Ultimate superstructure response, lateral resistance and bearing capacity of a shallow foundation during strong shaking

2016 Fiscal Year Final Research Report

• Project/Area Number: 24360228
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Building structures/materials
• Research Institution: Tokyo Institute of Technology (2014-2016); Kyoto University (2012-2013)
• Principal Investigator: TAMURA SHUJI 東京工業大学, 環境・社会理工学院, 准教授 (40313837)
• Co-Investigator(Kenkyū-buntansha): 時松 孝次 東京工業大学, 理工学研究科, 教授 (50134846)
• Research Collaborator: Boulanger Ross W. University California, Davis, Professor
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: 直接基礎 / 水平抵抗 / 極限支持力 / 極限応答 / 大地震 / 格子状地盤改良 / 地震時土圧

Outline of Final Research Achievements

Geotechnical centrifuge tests were performed on soil-footing-superstructure models to investigate response of shallow foundation structures during strong shakings. Superstructure acceleration amplitudes tended to reach the limit, although ground surface acceleration amplitudes increased with increasing input motions. The ultimate response of the superstructure depends on the overturning moment limitation that was caused by local soil failure under the footing edge. Risk of overturn of a structure is small when the safety factor of the bearing capacity is large. Centrifuge tests are also performed to examine the dynamic response of structures supported by shallow foundations on soft clay reinforced by soil-cement grids. Soil-cement grids were effective at controlling foundation settlements in most cases. The more significant foundation settlements were caused by extensive crushing of the soil-cement when footing rotations were extremely large.

Free Research Field

地盤地震工学