Document Type

Conference Paper

Publication Date


Publication Details

Robert Purser, Mutaz El-Amin Mohmoud, Mehdi Serati, Zhongwei Chen, Determining rock elastic parameters using a new true-triaxial-based technique, Proceedings of the 2021 Resource Operators Conference, University of Wollongong - Mining Engineering, 10-12 February 2021, University of Southern Queensland, 285-293.


ABSTRACT: Rock elastic parameters (e.g., elastic modulus and Poisson’s ratio) are the most critical design features in geotechnical engineering since intact and rock masses generally respond in an elastic fashion up to the yield point when under complex three-dimensional stress-strain states. For instance, when a low-porosity rock is subjected to a uniaxial loading condition, it responds elastically up to the Crack Initiation (CI) point which is defined as the onset of stress-induced damage after the closure of pre-existing cracks. The CI stress level can then be used as an estimate for designing a rock structure against in-situ spalling if the elastic properties of the material are known. However, measurement of elastic parameters for rocks could readily become very challenging when adopting conventional methods that heavily involve strain gauging of rock samples. This study proposes and investigates a new technique based on step-loading of a rock sample under true-triaxial (polyaxial) loading conditions to measure rock elastic parameters without strain-gauging. The results obtained with the new test method are first compared with the traditional techniques, and future work is suggested to validate the method further with anisotropic and orthotropic solids.