A Validated Discrete Element Modeling Approach for Studying Geogrid-Aggregate Reinforcement Mechanisms

摘要

Geogrids are commonly used in transportation applications for stabilization and reinforcementpurposes. Factors affecting the interactions or interlock mechanisms between geogrids andaggregates may include but not limited to aggregate size and shape properties, geogrid typesand properties, compactive efforts during installation, and loading conditions. To betterquantify these effects, our recent research efforts at the University of Illinois have introducedthe use of an image-aided Discrete Element Modeling (DEM) approach for studying theinteractions of such local effects, i.e., aggregate particles and geogrid properties interacting atthe micro-level to produce a “stiffened or reinforced” zone. A recent experimental study wasutilized to model and demonstrate the effectiveness of different aperture-sized biaxial geogridsin the reinforcement of ballast aggregates to reduce settlement under cyclic loading. Theimage-aided 3-D DEM methodology successfully modeled the interactions between the ballastaggregate size and shape properties and the different aperture sized biaxial geogrids. Similar tothe experimental study, only certain biaxial geogrid aperture sizes improved the performanceof the reinforced ballast when compared to the larger settlement accumulated in theunreinforced ballast. The methodology has the potential for quantifying individual effects ofvarious geogrid products on aggregates with different size and shape properties.