Evaluation of RMR89 Geomechanical classification based on RQD, UCS, and Discontinuity Characterizes in the Dardvey of Sangan iron ore mine

Hafezi Moghadas, Naser; Rahili Khorasani, Leila; Lashkaripour, Gholamreza; Ghafoori, Mohammad

doi:10.22034/jiraeg.2026.552739.1360

Evaluation of RMR89 Geomechanical classification based on RQD, UCS, and Discontinuity Characterizes in the Dardvey of Sangan iron ore mine

Articles in Press

Document Type : Original Article

Authors

Naser Hafezi Moghadas ¹

Leila Rahili Khorasani ²

Gholamreza Lashkaripour ¹

Mohammad Ghafoori ¹

¹ Ferdowsi university

² Ferdowsi university st.

10.22034/jiraeg.2026.552739.1360

Abstract

Dardvey mine is located in the central part of Sangan area. Dardvey fault which is one of branch of Darooneh fault has caused intense tectonic deformation.This study aims to develop a surface geomechanical model using RMR89 classification that based on, the rock mass conditions can be evaluated during the exploration and extraction stages. For this purpose initially, core drilling data were collected, and the Rock Quality Designation index was measured for 220 samples. In addition Uniaxial Compressive Strength measured on 27 samples. Subsequently, the discontinuity characteristics of mine surveyed at 11 field stations.

Subsequently, the RMR89 classification rating was then calculated for each geological unit, and with using ArcGIS software, the RMR scores were implemented on the digital elevation model and then categorized accordingly.

The surface plans of both the optimistic and pessimistic RMR89 models Showed that the largest area corresponds to the RMR class of 40–61 that Due to the expansion of the ore zone with the highest RMR scores and its increasing distance from the main Dardvey fault, the rock quality and strength improve towards the north to northeast. So, this helps to make the pit walls more stable at steeper angles and do not require expensive stable operation. And On the other hand the presence of discontinuities in the weaker layers of the western part caused to a reduction in the consumption of throwing explosives, such as boosters, in blasting operation although crushed zone increase cement and casing cost in exploration and maintenance cost in extraction.

Keywords

RMR geomechanical model

RQD

UCS

joint characters

Sangan iron ore mine

Subjects