reduces the resistance to concrete compression. Furthermore, depending on the case, it cannot prevent that the main muscle part 3a protrudes outside, and brings about the buckling. In this way, the wall 1 is damaged.
[0005]
On the other hand, in an industrialized house (prefabricated house), a precast wall panel is fixed to an upper end portion of an anchor bar (anchor) embedded in a concrete foundation by welding. If a tensile load is applied to the anchor bar during the earthquake, the welded part between the anchor bar and the wall panel will break. To prevent this, if the wall panel is firmly fixed to the anchor bar, the strain concentrates on one point at the upper end of the anchor bar and breaks.
[0006]
[Means for Solving the Problems]
In the first invention of the present application, a plurality of main reinforcing bars arranged at intervals in the width direction of the wall and perpendicular to the inside of the wall are connected to a plurality of anchor reinforcing parts in the foundation, respectively. In the structure fixed to the foundation,
In the region near the lower edge of the wall of the anchor bar, a yielding portion having a lower yield load than the region near the lower edge of the wall of the main bar and preferentially yielding in the event of an earthquake is formed over a predetermined length. Features.
According to this configuration, in the event of a large earthquake, yielding preferentially occurs at the anchor portion of the foundation, yielding in the region near the lower edge of the wall of the main reinforcing portion can be avoided, and damage to the wall can be significantly reduced.
[0007]
Preferably, in the anchor muscle portion, the planned yield portion is separated from the lower wall edge of the wall, and a region from the lower wall edge to the planned yield portion is provided as a non-yield portion having a yield load larger than the planned yield portion. The According to this configuration, when the planned yield portion is extended during an earthquake, the shear load applied to the planned yield portion can be reduced by the resistance between the non-yield portion and the foundation concrete. For this reason, the planned yield portion can handle the alternating load of tension and compression well, and can absorb the seismic energy well.
[0008]
As one aspect, the main reinforcing bar portion and the anchor reinforcing bar portion are formed by continuous rebars, and the region near the lower edge of the wall of the main reinforcing bar portion is formed with a large diameter. According to this, a yield plan part can be provided only by changing the cross-sectional area of a continuous reinforcing bar.
Preferably, the large-diameter portion protrudes toward the foundation, and the protruding portion becomes a non-yield portion having a yield load larger than that of the planned yield portion. Thereby, the non-yield part for reducing the shear load given to a yield plan part can be formed easily.
As another aspect, the main reinforcing bar portion and the anchor reinforcing bar portion are formed of continuous rebars, and a reinforcing cylinder is fixed to the outer periphery of the vicinity of the wall lower end edge of the main reinforcing bar portion. Thereby, it is possible to obtain the difference in yield load between the region near the lower end edge of the wall of the main reinforcement and the planned yield portion of the anchor reinforcement with a simple structure including only the reinforcing cylinder.
[0009]
Preferably, the reinforcing cylinder protrudes toward the foundation, and the protruding portion is provided as a non-yielding portion having a yield load larger than that of the planned yield portion. Thereby, the non-yield part for reducing the shear load given to a yield plan part can be formed easily. Preferably, the strength of adhesion of the anchor reinforcement portion to the concrete at the planned yield portion is made substantially zero. Thereby, preferential yielding at the planned yield portion of the anchor muscle portion can be further ensured.
[0010]
Another invention of the present application is based on the lower edge of the wall by connecting the first reinforcing bars arranged at intervals in the width direction of the wall and perpendicular to the second reinforcing bars in the foundation. In the fixing structure,
A reinforcing cylinder is disposed in a region near the lower end edge of the wall, and the first rebar does not reach the lower end edge of the wall, and an end portion of the reinforcing bar is accommodated in and attached to the reinforcing cylinder. Enters the wall beyond the lower edge of the wall, and its end is accommodated in the reinforcing cylinder. The end of the second reinforcing bar in the reinforcing cylinder includes a first region extending from the upper end to a predetermined length, and a reinforcement. A second region extending from the lower end of the tube to a predetermined length, the first region is attached to the reinforcing tube, and the adhesion strength between the second region and the reinforcing tube is lower or substantially zero than the first region. The second region is provided as a planned yielding portion that yields in the event of an earthquake.
According to this configuration, yielding occurs at the planned yield portion of the reinforcing bar in the reinforcing cylinder during a large earthquake. Even if the planned yield portion extends, since the planned yield portion is surrounded by the reinforcing cylinder, it does not adversely affect the concrete of the constituent material such as cracks. Further, the strength of the constituent material can be increased by the reinforcing cylinder itself. As a result, damage to the components during an earthquake can be significantly reduced. Furthermore, it is possible to prevent the yielding of the reinforcing bars from extending upward from the upper end of the reinforcing cylinder, and from this point as well, damage to the wall concrete can be avoided. Moreover, the structure is simple because the reinforcing cylinder is simply attached to the reinforcing bar.
[0011]
According to still another invention of the present application, in order to fix the lower end edge of the wall to the foundation, the main reinforcement in the wall and the anchor reinforcement in the foundation are constituted by continuous reinforcing bars, and a plurality of the reinforcing bars are arranged in the width direction of the wall. In the fixed structure of the wall formed by this arrangement
A reinforcing cylinder is disposed in a region near the lower edge of the wall, and the reinforcing bar is inserted through the reinforcing cylinder. Within the reinforcing cylinder, a first region extending from the upper end of the reinforcing cylinder to a predetermined length, and the reinforcing cylinder A second region extending from the lower end to a predetermined length, the first region is attached to the reinforcing cylinder, and the adhesion strength between the second region and the reinforcing cylinder is lower than the first region or substantially zero, The second region is provided as a planned surrender portion that yields in the event of an earthquake.
