Correlating physico-mechanical properties of intact rocks with P-wave velocity

The physico-mechanical properties of five different intact rock types including sandstone, arkoses and limestone were determined through standardized laboratory tests. Ninety six specimens were tested to obtain the relationships between P-wave velocity (V-p), dry unit weight (DUW), uniaxial compressive strength (UCS), point load index Is(50), Brazilian tensile strength (TS), porosity (Phi), and Schmidt hardness (RN). This study also reviews some recent correlations between P-wave velocity and physico-mechanical properties as well as investigates the reliability of these correlations. Findings show the results of the experimental tests are in good agreement with previous studies. Statistical equations have been determined for estimating the physico-mechanical properties of rocks using nondestructive and indirect test methods. Results of regression analysis showed satisfactory correlations. Based on the results, new strong correlation with correlation coeffecients above (R-2 > 0.80) are introduced for predicting the UCS, Is(50), Phi and RN and reasonable good correlations (R-2 >= 0.78) are introduced to predict TS and DUW from P-wave velocity of different intact rock core samples. There is a discrepancy between P-wave velocity (Vp) in situ values with laboratory results. The large reductions in Vp in situ values are clearly the functions of fractures and natural joints.