Compressibility of Field Compacted Clay

摘要

The compressibility of a plastic Indiana clay (St. Croix) is studied for both laboratory and field compaction. This interim report deals with the field compacted phase. Conventional oedometer tests were performed on a field compacted plastic clay to determine the effects of water content, dry density and compaction pressure on the as-compacted and soaked compressibility behavior. As-compacted samples were incrementally loaded; of particular interest was the value of compactive prestress induced during the compaction process. Environmental changes due to increased saturation were simulated using a back pressure technique. Of interest was the one-dimensional percent volume change of wetting under load. Statistical analyses were performed to establish the best predictive models for prestress and one-dimensional percent volume change on wetting, in terms of the important compaction variables. The field compacted relationships are similar to the laboratory compacted relationships developed by DiBernardo (1979), involving the same variables, exponents and signs. Predictions of field compacted relationships from laboratory tests can be accomplished for soils which are somewhat different by using plasticity index ratio.