Point Load Strength Index

The Point Load Strength Index Test is a rapid and convenient method for estimating the strength and fracture toughness of rocks.

A sample of rock is mounted between two conical loading rams and a uniaxial load is applied incrementally until failure of the sample occurs. The peak applied load is used to calculate the Point Load Index, which can then be correlated to uniaxial compressive strength.

Equipment: Analog Point Load Test Apparatus (Hemmer)

Reference Standard: Recommendation Nr. 5 (Working group 3.3. German Geotechnical Society)