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  4. Vol.43 No.132 2019.3


Vol.43 No.132 2019.3


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

【巻頭言】Prefatory note

  • 本四高速の更なる発展に向けて

    For further growth of Honshu-Shikoku Bridge Expressway


    Takashi Sakai

【技術論文】Technical report

  • 生口橋の耐震補強設計

    Seismic retrofit design of Ikuchi Bridge


    Yasuyuki Hirayama, Kazunori Yamaguchi, Yoshiaki Mizokami


    The Ikuchi Bridge is at the area where the probability of the occurrence of large earthquakes with a seismic intensity level of Lower 6 or higher in coming 30 years is 26 percent or higher. Therefore the seismic retrofit of the bridge will be completed by 2022. As the result of seismic performance verification, it was found that the displacement in the longitudinal direction would be large because the bridge is supported at multiple support points with rubber bearings and that the main tower and girder would be partially plasticized and the piers, foundations, bearings, and stoppers would be damaged. If all of these members are reinforced, the scale of seismic retrofit will be large. Therefore the reduction of longitudinal displacement by dampers were studied. As the result, it was found that the scale of seismic retrofit would be reduced. This paper presents the seismic retrofit design of the Ikuchi Bridge.

  • 伯方橋の耐震補強設計

    Seismic retrofit design of Hakata Bridge


    Kazunori Yamaguchi, Yoshiaki Mizokami, Yasuyuki Hirayama


    Hakata Bridge was designed with the Specifications for Highway Bridges (1980) that did not take into consideration level 2 earthquake. As the result of seismic performance verification with Specifications for Highway Bridges (2012), it was found that the piers and bearings would be damaged, and retrofit of that damage was studied. As superstructure is longitudinally supported only at the end abutment, 4A, comparative study for exchange of support condition was carried out. This paper reports the study for the seismic retrofit of the Hakata Bridge.

  • センターステイロッドの疲労耐久性向上及び合理的点検手法の考案

    The center stay rod’s improvement of the fatigue durability and proposing rational inspection system


    Hiromichi Yamamoto, Yuji Hidaka, Atsuhiro Okumura


    For the center stay rod (hereinafter referred to as “rod”) installed at the 1st Kurushima Kaikyo Bridge, it was confirmed that the breakage occurred at the mounting threaded portion of the stiffened girder and the rod, rather than the small diameter portion which is the supposed breaking point in the design. From the result of confirming the fracture surface in the previous paper, the fracture of the rod thread portion is estimated to be caused by fatigue, and an improved structure is considered as a measure against fatigue. In this paper, it is described that the result of the fatigue test by full-size rods in order to verify the influence of the screw base radius, and that the examination method using ultrasonic flaw detection.

  • トンネルLED照明の適正な清掃頻度の検討

    The study of proper cleaning frequencies for the LED tunnel light equipment


    Eiji Hidaka, Shinji Nishino


    Longer life expectancy of the LED tunnel light is realized than the conventional lamp light by renovating the Maiko Tunnel lighting facility. Increasing efficiency of the maintenance work is expected because LED units are exchanged every ten years corresponding to the exchange of the lamp bulbs. In the conventional tunnel light, exchanging lamp bulbs and cleaning work at the same time have prevented decreasing the luminous flux of the light equipment due to the dust coated on the glass of the light equipment. After the renovation to LED light facility, exchanging lamp bulbs is not needed. Because dirty environment around light equipment has been never changed, the periodical cleaning work of the LED light equipment are required like the same as before. There is, however, no standard designating the frequency of cleaning work for tunnel light equipment. This paper reports the investigation of the dirty condition of the tunnel light equipment and the study of cleaning frequency by the accelerated tests.

【技術ニュース】Technical news

  • 2018ケーブル橋梁国際カンファレンス

    2018 International Conference of Cable-supported bridge


    Yuki Kishi

  • 第40回 IABSE シンポジウム(ナント)

    40th IABSE Symposium Nantes 2018


    Akira Machida

  • 第10回国際吊構造橋梁管理者会議

    The 10th International Cable Supported Bridge Operators’ Conference (ICSBOC2018)


    Masato Hongo