Design Method of RC Beam with Openings, Cut-off Longitudinal Bars, and Lap Splice by Considering Combined Failure Mode

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02282
• 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: Tokyo Institute of Technology
• Principal Investigator: Nishimura Koshiro 東京工業大学, 科学技術創成研究院, 准教授 (00343161)
• Co-Investigator(Kenkyū-buntansha): 岸田 慎司 芝浦工業大学, 建築学部, 教授 (10322348) ; 河野 進 東京工業大学, 科学技術創成研究院, 教授 (30283493) ; 小原 拓 東京工業大学, 科学技術創成研究院, 助教 (50845451)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 鉄筋コンクリート梁 / 貫通孔 / せん断耐力

Outline of Final Research Achievements

Openings for plumbing are often constructed in the reinforced concrete beam, and the beam may suffer damages when the building is subjected to a strong earthquake. We conducted the experimental tests to investigate the influences of the number and location of the openings, cut-off longitudinal bars, and lap splices on the structural performance of the RC beam. The measurement method using MEMS accelerators were also verified in the tests. The numerical model of the RC beam was analyzed by the Finite Element Method to discuss the compressive stress transfer in concrete. We proposed the design method for the portions with the opening and without the opening of the RC beam based on the experiment and the numerical results.

Free Research Field

建築構造

Academic Significance and Societal Importance of the Research Achievements

貫通孔を有する鉄筋コンクリート梁の実験研究では、これまで開孔部の破壊に着目させることがほとんどであった。本研究では、無開孔部での圧縮応力伝達の変化を実験により示唆できたことが学術的意義の一つであり、開孔部分と無開孔部分の両方について設計方法を提案したことは社会的意義と言える。また、MEMS加速度センサを用いた多点観測により、梁の変形をモニタリング可能なことを実証したことは、建物の維持管理技術の進展に資する成果と言える。