Design and construction of a strain-gaged resin bolt for the measurement of in-situ axial loads

Technical Report · Thu Jan 01 04:00:00 EST 1976

DOI:https://doi.org/10.2172/5943524· OSTI ID:5943524

Sawyer, S. G.; Eakin, G. L.

The Roof Control Group of the Pittsburgh Technical Support Center, MESA, has designed and developed, and has employed in underground coal mines, a strain-gaged resin bolt for the in-situ measurement of axial loads. This instrumented bolt, which can be installed in cycle with regular fully, resin-grouted bolts, consists of a strain-gaged, 1-inch diameter, resin bolt that can be made in varying lengths up to 5 feet and when grouted in 1-3/8-inch holes in the mine roof, can record in-situ axial loads at any three preselected locations along the bolt's shaft. Specially designed, half Wheatstone bridges, powered by an intrisically safe strain box, give readings independent of the effects of temperature, humidity, bending, and torsion. The design and development of the strain-gaged bolt is discussed and the step-by-step procedure by which such a bolt can be constructed is given.

• Research Organization: Mining Enforcement and Safety Administration, Pittsburgh, PA (USA). Pittsburgh Technical Support Center
• OSTI ID: 5943524
• Report Number(s): MESA-IR-1039; ON: DE83902994
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420206* -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
440300 -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
COAL MINES
CONSTRUCTION
DESIGN
ELECTRIC BRIDGES
ELECTRICAL EQUIPMENT
EQUIPMENT
MEASURING INSTRUMENTS
MINES
MINING EQUIPMENT
ROOF BOLTS
STRAIN GAGES
UNDERGROUND FACILITIES