EVALUATION OF CONSOLIDATION SETTLEMENT IN SOFT SOILS UNDER HIGHWAY EMBANKMENT: A COMPARATIVE STUDY BETWEEN ONE-DIMENSIONAL SETTLEMENT THEORY AND FINITE ELEMENT MODELING USING MODIFIED CAM-CLAY MODEL

ABSTRACT: Assessment of consolidation settlement under a highway embankment requires consideration in terms of variability in fill heights as well as clayey soil thickness and proprieties. Settlement calculation based on one-dimensional consolidation theory often relies on the evaluation of the critical section and assumes the applied load to be infinite in the x and z directions. Advanced solutions based on the modified Cam-Clay theory that evoke 2D and 3D finite element modeling and account for the stress distribution and volume changes during yielding as well as the geometric configurations of the studied area could result in optimized conceptions when light weight fill is required. This paper examines as a case study the consolidation settlement under an existing embankment on highway 50, in Quebec, Canada using 2D and 3D FEM modified Cam-Clay theory, to first validate the models against historical data. Then, the models are applied to design the new embankment of the adjacent north bound lanes where light weight fill will be required. The results obtained from these models are compared with those provided by the 1D consolidation theory.