For geogrid-reinforced soil walls and slopes, most of the design guidelines require use of clean granular material as backfill soil. Considering the high cost, limited availability and transportation problems related with clean granular fill, use of locally available marginal fills (predominantly granular materials containing significant percentage of fines) is becoming a challenging topic for design and construction of geogrid-reinforced soil walls and slopes. Although marginal fills are known to have poor drainage and shear strength characteristics, they can provide environmental benefits in terms of saving natural resources (such as sand and gravel), reduced construction waste and waste disposal cost, sustainability, reduced carbon footprint and life-cycle assessment of projects. Recent research and applications indicate that granular soils containing fine grained materials can also be successfully used as backfill material as long as adequate drainage is provided in the body of the structure. There is a lack of consensus in the current practice of design and analysis for the reinforcement of predominantly granular material which has high fines content (marginal material). The objectives of this study are to present a review on the definition of a marginal fill and fill material selection criteria used around the world, together with presenting examples of case studies of using marginal fills in GRSWS.
Menu