According to this configuration, in the case where continuous reinforcing bars are used, the same effects as the above-described invention can be obtained.
[0012]
According to still another invention of the present application, in order to fix the lower end edge of the wall to the foundation, the main reinforcement in the wall and the anchor reinforcement in the foundation are constituted by continuous reinforcing bars, and a plurality of the reinforcing bars are arranged in the width direction of the wall. In the fixed structure of the wall formed by this arrangement
A reinforcing cylinder is arranged on the outer periphery of the region near the lower edge of the wall, and the reinforcing bar is inserted through the reinforcing cylinder, and the adhesion strength over the entire length of the reinforcing bar and the reinforcing cylinder is the adhesion between the other part of the reinforcing bar and the concrete. It is lower than the strength or substantially zero, and the reinforcing bar in the reinforcing cylinder is provided as a planned yielding portion that yields in the event of an earthquake.
According to this structure, according to this, the yield area in the event of an earthquake can be lengthened.
[0013]
Preferably, the reinforcing cylinder protrudes from the wall lower edge to the foundation. According to this configuration, when the planned yield portion is extended during an earthquake, the shear load applied to the planned yield portion can be reduced by the resistance between the lower end portion of the reinforcing cylinder and the concrete on the foundation. For this reason, the planned yield portion can handle the alternating load of tension and compression well, and can absorb the seismic energy well. Also, the configuration is simple.
[0014]
Still another invention of the present application is a structure in which a plurality of vertical reinforcing bars arranged at intervals in the width direction of a wall are continuously passed through the wall and the foundation to fix the lower end edge of the wall to the foundation. In
The area over the specified length near the bottom edge of the rebar wall is weaker or substantially zero compared to other areas, and this area is provided as a planned yielding area that yields preferentially during an earthquake. It is characterized by.
According to this configuration, since the adhesion between the yielding portion of the reinforcing bar and the concrete of the wall or foundation is weak, the yielding is preferentially performed at the planned yielding portion in the event of an earthquake, and the damage to the wall can be reduced.
[0015]
Still another invention of the present application is arranged at intervals in the width direction of the wall panel, in the structure for fixing the lower edge of the wall panel to the concrete foundation,
A mounting member provided at a lower edge of the wall panel; and an anchor vertically embedded in a concrete foundation and having an upper end fixed to the mounting member. The anchor has a lower edge of the wall panel in the foundation. A region over a predetermined length in the vicinity is provided as a planned yield portion that yields a lower yield load than an upper end portion thereof and yields during an earthquake.
In this configuration, since a yield occurs at a planned yield portion of the anchor over a predetermined length in the event of an earthquake, it is possible to prevent the welded portion between the anchor and the wall panel from breaking or the anchor's upper end from breaking locally. . In addition, the planned yield portion can repeat plastic deformation in response to alternating tensile and compression loads applied to the anchor, and can effectively absorb seismic energy.
[0016]
Preferably, the said yielding plan part is located away from the lower end edge of the said wall panel. Thereby, when the planned yield portion is extended during an earthquake, the shear load applied to the planned yield portion can be reduced by the resistance between the upper end portion of the anchor and the foundation concrete.
[0017]
In one aspect of the present invention, a connecting member is further provided, and an upper portion of the connecting member protrudes from an upper surface of the concrete foundation and is fixed to the mounting member, and a lower portion of the connecting member is embedded in the concrete foundation and is fixed to the anchor. A portion below the connecting member is fixed to the upper end portion and provided as the planned yield portion in the anchor. In another aspect, the upper end portion of the anchor is directly fixed to the attachment member.
[0018]
Preferably, the anchor is formed of the same material over the entire length, and the cross-sectional area of the expected yield portion of the anchor is smaller than the cross-sectional area of the upper end portion of the anchor. As a result, the planned yield portion can be easily formed.
Preferably, the adhesion strength between the expected yield portion of the anchor and the concrete is lower than or substantially zero than the adhesion strength between the other part of the anchor and the concrete. Thereby, it is possible to further ensure the yield of the planned yield portion in the event of an earthquake.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The present embodiment is a structure for fixing a wall 1 to a foundation 2 in a reinforced concrete building. The wall 1 and the foundation 2 have concrete 1a, 2a which is made continuous by being handed over. The arrangement of the reinforcing bars of the wall 1 and the foundation 2 is the same as that of the conventional structure described above. A plurality of continuous reinforcing bars 10 are vertically embedded in the concrete 1 a and 2 a of the wall 1 and the foundation 2. In the reinforcing bar 10, the upper side from the wall lower end edge E of the wall 1 becomes the main reinforcing part 11 of the wall 1, and the lower side from the wall lower end edge E becomes the anchor reinforcing part 12.
[0020]
The rebar 10 is made of the same material over its entire length, and the area near the wall lower edge E has a large diameter. The large diameter portion 13 extends upward from the wall lower end edge E over a predetermined length and forms the lower end portion of the main muscle portion 11. Further, it extends downward from the wall lower end edge E over a predetermined length to form the upper end portion of the anchor bar portion 12, and becomes a non-yielding portion N described later.
[0021]
