Initial Stress Measurements in Rock using a Conical-Shaped Strain-Gage Cell

使用锥形应变计测量岩石的初始应力

基本信息

批准号：
02650344
负责人：
KOBAYASHI Shoichi
金额：
$ 1.28万
依托单位：
Kyoto 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

项目摘要

As a result of this research, we proposed a new convenient and efficient method for measuring initial stresses in a rock using only one conical-ended borehole applying a newly-developed conical shaped strain-gage cell at the bottom of It in conjunction with the overcoring technique and testified the usefullness of the proposed method at a site of an underground power house. The main achievements are as follows :1)On measurementsa)We determined accurately the stress-sensitivity coefficients(strains due to the unit initial stress)for the conical-end shape and conical-end shape with a small hole ahead of it(the improved version)by use of the boundary element methods.b)We determined the observation equations for arbitrary numbers of measured strain components using the least-squares method.c)We proposed a method for determinig accurate stresses from the strains measured at only one borehole.2)On instruments and implinqntationa)We proposed an efficient strain measurement technique at the bottom of the conical-end of a borehole by using a newly-developed conical-shaped strain gage cell having 12 components with 6 cross-gages equidistantly-spaced on the surface of the shell.b)We proposed a technique to control the vertical direction of the strain-gage cell at the conical-end borehole using an unboned-type strain-gage accelogeter.c)We developed a diamond-solded bit for shaping the conical end of a borehole.d)Improving the suibel of the boring machine, we made it possible to measure strains during the progress of boring.e)An improvement was made for recognizing the rock state behind the conical-end of a borehole simply boring a small-sized hole ahead of the conical-end(an improvement).

这项研究的结果是，我们提出了一种新的方便，有效的方法，用于测量岩石中的初始应力，仅使用一个圆锥形的钻孔在其底部使用新开发的锥形应变型细胞，并与过度锻炼技术结合使用，并证明了地下动力房屋的提议方法的有用性。主要成就如下：1）在测量中），我们准确确定锥形末端形状和圆锥形形状的应力 - 敏感系数（由于单位初始应力引起的菌株），并通过使用边界元素的方法确定了最小的prosecon方法，以确定最低的脉动方法，以确定最低的限量方法，以确定其在其前方的小孔（改进版本）（改进的版本）。 2）在仪器和inmplinqntationa上，我们提出了一种有效的应变测量技术，该技术是在钻孔的圆锥形末端的底部通过使用新发育的圆锥形应变量规格的圆锥形末端的圆锥形末端，该圆锥形的应变量规格具有12个成分，该分量具有12个跨度元素的固定元素，以在壳体上进行均等型，以控制壳的表面。 c）我们开发了一个钻石售出的位，以塑造钻石孔，以塑造钻孔的圆锥形末端。d）提高无聊机器的Suibel，我们使您有可能在无聊的过程中衡量毫无疑问的岩石。锥形末端（改进）。