Statistical Analysis of CAI Variability Among Rock Types

The Cerchar Abrasiveness Index (CAI) is widely used in rock mechanics and excavation engineering to assess rock abrasiveness, which influences tool wear and excavation efficiency.Understanding how CAI varies across different rock types (igneous, metamorphic, and sedimentary) is crucial for optimizing machine selection and excavation methods.This study conducts a statistical analysis of CAI values obtained from existing literature to identify variations among different rock origins and specific rock types, including granite, basalt, sandstone, clay, and marble.Using descriptive statistics, Analysis of Variance (ANOVA), and post-hoc tests, we evaluate whether statistically significant differences exist between these categories.The methodology includes data collection from published sources, normalization of CAI values, and statistical calculations using SPSS software.ANOVA is applied to test differences between rock groups, while Tukey's HSD post-hoc test determines specific group differences.Additionally, boxplots and histograms are used to visualize CAI distributions, and correlation analysis explores relationships between CAI and rock properties such as Uniaxial Compressive Strength (UCS) and density.Findings are expected to show that igneous rocks (granite, basalt) have higher CAI values due to their mineral hardness, while sedimentary rocks (sandstone, clay) exhibit lower abrasiveness.Metamorphic rocks (marble) may show intermediate values due to mineral recrystallization.The results provide practical implications for excavation tool selection, wear prediction, and cost estimation in the mining and tunneling industries.This study contributes to the quantitative understanding of CAI variability, offering insights for geologists and mining engineers to enhance excavation efficiency and reduce operational costs.