海水飛沫帯における橋脚砂岩塊のくぼみ深さに関する定量的把握 : 日南海岸・青島弥生橋の事例  [in Japanese] A Quantitative Prediction for Depth of Depression at Sandstone Blocks in Coastal Spray Zone : An Example of Yayoi Bridge at Aoshima Island on the Nichinan Coast  [in Japanese]

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Author(s)

    • 青木 久 AOKI Hisashi
    • 筑波大学大学院・生命環境科学研究科 Graduate School of Life and Environmental Sciences, University of Tsukuba
    • 松倉 公憲 MATSUKURA Yukinori
    • 筑波大学大学院・生命環境科学研究科・地球環境科学専攻 Geoenvironmental Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba

Abstract

Tafoni-like depressions occur on sandstone blocks used for a masonry pier of Yayoi Bridge at Aoshima Island on the Nichinan coast. The blocks are exposed to the spray zone and suffer weathering and wave erosion. The depth of depression was measured for all blocks in 1971, 1989, and 2001 corresponding to 20, 38, and 50 years, respectively, since the construction of the bridge. Rock strength of sandstone blocks was measured using an Equotip hardness tester. These data showed that the depth of depressions was smaller in the blocks having larger strength. The depth was described as a function of the salt weathering susceptibility of sandstone blocks W_s, the height above mean high water level h^* located the blocks, and time t ; the depth D was expressed by : D=68.6W_se^<-0.0038h^*>(1-e^<-0.031t>) where W_s is represented by W_s=P/S_t, P is the total pressure potential generated in unit volume of the rock, and S_t is the tensile strength estimated from Equotip hardness.

Journal

  • Transactions,Japanese Geomorphological Union

    Transactions,Japanese Geomorphological Union 26(1), 13-28, 2005-01-25

    日本地形学連合

References:  21

Cited by:  1

Codes

  • NII Article ID (NAID)
    110001272931
  • NII NACSIS-CAT ID (NCID)
    AN00333248
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    03891755
  • NDL Article ID
    7247101
  • NDL Source Classification
    ZM49(科学技術--地球科学--地質)
  • NDL Call No.
    Z15-386
  • Data Source
    CJP  CJPref  NDL  NII-ELS  NDL-Digital 
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