Studies on the Performance of Geogrid Reinforced Soil Walls with Compressible Inclusion

In the present study, the concept of placing compressible inclusion behind the reinforced zone of geogrid reinforced soil walls was explored through finite element modeling approach. Centrifuge model tests on geogrid reinforced soil walls with two different vertical spacing of reinforcement layers were conducted in a geotechnical centrifuge by increasing gravity from 10g in intervals of 5g up to 75 g or failure, whichever occurred earlier. A wrap around technique was used to represent a flexible facing and in order to initiate rupture failure in reinforcement layers, ratio of the length of the reinforcement layer to the height of the wall was maintained as 0.85. Marker based digital image analysis was adopted to compute straining of geogrid reinforcement layers with an increase in gravity level. Further. finite element models were developed for these two centrifuge models and compared with centrifuge test results. Thereafter, the effect of compressible inclusions having low density and thickness ranging from 0.02 to 0.2 times the height of the wall on the stability and deformation behavior of geogrid reinforced soil walls was analyzed using a geotechnical finite element code. Geofoam inclusions were placed just behind the reinforced zone vertically. The analysis and interpretation of centrifuge and finite element analyses results indicate that the thickness of geofoam is vital in improving the performance of geogrid reinforced soil walls.