BOREHOLE STRESS-METER AND METHOD AND APPARATUS FOR THE INSTALLATION THEREOF

摘要

A borehole stress-meter includes a resiliently radially expandable hollow body within which can be positioned a gage plug having strain gages fixed thereto. The interior section of The hollow body is tapered, as is the gage plug so that advancement of the gage plug within the hollow body will cause the gage plug to become prestressed. The hollow body can be inserted into a bore drilled in earth material whose stress is to be measured by an installation or setting tool. Subsequently, the gage plug is advanced within the hollow body so as to prestress the gage plug. The setting tool is then removed and stress may be measured by an appropriate strain indicator. 132/sjh