Study on casting finish control method for pile driving using vibratory hammer

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K14764
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Building structures/Materials
• Research Institution: Nihon University
• Principal Investigator: SHIMOMURA Shuichi 日本大学, 生産工学部, 准教授 (50443726)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 杭 / 支持層確認 / バイブロハンマ / H形鋼

Outline of Final Research Achievements

In this study, we conducted model tests, field tests, and collection and analysis of field construction data for the purpose of improving the casting finish control method for steel pile driven by the vibratory hammer method. As a result, the magnitude of the crowd force during the pile driving affects the casting finish control index, and if the crowd force is weak, there is a risk of overestimating the hardness of the bearing strata. It was clarified that this tendency becomes more remarkable as the size of the pile is larger and the ground is harder. By reflecting this result in the casting finish control method, it is possible to contribute to the improvement of the bearing strata confirmation accuracy. In addition, although these are model tests under limited conditions, there is a possibility to estimate the bearing capacity of piles using the casting finish control index.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

建物に使用されている杭が支持層へ確実に貫入されていないことにより、建物の安全性が懸念され、建物の解体にまで至るなどのトラブルがあったことは記憶に新しい。この問題の原因は種々あるが、その一つとして杭施工時の支持層確認手法が十分に確立できていないことが挙げられる。本研究では杭の施工方法のひとつであるバイブロハンマ工法を対象に支持層確認指標の特性を模型実験並びに現場施工実験により分析し、支持層確認の高度化に資する知見を得た。