Performance Monitoring of a Rammed Aggregate Pier Foundation Supporting a Mechanically Stabilized Earth Wall

Abstract

The use of rammed aggregate pier (RAP) foundations for support of retaining walls and earth fill embankments has increased in recent years to become a geotechnical solution for rapid construction of earth structures in soft ground conditions. A nominal 6-m mechanically stabilized earth wall was constructed over piers installed in relatively compressible soil to investigate the performance of RAP foundation elements in terms of stress-deformation and settlement behaviors for such applications. Geotechnical instrumentation consisting of total earth pressure cells, settlement plates, and vibrating wire piezometers was installed within the pier elements and at the foundation surface for short- and long-term monitoring of pier response. Monitoring data indicate: (1) mobilization and concentration of vertical stress on pier elements and matrix soil; and (2) load transfer response for the boundary condition associated with support of geogrid-reinforced earth fill. The practical implications of the experimental research findings are briefly discussed.