OBATA Makoto

写真a

Affiliation Department etc.

Department of Architecture, Civil Engineering and Industrial Management Engineering
Department of Architecture, Civil Engineering and Industrial Management Engineering

Title

Vice President

Mail Address

E-mail address

Graduating School

  • 1978.04
    -
    1982.03

    The University of Tokyo   Faculty of Engineering   Graduated

Graduate School

  •  
    -
    1985.03

    Northwestern University    Doctor's Course  Completed

  •  
    -
    1984.03

    Northwestern University    Master's Course  Completed

  •  
    -
    1982

    The University of Tokyo  Graduate School, Division of Engineering  Master's Course  Unfinished Course

Degree

  • Northwestern University -  Ph.D.

  • Northwestern University -  Master of Science

External Career

  • 1985.04
    -
    1987.03

    San Diego, California University   Researcher  

Field of expertise (Grants-in-aid for Scientific Research classification)

  • Structural engineering/Earthquake engineering/Maintenance management engineering

 

Research Career

  • Simulation of corrosive environment of steel bridges

    Collaboration in Japan   (not selected)  

    Project Year:  2008.04  -  Now

Papers

  • IMPROVEMENT OF STRESS-STRAIN RELATION UNDER MULTIAXIAL LOADING OF RUBBER FOR BEARINGS

    Makoto Obata, Takemasa Ebisawa, Yoshiaki Goto

    Journal of Japan Society of Civil Engineers Ser A1 (Structural Engineering & Earthquake Engineering (SE/EE)) ( Japan Society of Civil Engineers )  76 ( 2 ) 320 - 330   2020.08  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • Observation of suspended sea salt particles and its numerical simulation as estimation of corrosive environment

    Makoto Obata, Taro Murakami

      60 ( A ) 596 - 604   2014.04  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • Global-local approach to numerical simulation of adhesion of seasalt particles on bridge girders

    Makoto Obata,Li Guotai, Yasunari Watanabe, Yoshiaki Goto

    Journal of Structural Engineering A   58   668 - 678   2012.03  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • Numerical analysis of fracture phenomena observed in a locally buckled circular steel column

    Hideyuki Fujiwara, Makoto Obata, Yoshiaki Goto

    Journal of Structural Engineering A   58   310 - 318   2012.03  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • YIELDING STEEL DAMPERS TO REPLACE CONCRETE SHEAR KEYS FOR SEISMIC RETROFIT OF BRIDGES WITH UNEQUAL HEIGHT PIERS

    Nailiang Xiang, Y Goto, Makoto Obata, M. Shahria Alam, Jianzhong Li

    Proc. 17th World Conference on Earthquake Engineering     2020.09  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    Irregular multi-span continuous bridges with unequal height piers are commonly adopted in mountainous areas when crossing steep-sided valleys. As common practice, economical unbonded laminated rubber bearings and concrete shear keys are usually installed in such bridges as superstructure-to-substructure connections. In strong earthquakes, the sliding of rubber bearings and the shear key failure are mostly expected, which may weaken the seismic resistance of the irregular bridges. The current study is mainly divided into three parts: the first one investigates the effect of concrete shear keys on the transverse seismic performance of the irregular bridges by incorporating the potential sliding of laminated rubber bearings; the second part proposes the concept of using yielding steel dampers to replace shear keys for mitigating the irregular seismic responses of the unequal height bridges with the practical design method being developed; the third part demonstrates the retrofit effectiveness by conducting nonlinear time-history analyses. The results indicate that the existence of concrete shear keys increases the bridge irregularity by inducing a significant in-plane superstructure rotation response around the vertical axis, posing nonuniform displacement demands at the substructures. The shear keys also contribute to the unbalanced ductility demands on the unequal height substructures, rendering the taller piers more vulnerable to the seismic damages. This differs from the case with fixed bearings, where the shorter piers are more subjected to damages. Using yielding steel dampers that are appropriately designed as per the proposed method, the seismic rotations of the bridge superstructure can be considerably mitigated with a relatively uniform superstructure movement maintained. The steel dampers are also effective in distributing the inertia forces among the unequal height piers. The effectiveness of yielding steel dampers replacing concrete shear keys in unequal height irregular bridges is successfully verified by the results from the numerical simulation.

