Response of overconsolidated kaolinites to salt-leaching Available to Purchase

Salt leaching from pores and chemical transformation of minerals in slip zones are some factors responsible for the reduction in shear strength of soft marine clays in the remoulded state. This study examines the influence of salt leaching from clay pores as a function of time on undrained strength and sensitivity of soft, overconsolidated kaolinites that were produced by slurry consolidation in conventional oedometers in a synthetic seawater medium. The overconsolidated kaolinite specimens (overconsolidation ratio = 1·2:4) were allowed to experience changes in pore salt concentration over periods ranging from 1 to 56 days at a vertical effective stress of 25 kPa. During this period, sodium and chloride ions migrated from the pore solution in response to osmotic gradients. Weakening of A–R forces from ion migration reduced the undrained strengths of the reconstituted specimens and enhanced sensitivity of the overconsolidated specimens.