Technical Note Calculation of Mohr-Coulomb Parameters for Rocks of Doha, Qatar

Among practitioners, designers and researchers, modern-day geotechnical software packages still predominantly use Mohr-Coulomb (MC) input modeling parameters, despite the immense computing power of today’s software and hardware. The same applies to this field of work in the State of Qatar. However, because the calculation of MC parameters for Qatari rocks has been inconsistent with varying results, this technical note aims to demonstrate the most appropriate derivation method for MC parameters. To do so, we must first obtain or estimate proper Hoek-Brown (HB) parameters, followed by an appropriate conversion method. Such an approach can remove the uncertainty and high variability of geotechnical estimations and design inputs. The technique demonstrated uses the approach of Hoek and Brown (Int J Rock Mech Sci, 34:1165–1186, 1997), presented in Appendix C. This method simulates triaxial tests using data-based estimated m_i values and is suitable because there are very limited valid triaxial test results for Qatari rocks.