Experimental study on stiffness properties of non-engineered clay and granular fills

摘要

Non-engineered fills are produced by human activity or natural occurrences. They can be placed without any controlled compaction effort or processing operation. In order to determine the stiffness properties of non-engineered fills, laboratory experimental studies have been performed and case history records are compiled. Some laboratory tests were conducted on poorly graded sand and fragmentary cohesive materials from a non-engineered fill made during canal excavation in the northern area of Iran. One-dimensional compression behavior of the fill materials was assessed and the deduced constrained moduli were compared with the results of other studies. Evaluation of case histories indicates that settlement caused from water infiltration into spoil fills may lead to excessive settlements. Moreover, in massive cohesive fills, hydro-compression settlement is significant. However, in loose granular fills, settlements due to dynamic loading and liquefaction can be substantial. Investigations revealed that, except for the cases with saturated cohesive materials, stiffness properties seemed to be a major aspect in comparison to the strength characteristics in geotechnical practice.