In the anchor part 12, the diameter (cross-sectional area) of the intermediate part is smaller than the upper end part (non-yield part N) and the lower end part, and the area in the vicinity of the non-yield part N in this intermediate part is a yielding part Y to be described later. It has become. The lower end portion having a large diameter serves as a fixing portion 14 for the concrete 2a of the foundation 2.
[0022]
A planned yield portion Y is provided in the vicinity of the wall lower end edge E of the anchor bar portion 12, and the cross sectional area of the planned yield portion Y is smaller than the region near the wall lower end edge of the main bar portion 11, so that the yield load is also reduced. Yes.
The reinforcing bar 10 is a deformed reinforcing bar (including a screw reinforcing bar) similarly to the reinforcing bars used in all embodiments described later, and a fistula is formed on the outer periphery thereof to ensure adhesion to the concrete 1a, 2a. ing. However, since the tape is wound around the outer periphery of the planned yield portion Y of the anchor bar portion 12 or clay or epoxy resin is applied, the adhesion strength of the planned yield portion Y to the concrete is different from that of other portions of the reinforcing bar 10. In comparison, it is very small or substantially zero (unbonded state). In the present embodiment, the adhesion strength of the non-yield portion N may be made substantially zero by similarly providing an unbond material on the outer periphery of the non-yield portion N. The unbonded state may be obtained by removing the reinforcing bar 10 and forming a round bar.
[0023]
In the fixed structure of the wall 1, when a reinforced concrete structure rolls due to an earthquake, a large bending moment is applied to the wall 1 as in the conventional structure. At this time, the point in which the cracks occur between the concrete 1a and 2a is similar to the conventional structure, but the point that the anchor bar 12 yields preferentially instead of the main bar 11 of the reinforcing bar 10 is significantly different from the conventional structure.
[0024]
Specifically, as shown in FIG. 2, when a moment is applied so that the wall 1 is inclined to the right side, a tensile load is applied to the left reinforcing bar 10. At this time, a large tensile load is applied to the region near the lower edge of the wall of the reinforcing bar 10, but since the yield load of the planned yield portion Y of the anchor bar portion 12 is small, yielding preferentially occurs at this portion. As a result, it is possible to reduce yielding and buckling in the vicinity of the lower end edge of the wall of the main reinforcing bar 11, and to reduce cracks and breakage of the concrete 1 a of the wall 1. Since the planned yield portion Y is in an unbonded state, preferential yielding at the planned yield portion Y can be further ensured.
[0025]
In the anchor muscle portion 12, the yielding is performed in the planned yield portion Y, but no yielding occurs in the non-yielding portion N having a larger yield load. Moreover, since the tensile load decreases due to adhesion with the concrete 2a even below the planned yield portion Y, yield does not occur.
[0026]
In the process in which the wall 1 moves from right to left, a compressive load is applied to the region near the lower edge of the wall of the left reinforcing bar 10 (pushing force works). Due to this compressive load, the planned yield portion Y of the anchor bar 11 is compressed and returned to its original length. Thus, with the rolling of the building, the yielding planned portion Y of the anchor bar portion 11 can repeat plastic deformation while taking charge of the tensile load and the compressive load. As a result, seismic energy can be absorbed and the earthquake resistance of the building can be improved.
[0027]
Returning to FIG. 2, the non-yielding part N of the anchor bar 12 is partially extracted from the concrete 2 a of the foundation 2 due to the elongation accompanying the yield at the yielding part Y of the anchor bar 12. The planned yield portion Y remains in the concrete 2a. In this state, the shear load applied to the planned yield portion Y can be reduced by the resistance between the non-yield portion N and the concrete 2a. Therefore, the planned yield portion Y can satisfactorily handle alternating loads of tension and compression, and can absorb seismic energy well. In addition, since the axial length of the non-yielding part N is longer than the amount of elongation (maximum elongation) of the planned yielding part Y that occurs during the largest scale earthquake motion stipulated by the Building Standard Law, the non-yielding part The complete escape of N can be reliably prevented, and the above action can be ensured.
[0028]
In the first embodiment, the main reinforcing bar portion 11 of the reinforcing bar 10 may have the same diameter as the non-yielding portion N over the entire length. Moreover, you may make it the same diameter over the full length of the reinforcing bar 10, and may form a yield plan part in a cavity.
[0029]
Next, another embodiment of the present invention will be described. In these embodiments, descriptions of features common to the preceding embodiments will be omitted. In 2nd Embodiment shown to FIG. 3 (A), the same material and the same diameter reinforcing bar 20 are used over the full length. A reinforcing cylinder 23 is fixed over the entire length of the outer periphery of the region near the lower edge of the wall of the reinforcing bar 20 by means such as crimping, screwing (in the case of a screw reinforcing bar), mortar filling, or the like. The reinforcement cylinder 23 is longer on the upper side than the wall lower end edge E than on the lower side. As for the main reinforcement part 21 of the wall 1, the area | region near a wall lower end edge is comprised by the reinforcing bar 20 and the reinforcement cylinder 23, and the upper part is comprised only from the reinforcing bar 20. FIG. As for the anchor reinforcement part 22 of the foundation 2, the area | region near the wall lower end edge E is comprised by the reinforcing bar 20 and the reinforcement cylinder 23, and becomes the non-yielding part N, The yield plan part Y which consists only of the reinforcing bar 20 is comprised under it. .
[0030]
In the second embodiment, with the simple structure in which the reinforcing cylinder 23 is simply fixed to the reinforcing bar 20, the yield load of the expected yielding portion Y of the anchor bar portion 22 is determined from the region near the lower edge of the wall of the main bar portion 21 and the anchor portion 22. The yield load of the non-yield portion N can be made smaller. Since the operation of this embodiment is the same as that of the first embodiment, description thereof is omitted. In the present embodiment, the fixing cylinder 24 is fixed to the lower end portion of the reinforcing bar 20.
