Evaluation of rock property variability

Rocks are natural geo-materials, whose properties are affected by many spatially-varying factors, such as the properties of their parent materials, weathering processes, and discontinuity conditions. Engineering properties of rocks therefore vary spatially and exhibit significant variability. To evaluate rock property variability, an extensive literature review is performed in this study to collect data reported in literature for igneous, sedimentary and metamorphic rocks during the last several decades. The typical ranges of rock property data, mean values and coefficient of variations of rock properties are evaluated and summarized. These typical ranges of rock properties can be used as guidelines for approximation when rock property data are not available at a project site. Furthermore, they can be used as prior knowledge when developing Bayesian framework for quantifying the variability of rock properties at a specific project site.