Improved Method and Apparatus for Testing the State of Stress in a Solid especially Soil

摘要

Apparatus for determining the stress in e.g. soil or rock, comprises a tapered cylinder of plastic material which has embedded in it a number of resistance strain gauges aligned in different directions to determine the magnitude and direction of the local stress. The cylinder is let into a borehole, secured to the wall by the same plastic material, and subsequently removed by cutting out a much larger core, the change in stress shown by the strain gauges being indicative of the initial stress in the solid.