Liquefaction and postliquefaction behavior of low plasticity silts using cyclic triaxial tests

A considerable amount of research has been conducted on the strength of both clays and sands, while research on low plasticity silt has been limited. The objective of this experimental study is to evaluate the cyclic behavior and liquefaction potential of low plasticity silts. The cyclic behavior of sand-like and clay-like soils have been compared to the cyclic behavior of low plasticity silts. The soil used in the study program has been obtained from the Mississippi River Valley and consists of modified loessial silt deposits with a plasticity index of about 6. In order to achieve a soil fabric similar to what occurs in natural deposition, samples have been consolidated from slurry inside a large consolidometer and inside a split mold using top and bottom loading. The liquefaction potential of the low plasticity silt specimens have been evaluated using cyclic triaxial tests. The effects of stress history, confinement pressure, anisotropy, and plasticity have been evaluated in order to better understand their cyclic behavior. The study extends to post liquefaction analysis and strength characteristics of liquefied silt. Finally, laboratory CPT and Vane Shear tests were conducted and the results were compared to triaxial test results --Abstract, page iii