Prediction of Engineering Properties of Sedimentary Rocks Using Ultrasonic Velocity Test

In the present research, geotechnical properties of some sedimentary rock samples were measured to assess the correlations between P wave velocity and mechanical properties. For this purpose, a comprehensive laboratory testing program was conducted after collecting nine various sedimentaryrock samples including limestone, travertine and conglomerate from north and northwest parts of Damghan, northern Iran. Based on mineralogy and petrography studies, the rock samples were commonly composed of quartz and calcite. Physical properties test showed that most of the samplesare moderate in dry unit weight and low to moderate in porosity. Ultrasonic velocity classification indicated that the P wave velocity values of the rocks are from low to very high. The mechanical properties including uniaxial compressive strength (UCS), point load Strength (PLS), Brazilian tensilestrength (BTS), and block punch strength (BPS) were determined by using prepared standard core specimens. In the following, empirical equations were developed by using simple regression analyses (SRA) between P wave velocity and the measured properties. The obtained results showed that all ofthe geotechnical properties are strongly correlated to P wave velocity with direct exponential relation and high regression coefficient between R = ۰.۸۳ to R = ۰.۸۹. It was found that the experimental models of this research provide acceptable equations for predicting the mechanical properties of the studied rocks.

Keywords:

Engineering properties , Sedimentary rocks , P wave velocity , Uniaxial compressive strength.