[0031]
In the third embodiment shown in FIG. 3B, the main reinforcing bar 31 of the wall 1 and the anchor reinforcing bar 32 of the foundation 2 are constituted by the continuous reinforcing bars 30 as in the first and second embodiments. However, in the reinforcing bar 30, the material and the material are different from each other with the position P below the wall lower end edge E as a ridge, and the yield point of the lower part of the position P is lower than the yield point of the upper part. As a result, a non-yield portion N is formed between the wall lower end edge E and the position P in the anchor muscle portion 32, and a planned yield portion Y is formed below the position P. In the anchor line portion 32, only the planned yield portion Y may be made of a material having a low yield point.
[0032]
4A, 4B, and 4C show fourth to sixth embodiments of the present invention. In these embodiments, the first reinforcing bar 40a on the wall 1 side and the second reinforcing bar 40b on the foundation 2 side are provided. The first reinforcing bar 40 a occupies most of the main reinforcing bar portion 41, but its lower end does not reach the wall lower end edge E. The second reinforcing bar 40b occupies the entire length of the anchor reinforcing bar portion 42 of the foundation 2, and a part of the second reinforcing bar 40b exceeds the wall lower end edge E and enters the concrete 1a of the wall 1. The upper end portion and the lower end portion of the second reinforcing bar 40b are large-diameter portions 40x and 40y. In the large-diameter portion 40x, the upper side of the wall lower end edge E is longer than the lower side, and the upper portion constitutes the region near the wall lower end edge of the main muscle portion 41, and the lower portion is the non-yielding of the anchor muscle portion 42. It is part N. The lower large-diameter portion 40y is a fixing portion to the concrete 2a. The intermediate portion of the second rebar 40b has a smaller cross-sectional area and a lower yield load than the large diameter portion 40x. The lower portion of the large diameter portion 40x is a yielding portion Y.
[0033]
Since the 4th-6th embodiment differs in the connection method of the 1st reinforcing bar 40a and the 2nd reinforcing bar 40b, it demonstrates easily. In 4th Embodiment of FIG. 4 (A), the connection hole is formed in the large diameter part 40x of the 2nd reinforcing bar 40b, and the lower end of the 1st reinforcing bar 40a is inserted and fixed to this connection hole. In the fifth and sixth embodiments of FIGS. 4B and 4C, the upper end portion of the second reinforcing bar 40b and the lower end portion of the first reinforcing bar 40a are connected by the connecting cylinders 48 and 49, respectively. .
[0034]
The seventh embodiment shown in FIG. 5A has a configuration similar to that of the first embodiment shown in FIG. 1, but the lower end of the large-diameter portion 13 of the reinforcing bar 10 substantially coincides with the wall lower end edge E. The non-yielding part N is not formed in the anchor part 12, and the planned yielding part Y extends downward from the lower end edge E of the wall. Other configurations are the same as those in FIG.
[0035]
The eighth embodiment shown in FIG. 5B has a configuration similar to that of the second embodiment shown in FIG. 3A, but the lower end of the reinforcing cylinder 23 substantially coincides with the wall lower end edge E, and the anchor The non-yield portion N is not formed in the streak portion 22, and the planned yield portion Y extends downward from the wall lower edge E. Other configurations are the same as those in FIG.
[0036]
In the seventh and eighth embodiments, since no non-yield portion is provided, the effect of reducing the shear load to the planned yield portion Y as in the first and second embodiments cannot be expected. Then, the same effect can be obtained. In addition, in an anchor muscle part, the structure which does not provide a non-yield part between the yield plan part Y and the wall lower end edge E is applicable to all the other embodiment mentioned above.
[0037]
Next, a ninth embodiment of the present invention will be described with reference to FIG. In this embodiment, similar to the second embodiment shown in FIG. 3, a continuous reinforcing bar 20 and a reinforcing tube 23 made of metal such as cast iron are provided. The lower end of the reinforcing bar 20 is bent to form a fixing unit 25. The reinforcing cylinder 23 is attached to the outer periphery of the region near the lower edge of the wall of the reinforcing bar 20. The reinforcing bar 20 has a first region F and a second region Y in the reinforcing cylinder 23. The upper first area F extends from the upper end of the reinforcing cylinder 23 to a predetermined length, and the lower second area Y extends from the lower end of the reinforcing cylinder 23 to a predetermined length.
[0038]
In the first region F, the reinforcing bar 20 and the reinforcing cylinder 23 are attached by mortar, and the adhesion strength is sufficiently ensured. On the other hand, in the second region Y, tape is wound around the outer periphery of the reinforcing bar 20 or viscosity or resin is applied. In this state, the mortar is filled and solidified between the reinforcing cylinder 23 and the reinforcing bar 20. Both are attached. For this reason, the adhesion strength between the reinforcing bar 20 and the reinforcing cylinder 23 in the second region Y is very low in the first region F and is substantially zero (unbonded state). Furthermore, the adhesion strength between the reinforcing bar 20 and the reinforcing cylinder 23 in the second region Y is much lower than the adhesion strength between the reinforcing bar 20 and the concrete 1a, 2a of the wall 1 and the foundation 2. The second region Y is provided as a planned yield portion that has the effect described below.
[0039]
Note that the unbonded state may be obtained by removing the reinforcing bars 20 and forming a round bar portion. The reinforcing cylinder 23 may be crimped and screwed to the reinforcing bar 20 only in the first region F. In the present specification, these crimping and screwing also fall within the range of adhesion.
[0040]
The length above the wall lower end edge E of the reinforcing cylinder 23 is a predetermined length in consideration of an action in the event of an earthquake described later. Further, the reinforcing cylinder 23 protrudes downward from the wall lower end edge E, and the protruding region T is embedded in the concrete 2 a of the foundation 2. Although this protrusion amount is shorter than the length above the wall lower end edge E, it is longer than the extension amount (maximum extension amount) of the planned yield portion Y that occurs during the maximum-scale earthquake motion determined by the Building Standard Law.
