Volume 2, Issue 1 — Year 2025 — Article e100026

Narges Hayati¹; Mohammad Khaleghi²

1. Department of Geology, Shiraz Payam Noor University, Shiraz 1743638565, Iran
2. Department of Geology, Urmia University, Urmia 5756151818, Iran

Rock Quality Designation (RQD) is a widely recognized empirical method for quantifying and describing rock mass quality and durability, extensively utilized by geotechnical experts. RQD plays a critical role in designing and constructing support systems, as well as in assessing the stability of rock masses for surface and subsurface construction projects. Accurate RQD values are essential for ensuring reliable and effective designs in civil engineering applications. This study focuses on developing an empirical RQD modification tailored for sandstone formations in Isfahan Province, Iran. A comprehensive field survey was conducted, involving the collection of 75 rock samples from 25 stations, alongside detailed field measurements of rock masses to estimate RQD values. The calculated RQD values were further employed to evaluate geomechanical classification indices specific to the sandstone formations in the region. The findings of this study provide valuable insights into the geotechnical properties of Isfahan's sandstone formations, offering improved accuracy in RQD estimation and enhancing the reliability of designs for civil engineering projects in similar geological settings. These results contribute to optimizing support system designs and ensuring stability in both surface and subsurface constructions.

Rock mass classification, Empirical RQD, Isfahan sandstone, Geotechnical assessment, Rock mechanics