CYCLIC BEHAVIOR OF REINFORCED EXPANSIVE CLAY

R. R. AL-OMARI and W. K. ORAIBI

 ABSTRACT: The advantage of using geogrid reinforcement for the mitigation of swell during first flooding has been previously established. The performance of reinforced expansive clay undergoing cycles of wetting and drying is presently investigated using an apparatus principally similar to an enlarged oedometer. Soils of different plasticity indices were subjected to full swell-full shrink as well as full swell-50% Shrink cycles until reaching the steady state. The geogrid has been found to continue functioning throughout the cycles of swell and shrink. Increasing the geogrid stiffness reduced both the swell and shrink and the steady state band. Excluding the first wetting and drying cycle, the improvement factors for swell and shrink are almost the same and they may exceed 80% depending on the grid stiffness.

Key words: cyclic behavior, expansive soil, geogrids, laboratory test, soil reinforcement, swell-shrink (IGC: D5)