2973
Container Terminal on Soft Soil
Terminal de conteneurs sur un sol mou
Popovic N., Stanic B.
OpusGEOd.o.o., Zagreb, Croatia
ABSTRACT: This paper analyzes soil - structure interaction and effectiveness of soil improvement through the back- analyses based
on measurements conducted on the example of a new container terminal in the port of Ploce. The terminal was built on part of the
Neretva River delta, which is dominated by Quaternary sediments represented by delta deposits over 100 m thick, accumulated over
carbonates. Coastal construction is based on bored vertical reinforced concrete piles and hammered steel battered piles. Storage areas
(fibre-reinforced concrete slabs) are located behind the coastal structure, and they are founded on soil improved by vibrated stone
columns. Construction of container terminal was divided into four main phases. Each phase of the project is analyzed through
interactive collaboration of construction designers and geotechnical designers. The applied measurement system consisted of geodetic
and geotechnical measurements - geodetic points, vertical inclinometers-deformeters in the vertical piles, horizontal inclinometers,
vertical deformeters, tiltmeters and load testing of piles. Works were success fully completed and verified by test loads.
RÉSUMÉ : Cet article analyse l’interaction sol – structure et l'efficacité de l’amélioration des sols en utilisant une analyse en retour,
basée sur des mesures effectuées sur le cas du nouveau terminal à conteneurs du port de Ploče. Ce terminal a été construit sur une
partie du delta du fleuve Neretva dont le sous-sol est constitué par des sédiments quaternaires formés des dépôts deltaïques de 100
mètres d'épaisseur, surmontant une base calcaire. La construction repose sur des pieux forés en béton armé et des pieux en acier
inclinés. La zone de stockage des conteneurs du terminal (dallage de béton renforcé de fibres), située en retrait des constructions
côtières, est construite sur les colonnes ballastées. La construction du terminal à conteneurs a été divisée en quatre grandes phases.
Chaque phase du projet est analysée grâce à la collaboration entre les ingénieurs de génie civil et les ingénieurs en géotechnique. Le
système de mesures utilisé comportait des mesures géodésiques et géotechniques : points de contrôle géodésiques, tassomètres et
inclinomètres dans les pieux verticaux, inclinomètres horizontaux, tassomètres verticaux, capteurs de rotation et tests de charge des
pieux. Ces travaux ont été réalisés avec succès et puis contrôlés lors de la mise en oeuvre des tests de charge.
KEYWORDS: Container terminal, soft soil, bored vertical piles, vibrated stone columns, field mesaurements, back analyses.
1 INTRODUCTION
The container terminal is located in the Port of Ploče, which is
situated in a part of the large Neretva River Delta. Quaternary
deposits represented by delta sediments, accumulated over
limestone paleorelief dominate in this area. The thickness of
Quaternary deposits exceeds 100 m. Deposits have different
grain size distribution. One contrasting environment in the
vertical geological profile is represented by gravels, and partly
sands.
The coast for containers is a surface structure at the level
+3.0 m a.s.l., of width 27.4 m and berth length of 280.0 m. The
coastal structure is divided in three segments by length. The
total length of coastal structure is 88.6 + 102.8 + 109.5 = 300.9
m. The coast is 15.1 m in depth, for vessels of bearing capacity
up to 60,000 DWT and draught of 13.5 m. The coastal structure
is founded on drilled reinforced-concrete vertical piles (Benoto)
of nominal diameter 1,500 mm, and on hammered steel battered
piles of diameter 812.8 mm. Vertical piles end in a layer of
gravel at the depth of -44 m a.s.l. They are made in single sided
formwork from -20 to -44 m or double sided steel formwork
down to the depth –20.0 m. Axial distance of piles in
longitudinal direction is 7.1 m and in the transversal 8.0 m (four
pile rows along coast width).
Storage and traffic surfaces are located behind the coastal
structure. Pavement structure consists of fibre-reinforced
concrete slabs which are founded on soil improved by stone
columns. Stone columns are of 110 cm diameter on a grid 2x2
m to 2.8x2.8 m, of depth down to -15 m a.s.l., i.e. -20 m a.s.l.
COASTAL CONSTRUCTION
280
23,4 60,4
27,4
60,4
30,5
STORAGEAREA
MEASURING PROFILE -PRELOADING
MEASURING PROFILE -PILES
Figure 1 Plan view of the container terminal.
As a part of site investigations, a total of 27 CPT probes were
made and 7 boreholes on an area of 15 ha. The lengths of CPT
probes range from 22 m to 43 m, while the lengths of boreholes
were from 42 m to 58 m. Out of in-situ testing in boreholes,
vane tests and standard penetration tests were performed.
Laboratory tests included the following: testing of grain size
distribution, direct shear test, consolidated undrainedtriaxial
test, etc.
2 GEOTECHNICAL SOIL PROFILE
Through implementation of geotechnical investigations and
laboratory tests, the following geotechnical soil profile in the
area of the container terminal was established:
Surface layer is represented by siltysand and low
plasticity silt, of thickness 8 m.
Under the surface layer, clays of low to high
plasticity dominate. This layer is 25 m thick.
Low plasticity silt to sand, poorly graded.
Well-compacted gravel of layer thickness 10m.
Gray to gray-green clay of stiff consistency.
