Numerical modeling of a highway embankment using geofoam material as partial fill replacement

Geofoam material has been used as a partial replacement for conventional fill material in a highway embankment in Texas, USA, to mitigate bridge-approach slab settlements. The embankment under current focus was constructed more than a decade ago and has experienced nearly 405 mm (16 in.) of settlement since its construction. Several treatment methods were attempted in mitigating the settlement, which were proven to be ineffective. One of the primary causes of the settlement was attributed to embankment and its self-weight. To reduce the weight, part of the embankment fill was replaced with a lightweight EPS geofoam material. This site was extensively instrumented with horizontal inclinometers at different locations for monitoring the settlements after rehabilitation. Settlements occurring in the field have been monitored periodically. To understand the settlement patterns occurring in the field and also to identify the long-term performance of this section, numerical and analytical hyperbolic modeling were attempted. Both these models are used to predict the approximate long-term settlements. Prediction results indicate that the settlements predicted by the hyperbolic model are higher when compared with the same predicted by numerical model.