[0041]
In the fixed structure of the wall 1, when a reinforced concrete structure rolls due to an earthquake, a large bending moment is applied to the wall 1. As shown in FIG. 6B, when a bending moment is applied so that the wall 1 is inclined to the right side, a tensile load is applied to the left reinforcing bar 20. At this time, a large tensile load is applied to the region near the lower edge of the wall of the main reinforcing bar portion 21 of the reinforcing bar 20. However, since the reinforcing bar 20 is in the unbonded state, the yielding portion Y in the reinforcing cylinder 23 is preferentially yielded at this part. Arise. Since the planned yield portion Y is in the reinforcing cylinder 23, the yield at the planned yield portion Y does not affect the surrounding concrete 1a, and the cracks can be avoided or reduced. In addition, since the reinforcing bar 20 is secured to the reinforcing cylinder 23 in the first region F in the reinforcing cylinder 23, the yield of the reinforcing bar 20 does not reach the upper side of the reinforcing cylinder 23, and the surrounding concrete 1a is also cracked. It can be avoided or reduced. The reinforcing cylinder 23 itself can also strengthen the lower end of the wall 1. As a result, damage to the wall 1 can be avoided or reduced.
[0042]
In the process in which the wall 1 shifts from right to left, a compressive load is applied to the region near the wall lower end edge of the main reinforcing bar portion 21 of the left reinforcing bar 20 (pushing force works). By this compressive load, the yielding portion Y that has been stretched is compressed and deformed, and returns to its original length. Thus, with the rolling of the building, the yielding planned portion Y of the anchor bar portion 11 can repeat plastic deformation while taking charge of the tensile load and the compressive load. As a result, seismic energy can be absorbed and the earthquake resistance of the building can be improved. Further, since most of the planned yield portion Y of the reinforcing bar 20 is protected by the reinforcing cylinder 23, buckling is prevented even when a compressive load is applied.
[0043]
Returning to FIG. 6B, the reinforcing cylinder 23 is partially extracted from the concrete 2 a of the foundation 2 when the planned yield portion Y of the reinforcing bar 20 extends. This extraction amount is substantially equal to the extraction amount of the planned yield portion Y from the reinforcing cylinder 23 (the elongation amount of the planned yield portion Y). In this state, due to the resistance between the lower end of the reinforcing cylinder 23 and the concrete 2a (specifically, the peripheral edge of the hole 2x in which the lower end of the reinforcing cylinder 20 was accommodated), the shear load applied to the planned yielding portion Y is Can be reduced. Therefore, the planned yield portion Y can satisfactorily handle alternating loads of tension and compression, and can absorb seismic energy well. In addition, since the protrusion amount from the wall lower end edge E of the reinforcement cylinder 23 to the foundation 2 is longer than the elongation amount (maximum elongation amount) of the planned yield portion Y that occurs during the largest scale earthquake motion, Complete removal can be reliably prevented, and the above action can be ensured.
[0044]
Next, a tenth embodiment of the present invention will be described with reference to FIG. In this embodiment, the reinforcing bar 20 is in an unbonded state with the reinforcing cylinder 23 over the entire length of the reinforcing cylinder 23 (the adhesion strength between them is lower than the adhesion strength between the reinforcing bar 20 and the concrete 1a, 2a). The area is provided as a planned yield section Y that repeatedly expands and contracts during an earthquake. In this configuration, a slight yield of the reinforcing bar 20 is expected above the reinforcing cylinder 23, but the damage reduction of the concrete 1a around the reinforcing cylinder 23 is the same as in the first embodiment.
[0045]
Next, an eleventh embodiment of the present invention will be described with reference to FIG. In this embodiment, the first reinforcing bar 21A (main bar or main bar part) of the wall 1 and the second reinforcing bar 22A (anchor bar or anchor bar part) of the foundation 2 are constituted by different reinforcing bars, and these end portions are formed. They are connected by a reinforcing cylinder 23 (joint). The arrangement position of the reinforcing cylinder 23 is the same as that of the tenth embodiment.
[0046]
The first reinforcing bar 21A does not reach the wall lower end edge E, and its end is accommodated in the reinforcing cylinder 23 and attached to the reinforcing cylinder 23 by mortar or the like. The second reinforcing bar 22 </ b> A enters the wall 1 beyond the wall lower end edge E, and its end is accommodated in the reinforcing cylinder 23. The end of the second reinforcing bar 22A in the reinforcing cylinder 23 has a first area F ′ extending from the upper end to a predetermined length, and a second area Y ′ extending from the lower end (end of the foundation 2 side) to the predetermined length. have. The first region F ′ is attached to the reinforcing cylinder 23 by mortar or the like, but the second region Y ′ is in an unbonded state with respect to the reinforcing cylinder 23 as in the tenth embodiment, and is provided as a planned yield portion. Is done. (The adhesion strength between the second region Y ′ and the reinforcing cylinder 23 is lower than the adhesion strength between the first region F ′, the first reinforcing bar 21A and the reinforcing cylinder 23, and the adhesion strength between the reinforcing bars 21A, 22A and the concrete 1a, 2a. Lower.
[0047]
Since the action of the eleventh embodiment during an earthquake is the same as that of the ninth embodiment, description thereof is omitted.
In the eleventh embodiment, the planned yield portion Y ′ may be made thinner than other parts of the second reinforcing bar.
[0048]
In the ninth to eleventh embodiments, the reinforcing bar is in an unbonded state with the base concrete over a predetermined length from the lower end of the reinforcing cylinder (lowering the adhesion strength with the base concrete compared to other regions in the base), This area may also be a planned yielding part. Since this region is continuous with the planned yield portion in the reinforcing cylinder, the planned yield portion can be lengthened.
[0049]
In the ninth to eleventh embodiments, the lower end of the reinforcing cylinder may substantially coincide with the wall lower end edge E and may not protrude toward the base side. In this case, the effect of reducing the shear load on the planned yield portion cannot be expected, but the same effect as in the above embodiment can be obtained with respect to avoiding damage to the wall.
