Assessment of Geo-Mechanical Characteristics of Carbonate Rocks Using Non-destructive Pulse Velocity Measurements

Abstract

Abstract Determining the geomechanical characteristics of the rock formations is critical to the design and analysis of various underground geotechnical structures. This research applied an experimental approach to determining the properties of rock cores based on ultrasonic wave velocities. Three types of carbonate rocks sampled from three different regions were thus experimentally tested and evaluated, with the regions from which the rock samples were collected being located in south-eastern, south-western, and north-eastern areas of Iraq. The geomechanical characteristics of the carbonate rocks were compiled based on ultrasonic pulse velocity tests and uniaxial compressive strength tests implemented under two sets of laboratory testing conditions: dry and saturated. The data are thus reported and discussed for both dry and saturated rock specimens. In general, the results showed a reduction in rock engineering properties with increasing moisture content. The measurements of compressional and shear wave velocities were analysed and correlated with various mechanical properties including: strength, elastic moduli, bulk density, Poisson’s ratio and Lame’s constant; the results of this process revealed that there is a strong correlation between velocity measurements and rock engineering properties. Several statistical relationships with high degrees of regression coefficient are thus proposed to efficiently the evaluate geomechanical properties of carbonate rocks based on compressional and shear wave measurements.