CENTRIFUGAL TEST ON REINFORCED EMBANKMENT WITH LIME-STABILIZED SOIL AS BACKFILL ON SOFT CLAY

Two centrifugal tests of reinforced and unreinforced embankments with lime-stabilized soil as backfill on soft clay with vertical drains were performed to investigate the reinforcement mechanisms and effects.The instruments used to measure displacement,pore water pressures and earth pressures were installed;and the strain gauges were glued with epoxy resin on the surface of the model with geogrid.The following test results are achieved.(1) Compared with the unreinforced embankment,the settlement of reinforced embankment is reduced approximately by 8%;and the heave of the reinforced embankment foundation is observed,whereas unreinforced embankment dominantly shows settlement.(2) Pore water pressures in the foundations of reinforced and unreinforced embankments are basically similar;and during each loading break,pore water pressures are obviously dissipated.(3) Earth pressures under embankment base are distributed uniformly due to geogrid reinforcement.Earth pressures under central part of the reinforced embankment are 6%–10% less than those of unreinforced embankment,whereas earth pressures under the slope toes of the former are approximately 40% greater than those of the latter.(4) Tensile forces in the model geogrid have a good changing law with the acceleration increasing.During loading break,tensile forces increase,which is consistent with the settlement changing law.The distribution of the tensile forces shows uniform until the reinforced embankment is loaded up to 2 m in height.Afterwards,the tensile forces at the central part obviously increase more than those at two sides.(5) An idea to add geosynthetics to the embankment′s lime-stabilized soil is proposed so as to improve its tensile strength,which also makes the embankment more stable.