STUDY ON THE EFFECT OF THE VERTICAL RC BOLTING ON THE UNSTABLE SLOPE ---PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON THEORY AND PRACTICE OF EARTH REINFORCEMENT, FUKUOKA, KYUSHU, JAPAN, 5-7 OCTOBER 1988

The vertical reinforced concrete bolting method used to stabilize the face of excavation tunnels was discussed in this article, and an example of its use described. The method was normally executed by driving fixed pitch mortar reinforced concrete piles into holes bored into the surface. This method was used during the construction of the 2nd shirasaki tunnel on the shinonoi railway, where the tunnel was constructed under an unstable slope. The spot where the tunnel was to cross the yodogasawa marshland was at a point where both banks formed oblique 35 degree slopes. Soil consisted of lower layers of Cenozoic neocene Miocene Japanese red pine alternating with a high proportion of sandstone, sandy mudstone and mudstone. The bolt zone was positioned where the soil thickness was 1.5 times that of the diameter of the crown of the tunnel. Piles were driven every 1.5 square metres. Measurements of surface subsidence, and of both vertical and horizontal ground displacements were made. It was found that concrete bolting successfully restrained the displacement of the natural ground and decreased the effect of tunnel excavation on the front of the slope. For the covering abstract of the symposium see IRRD 818063.

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  • Corporate Authors:

    AA Balkema

    P.O. Box 1675
    Rotterdam,   Netherlands  BR-3000
  • Authors:
    • Iwata, M
    • Mitarashi, Y
    • Masuda, Mitsutoshi
  • Publication Date: 1988

Language

  • English

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Filing Info

  • Accession Number: 00487008
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • ISBN: 90-6191-820-0
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1989 12:00AM