2D- and 3D-FEM modeling of rock masses at the Şilenkar viaduct site (NE Turkey) with regard to bearing capacity

The aim of this research was to examine the bearing capacity features of the rock masses at the site of Şilenkar viaduct which is a part of the highway substitution project at the Yusufeli Dam construction in NE Turkey. The rock masses at the study area are consisting of Late Cretaceous-aged micritic limestones and sandstones. Geotechnical analyses were conducted as part of the present study to include three phases as field and laboratory examinations, bearing capacity evaluations, and numerical analyses. The bearing capacity properties of the rock masses were examined via Hoek-Brown failure criterion-based empirical methods. A finite element method-based 2D and 3D models were used for defining the principal stresses and vertical displacements that make up at the level of foundation caused by viaduct building and traffic loads. A comparison was then made between the calculated bearing capacity values and the major principal stress values determined numerically. For this study, the 2D-FEM modeling gives realistic solutions compared to the 3D-FEM modeling. It was found that the major principal stress (σ: 2.10 MPa) is smaller than the allowable bearing capacity (q: 2.93 MPa). Furthermore, the vertical displacements at the level of foundations ranged between U: 0.058 and 2.04 cm. Based on the findings, it was concluded that no engineering problem may develop at the viaduct site with regard to bearing capacity. Lastly, in order to make a strong construction design, it is suggested that the 2D- and 3D-FEM modeling techniques by comparing their results should be combined together.