Load transfer and arching analysis in reinforced embankment

Abstract

In a previous study, a series of 9 model tests performed on embankment models resting on soft clay treated with and without ordinary stone columns (OSC), encased stone columns (ESC), and with horizontal layer of geogrid at interface and at 0·1 h height has been carried out to investigate the behaviour of piled (stone columned) and geogrid reinforced embankments. In this paper, these tests are simulated numerically by the finite element method using the program Geostudio (SIGMA/W). Firstly, reanalysis was done of experimental work of embankment models constructed on soft clay treated with OSC and ESC. Secondly, embankment models reinforced by a horizontal layer resting on soft clay strengthened with OSC and ESC were analyzed. A horizontal layer of geogrid is embedded at different levels of embankment height. It was concluded that in the embankment models constructed on soft clay treated with stone columns at a spacing s = 2·5 d with length to diameter ratio L/d ratio = 8, the maximum bearing improvement ratio (qt/qunt) equals 1·33 for the ordinary stone columns and 1·59 for the encased stone columns and about 1·13 and 1·23 when one layer of geogrid is embedded at interface or at 0·1 h height, respectively.