Development of Stress Measurement Method for Rock Mass under Severe Condition

恶劣条件下岩体应力测量方法的研制

• 批准号: 08555252
• 负责人: ISHIJIMA Yoji
• 金额: $ 11.58万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08555252/
• 关键词: Borehole Wall Deformation; Change in Borehole Diameter; Axial Strain; Shear Displacement; Coefficient of Sensitivity; Built-in Data Logger; Soft Rock; High Stress Zone; 孔径変化法; 孔軸方向のひずみ; 軟弱な岩盤; 硬岩; コアディスキング; 原位置計測; 地圧計測; 孔壁ひずみ; ダブルボアホール; 悪

In-situ stress measurement is usually cost and time-consuming and can be carried out for rock mass under limited good conditions. The chief investigator developed the theory of the borehole wall deformation method 25 years ago in order to make the measurement simple and to extend the applicable fields. The technology innovation in the measurement field enabled us to develop the stress probes for the borehole deformation method. The main results of the investigation are as follows :(1) The theory was re-examined and it was recognized that the calculation errors can be easily estimated and the probe can be used for rock mass that shows creep behavior since the observation equations are very simple ;(2) Two types of probe were developed. One measures the change in borehole diameter in three directions and the axial strain. Another measures the shear deformation in the two planes which are parallel to the axial direction. The three dimensional stress state can be determined by using these two probes in one borehole ;(3) The probes are mechanically tough and waterproof so that they are easily set at desired depth in a borehole even if is filled by water. The measurement can be carried out as soon as the probe is set with no waiting ;(4) A small built-in data logger was developed. It enabled us to eliminate the cable between the probe and the measurement system out the borehole. This made the possibility of troubles such as cable jamming etc. much less and deeper measurements enable ; and,(5) Stresses at a down hole in soft rock mass, uniaxial compressive strength of rock specimens is between 0.02 and 0.08 MPa, and at a high stress zone, where disking was observed, were successfully measured. This implies that the developed measurement method is suitable for the severe conditions.

原位应力测量通常是成本和耗时的，可以在有限的良好条件下对岩体进行。首席研究员开发了25年前钻孔壁变形方法的理论，以使测量简单并扩展适用的磁场。测量场中的技术创新使我们能够开发井眼变形方法的应力探针。研究的主要结果如下：（1）对理论进行了重新检查，并认识到可以易于估算计算误差，并且可以将探针用于岩体质量，该岩体显示出蠕变行为，因为观察方程非常简单；（2）开发了两种类型的探针。一种测量井眼直径在三个方向和轴向应变的变化。另一种测量了与轴向方向平行的两个平面中的剪切变形。可以通过在一个钻孔中使用这两个探针来确定三维应力状态；（3）探针在机械上坚硬且防水，以便即使被水填充，它们即使在井眼中的所需深度很容易设置。一旦设置了探针，可以在没有等待的情况下进行测量；（4）开发了一个小的内置数据记录仪。它使我们能够消除探针和测量系统之间的电缆。这使得诸如电缆干扰等问题的可能性更少，更深入的测量值可以实现。 （5）在软岩质量的下孔处的应力，岩石标本的单轴抗压强度在0.02至0.08 MPa之间，并且在观察到盘的高应力区域在高应力区域被成功测量。这意味着开发的测量方法适用于严重条件。

项目成果

Fujii, Y.: "A Study on Mechanical Backgrounds of Sheeting Joints in a V-shaped Valley" J.MMIJ.Vol.114, No.12 (in Japanese). 869-874 (1998)

Fujii, Y.：“V 形山谷中板材接缝的机械背景研究”J.MMIJ.Vol.114，No.12（日文）。

藤井義明: "あるV字谷におけるシーティングの力学的背景に関する研究" 資源と素材. 114・12. 869-874 (1998)

藤井义明：“V 形谷片的机械背景研究”资源和材料 114・12（1998）。