Stress Distribution in Basal Geogrid Reinforced Pile-Supported Embankments Under Seismic Loads

Basal geosynthetic reinforced pile-supported embankments are proven as the more appropriate ground improvement technique for constructing embankments for roads over very soft clay deposits and approach roads or embankments to bridges. Numerous experimental and analytical works are available on the soil arching phenomenon of geosynthetic reinforced piled embankments subjected to static loading conditions. This study attempts to evaluate the stress distribution and soil arching in geosynthetic reinforced pile-supported embankments subjected to seismic excitations. Time-history analysis has been performed on the basal geogrid reinforced pile-supported embankments by varying the height of embankment and tensile modulus of geogrid. Analyses of results show that for alpha (the ratio of height of embankment to pile centre to centre spacing) less than or equal to 4.5, a geogrid tensile modulus of 3000 kN/m is sufficient to withstand vertical stresses due to earthquakes. And for the considered embankment height and pile diameter when alpha nearly equal to 4.5, differential settlements are very less irrespective of seismic excitations.