Cyclic Resistance, Pre and Post-Liquefaction Behavior of Dry Pluviated Silty Sands

Document Type : Geotechnical Earthquake Engineering




The cyclic resistance along with pre and postliquefaction behavior of mixtures of a saturated sand with varying amounts of a nonplastic silt are evaluated by cyclic triaxial tests, performed on undisturbed samples retrieved from calibration chamber and reconstituted samples prepared in laboratory utilizing dry pluviation method. Test results exhibit a clear trend between cyclic resistance and fines content in undisturbed specimens. The same trend is found in reconstituted specimens but with more scattering. Regardless of fines content, dilative behavior is observed in both types of specimens prior to liquefaction. Monotonic tests on reconstituted specimens also reveal the existence of dilative behavior. Indeed, increasing fines content would increase the post-liquefaction volumetric strain. The results of laboratory tests are also compared with cone penetration test (CPT) results. It is shown that strength reduction in CPT is much more than triaxial tests, when silt content is raised. Hence, fines tend to increase cyclic resistance ratio for the same normalized cone penetration resistance.