Stability Assessment of the Slopes of an Oceanside Coral Limestone Quarry under Drawdown Condition of Semidiurnal Ocean Tides

IR (HANDLE) Open Access
  • Joan Atieno Onyango
    Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University Department of Mining, Materials and Petroleum Engineering, Jomo Kenyatta University of Agriculture and Technology
  • Sasaoka, Takashi
    Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University
  • Shimada, Hideki
    Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University
  • Hamanaka, Akihiro
    Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University
  • Moses, Dyson
    Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University Department of Geography, Earth Science, and Environment, School of Pure and Applied Science, University of Malawi

Description

Vipingo quarry in Kilifi county, Kenya, is one of the quarries supplying coral limestone for limestone manufacturing in the coastal region. Due to its close proximity to the Indian ocean, the semidiurnal ocean tides tend to have an influence on the stability of the quarry slopes adjacent to the shoreline. Finite element numerical analysis using the generalized Hoek–Brown criterion is conducted to assess the stability condition of the slopes followed by slope-angle optimization to determine the safest overall slope angle as well as analyzing the stability of the slopes due to action of varying ocean tides. The optimum overall slope angles for various excavation depths are found to be 52° for 20 m, 46° for 30 m, 42° for 40 m, and 39° for 50 m, which are the same even with varying distance of the slope face from the shoreline. A parametric analysis shows that there is no significant effect of the tides on slope stability for excavations above the water table, but as the quarry gets deeper, the slope stability is affected. A sensitivity factor (ζ) is introduced, being a measure of how much the slope safety factor is reduced as a result of the semidiurnal tidal action.

Journal

  • Mining

    Mining 2 (3), 589-615, 2022-09

    Multidisciplinary Digital Publishing Institute : MDPI

Keywords

Details 詳細情報について

  • CRID
    1050861482656888832
  • ISSN
    26736489
  • HANDLE
    2324/5208220
  • Text Lang
    en
  • Article Type
    journal article
  • Data Source
    • IRDB

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