A Study on the Methods for Measuring In-situ Stresses at Great Depth by Use of Boring Cores

岩心大深度地应力测量方法研究

• 批准号: 02805076
• 负责人: MATSUKI Koji
• 金额: $ 0.9万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02805076/
• 关键词: In-situ Stress Measurement at Great Depth; Rock Core; Anelastic Strain Recovery Method; Differential Strain Analysis Method; コアの損傷; 非弾性ひずみ回復コンプライアンス

Anelastic strain recovery method (ASR method) and differential strain analysis method (DSA method) have been theoretically and experimentally investigated in order to enhance the reliability of the methods for measuring in-situ stresses at great depth. The main results obtained in this study were summarized as follows :1. ASR method(1) Anelastic strain recovery compliance (ASRC) ranges widely depending on the rock type. The ASRC in shear mode is greater than that in volumetric mode.(2) The ASRC of rocks depends on the mean stress. The mean stress increases the ASRC in shear mode and decreases that in volumetric mode.(3) A method for measuring three-dimensional in-situ stresses from anelastic strain recovery of a rock core has been proposed without assumptions except that the rock is isotropic and visco-elastic material.(4) The directions of principal in-situ stresses and the ratio of principal stress deviations in Yunomori district, Iwate Prefecture, have been successfully measured with the method developed in this study.2. DSA method(1) The physical Meaning of the crack parameters used in DSA method for measuring in-situ stresses have been clarified by theoretical consideration.(2) A testing system, whose main component is a pressure vessel of the capacity of 180 MPa, was constructed and the standard testing procedure for differential strain analysis has been established.(3) In-situ stresses have been evaluated by DSA method for the boring cores which were taken by over-coring technique for measuring in-situ stresses. The results from DSA method were not always consistent with those from over-coring methods.(4) The increase of crack parameters due to uniaxial tensile stress is not large enough compared to that measured by DSA for the rock speciments from in-situ. This suggests that the inconsistency described above is due to pre-existing cracks in the specimens.

为了提高大深度地应力测量方法的可靠性，对非弹性应变恢复法（ASR法）和差分应变分析法（DSA法）进行了理论和实验研究。本研究的主要结果总结如下：(1)非弹性应变恢复柔度（ASRC）随岩石类型的不同而变化很大。剪切模式下的ASRC大于体积模式下的ASRC。(2)岩石的ASRC取决于平均应力。在剪切模式下，平均应力增大ASRC，而在体积模式下，平均应力减小ASRC。(3)提出了一种从岩心非弹性应变恢复中测量三维地应力的方法，除了假设岩石是各向同性和粘弹性材料外，没有任何假设。(4)利用该方法成功测量了岩手县Yunomori地区的主地应力方向和主应力偏差比。(1)通过理论分析，阐明了DSA法测量地应力中裂纹参数的物理意义。(2)构建了以容量为180 MPa的压力容器为主要部件的试验系统，建立了差分应变分析的标准试验程序。(3)对采用过取心技术测量地应力的钻孔岩心，采用DSA法计算了地应力。DSA法的结果并不总是与复盖法的结果一致。(4)单轴拉应力对岩石试件裂纹参数的影响，与原位DSA测量结果相比，增加幅度不够大。这表明上述不一致是由于试样中预先存在的裂缝。

项目成果

松木 浩二: "コアを用いた地圧計測法の現状と展望" コアを用いた地圧計測ワ-クションプ論文集. 1-7 (1991)

Koji Matsuki：“使用岩心的土压力测量方法的现状和前景”《使用岩心的土压力测量工作手册》论文集 1-7 (1991)。

Matsuki, K. et al.: "In-situ stress measurements at Yunomori district, Iwate Pref., with ASR and DSA methods (in Japanese)" Proc. of Spring Meeting of MMIJ. (1992)

Matsuki, K. 等人：“使用 ASR 和 DSA 方法在岩手县汤之森区进行现场应力测量（日语）”Proc.

松木 浩二: "岩石の非弾性ひずみ回復特性と三次元地圧計測法" 第8回岩の力学国内シンポジウム講演論文集. 297-302 (1990)

松木浩二：《岩石非弹性应变恢复特性及三维地压测量方法》第八届全国岩石力学学术研讨会论文集297-302（1990）。

Matsuki, K.: "Anelastic strain recovery of rocks and three-dimensional in-situ stress measurement (in Japanese)" Proc. of 8th Japan Sympo. on Rock Mechanics. 297-302 (1990)

Matsuki, K.：“岩石的滞弹性应变恢复和三维原位应力测量（日语）”Proc。

志水 俊仁: "DSAによる地圧計測法について" 資源・素材学会平成3年度研究発表講演要旨集. 311-312 (1991)

Toshihito Shimizu：“关于使用 DSA 的地面压力测量方法”日本资源材料学会 1991 年研究报告摘要 311-312 (1991)。