Geotechnical numerical modelling; soil-structures interactions; failure mechanisms and design of column-supported embankments.

Project Background

The Federal Highway Administration has designated the column-supported embankment as a critical technology for accelerated construction. This technology overcomes difficulties commonly associated with construction on weak soils, such as prolonged construction time, excessive settlement and instability of the structure. Construction of embankments on poor soil will become increasingly frequent with plans to expand existing infrastructure. A number of initiatives, including new alignment of roadways, widening of existing roadways and new developments over weak soils will rely on the performance as well as the financial benefits provided by column-supported embankments. With the placement of stiff columns in a soft foundation, the embankment can be immediately constructed such that the cost savings of accelerated construction could potentially offset the initial cost of construction. In addition, the implementation of the technology avoids disturbance of contaminated soil and water, an important consideration for developments in contaminated sites.

Geosynthetic-Reinforced Column-Supported Embankment

The rational design of the embankment system is critical to its widespread application. Currently, the contribution of two key components of the system – the geosynthetic reinforcement(s) and the columns – are not fully understood, and thus they cannot be rationally and conservatively accounted for in design. My research goal is to conduct numerical modelling in FLAC3D to┬áinvestigate the geosynthetic influence in lateral spreading and stability. A better understanding of the soil-reinforcement interaction and the likely modes of failure can be applied to improve the design procedure, thus permitting more confident and cost-effective application of a critical technology.

This project is funded by the Center for Geotechnical Practice and Research (CGPR), a consortium of geotechnical industries affiliated with the geotechnical engineering program at Virginia Tech.