等価線形化法による既存中層鉄骨鉄筋コンクリート造建築物の地震時最大応答変形の推定精度

摘要

In this paper, the peak seismic response of an existing middle-rise steel reinforced concrete (SRC) building, which is composed both brittle and ductile members, is evaluated by the equivalent linearization technique and its accuracy is discussed. In this study, nonlinear time-history analyses of an example SRC building is carried out considering the strength degradation of shear-dominated brittle members, by using two groups of artificial ground motions; the phase angles are given by uniform random value and envelope function for the first group of ground motions, and for the another group their phase angles are given from records of the past earthquakes. The results show that the accuracy of the predicted peak response by the equivalent linearization technique is strongly depends on the phase characteristics of ground motions. To evaluate the difference of nonlinear response of an analyzed building, the substitute damping defined at peak response is calculated and compared to that defined at end.%近年，新築建築物の耐震設計のみならず，既存建築物の耐震性能評価においても，想定される地震動に対する対象建築物の地震応答を陽な形で評価できる手法が必要とされている.この方法として，対象建築物が地震時に代表的な単一のモードで応答すると仮定し，静的漸増載荷解析に基づき対象建築物の等価1自由度系縮約を行って最大応答を推定する手法(等価線形化法)が開発されている.一方，1981年以前に設計された既存の中層鉄筋コンクリート造ならびに鉄骨鉄筋コンクリート造(以下それぞれRC造，SRC造と表記)建築物を対象として，日本建築学会において等価線形化法による地震応答評価の適用可能性が検討されている.