Journal of the Japan Society of Engineering Geology
Online ISSN : 1884-0973
Print ISSN : 0286-7737
ISSN-L : 0286-7737
Volume 61, Issue 6
Displaying 1-4 of 4 articles from this issue
Original Article
  • Yukiyasu FUJII
    2021 Volume 61 Issue 6 Pages 313-320
    Published: February 10, 2021
    Released on J-STAGE: May 02, 2021
    JOURNAL FREE ACCESS

    In Japan where many earthquakes occur, there are few historical stone structures compared to the countries located in the craton. However, various kinds of rocks have been produced as stone materials or building stones in various places all over the nation, according to the usage pattern of each region or each era. In this paper, five stone materials, Ohya, Kimachi, Tago, Inada and Komatsu, will be explained for the types of rocks and the geological background. In addition, the uniaxial compressive strength, which is related to the ease of collecting and processing stones, and the time when the stones were first used were investigated by articles. Ohya of tuff, Kimachi and Tago of sandstone show the strength of less than 50 MPa. These sedimentary rocks have been used more than 1000 years since tumulus period. On the other hand, Inada of granite and Komatsu of andesite or rhyolite show the strength of more than 100 MPa. Those igneous rocks have been used less than 1000 years since Heian period. In Japan imported building stones have been used many cases these days. However, there are some quarries that are still in operation for the stone materials picked up in this research. I hope they can be continued as a local industry.

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Report
  • Kazuhide YASHIRO, Noriyuki OKANO, Tsunetaka TSURU
    2021 Volume 61 Issue 6 Pages 321-325
    Published: February 10, 2021
    Released on J-STAGE: May 02, 2021
    JOURNAL FREE ACCESS

    Most of the railway mountain tunnels were constructed before the war, and spalling may occur due to deterioration or cracking. In railway tunnels, the repair method is required that does not invade the cross section as much as possible and can be applied even for a short time. The authors have developed the repair method using FRP plates made from basalt fiber as a countermeasure against the spalling of mountain tunnels lining in service. In this method, the FRP plates are bonded to the tunnel lining with an epoxy resin and fixed to the tunnel lining with anchors and stainless-steel plates. By the basalt plates, the effect of reinforcing the tunnel lining and preventing falling off of the concrete blocks can be expected. In addition, the effect of preventing spalling of small pieces from lining also can be expected. In this paper, the outline of the development method is explained, and the application examples are introduced.

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