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  4. Vol.42 No.129 2017.9


Vol.42 No.129 2017.9


* By clicking ▸ on the title of Technical Reports, abstract will be indicated.

【巻頭言】Prefatory note

  • 保全事業もAI で超効率化

    Enhance Efficiency of Maintenance Activity with AI


    Yoshiaki Kawakami

【技術論文】Technical report

  • 技術開発計画(H26-H28)の成果

    Outcomes of Technological Development Project between 2014 and 2016


    Katsuya Ogihara, Masahiro Nishitani


    Three-year technological development project was worked on to practice preventive maintenance for long-span bridges between 2014 and 2016. This paper reports outcomes from the three-year project. The following three-year project that started in 2017 is explained as well.

  • 海峡部橋梁マスコンクリート表面被覆要領の改訂

    Revision of Guideline for Coating of Mass Concrete Structure of Long-Span Bridge


    Taku Hanai, Akira Yamane, Shigeki Kusuhara


    The foundations of the Honshu-Shikoku Bridges are large-scale mass concrete structures. In order to maintain them in a good condition, it is dispensable to prevent intrusion of deterioration factors such as salt, carbon dioxide, etc. For this purpose, surface coatings were applied to many of the foundations according to the “Guideline for Coating of Mass Concrete Structure of Long-Span Bridge.” The Guideline was revised based on resent studies. In this report, issues to be solved in the last Guideline, results of recent studies, and the key points of the revision of the Guideline are explained.

  • 本州四国連絡高速道路の経済効果分析

    Empirical Studies of Spatial & Economic Effect of Utilizing the Honshu-Shikoku Bridge Based on Inter-Regional Input-Output Tables


    Toshihide Shimomoto, Kazumichi Maeshima



    The Honshu-Shikoku bridge has dramatically improved the traffic condition between Shikoku and Honshu, that had ever been depending on sea traffic with most. Furthermore, the Honshu-Shikoku bridge has been connected to the expressway network of both Honshu and Shikoku areas and is now given status as the traffic infrastructure to bear the part of a high speed transportation network extending throughout Japan. As a result, it improves movement time, and it is assumed that the economic effect spreads to not only the prefectures close to the Honshu-Shikoku bridge, but also nationwide each area through spatial interdependency.

    To measure these economic effect quantitatively, inter-regional input-output analysis was applied on intermediate inputs. Besides, the economic effect of trip consumption through the Honshu-Shikoku bridge was measured with the Balanced Multiregional Input-Output Model.

  • 孫崎高架橋支承補修に伴う挙動調査

    Behavior of the bearings of the Magosaki Viaduct before and after the rehabilitation


    Takahiro Shinno, Yuki Kishi, Yukio Nagao


    Magosaki Viaduct, south approach of the Ohnaruto Bridge, is 3-span continuous and non-composite steel girder bridge with the total length of 134m. Since the viaduct has 14 main girders, surface painting area is large. Although repainting was implemented in 1999, since the viaduct is located near the Naruto Channel, increase of corrosion in steel members was reported 32 years after the completion. In particular, the bearings (BP-A bearing) are severely corroded, and 28 movable bearings of 2 intermediate piers (14 bearings on each pier top) were found to be non-functioning due to the accumulation of corroded products between top and bottom bearing components. If the situation is left unchanged, the intermediate piers cannot bear the shear force when the viaduct is subjected to Level 2 Earthquake Ground Motion. In this article, the preliminary study, the rehabilitation works of the bearings (replacement of the top bearing, Zinc and Aluminum thermal spray coating of the bottom bearing), and the investigation of the behavior of the bearings are described.

  • 下津井瀬戸大橋PC 桁部と櫃石島高架橋の耐震補強

    Seismic Retrofit for PC-girders at Both Ends of Shimotsu-Seto Bridge and Hitsuishijima Viaduct


    Masahiro Nishitani, Ryu Hashimoto, Kazuo Endo



    Seismic retrofit of the Seto-Ohashi Bridges and approach viaducts was started in 2013. It will be completed in 2020. Seismic retrofit has been conducted considering retrofit work schedule and dividing the Seto-Ohashi Bridges into four groups such as girder bridges, truss bridges, cable-stayed bridges, and suspension bridges. This paper describes seismic retrofit design and site work for the PC-girders at both ends of the Shimotsui-Seto Bridge and the Hitsuishijima Viaduct between 1P and 12P piers. Retrofitting work for such parts was completed in spring, 2017.

    Seismic verification and retrofit design were carried out to consider “Seismic Performance Level-2” specified in “the Design Specifications for Highway Bridges.” It was found that shear capacity of bridge piers and strength for bearings in each viaduct were not sufficient against large-scale seismic motions. Fiber lining around the piers and reinforcement of such bearings were done as seismic countermeasures.

【技術開発年次報告】Annual report of technology development

  • 防食分科会 塗装(鋼)WGの取組

    Report of Working Group for Metal Coating System, Anticorrosion Subcommittee


    Masahiro Takeguchi, Yuki Kishi, Masao Kume

  • 防食分科会 海中基礎防食WGの取組

    Report of Working Group for Anticorrosion for Underwater Foundations, Anticorrosion Subcommittee


    Masahiro Takeguchi, Yutaka Okamoto

  • 防食分科会橋梁付属物WG の取組

    Report of Working Group for bridge accessories, Anticorrosion Subcommittee


    Masahiro Takeguchi, Yutaka Okamoto

  • 疲労分科会の取組

    Report of Fatigue Subcommittee


    Masahiro Hayashi, Akira Moriyama

  • 耐震分科会の取組

    Report of Seismic Subcommittee


    Masahiro Nishitani, Chihiro Kawatoh

  • 耐風分科会の取組

    Report of Wind-Resistance Subcommittee


    Shigeki Kusuhara, Taku Hanai

【技術ニュース】Technical news

  • 韓国NAH社との技術交流

    Technical information exchange with NAH, Korea


    Masahiro Nishitani

  • 第15回REAAA道路会議(インドネシア)

    15th REAAA Road Cnference, Indonesia


    Yoshiya Sakamoto

  • 斜張橋耐震固定装置用ばねのばね技術遺産認定

    Recognition of the spring of aseismatic faciliries for cable-stayed bridges as Spring technological heritage


    Yasushi Otani