Prediction of Uniaxial Compressive Strength (UCS) of Sakesar Limestone in Salt Range - Pakistan by Indirect Methods

ABSTRACT—Intact rock specimens are routinely tested in the laboratory for uniaxial compressive strength (UCS) which is an important design parameter in rock engineering. However, laboratory measurement is always expensive and time consuming and is generally not available as part of the small projects. Alternatively, indirect tests are relied to estimate UCS of various rocks through developing simple correlations among the results of uniaxial compressive strength (UCS) and indirect tests on the same rock. In the present study, efforts were made to make such correlations for Sakesar Limestone of Central Salt Range. In the study cored rock specimens were tested for UCS tests, Point Load tests (PLT) and Schmidt Rebound Hammer Tests (SRHT). All the tests’ results were analysed using statistical techniques to find their interrelationships. The developed relations indicated strong correlations between UCS and Point Load Index (PLI), and UCS and Schmidt Rebound number (Rn).From these relations, UCS is predictable from PLT and SRHT with a reasonable precision.