Hydroconsolidation Potential of Palouse Loess

Many loessial soils are susceptible to structural collapse due to inundation or a rise in ground-water levels near hydraulic structures. These soils are often classified as unstable without adequate testing, as has been the case with a loess formation found in southeastern Washington. A study was conducted to determine if spread footing foundations on Palouse Loess would experience additional settlement due to increases in moisture contents. The physical and mineralogical properties were examined and compared to the corresponding properties of loess found in the midwestern states. Modified consolidation tests were performed on undisturbed specimens to examine the effect of initial water content on the settlement characteristics. Test results indicate that increases in moisture contents do not result in excess settlements. The type of clay cementing loessial soils appears to be the determining factor.