Long-Term Deformation of Soft Ground at a Trial Embankment Site and its Simplified Numerical Modeling

Ground deformation was monitored at the site of a 4m high trial embankment, as part of a highway construction project in Switzerland. The soil conditions included a complex stratification sequence with 7m of compressible soil located at shallow depth. The test embankment main purpose was to assess the magnitude of final settlement to be expected with the actual construction project. It served also as a benchmark to evaluate the applicability of various computation methods. The latter included classical one-dimensional consolidation theories and simplified numerical modeling of the trial embankment. In this paper, the site conditions, instrumentation program and performance of the embankment are described. The main features of the numerical model are summarized. Its outcome is compared to other methods of analysis and to observed deformation. Possible sources of discrepancy are discussed, including limitations of the simplified constitutive model and possible shortcomings of the instrumentation system.