In the reinforcing cylinder, the planned yield portion of the reinforcing bar does not have to be in an unbonded state, and for example, both may be directly attached with a mortar having weak adhesive force.
Prior to mortar filling, resin or the like is applied to the inner peripheral surface of the reinforcing cylinder to smooth the inner peripheral surface, or by using a reinforcing cylinder with a smooth inner peripheral surface, the unbonded state between the reinforcing bar and the reinforcing cylinder can be reduced. May be obtained.
[0050]
Next, a twelfth embodiment of the present invention will be described with reference to FIG. The present embodiment is the same as the ninth embodiment in that a continuous reinforcing bar 20 is used for fixing the wall 1, but the reinforcing cylinder 23 is not used. In this embodiment, the wall lower end edge vicinity area Y ″ of the main reinforcing bar portion 21 of the reinforcing bar 20 is in an unbonded state with respect to the concrete 1a (the adhesion strength between the wall lower end edge adjacent area Y ″ and the concrete 1a is the main reinforcement section. The adhesion strength between the other region 21 and the concrete 1a is low). As a result, the area Y ″ near the lower edge of the wall is provided as a planned yield portion that yields in the event of an earthquake. According to this embodiment, although the effect of the reinforcing cylinder cannot be obtained, the planned yield portion Y of the reinforcing bar 20 It is possible to reduce the damage to the concrete 1a due to the yielding at "".
[0051]
In addition, the above-mentioned reinforcing bar 20 also makes the region near the lower edge of the wall of the anchor bar part 12 unbonded (with lower adhesion strength to the concrete of the foundation 2 than the other area of the anchor bar part), It may be configured. In this case, this planned yield portion is continuous with the planned yield portion of the main reinforcement, and the planned yield portion of the reinforcing bar 20 can be lengthened.
Furthermore, in the twelfth embodiment, the above-described planned yield portion Y ″ may be formed only in the anchor muscle portion 12 by bringing the upper end portion of the anchor muscle portion 12 into an unbonded state.
[0052]
Next, a thirteenth embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 10, the precast wall panel 1 ′ (wall) of the prefab house is placed on the concrete foundation 2 ′. The lower end edge of the wall panel 1 ′ is fixed to the concrete foundation 2 ′ by a plurality of fixing structures 50 arranged at intervals in the width direction (horizontal longitudinal direction, left-right direction in FIG. 1).
[0053]
Each fixing structure 50 includes two mounting plates 51 (plate-shaped mounting members) provided on both side surfaces of the lower end edge of the wall panel 1 ′. 10 to 12 show only one sheet. The mounting plate 51 has high rigidity and is firmly fixed to the wall panel 1 ′ via anchors in a plurality of walls (not shown). Further, each fixing structure 50 includes one connection plate 52 (a plate-shaped connection member) having high rigidity and a plurality of anchors 53 for each attachment plate 51.
[0054]
The anchor 53 is formed of the same material over the entire length by a reinforcing bar or the like, has a circular cross section, and is vertically embedded in the concrete foundation 2 ′. The anchor 53 has a first part 53a (upper end part), a second part 53b (intermediate part), and a third part 53c (lower end part) in order from the top. The second portion 53b is longer than the first portion 53a and the third portion 53c, but has a small diameter (small cross-sectional area) and a small yield load.
[0055]
In the present embodiment, the upper end of the anchor 53, that is, the upper end of the first portion 53a is preferably the same height as or higher than the upper surface of the concrete foundation 2 ′ as shown in the figure. The lower part of the connecting plate 52 is embedded in the concrete foundation 2 ′, and is fixed to the first portions 53 a of the plurality of anchors 53 by welding. The upper part of the connection plate 52 protrudes from the upper surface of the concrete foundation 2 ′, and is fixed to the mounting plate 51 by welding in a surface contact state. In this way, the wall panel 1 ′ is fixed to the anchor 53 via the mounting plate 51 and the connecting plate 52.
[0056]
In the second portion 53b, the vicinity of the first portion 53a (the vicinity of the connecting plate 52) is provided as a planned yield portion Y to be described later. The 3rd site | part 52c with a larger diameter than the 2nd site | part 52b is provided as a fixing | fixed part to concrete foundation 2 '. Between the planned yield portion Y and the concrete foundation 2 ′, it is in an unbonded state or has a very small adhesive force.
[0057]
In the fixing structure 50 for the wall panel 1 ′, when the house is shaken by an earthquake, a moment is applied to the wall panel 1 ′. At this time, there is a possibility that the welded portion between the wall panel 1 ′ and the anchor 53 may be broken, or distortion may be locally concentrated near the upper end of the anchor 53 and broken. However, in this embodiment, such a fracture can be avoided by preferentially yielding the yield planned portion Y over a predetermined length of the anchor 53.
[0058]
Details will be described below. When a tensile load is applied to the anchor 53 from the wall panel 1 ′ via the mounting plate 51 and the connecting plate 52, yielding occurs at the planned yield portion Y of the second portion 53 b of the anchor 53. This is because the yield load of the second part 53b is smaller than the total yield load of the first part 53a (non-yield part) of the connection plate 52 and the anchor 53. In the second part 53b, the vicinity of the first part 53b becomes the yield planned portion Y because the part below it receives the resistance of the concrete and does not yield.
[0059]
The yield planned portion Y of the second portion 53b of the anchor 53 extends along with the yielding, so that a part of the first portion 53a of the anchor 53 and a portion of the lower portion of the connecting plate 52 (the lower portion not welded to the mounting plate). Escapes from the concrete foundation 2, but the planned yielding portion A remains in the concrete foundation 2. This is because the original position of the planned yielding part A is located below the upper surface of the concrete foundation 2.
[0060]
When the wall panel 1 ′ is displaced toward the concrete foundation 2 ′ by applying a moment opposite to the above, a compressive load is applied to the anchor 53. Due to this compressive load, the planned yield portion Y of the anchor 53 is compressively deformed and returns to its original length. In addition, since the planned yield portion Y is in the concrete foundation 2 and is supported by the concrete, the planned yield portion Y surely returns without buckling.
