Investigation on the mechanical properties of a calcareous sand: the role of the initial fabric

Abstract

This study examines the effect of the initial fabric on the coefficient of the lateral earth pressure at rest K0, the undrained monotonic loading strength and the liquefaction resistance of a calcareous sand from a reclamation land in Persian Gulf. K0 consolidation, undrained compression and extension and cyclic undrained loading triaxial tests are performed on laboratory samples reconstituted by air and water pluviation, dry and moist tamping and dry funnel deposition methods. Test results show that the air pluviation and moist tamping samples own the highest and the lowest K0 respectively. All the samples at medium loose and medium dense states show strain hardening when subjected to undrained monotonic loading. The air pluviation samples are more contractive than the other samples at the phase transformation points and the moist tamping samples exhibit an over-consolidated behavior. In the cyclic loading tests, the air pluviation and the moist tamping samples exhibit the lowest and the highest liquefaction resistance. It is shown that the evaluation and comparison of the cyclic undrained strength of various sands should take the sample preparation method into consideration scrupulously. The test results also indicate that although the mechanical property of soil sample is influenced by the fabric differences induced by sample preparation method, other factors such as homogeneity and stress history should not be neglected.