Study on design of composite ground with existing piles to enable shallow foundation buildings with high seismic performance

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02306
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 23010:Building structures and materials-related
• Research Institution: Osaka University
• Principal Investigator: Kashiwa Hisatoshi 大阪大学, 大学院工学研究科, 教授 (40550132)
• Co-Investigator(Kenkyū-buntansha): 石原 直 東京工業大学, 科学技術創成研究院, 教授 (50370747) ; 中川 博人 国立研究開発法人建築研究所, 国際地震工学センター, 主任研究員 (80713007) ; 大村 早紀 国立研究開発法人建築研究所, 構造研究グループ, 研究員 (70848283)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 既存杭の利活用 / 基礎構造 / 地盤工学 / 振動台実験 / 有限要素解析

Outline of Final Research Achievements

Centrifugal shaking table tests and shaking table tests in 1G were conducted to study design methods for composite ground with existing piles and evaluation methods for the seismic behavior of buildings on the composite ground, with the following results.
First, the influence of torsional vibrations associated with the stiffness eccentricity of the foundation on the seismic response of the superstructure, which appears when adopting a pile foundation with existing piles, was ascertained. Next, shake table tests were conducted to investigate the seismic behavior of insulated pile foundations, which separate the pile head from the footing. The tests indicated that the piles in the ground reduce building inclination due to earthquakes. Furthermore, it was shown that a three-dimensional non-linear finite element method could be applied to develop an analytical model for estimating experimental results.

Free Research Field

建築構造

Academic Significance and Societal Importance of the Research Achievements

本研究で実施した各種模型実験および解析的検討により、既存杭を利用する上での課題の具体を明らかにするとともに、既存杭の新しい活用法に関する有用な知見を得ることができた。得られた知見は既存杭を利用した地盤改良併用基礎の設計法を構築するための基盤となるもので、既存杭の利用促進に資するものであり、災害レジリエンスの向上だけでなく、建築業の環境負荷低減に貢献することができる。