A study on out-of-plane strength of reinforced concrete wall by tsunami wave load

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04795
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 23010:Building structures and materials-related
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Kabeyasawa Toshikazu 東京都立大学, 都市環境科学研究科, 准教授 (10533953)
• Co-Investigator(Kenkyū-buntansha): 壁谷澤 寿海 東京大学, 地震研究所, 名誉教授 (00134479)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 津波避難ビル / 鉄筋コンクリート造 / 耐津波設計 / 水理実験

Outline of Final Research Achievements

In this study, the water pressure loading test of RC outer wall specimen was conducted. A thin steel plate was fixed to the back of the wall specimen to make an internal space for water. A gas pipe was embedded to the upper part of the frame beam and extended to a height of about 8 m. The water pressure on the specimen was measured with a water pressure gauge through a hole in the steel plate. As the water level increased, the outer wall gradually deformed out of plane. It made flexural failure at the maximum water level of about 6m. A three-dimensional nonlinear finite element analysis was performed to overestimate the out-of-plane flexural strength in the test. It was pointed out that the bond force between the steel rebar and concrete decreased due to the out-of-plane deformation of the wall plate in two directions. It is pointed out that the conventional model can not simulate this stress and collapse mechanism of the wall.

Free Research Field

建築構造

Academic Significance and Societal Importance of the Research Achievements

本研究で実施した水圧実験は実験加力装置や大規模な水槽が無くとも一般的な耐震実験と同程度の縮小スケールの耐震壁の面外破壊性状を試験体に鋼板とガス管を取りつけることだけで検証可能な方法を示した。今後，耐津波補強を行った外壁部材等の水圧に対する性能検証の方法として広く普及すると考えられる。また，従来の3次元有限要素解析では2方向変形に伴う付着力の低下について再現できず，面外曲げを受ける部材における強度を過大評価する傾向にあることを指摘した。面外荷重に対するRC造板部材の設計法として仮想仕事法に基づく強度算定法により安全側に面外破壊強度を推定しうることも示した。