Understanding Geogrid-Stabilised Soils using DEM

Dr. John P. Morrissey, Research Fellow at the University of Edinburgh presents at the 2024 ATCx DEM.

Geosynthetics have been utilised in the construction industry for decades and have been increasingly used to stabilise foundation subbases and ballasted trackbed in construction. Whilst there have been some previous studies of geogrid stabilisation and reinforcement, there is still a significant lack of understanding of the soil-geogrid interaction and the mechanisms involved. The current design methods with geogrids are also largely empirical and do not consider the actual soil-geogrid interaction at the particle level which has the potential to provide important insights to support geogrid technological development.

The complex soil-geogrid interactions are quite difficult to study experimentally and traditionally were beyond the capabilities of DEM as the problems were both complex and computationally expensive. Recent developments such as new physics, coupling methods and GPU computing have made these problems more tractable, while advances in analytics allow us to interrogate the simulations in greater detail than ever before, helping to extract new knowledge about the complex interactions and move geogrid design away from the empiricism of its early years.

In this presentation I will describe some of the challenges faced in simulating geogrids and present some simulation results which demonstrate the insight that can be delivered from utilizing DEM by highlighting the key mechanisms that lead to enhanced strength and stability in the granular soils.