|
FELD PLACING TEST OF LIGHTWEIGHT TREATED SOIL UNDER
SEAWATER IN KUMAMOTO PORT
TAKAO SATOH , TAKASHI TSUCHIDA , KOJI MITSUKURI
and ZHENSHUN HONG
ABSTRACT: lightweight treated soil method has recently been
developed to reuse dredged soils as artificial lightweight geomaterials,
the density of which ranges from1.0 -1.2 g/cm3,
for coastal construction projects. In the two types of weight soils,
foam-treated soil (FTS) and bead-treated soil (BTS), the slurry of
dredged soil is mixed with cement air foam, or cement and EPS beads (the
diameters are 1 - 3 mm), respectively. The lightweight treated soil
method have been applied in several seaports and coastal airport
projects, but only in the sites at a level shallower than m to avoid
density change due to large water pressure and the possibility of
washout during underwater placing. In this study, full scale field
placing tests of lightweight soils were carried out at sites 10 m below
the sea level in Kumamoto Port with the purpose of investigating the
material properties of lightweight soils placed under deep water.
Especially the change of density through the process of mixing,
transportation, placing and hardening was examined in detail. It was
found that the lightweight soil method can be applied under sea water of
- 10 m, although part of the total volume of mixed foam or mixed
EPS beads is swept away during the construction process. However
wet-density of lightweight soil measured I year after the construction
was almost the same as that of a 28-day specimen, while the 1 year
strength was 40% larger than the 28-day strength.
key words: Ariake clay, cement, density, harbor, lightweight
soil, unconfined compressive strength (IGC: K12/D1O)
|
