TITLE:
Quick Clay Development and Cation Composition of Pore Water in Marine Sediments from the Ariake Bay Area, Japan
AUTHORS:
Phanny He, Masami Ohtsubo, Hiroshi Abe, Takahiro Higashi, Motohei Kanayama
KEYWORDS:
Ariake Sediment, Salt Leaching, Quick Clay, Divalent Cation, Shear Strength, Sensitivity
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.6,
May
8,
2014
ABSTRACT: By
analyzing the cation composition of pore water in the soil samples of Ariake
Bay sediments, the present study assesses the development of quick clay by
leaching in both the original and seawater-saturated soil samples. Divalent
cations were dominant in the pore water of the original soil sample, whereas Na+ was the major cation in that of the seawater-saturated soil sample. The cation
proportion in the pore water for both soil samples remained the same after
leaching. The difference in pore water cation composition between the original
and seawater-saturated soil samples affected how their geotechnical properties
changed through leaching. The undisturbed shear strength of both soil samples
remained almost the same, but a large disparity between the soil samples was
observed in the remolded shear strength: it remained almost the same in the
original soil sample after leaching. Hence, sensitivity was not increased and
quick clay was not formed. However, in the seawater-saturated soil sample, the
remolded shear strength decreased to a great extent, and quick clay with a
sensitivity exceeding 700 developed. The lack of development of quick clay in
the original soil sample is attributed to the dominance of divalent cations in
the pore water, and the development of quick clay in the seawater-saturated
soil sample is ascribed to the dominance of Na+ in the pore water.