EXPERIMENTAL AND ANALYTICAL STUDY ON ESTIMATION OF REACTION FORCE BY STRAIN MEASUREMENT OF STEEL GIRDER

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04584
• 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: Meijo University
• Principal Investigator: watanabe koichi 名城大学, 理工学部, 教授 (90387762)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 支承取替え / ジャッキアップ / モニタリング / ひずみ測定 / FEM解析

Outline of Final Research Achievements

If a severe earthquake strike a steel bridge bearing, and the bridge loses its function, it is necessary to restore the function of the bridge as soon as possible. However, in the 2016 Kumamoto Earthquakes, strong earthquakes occurred continuously in a short period, so it is desirable to adopt a reinforcement structure that appropriately reflects the measured stress of the bridge, even for emergency repair reinforcement.
In this study, we investigated a method for estimating the fulcrum reaction force with high accuracy by measuring the change in external force during temporary receiving jack-up with a strain gauge by a test using a reduced model of a steel girder.The proposed method can be applied to one side of a steel I-girder web to be jacked up to obtain accuracy and is effortless gauge workability. This　measurement method was verified through experiments and FEM analysis to show that jack-up can be safely and reliably controlled by commonly used stress measuring instruments.

Free Research Field

構造工学

Academic Significance and Societal Importance of the Research Achievements

本研究で提案した桁のジャッキアップ時における荷重推定手法は，橋梁の応力測定で一般に用いられるひずみゲージを用いる．ゲージをウェブの断面鉛直方向へグリッド状に貼付することでセンサーとしての施工が完了し，計測機器の演算によって，ジャッキアップ時のジャッキ荷重ならびに，支点反力を高精度に推定可能なモニタリング手法である．
この推定手法をジャッキアップに適用することで，支承が損傷した橋梁の復旧工事において，安全・確実なジャッキアップを実施することが可能となる．また，解析による補強効果のシミュレーションを併用することで，ジャッキアップ時の桁の局所的な損傷を予防し，補強構造を設計可能である．