Effective Stress Coefficient of Rock for Peak and Residual Strengths

• Project/Area Number: 26420840
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Earth system and resources engineering
• Research Institution: Hokkaido University
• Principal Investigator: Fujii Yoshiaki 北海道大学, 工学研究院, 教授 (70192309)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2014: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 岩石 / 有効応力係数 / ピーク強度 / 残留強度 / 有限要素法 / ピーク応力 / MFEM / 多段階三軸圧縮試験

Outline of Final Research Achievements

Modified Failure Envelope Method was developed and applied to some types of rocks. Effective stress dependent-effective stress coefficient was evaluated with the method which coefficient can represent failure envelope by effective stress. The modified method is better than conventional Failure Envelope Method because the modified method neither requires assumed failure envelopes nor trial and errors. The evaluated coefficients were formulated as a function of total stress and pore pressure, and installed in a finite element code. Stress severity around a underground rock cavern was analyzed and it was confirmed that stress severity was more precisely evaluated with the effective stress dependent-effective stress coefficient than conventional approaches.

Research Products

• [Journal Article] A New Approach to Evaluate Effective Stress Coefficient for Strength in Kimachi Sandstone (2015)
  • Author(s): Dassanayake, A.B.N., Fujii, Y., Fukuda, D. and Kodama, J.
  • Journal Title: J. Petrol. Sci. Engng. Volume: 131 Pages: 70-79
  • DOI: 10.1016/j.petrol.2015.04.015
  • NAID: 120006313407
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Formulation and Implementation of Effective Stress Coefficient of Rock to FEM (2016)
  • Author(s): Fujii, Y., Dassanayake, A., Alam, A.K.M.B., Fukuda, D.
  • Organizer: 平成28年度資源・素材関係学協会合同秋季大会
  • Place of Presentation: 岩手大学（盛岡市）
• [Presentation] Significant Differences in Effective Stress Coefficient for Rocks within Elastic Region and Peak and Residual Strengths (2014)
  • Author(s): Dassanayake, A. B. N., Fujii, Y., Fukuda, D. and Kodama, J.
  • Organizer: ARMS8
  • Place of Presentation: Sapporo, Japan
  • Year and Date: 2014-10-14 – 2014-10-16
• [Presentation] 岩石のピーク応力と残留強度における有効応力係数の値とそれらの応用 (2014)
  • Author(s): 藤井義明・Dassanayake Anjula・福田大祐・児玉淳一
  • Organizer: 資源・素材2014（熊本）
  • Place of Presentation: 熊本市
  • Year and Date: 2014-09-15 – 2014-09-17
• [Presentation] Biot’s Effective Stress Coefficient of Rocks for Peak and Residual Strengths by Modified Failure Envelope Metho (2014)
  • Author(s): Dassanayake, A. B. N. and Fujii, Y.
  • Organizer: EUROCK 2014
  • Place of Presentation: Vigo, Spain
  • Year and Date: 2014-05-27 – 2014-05-29