Development of a new low-tech, low-cost, small-change seismic retrofit technique for severely damaged RC columns

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04244
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22020:Structure engineering and earthquake engineering-related
• Research Institution: University of the Ryukyus (2023); Ariake National College of Technology (2021-2022)
• Principal Investigator: KANEDA KAZUO 琉球大学, 工学部, 客員研究員 (50793907)
• Co-Investigator(Kenkyū-buntansha): 中田 幸造 琉球大学, 工学部, 教授 (80347129)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ピロティRC造建物 / 既存RC柱 / 応急耐震補強 / 恒久耐震補強 / 鋼板 / PC鋼棒 / 面内方向 / 面外方向

Outline of Final Research Achievements

The purpose of this study was to develop a permanent and emergency seismic　retrofit technique that simultaneously prevents from the expansion of damages in the pilotis-type RC buildings due to the aftershocks, restores the strength of damaged RC columns, and improves their seismic performance. In this technique, the steel plate is used to sandwich the damaged columns, while the PC bars actively bond them. It is a low-tech and low-cost seismic retrofit technique that has insignificant impact on the usability of RC piloti buildings. Through the experimental and analytical studies, it was observed that this technique can be applied to retrofit the damaged RC columns after a major earthquake. Consequently, the damaged columns reach excellent seismic performance after seismic retrofit. This technique can be used as the emergency and permanent seismic technique on damaged RC buildings after a major earthquake.

Free Research Field

工学-建築学-建築構造・材料

Academic Significance and Societal Importance of the Research Achievements

本研究では、PC鋼棒で緊結した鋼板サンドイッチ工法を用いて、大地震で大きく損傷したRC柱の耐震性能向上を示し、応急補強と恒久補強法としての適性を示した。この工法は施工の簡便さ（ローテク）・高い経済性（ローコスト）・ピロティ建物の使用性への影響が少ない（スモールテェンジ）特性を有し、新しい耐震補強法として、大地震で大きく損傷したRC柱の応急兼恒久耐震補強に適用できることは社会的影響が大きいと思われる。