Prediction of brittleness index and determination of experimental correlation between physical and mechanical properties of limestone of TaleZang Formation in Hawasan dam basement

Determination of brittleness and geomechanical parameters, especially uniaxial compressive strength (UCS) and Young's modulus (ES), is required for designing and various applications of rock engineering. Evaluation of these parameters is a time-consuming, tedious and costly process requiring the preparation of suitable rock cores, therefore, experimental correlations are being used to predict the properties of rocks. In this study, to predict brittleness and determining the experimental correlation between physical and mechanical parameters of Talezang limestone formation, 74 rock core samples obtaining from 10 geotechnical boreholes with a depth of 70 m in the basement of Hawasan dam in dry and saturated conditions were used. After analyzing the descriptive statistics of the samples in SPSS 25 software, simple regression correlation relationships were approached based on the best fit between physical and mechanical parameters and according to multiple regression model, an experimental equation with coefficient of determination (R2 = 96) was applied to predict brittleness index of Talezang limestone. Finally, the obtained experimental equation based on the values of uniaxial compressive strength (UCS), Brazilian tensile strength (BTS) and compressive wave velocity (Vp) and statistical relationships between physical and mechanical parameters for determining the brittleness index (BI) in saturated conditions was compared with previous relationships in the literature. The results show that the accuracy of the statistical relationships presented is consistent with previous relationships.