A desiccated crust of overconsolidated soil commonly forms at the surface of compressible soil deposits. If a depression of the groundwater level occurs, the desiccation zone penetrates into the soil profile. At sites where the groundwater level has subsequently risen, a net overconsolidation will exist in the soil profile below the crust. Settlements of structures may be affected by the overconsolidation and by the ability of the desiccated layer to distribute surface stresses over the lightly overconsolidated soil below the crust. This paper presents the use of profiles of laboratory test results and observation of color changes within the soil profile as independent methods to evaluate the thickness of the desiccated crust and the amount of overconsolidation below the crust. The settlements of steel grain storage tanks founded upon alluvium exhibiting desiccation profiles at two sites in Western Iowa are presented. The net overconsolidation stress was estimated from the yield point of the load-settlement curve using elastic stress distribution methods. Estimates of the stress history of the project sites obtained through settlement observations are compared with estimates based on profiles of laboratory tests and color changes within the profile
