Soil/Geogrid Behavior Subjected to Cyclic Loading

In addition to static loading, reinforced earth structures are generally subjected to cyclic loading generated from earthquakes and traffic loads. The mechanism of interaction between soils and geogrids under cyclic loading is one of the topics that receive continuous attention from researchers. This paper presents a summary of the results and analyses of a laboratory testing program carried out in a large-scale multi-function geosynthetic testing apparatus designed to simulate both static and cyclic loadings. The apparatus accommodates soil samples up to 1.0 m³ and could perform different tests under both static and cyclic loadings including direct shear on soils, pullout tests on geogrid sheets from soils, and uniaxial tension tests on geogrid sheets in an unconfined condition. A laboratory testing program was carried out to investigate the controlling factors affecting soil/geogrid behavior under cyclic loading. Different types of geogrids were used in the testing program. Different dynamic loading cases at different frequencies, load amplitudes, and static load levels (at which cyclic loading starts) were considered. Tests under static loading condition were also carried out. The behavior of soils/geogrids interaction under cyclic loading was investigated upon analyzing the results of the testing program.