[0061]
As described above, the planned yield portion Y of the anchor 53 can repeat the plastic deformation while taking charge of the tensile load and the compressive load, and can absorb the vibration energy due to the earthquake.
[0062]
Hereinafter, fourteenth to sixteenth embodiments of the present invention will be described with reference to the drawings. In these embodiments, components corresponding to those in the thirteenth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 13 shows a fourteenth embodiment of the present invention. In this embodiment, the anchor 63 embedded perpendicularly in the concrete foundation 2 ′ has a plate shape, and the first part 63a (upper end part, non-yield part), second part 63b (intermediate part), third part in order from the top. 63c (lower end). The second part 63b is longer than the first part 63a and the third part 63c, but has a narrow width (small cross-sectional area) and a low yield load. In the second part 63b, the vicinity of the first part 63a and the connecting plate 52 is a planned yield portion Y. The first portion 63a is fixed to the connection plate 52 by welding in a surface contact state. The wide third portion 63c serves as a fixing portion to the concrete foundation 2 ′.
[0063]
FIG. 14 shows a fifteenth embodiment of the present invention. In the fixing structure of this embodiment, the connecting plate is not used, and a rod-like anchor 53 similar to that of the thirteenth embodiment is used. The first portion 53a (non-yield portion) of the anchor 53 is longer than that of the thirteenth embodiment, and the upper portion thereof protrudes from the upper surface of the concrete foundation 2 ′ and is directly fixed to the mounting plate 51 by welding. A lower portion of the first portion 53a is embedded in the concrete foundation 2 ′. Therefore, the planned yield portion Y of the second part 53b is separated from the upper surface of the concrete foundation 2 ′ (the lower end edge of the wall panel) and is positioned below the upper surface. Therefore, the same effect as that of the thirteenth embodiment can be obtained.
[0064]
FIG. 15 shows a sixteenth embodiment of the present invention. In the fixing structure of this embodiment, a flat plate-shaped anchor 63 similar to that of the fourteenth embodiment is used without using a connecting plate. The first portion 63a of the anchor bolt 63 is longer than that of the fourteenth embodiment, and the upper portion thereof protrudes from the upper surface of the concrete foundation 2 and is directly fixed to the mounting plate 51 by welding in a surface contact state. A lower portion of the first portion 63a is embedded in the concrete foundation 2. Therefore, the planned yield portion Y of the second part 63b is away from the upper surface of the concrete foundation 2 ′ and is located below the concrete base 2 ′. Therefore, the same effect as that of the fourteenth embodiment can be obtained.
[0065]
In the thirteenth to sixteenth embodiments, the upper end of the planned yield portion Y may be the same height as the lower edge of the wall. Moreover, the cross-sectional area of the 1st site | part and the 2nd site | part below this may be the same as an anchor. In this case, the material is selected so that the yield point of the second part is lower than the yield point of the first part.
In the thirteenth to sixteenth embodiments, an anchor having a semicircular cross section, a T shape, an L shape, or a triangle may be used, and the flat surface of the upper end portion may be welded to the plate.
In the anchor of this invention, you may fix to the frame in a concrete foundation, without providing a fixing | fixed part.
[0066]
【The invention's effect】
As described above, according to the wall fixing structure of the present invention, it is possible to reduce damage to the wall during an earthquake, and according to the wall panel fixing structure of the present invention, it is possible to prevent breakage of the anchor that fixes the wall panel. .
[Brief description of the drawings]
FIG. 1 shows a normal state of a wall fixing structure according to a first embodiment of the present invention, in which (A) is a front view showing a cross section, and (B) is a side view showing a cross section.
FIG. 2 is a front view showing a cross section of the wall fixing structure during an earthquake.
FIGS. 3A and 3B are front views showing a part of the wall fixing structure forming the second and third embodiments of the present invention in section.
FIGS. 4A to 4C are front views showing a part of the wall fixing structure forming the fourth to sixth embodiments of the present invention in cross section. FIG.
FIGS. 5A and 5B are front views each showing a cross section of a part of a wall fixing structure according to seventh and eighth embodiments of the present invention. FIGS.
FIGS. 6A and 6B are front views showing a wall fixing structure according to a ninth embodiment of the present invention in section, where FIG. 6A shows a normal state and FIG. 6B shows an earthquake state.
FIG. 7 is a front view showing a cross section of a wall fixing structure according to a tenth embodiment of the present invention.
FIG. 8 is a front view showing a wall fixing structure according to an eleventh embodiment of the present invention in section.
FIG. 9 is a front view showing in cross section a wall fixing structure according to a twelfth embodiment of the present invention.
FIG. 10 is a front view showing, in section, a wall panel fixing structure according to a thirteenth embodiment of the present invention.
FIG. 11 is an enlarged front view of the fixing structure.
FIG. 12 is a longitudinal sectional view of the fixing structure.
FIG. 13 is an enlarged front view showing a wall panel fixing structure according to a fourteenth embodiment of the present invention.
FIG. 14 is an enlarged front view showing a wall panel fixing structure according to a fifteenth embodiment of the present invention.
FIG. 15 is an enlarged front view showing a wall panel fixing structure according to a sixteenth embodiment of the present invention.
FIG. 16 is a front view showing a normal state of a conventional wall fixing structure in cross section.
FIG. 17 is a front view showing in cross section the state of the conventional wall fixing structure during an earthquake.
[Explanation of symbols]
Y, Y "Yield scheduled part
N Non-yielding part
E Wall bottom edge
1 wall
1 'wall panel
2,2 'basics
10, 20, 30 Rebar
11, 21, 31, 41 Main muscle
12, 22, 32, 42 Anchor muscle
13 Large diameter part
23 Reinforcing cylinder
40a No. 1 rebar
40b Second rebar
40x large diameter part
50 Fixed structure
51 Mounting plate (Mounting member)
52 Connection plate (connection member)
53, 63 anchor
53a, 53a first part
53b, 53b second part
53c, 63c 3rd part

