IMPROVING SLOPE STABILITY ANALYSES BY USE OF 3D FEM FOR HIGHWAY EMBANKMENT WITH COMPLEX GEOMETRY OVER CLAYEY SOIL

ABSTRACT: In Quebec, highways are mostly constructed on clayey deposits. Embankments constructed on such compressible soft soils are further subjected to slope stability issues and require an in-depth understanding of the failure mechanism in order to choose the right analysis method. These embankments are sometimes constructed on highly fluctuated areas where 3D calculations are necessary in order to take the complexity of geometry and subsurface geology under consideration. The aim of this study is to compare the results of 2D and 3D analyses using Midas GTS NX and Soilworks. The construction of a north direction of highway 50 in Gatineau, Quebec, will be used as a case study. A large segment of the new highway will be simulated on the 3D model and compared to the chosen critical sections that were evaluated for the same segment using a 2D analysis.