報告書番号

U01033

タイトル（和文）

鉄筋コンクリート製地中構造物の耐震性能照査法の高度化(その１） --地中構造物の塑性変形挙動に関する実験的検討--

タイトル（英文）

Development of Advanced Earthquake Resistant Performance Verification on Reinforced Concrete Underground Structures Part 1 -Experimental Aspects of Seismically Induced Plastic Deformation Performance of Underground Structures-

概要 （図表や脚注は「報告書全文」に掲載しております）

強震時の鉄筋コンクリート製地中構造物横断面方向の塑性変形挙動を把握し，その知見を耐震性能照査法に反映するため，二連ボックス試験体を対象にした地盤・構造物連成系の大規模振動台実験を実施した．この結果，土かぶりが3.0mならびに1.5mの２ケースにおける試験体のせん断変形について，1)主要な荷重は土かぶりに応じた上面地盤せん断力であること，2)最大層間変位は降伏変位の12～13倍となること，3)弾性から塑性領域まで周辺地盤の変形に従うこと，4)曲げ破壊先行型の損傷・残留変形を示すこと，などを明らかにした．以上を総合し，1)動的相互作用，塑性変形，損傷などに関する知見を各種耐震解析手法の妥当性検証用データに供しえること，2)構造系全体のせん断変形を地中構造物の限界状態に設定できること，などが耐震性能照査法の高度化に活用できることを示した．

概要 （英文）

The present paper discusses seismically induced cross section plastic deformation of reinforced concrete underground structures during strong earthquakes and provides some key issues on earthquake resistant performance verification development. For this purpose, the authors conducted a larger scale shake table test that incorporates soil-structure interaction effect on reinforced concrete two-box type model structures. Two cases with respect to overburden depth of 3.0m and 1.5m, respectively, were arranged. Observed seismic ground motions were then applied in both cases. As a result, the authors obtained the following results: 1) Shear force on the upper slab surface of the model structure plays a major role on structural deformation among other forces. 2) Maximum relative displacement between upper and lower slabs of the model reaches twelve or thirteen times as large as yield relative displacement. 3) Structural deformation is fully controlled by surrounding ground deformation. 4) The model structure undergoes flexural failure mode type residual deformation and damage. These findings can be summarized and applied for advanced verification of earthquake resistant performance in the following manners: 1) Plastic deformation aspects regarding dynamic-soil structure interaction, structural deformation and damage features are utilized for numerical analysis correlations and qualifications 2) Shear deformation of structural system well represents limit state of underground structures.

報告者

キーワード