亀裂性岩盤の比貯留係数の推定に関する一考察 A study of the estimation of specific storage in a fractured rock mass

この論文にアクセスする

この論文をさがす

著者

抄録

Specific storage, one of the hydraulic constants, is defined as a rate of volume change caused by the elastic deformation of structural skeleton and pore water in a porous media associating with changing hydraulic pressure. In this report,, the specific storage was theoretically estimated from the combination of compressibility of skeleton of rock mass, compressibility and density of pore water, and porosity.<BR>The basement rocks of the studied area, mainly composed of rhyolitic welded tuff, are considerably fractured from the observation of the survey tunnels having a total length of 300 meters and of the vertically drilled four bore-holes to the tunnels. The basement rocks also have high permeability, determined from the Lugeon water tests carried out at about four bore-holes. Hydraulic conductivities and specific storages have precisely been determined by the cross-hole hydraulic pressure tests performed at selected four bore-holes. An apparent principal hydraulic direction can be distinguishable from the differences of hydraulic pressure propagation among horizontal three directions during cross-hole hydraulic pressure tests. The specific storage value is larger in the apparently minimum principal hydraulic direction than that in the maximum principal hydraulic direction.<BR>The compressibility of skeleton was determined from the data of elastic wave exploration around survey tunnels and bore-hole horizontal loading test at several bore-holes. The specific storage of a fractured rock mass can be calculated from the combination of the compressibility of skeleton, compressibility and density of pore-water and porosity. Consequently, the calculated specific storages is concordant with that of the apparent minimum principal hydraulic direction. Specific storages of the apparent maximum principal hydraulic direction have smaller of 2 orders and more than those calculated above. The smaller values are explained that volume of the pore in fractures varies with ground water seepage along the apparent maximum principal hydraulic direction without the volume change of the rock skeleton. When the rock skeleton along the apparent maximum principal hydraulic direction has no volume change associating with seepage flow, the specific storage is given by the product of compressibility and density of pore water, porosity and coefficient, α, where α is the ratio of pore volume in the main flow paths, which volume changes during seepage flow, to total pore volume. In the studied rock mass here, α ranges from 0.07 to 1.3. The α is smaller than 1, because ground water flows in a part of fractures which regard as channels, and the storage of the ground water is due to the volume change of a certain part of pore space in the main ground water flow path.

収録刊行物

  • 地下水学会誌  

    地下水学会誌 39(3), 201-215, 1997-08-25 

    公益社団法人 日本地下水学会

参考文献:  21件

参考文献を見るにはログインが必要です。ユーザIDをお持ちでない方は新規登録してください。

各種コード

  • NII論文ID(NAID)
    10002383235
  • NII書誌ID(NCID)
    AN10088275
  • 本文言語コード
    JPN
  • 資料種別
    ART
  • ISSN
    09134182
  • NDL 記事登録ID
    4313294
  • NDL 雑誌分類
    ZM44(科学技術--地球科学--海洋・陸水・火山)
  • NDL 請求記号
    Z15-140
  • データ提供元
    CJP書誌  NDL  J-STAGE 
ページトップへ