  • Passive seismic unseating prevention strategies implemented in highway bridges: A state-of-the-art review

    Nailiang Xiang , Yoshiaki Goto, Makoto Obata, M. Shahria Alam

    Engineering Strucures ( Elsevier )  194   77 - 93   2019.09  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • Analysis of rubber bearing behavior with material deterioration

    Makoto Obata, Yoshiaki Goto

    Proceedings of ICASS2018     2018.12  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

  • Analysis of rubber bearings with mullins effect uner cyclic loading

    Makoto Obata, Chisa Koiwa, Yoshiaki Goto

      1 ( 1 ) 335 - 338   2017.07  [Refereed]

    Research paper (research society, symposium materials, etc.)   Multiple Authorship

  • Ultimate Behavior of Steel and CFT Piers in Two-Span Continuous Elevated-Girder Bridge Models Tested by Shake-Table Excitations

    Yoshiaki Goto, Takemasa Ebisawa, Makoto Obata, Jianzhong Li, Yan Xu

    Journal of Bridge Engineering ( American Society of Civil Engineering )    2017.01  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

  • Effects of land use data on numerical simulation of corrosive environment caused by airborne sea salt particles

    Makoto Obata, Masato Fukushima, Seiya Suzuki

    Proc. the 7th ISSS   1 ( 1 ) 228 - 229   2013.11  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    Corrosion of steel bridges in a coastal area is mainly caused by sea salt particles coming from ocean. Appropriate estimation of such airborne sea salt particles is critically important for a proper anticorrosion management program. At present, the most reasonable simulation of sea salt concentration can be performed as a part of meso scale meteorological analysis. However, accuracy of such simulation is not verified well so far. The objective of this work is to verify and to improve the accuracy of numerical simulation of airborne sea salt particles by introducing enhanced land use data. Other factors affecting accuracy of airborne sea salt concentration will also be discussed.

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Presentations

  • Effects of Land Use Data on Numerical Simulation of Corrosive caused by airborne seasalt particles

    Masato Fukushima, Seiya Suzuki

    ISSS2013  (Jeju, Korea)  2013.11  -  2013.11  KAIST

  • Numerical prediction of ductile crack initiation in a steel column under cyclic loading

    Makoto Obata, Hideyuki Fujiwara, Yoshiaki Goto

    ASCCS  (Singapore)  2012.07  -  2012.07  Singapore Structural Steel Society

  • Numerical estimation of corrosion environment by airborne sea salt particles

    Liu Chenchen, Makoto Obata

    GCCSEE  (Yichang)  2012.10  -  2012.10  Geoenviornmental Engineering Branch, Chinese Society for Rock Mechanics and Engineering

  • 高解度地表面情報導入による飛来塩分量予測の改良

    村上 太郎,福島 雅人,鈴木 誠也,小畑 誠

    土木学会全国大会  (千葉県)  2013.09  -  2013.09  土木学会

  • 連続高架橋模型の2方向加振実験に基づくゴム支承の挙動特性に関する検討

    奥村徹,後藤芳顯,海老澤健正,小畑 誠

    土木学会全国大会  (岡山大学)  2015.09  -  2015.09  土木学会

  • 名古屋市における浮遊塩分濃度の観測と数値解析による検討

    鈴木誠也,村上太郎,小畑誠

    土木学会全国大会  (大阪大学豊中キャンパス)  2014.09  -  2014.09  土木学会

  • 名古屋市における浮遊塩分濃度の観測と数値解析による検討

    鈴木誠也,村上太郎,小畑誠

    土木学会全国大会  (大阪大学豊中キャンパス)  2014.09  -  2014.09  土木学会

  • Numerical simulation of adhesion of sea salt particles for anticorrosion of steel bridges

    Makoto Obata, Shunya Yokoi, Li Guotai, Yoshiaki Goto

    ASEM11  (Seoul)  2011.09  -  2011.09  IASEM

  • Numerical analysis of sea-salt particulate matter adhesion on bridge surfaces

    ICASS09  2009.04  -  2009.04 

  • Effects of stiffeners on stability and ductility of stiffened thin-walled steel columns with rectangular cross section under bi-directional loading

    CIMS2008  2008.04  -  2008.04 

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