Borehole Stress Meter

IGI Bore Hole stress meter consists of a capsule having length 40mm and diameter 30mm. It has a hollow, steel cylindrical body having a vibrating wire tensioned across one diameter. The perpendicular diameter is wedged tightly inside a diamond drilled bore hole in the rock/ coal by a wedge platen assembly.

A custom designed tool is used for installing and prestressing the stress meter at the required depth and orientation inside the bore-hole.

The tool positions the stress meter inside a predrilled hole at the required depth and fixes it by the help of a wedge and platen assembly. The capsule is pre-stressed by the help of the same tool.

Bore hole stress meter is used specifically for monitoring stress changes in underground mines, hard rock and concrete structures. It also serves as a load cell when incorporated between steel members. Provision of gas discharge tube protects the sensor against surge and lightning.

General applications include

• In mines; roof, wall and pillar.
• Around tunnels and within linings.
• In underground storage chambers.
• In concrete structures.
• In foundations bearing plates and between girders.