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  4. Vol.33 No.111 2008.9


Vol.33 No.111 2008.9


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

【巻頭言】Prefatory note

  • 道路構造物のリスクマネジメント

    Risk management of highway structures


    Daizo Tomita

【技術論文】Technical report

  • 明石海峡大橋イルミネーションケーブルの振動計測(中間報告)

    Vibration measurement for illumination cables of the Akashi-Kaikyo Bridge (Interim report)


    Shigeki Kusuhara, Yoshiteru Yokoi



    Slight damage has occurred on the illumination cables, which consist of electric power supply and signal control for cable illumination system of the Akashi-Kaikyo Bridge. According to the appearance of damage, it is suspected that the damage was caused by the vibration of hand ropes. Therefore, field measurement was carried out, in order to recognize the situation of the vibration and to clarify the reason of the vibration.

    This paper describes the field measurement method by means of optical fiber sensors for hand ropes on the main cable and the analytic results of vibration characteristics.

  • 門崎高架橋における塩害の実状と対策

    The present status of chloride attack and the measurement on the Tozaki Viaduct


    Tomoji Murata, Takahiro Ohnishi



    The Tozaki Viaduct, which is under severe weather conditions and oceanographic phenomena, is 20 years old after its opening. Piers of the viaduct are damaged by chloride attack. Its steel bars have been corroded therefore concrete section has been lost by floating and flaking. As a result, the performance of the structure has decreased.

    This is a report of the present status of chloride damage of the concrete piers based on the result of researches into chloride ion content survey of the pier and measures taken after the survey.

  • 多々羅大橋鉛直支承のすべり板改良

    Improvement of slide plates at vertical bearings in Tatara Bridge


    Hiroyasu Suehiro, Masao Moriwaki



    Closed type rubber bearing plate shoes are applied at the piers of the side spans in Tatara Bridge. Upper bearings (stainless plates) were damaged partially because slide plates (PTFE plates) in the shoes stuck out. Therefore, slide plate had been replaced considering the decline of the bearing's performance.

    This report shows the cause of the damage, tests carried out to clear the cause, the structure of newly installed slide plates, and its replacement work.

  • 耐震補強検討に用いる大規模地震動の設定

    Large-scale earthquakes for seismic upgrading


    Susumu Fukunaga, Kazuo Endo


    Presented in this paper is to define large-scale earthquakes for seismic upgrading of strait crossing bridges. In the definition, site-specific seismic motions coming from plate-boundaries, subducted slabs and inland active faults based on recently-promulgated earthquake information from the government- affiliated organizations were estimated using a hybrid method. Besides, seismic motions coming from earthquake with a magnitude of MJ6.8 occurring just beneath the sites were investigated in consideration of unknown inland active faults.

  • 明石海峡大橋の大規模地震に対する耐震性照査

    Seismic performance verification of the Akashi-Kaikyo Bridge against large-scale earthquakes


    Susumu Fukunaga, Kazuo Endo


    Presented in this paper is a seismic performance verification of the Akashi-Kaikyo Bridge against large-scale earthquakes. In the verification, an analytical model incorporated nonlinear behaviors, such as plastic deformation of steel members, bearing failure and collision between a girder and an anchorage, was used for dynamic analyses and limited damages, which had less effect on seismic performance, were permitted. As a result, it was found that taking some minor countermeasures possibly ensured the target seismic performance.

【海外報告】Overseas report

  • 海外報告(バングラデシュ)

    Overseas report (Bangladesh)


    Toshihiro Kurihara

【技術ニュース】Technical news