FIELD PERFORMANCE OF A GEOGRID-REINFORCED EMBANKMENT

The field performance of a geogrid-reinforced levee test section built in Marrero, Louisiana, is discussed. The section was a full-scale model for a 1-mi-long levee built to protect a subdivision in Marrero from hurricane tidal waves. The section was built and monitored to assess the behavior of reinforced embankments on the extremely soft clays found in the Lower Mississippi Valley. The section was fully instrumented with inclinometers, settlement plates, and piezometers. Two rolls of geogrids were instrumented with strain gauges. Measurements were taken during and for a long period of time after construction. Field measurements included horizontal movements, vertical settlements, pore pressures, and strains in geogrids. Analyses of the data from the test section indicate that the geogrids allowed the use of smaller stabilizing berms. This conclusion was applied to the final design, resulting in appreciable savings. In addition, such large-scale tests are useful in developing design guidelines for the use of geosynthetics in protection levees in the Lower Mississippi Valley region.