不連続面の少ない中国の花こう岩地域での水圧破砕実験（第３報）　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

• 新 孝一

  (財) 電力中央研究所地質地盤部

• 李 方全

  中華人民共和国国家地震局地殻応力研究所

• 大久保 誠介

  東京大学工学系研究科地球システム工学

書誌事項

タイトル別名

• Hydraulic fracturing experiment in granitic rock with scarce joints in China(3rd Report). Characteristics of Initiation, Reopening and Closing Behavior of Hydraulic Fractured Crack.
• スイアツ ハサイ ニ オケル キレツ ノ ハッセイ ト カイコウ ヘイゴウ ノ
• Hydraulic fracturing experiment in granitic rock with searce joints in China (3rd Report)
• 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)

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 SH, the mean and the variability of hydro-fracturing tensile strength T 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 Pctc 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 Ps₂ is observed. Considering the crack-closing process, Ps₂ should be larger than (3Sh-SH)/2 while Pctc is equal to the minimum compression stress Sh.<BR>In this experiment, different values of Ps₂ have been observed at two depths while the values of Pctc (=Sh) are almost the same. According to the crack closing mechanism described above, smaller Ps₂ suggests larger SH. At a depth with smaller Ps₂, the variability of crack direction is small and SH is large. This result suggests that the variability of crack direction and Ps₂ possibly give useful information for stress estimation.

収録刊行物

• 資源と素材

  資源と素材 113 (2), 107-114, 1997

  一般社団法人 資源・素材学会

キーワード

• 水圧破砕
• 岩盤応力測定
• シャットインカーブ
• 最弱リンク説
• 亀裂方向のばらつき

詳細情報

• CRID: 1390001206016015104
• NII論文ID: 10003705987
• NII論文ID: 10002283157
• NII書誌ID: AN10062646
• DOI: 10.2473/shigentosozai.113.107
• ISSN: 18806244
• ISSN: 09161740
• NDL書誌ID: 4150599
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4150599
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可