Factors Affecting Liquefaction and Cyclic Mobility

Liquefaction is a phenomenon wherein a saturated mass of sand loses a large percentage of its shear resistance and flows in a manner resembling a liquid until the shear stresses acting on the mass are as low as its reduced shear resistance. Cyclic mobility is the progressive softening of a saturated sand specimen when subjected to cyclic loading at constant water content. Cyclic mobility has been observed in the laboratory. The writers believe that most observed cyclic mobility deformations in dilative clean sands are due to a test error, redistribution of void ratio, which is not representative of in-situ behavior. The manner in which soil type, confining stress, and initial consolidation stress ratio affect both liquefaction and cyclic mobility are shown by means of laboratory test results, for the purpose of permitting the reader to develop rational procedures for designing against the effects of earthquake loadings on soils.