Based on four FLAC3D modeling case studies, this webinar presents the numerical modeling approach and importance of considering strain compatibility (relationship between the deformation of the reinforcing elements and the surrounding soil mass) when evaluating rigid inclusions (concrete or grouted columns) for ground improvement.

The main takeaways from the webinar will include that:

1. rigid inclusions effectively reduce vertical settlements but are weak against lateral loads;
2. combining rigid inclusions with stiff horizontal constraints (e.g., steel rebars, not geogrids) is more cost-effective;
3. isolated columns beneath embankments require a horizontal distribution system at the top to prevent localized failures;
4. simplified analyses based on force equilibrium are obsolete and, most of the time, lead to a misleading measure of perceived safety; and
5. relying mainly on the global Factor of Safety (FoS) oversimplifies performance, leading to overdesign or hidden risks. For example, a high FoS does not ensure serviceability, especially when excessive deformations make structural supports unusable.

This webinar is presented by Augusto Lucarelli (Principal Engineer, ITASCA Minneapolis). Mr. Lucarelli has a background in soil mechanics, numerical modeling of geotechnical processes, shallow and deep foundation design, soil improvement, slope stability, mechanized excavation, conventional tunneling in urban areas, deep excavation, and support structures in difficult environments.