J. Appl. Environ. Biol. Sci., 4(10)140-148, 2014 © 2014, TextRoad Publication ISSN: 2090-4274 Journal of Applied Environmental and Biological Sciences www.textroad.com *Corresponding Author: M. Akbari, Ferdowsi University of Mashhad, Department of Geology, Mashhad, Iran, E.mail: maj_akb486@yahoo.com Assessment and Classification of Rock Mass Properties in Iran Central Iron Ore Mines Majid Akbari 1* , Gholam Reza Lashkaripour 1 , Alireza Yarahamdi Bafghi 2 , Mohammad Ghafoori 1 1 Ferdowsi University of Mashhad, Department of Geology, Mashhad, Iran 2 Yazd University, Department of Mining Engineering, Yazd, Iran Received: June 9, 2014 Accepted: September 1, 2014 ABSTRACT In order to optimizing of the blasting operations,we need to evaluate rock mass properties in studying mines. For this purpose, three methods of line mapping, seismic refraction method and experimental tests were used. Properties of 7730 discontinuities were measured at 1780 meters long of the scanline. To determine V pf (the velocity of longitudinal waves in rock mass) 73 seismic profile was run at 1771 meters long of seismic profiles. Also for characterization of intact rock such as UCS (uniaxial compressive strength), UTS (uniaxial tensile strength), density, V pl (the velocity of longitudinal waves in intact rock) and Schmidt hardness, the standard tests were used. For Engineering assessment, rock mass was classified according to the RMR classification system. Finally, in addition to analysis of each parameter and present the results for studying mines, equations to estimate RMR based on the results of seismic survey and relationships to predict some properties of intact rock were developed. KEY WORDS: rock mass classification, RMR, seismic refraction methods, discontinuities, line mapping. 1. INTRODUCTION Various factors are influential in blasting operation results in superficial mines. Generally, we can classify them in three categories: rock mass properties, blast design parameters and explosive properties. Rock mass properties are among the most important variables influencing blasting results [1] -[5]. Two different rock masses, when subjected to identical blast geometry and energy input from explosives, will produce quite different degrees of fragmentation. This is because the rock masses have inherently different resistance to fragmentation by blasting and referred to as the blastability of a rock mass [3]. Firstly, to study the blastability in the study area needs to develop a strong database of effective parameters on blasting results. For this purpose, According to studies conducted by various people in this field, the required parameters selected and measured [3], [4] and [6] -[15]. In this research rock mass property by line mapping method, seismic refraction method and experimental tests were evaluated.Inline mapping method Discontinuity properties include orientation, spacing, persistence, aperture, roughness, waviness and infilling materials at 1780 meters long of the scanline were evaluated. By seismic refraction method V pf at 1815 meters long of seismic profiles was measured. For determining of intact rock properties include UCS, UTS, density, V pl and Schmidt hardness standard experimental tests were used. In engineering assessments to evaluate the effect of rock mass properties, we need to classify it. The RMR classification system was used for this purpose. Therefore RMR for the rock mass in studying areas was determined. Finally, relationships were developed to estimate RMR from seismic results. The complete database integrity in relationships for estimating the tensile strength and Young's modulus under uniaxial compression strength and the estimated values based on the velocity Schmidt hardness longitudinal cases in the rock presented. Also, to complement the database In case of lack of information, equations to estimate the tensile strength and Young's modulus based on uniaxial compression strength and equation to estimate Schmidt hardness based on V pl were developed. 2. GEOLOGY OF STUDY AREAS The studied areas consist of Choghart, Chadormalu, Sechahun iron stone mines. These mines located in Bafgh block in ferriferous zone of Anarak-Bafgh-Kerman. The geographical situation of study areas represented in Figure 1. From the geology point of view, Choghart ore deposit situated in Precambrian formations of central Iran (Morad series). This series had been affected by different changes such as metamorphism and metasomatism. The enclosing rocks of this ore deposit are mainly granite, quartz albitophyr and metasomatits. From the tectonic point of view in 140