表層を締固めた飽和砂地盤上の直接基礎建物を対象とした遠心振動実験
飽和砂地盤上に建つ直接基礎建物が地震時に沈下したり傾斜したりする被害を防止するために締固め地盤改良が実施される場合がある。この締固め地盤改良の施工深さを合理的に設定するための知見を得ることを目的に，遠心力場での模型振動台実験を行った。
深い領域に未改良のゆるい層を残しつつも，基礎底直下の浅い領域をある程度の深さまで締固めることによって，まったく締固め改良を施さない場合に比べれば，地震時の直接基礎建物の沈下量を大幅に低減できることが確認された。
| キーワード： | 直接基礎，飽和砂地盤，締固め，沈下，遠心振動実験 |
＊１ 技術センター 建築技術研究所 建築構工法研究室
Dynamic Centrifuge Tests on Building Supported by Spread Foundation on Saturated Sandy Ground with Compaction
In order to reduce earthquake-induced settlement and inclination of a building supported by a spread foundation on saturated sandy ground, the soil improvement using a compaction method is sometimes employed. To study the effect of compaction depth on the degree of damage caused by an earthquake, shaking table tests in a centrifugal field were conducted.
It was found that, even if the ground is not improved deep below the surface and the material remains loose, compaction to a certain shallow depth can significantly reduce the settlement of a building during an earthquake as compared with an un-treated building.
| Keywords: | spread foundation, saturated sandy ground, compaction, settlement, dynamic centrifuge test |
*1 Building System and Material Research Section, Building Engineering Research Institute, Technology Center
