Empirical and numerical analyses of support designs for Kömürhan tunnel (Elaziğ)

Empirical and Numerıcal Analyses of Support Desıgns for Kömürhan Tunnel (Elazığ)In this study, the geotechnical properties of rock mass in route of the Kömürhan Tunnel, planned to be constructed as a double tube between 1+458-3+869 kilometers of the ElazigMalatya highway, were investigated. Kömürhan Ophiolities aged Upper Cretaceous are cropped out in route of the tunnel. Field studies and laboratory tests were carried out to determine geotechnical properties of these ophiolities. Engineering properties of discontinuities in the rock mass were determined by scan-line survey method; Rock Quality Design (RQD) and weathering degree of the rock mass were determined by examining borehole cores. Also, geophysical studies along tunnel route mass were realized to determine dynamic properties of the rock. The rock mass in route of the tunnel was classified according to the RMR, RMi, and GSI classification systems by using data obtained from field and laboratory studies and thus preliminary support design of the tunnel was designated. In order to determine the optimum support systems, numerical analyses of support systems obtained from RMR and RMi classification systems were evaluated. As a result of the numerical analyses, optimum support systems were suggested for the tunnel. Excavatability property of the rock mass was investigated using results obtained from laboratory tests, scan-line survey and geophysical studies and the rock mass is classified according to the excavatability classifications proposed by different researchers. According to these classifications, excavatability class of the rock mass in tunnel route was determined as very hard ripping-blasting requiredKey Words: Excavatability, Finite Element Method, Rock Mass Clasification Systems, Numerical Analysis