Seismic Performance Evaluation of External Beam-Column Connection at Foundation with Grade Beam and Pile

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K18179
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Building structures/Materials
• Research Institution: The University of Tokyo (2017-2019); Hokkaido University (2016)
• Principal Investigator: Onishi Naoki 東京大学, 大学院工学系研究科(工学部), 助教 (20579784)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 機械式定着 / 柱脚 / 基礎梁 / パイルキャップ

Outline of Final Research Achievements

Experiments were carried out on five partial frame test specimens at the foundation joint consisting of a grade beam, pile, pile cap, and external (corner) column of a reinforced concrete building. The specimens adopted headed threaded reinforcement, which has anchor plates at the end of reinforcement bars, to fix the beam reinforcement in the joint to the concrete. Headed reinforcement tends to spread cracks through the anchor plate. It is shown that the cracks passing through the anchor plate of the beam may affect the bending capacity of the column when column yielding precedes. We developed a capacity calculation model that can estimate the test results.

Free Research Field

耐震工学

Academic Significance and Societal Importance of the Research Achievements

本研究対象の基礎接合部および柱脚部は構造物の耐力上重要な部位であり、建物の保有水平耐力計算においてその耐力を把握している必要がある。本研究の荷重条件では柱の曲げ耐力の計算に注意が必要であることが示された。ただし本研究の実験では軸力が未考慮のため、実験結果が実際の建物内で生じる現象かどうかについても検証をすすめる必要があり、提案式はまだ実用的ではない。しかしながら基礎梁を機械式定着とした場合の具体的な設計方法の開発に向けて基礎的なモデルを示すことができた。