Morgenstern and Tchalenko (1967) pointed out that the microstructure
of a soil mass generally has two components: inherent
structure and shear-induced structure, which both have
a significant influence on the deformation and strength properties
of soils. Inherent structure has its origin in the composition
of the sediment and its sedimentary history. For remolded
soil, especially sands, the inherent structure is directly
related to the method of specimen preparation. Ladd (1974)
and Miura and Toki (1982) indicated that different specimen
preparation methods resulted in significantly different behavior
in terms of both peak strength and postpeak strain softening
being observed. To evaluate the effect of specimen preparation
methods on interface test results, air pluviation, vibration, and
tamping methods were used in the present study. Test results
indicated that specimen preparation methods had almost no
influence on the measured peak interface friction coefficient.
Generally, the air pluviation method can yield the most uniform
specimens, while those prepared by tamping are more
likely to be nonuniform. For a relatively smooth interface surface,
only the particles near the interface surface are expected
to be involved in the interaction between the interface and the
sand. The contribution due to the structure of the whole specimen
is negligible. However, if the interface surface becomes
significantly rougher, more and more particles in the specimen
(not limited to the particles near the interface surface) may be
involved in the shearing process, and the effect of the structure
may become more significant