ABSTRACT
The purpose of this investigation is to evaluate the differential settlements of a geogrid-reinforced slope founded on municipal solid waste. The geogrid-reinforced toe buttress was constructed in 1987 under the direction of the Environmental Protection Agency (EPA) in order to enhance the stability of the southeastern slopes of the Operating Industries, Inc. (OH) Landfill Superfund site. The landfill is located approximately 16 km east of downtown Los Angeles, in an area of high seismicity. The front of the approximately 4.6 m high, 460 m long toe buttress was founded on concrete piers. However, as the back of the reinforced slope was founded on waste, the structure has been subjected to more than 0.6 m of differential settlements since its construction. Finite element analyses were performed to evaluate the long-term integrity of the geogrid reinforcements under the loads induced by 30 years of additional differential settlements followed by the design earthquake. The calculated maximum strains in the geogrid reinforcements after the long-term static and design seismic loadings are well below the allowable strain, indicating that the integrity of the toe buttress should be maintained even when subjected to large differential settlements and severe earthquake loads.
