368PRELIMINARY SUPPORT DESIGN FOR A HAMROROAD TUNNEL: A CASE STUDY IN THE ROAD OF SANANDAJ - MARIVAN WEST IRANThis paper presents the results of rock masses engineering characteristics and tunnel support design studies, carried out at the road of Sanandaj - Marivansite, west of Iran. The road tunnel will be driven in rock mass, consisting of sandy limestone and dark gray shales aged Lower Eocene and Paleocene. Studies respectively performed in both field and laboratory. Field studies in both include discontinuity surveying, core drilling and sampling for laboratory testing. Laboratory studies were performed on core specimens taken from the boreholes, in order to determine the physical and mechanical properties of the main lithotypes. Empirical and numerical methods were used for tunnel design. The tunnel grounds were divided into 12 sections with respect to the rock mass geological engineering properties. Rock masses were characterized using Rock Mass Rating (RMR), Rock Mass Quality (Q) and Geological Strength Index (GSI) system, the tunnel ground support types, categories were determined according to the RMR and Q-system. The interaction of the recommended support systems by empirical methods with the rock masses were analyzed by two dimensional universal distinct element code(Dips, Unwedge). It was seen that empirical and numerical approaches showed similar results. This indicates that more reliable support design could be achieved by using the numerical method along with the empirical methods.ghafoori@um.ac.inResearch5112015Rock mass,Support,Classification system,Engineering characteristicsShiri M,Ghafoori M,LashkaripourG MSc Student, Ferdowsi University of Mashhad, Department of Geology, Mashhad, Iran, Professor, Ferdowsi University of Mashhad, Department of Geology, Mashhad, Iran., Professor, Ferdowsi University of Mashhad, Department of Geology, Mashhad, Iran.