The performance of an embankment on soft ground reinforced with geosynthetics and pile walls

The construction of high embankments on soft ground faces several challenges, such as potential bearing capacity failure, global slope instability, local failure, large total and/or differential settlements, and large lateral movement during both construction and post-construction periods. Horizontal geosynthetic reinforcement combined with vertical reinforcement using piles or pile walls can provide an economical and effective solution to ground improvement to support high embankments. This paper reports the results of a numerical study on the performance of embankments on soft ground with three different reinforcement conditions: (1) unreinforced, (2) reinforced with geosynthetics, (3) reinforced with both geosynthetics and pile walls. The influencing factors, such as the tensile stiffness of the geosynthetic, the number of geosynthetic layers, the elastic modulus of the pile wall, and the pile wall distance ratio, on the interaction of geosynthetic-pile wall-soil systems were investigated and the distribution and dissipation of excess pore water pressure in the soil were examined. The numerical results show that a combination of geosynthetic reinforcement and the pile walls was very effective for the improvement of soft ground. The numerical results were shown to be in good agreement with the field data observed at the end of consolidation.