杭基礎が用いられるような軟弱地盤では、強震動入力によって地盤は非線形化し、また抗および上部構造も塑性化するため地盤と建物の動的相互作用は複雑となる1).そのため、上部構造への真の地震力を評価するといった点から、地盤や杭基礎の非線形性に関する実証データの蓄積は必要である.また、2004年新潟県中越地震を含めた最近の地震被害報告では、大加速度の強震記録が観測されるにも関わらず、周辺建物に大きな被害が見られないという指摘がされている2).%To investigate effects of nonlinear soil-structure interaction, we study the influence of the nonlinearity of pile damage on building response. In this paper, it is presented that the results of the centrifuge tests considering elasto-plastic behavior of pile and its simulation analysis. The following conclusions were obtained: (1) The response of the building, which is calculated considering the nonlinear characteristics of pile damage during the main shock, is smaller than that of the building which is calculated without the nonlinearity of pile. (2) In frequency transfer function between the ground and the building, the reduction of predominant frequency is mainly caused by the nonlineariiy of the soil around piles. (3) The nonlinearity of pile damage has a very small effect in the building response in aftershock.
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