Claims

In the structure in which the lower end edge of the wall is fixed to the foundation by connecting a plurality of main reinforcing bars arranged at intervals in the width direction of the wall and connecting to a plurality of anchor reinforcing bars in the foundation, respectively.
In the area near the lower edge of the wall of the anchor muscle part, the yield planned part that yields preferentially in the event of an earthquake is formed over a predetermined length with a lower yield load than the area near the lower edge of the wall of the main muscle part,
In the anchor muscle portion, the planned yield portion is separated from the lower wall edge of the wall, and the region from the lower wall edge to the planned yield portion is provided as a non-yield portion having a higher yield load than the planned yield portion. fixing structure of the wall, it characterized.

In the structure in which the lower end edge of the wall is fixed to the foundation by connecting a plurality of main reinforcing bars arranged at intervals in the width direction of the wall and connecting to a plurality of anchor reinforcing bars in the foundation, respectively.
In the area near the lower edge of the wall of the anchor muscle part, the yield planned part that yields preferentially in the event of an earthquake is formed over a predetermined length with a lower yield load than the area near the lower edge of the wall of the main muscle part,
A wall fixing structure, wherein the main reinforcing bar portion and the anchor reinforcing bar portion are formed of a continuous reinforcing bar, and a region in the vicinity of the wall lower end edge of the main reinforcing bar portion has a large diameter.

The wall fixing structure according to claim 2 , wherein the large-diameter portion protrudes toward the foundation, and the protruding portion becomes a non-yield portion having a yield load larger than that of the planned yield portion.

In the structure in which the lower end edge of the wall is fixed to the foundation by connecting a plurality of main reinforcing bars arranged at intervals in the width direction of the wall and connecting to a plurality of anchor reinforcing bars in the foundation, respectively.
In the area near the lower edge of the wall of the anchor muscle part, the yield planned part that yields preferentially in the event of an earthquake is formed over a predetermined length with a lower yield load than the area near the lower edge of the wall of the main muscle part,
A wall fixing structure, wherein the main reinforcing bar portion and the anchor reinforcing bar portion are formed of a continuous reinforcing bar, and a reinforcing cylinder is fixed to an outer periphery of a region near the lower end edge of the wall of the main reinforcing bar portion.

5. The wall fixing structure according to claim 4 , wherein the reinforcing cylinder protrudes toward the foundation, and the protruding portion is provided as a non-yield portion having a yield load larger than that of the planned yield portion.

The wall fixing structure according to any one of claims 1 to 5 , wherein an adhesion strength of the anchor reinforcement portion to the concrete at a yield portion is substantially zero.

In the structure in which the first reinforcing bars arranged at intervals in the width direction of the wall and perpendicular to the walls are connected to the plurality of second reinforcing bars in the foundation, thereby fixing the lower edge of the wall to the foundation.
A reinforcing cylinder is disposed in a region near the lower end edge of the wall, and the first rebar does not reach the lower end edge of the wall, and an end portion of the reinforcing bar is accommodated in and attached to the reinforcing cylinder. Enters the wall beyond the lower edge of the wall, and its end is accommodated in the reinforcing cylinder. The end of the second reinforcing bar in the reinforcing cylinder includes a first region extending from the upper end to a predetermined length, and a reinforcement. A second region extending from the lower end of the tube to a predetermined length, the first region is attached to the reinforcing tube, and the adhesion strength between the second region and the reinforcing tube is lower or substantially zero than the first region. The wall fixing structure is characterized in that the second region is provided as a planned yielding portion that yields in the event of an earthquake.

In order to fix the bottom edge of the wall to the foundation, the main reinforcement in the wall and the anchor reinforcement in the foundation are composed of continuous reinforcing bars, and the wall is fixed by arranging multiple reinforcing bars in the width direction of the wall. In structure
A reinforcing cylinder is disposed in a region near the lower edge of the wall, and the reinforcing bar is inserted through the reinforcing cylinder. Within the reinforcing cylinder, a first region extending from the upper end of the reinforcing cylinder to a predetermined length, and the reinforcing cylinder A second region extending from the lower end to a predetermined length, the first region is attached to the reinforcing cylinder, and the adhesion strength between the second region and the reinforcing cylinder is lower than the first region or substantially zero, A wall fixing structure, wherein the second region is provided as a planned yielding portion that yields in the event of an earthquake.

The wall fixing structure according to claim 7 or 8 , wherein the reinforcing cylinder protrudes from the lower edge of the wall to the foundation.

In order to fix the bottom edge of the wall to the foundation, the main reinforcement in the wall and the anchor reinforcement in the foundation are composed of continuous reinforcing bars, and the wall is fixed by arranging multiple reinforcing bars in the width direction of the wall. In structure
A reinforcing cylinder is arranged on the outer periphery of the region near the lower edge of the wall, and the reinforcing bar is inserted through the reinforcing cylinder, and the adhesion strength over the entire length of the reinforcing bar and the reinforcing cylinder is the adhesion between the other part of the reinforcing bar and the concrete. It is lower than the strength or substantially zero, and the reinforcing bar in this reinforcement cylinder is provided as a planned yielding part that yields during an earthquake,
The wall fixing structure, wherein the reinforcing cylinder protrudes from the lower edge of the wall to the foundation .

In the structure that is arranged at intervals in the width direction of the wall panel and fixes the lower edge of the wall panel to the concrete foundation,
A mounting member provided at a lower edge of the wall panel; and an anchor vertically embedded in a concrete foundation and having an upper end fixed to the mounting member. The anchor has a lower edge of the wall panel in the foundation. A wall panel fixing structure characterized in that a region over a predetermined length in the vicinity is provided as a planned yield portion that has a yield load smaller than that of its upper end portion and yields during an earthquake.

12. The wall panel fixing structure according to claim 11 , wherein the planned yield portion is located at a position lower than the lower end edge of the wall panel.

Further comprising a connecting member, the upper part of the connecting member protrudes from the upper surface of the concrete foundation and is fixed to the mounting member, the lower part of the connecting member is embedded in the concrete foundation and fixed to the upper end of the anchor, 13. The wall panel fixing structure according to claim 12 , wherein a portion of the anchor below the connecting member is provided as the planned yield portion.

The wall panel fixing structure according to claim 11 or 12 , wherein an upper end portion of the anchor is directly fixed to the mounting member.

The wall panel according to any one of claims 11 to 14 , wherein the anchor is formed of the same material over its entire length, and the cross-sectional area of the expected yield portion of the anchor is smaller than the cross-sectional area of the upper end portion of the anchor. Fixed structure.

Adhesion strength between the yield scheduled portion and the concrete of the anchor according to any one of claims 11 to 15, characterized in that a low or substantially zero than the adhesion strength between the other parts and concrete anchor Wall panel fixing structure.