鉄筋コンクリート造耐震壁のせん断破壊形式と曲げ降伏後のせん断破壊時変形の評価法

摘要

本研究では,せん断破壊する耐震壁の変形性能の評価方法として,中立軸の移動に伴う圧縮束の変化によって生じる破壊メカニズムとそれに立脚した新たな評価式を提案した.提案式を既往の実験結果に適用した結果,コンクリートの終局ひずみやヒンジ領域の長さに関してさらに検討する必要があるものの,提案式により終局変形角を概ね適切に評価できることを示した.ただし,以前から指摘されているように,提案した評価式の前提条件で用いたコンクリートの終局時のひずみや枠柱の有効面積の取り方,拘束によるコンクリート強度の上昇の評価は今後の課題である.%The shear failure of reinforced concrete shear wall brought by diagonal strut inside of wall panel can be classified into two types regardless of before or after flexural yielding: 1) shear failure of wall panel; and 2) compression failure of concrete at the bottom of boundary column. In reinforced concrete shear wall, transition of neutral axis which has greatly effects on the shear strength under plastic deformation is not considered in evaluation of deformation capacity on present standards. This paper presented a method to evaluate the deformation capacity of reinforced concrete shear walls considering failure mode based on following assumptions: 1) area of compression field is being reduced in accordance with increasing plastic deformation; and 2) shear failure occurs when the stress of the compression field reaches to the compressive strength of concrete at the wall panel or boundary column. The presented method was verified by applying to 33 test results; however, evaluation of confined effect by the boundary columns and ultimate strain of concrete should be considered.