Experimental Study for the Geogrid-Reinforced Embankment with Clay Cover Under Static and Cyclic Loading

This paper presents an analysis on a geogrid-reinforced embankment with clay-cover by model tests under static and cyclic loading. The deformation and failure surface inside the embankment were obtained by particle image velocimetry (PIV). The test results showed that geogrids effectively improved the ultimate bearing capacity and reduced the vertical settlement and lateral displacement of reinforced embankment. The reinforcement effect increased with the increase in geogrid length, and the ultimate bearing capacity of the embankment reinforced with the longest geogrid was 51.9 kPa, which was 79% higher than that of unreinforced embankment. The wrapped clay formed an effective lateral constraint on the outward movement of the slope soil under pressure. When the reinforced embankment was damaged, the internal displacement significantly reduced, and the sliding surface in the middle of the embankment pointing to the foot of slope began to move into the embankment in an arc shape. In the cyclic loading test, the stress concentration effect inside embankment reduced by geogrid reinforcement. During each cycle, the earth pressure varied with a stable half-sine wave. The conclusions drawn from this study can provide an important fundamental data for the construction in geotechnical and road engineering.