Estimation of Strength Properties of Evaporitic Rocks from Their Quick-Measurable Physical Properties: A Case Study, Abu Dhabi City, United Arab Emirates

Estimation of rock strength like uniaxial compressive strength (UCS), indirect tensile strength (ITS), and point load index (PLI) is important responsibilities in various engineering applications. Rock masses are anisotropic, and the number of rock features highly influences rocks’ strength. Abu Dhabi, the capital of the United Arab Emirates (UAE), is sited upon evaporites and carbonate rocks that dominate the bedrock beneath the city. The evaporites have variable textures and structures strongly affected by the anthropogenic urbanization conditions, which lead to changes in the strength properties. In this study, to estimate the strength of evaporitic rock such as UCS, ITS, and PLI (Is(50)), a large number of UCS (257 samples), ITS (327 samples), and PLI (Is(50)) (357 samples) from 27 sampling locations were tested, and γn (natural unit weight) (989 samples), γs (saturated unit weight) (355 samples), and Gs (specific gravity) (989 samples), were measured. The linear and non-linear regression analyses were performed between the mean UCS–γs, ITS–γn, and PLI (Is(50))–Gs. The representative best-fit lines equations and the corresponding correlation coefficient, R values, were estimated. The relations between the mean UCS–γs, ITS–γn, and PLI (Is(50))–Gs are approximated with exponential and linear equations, and R values are 0.73, 0.57, and 0.62, respectively. Finally, this study proves that the strength properties can be estimated from their quick-measurable physical properties. Such findings can help engineers and decision-makers mitigate problems, especially during the preliminary design stage.