水圧破砕における亀裂の発生と開口・閉合の挙動について -不連続面の少ない中国の花崗岩地域での水圧破砕実験(第3報)- Characteristics of Initiation, Reopening and Closing Behavior of Hydraulic Fractured Crack -Hydraulic fracturing experiment in granitic rock with scarce joints in China(3rd Report)-

この論文にアクセスする

この論文をさがす

著者

    • 新 孝一 SHIN Koichi
    • (財)電力中央研究所 地質地盤部 Geology & Geotechnology Department, Central Research Institute of Electric Power Industry
    • 李 方全 LI Fangquan
    • 中華人民共和国国家地震局 地殻応力研究所 Institute of Crustal Dynamics, State Seismological Bureau of P. R. China

抄録

Through an extensive hydraulic fracturing experiment in granitic rock with low frequencies of joints, the initiation, reopening and closing behaviors have been carefully examined. zn this 3 rd report, the features which have not been dealt with in the previous two reports are discussed; the fracture direction and two deflection points in a shut-in curve.<BR>A numerical analysis based on the weakest-link theory reveals that, with increase of the maximum compression stress <I>SH</I>, the mean and the variability of hydro-fracturing tensile strength <I>T</I> increases, while the variability of fracture direction decreases.<BR>In this study, the vertical crack with a circular periphery tends to extend passing through the packers. When sufficient rate of flow is supplied for reopening the crack, the crack tip is fully open. After closing the water valve, the pressure is continuously decreasing, and the first deflection point <I>Pctc</I> is observed at the cracktip closing. With further pressure decrease, the crack surface is closing gradually from the outer to inner part. When the part of crack extended passing through the packers is closed, the second deflection point <I>Ps</I><SUB>2</SUB> is observed. Considering the crack-closing process, <I>Ps</I><SUB>2</SUB> should be larger than (3<I>Sh</I>-<I>SH</I>)/2 while <I>Pctc</I> is equal to the minimum compression stress <I>Sh</I>.<BR>In this experiment, different values of <I>Ps</I><SUB>2</SUB> have been observed at two depths while the values of Pctc (=<I>Sh</I>) are almost the same. According to the crack closing mechanism described above, smaller <I>Ps</I><SUB>2</SUB> suggests larger SH. At a depth with smaller <I>Ps</I><SUB>2</SUB>, the variability of crack direction is small and <I>SH</I> is large. This result suggests that the variability of crack direction and <I>Ps</I><SUB>2</SUB> possibly give useful information for stress estimation.

収録刊行物

  • 資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan  

    資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan 113(2), p.107-114, 1997-02 

    The Mining and Materials Processing Institute of Japan

参考文献:  9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)
    10002283157
  • NII書誌ID(NCID)
    AN10062646
  • 本文言語コード
    JPN
  • 資料種別
    ART
  • ISSN
    09161740
  • NDL 記事登録ID
    4150599
  • NDL 雑誌分類
    ZP41(科学技術--金属工学・鉱山工学)
  • NDL 請求記号
    Z17-315
  • データ提供元
    CJP書誌  NDL  J-STAGE 
ページトップへ