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Evaluation of the Performance of Road Embankments over North Jakarta-Soft Soils
Évaluation de la performance de remblais routiers sur les sols mous du Nord de Djakarta.
Murjanto D., Rahadian H., Hendarto
Directorate General of Highways, Ministry of Public Works, Indonesia
Taufik R.
Institute of Road Engineering, Ministry of Public Works, Indonesia
ABSTRACT: R.E. Martadinata road located in North Jakarta is a 7.3 km long - arterial road connecting the Tanjung Priok Port and
the Western part of Jakarta. It was initially built 30 years ago crossing over the reclamation of Ancol area. Its structure consisted of
the embankment with flexible pavements over North Jakarta-soft alluvial deposit which is classified as CH-MH soil based on USCS
classification system. To compensate settlement, the pavement level was raised several times. The first embankment failure is 100 m
long, occurred at KM 2+250 in September 16, 2010 at 03.16 AM. This collapsed segment was already repaired. However, another
indication of an embankment failure appeared at Km. 4+100 m in March 2011. To avoid another possible failure, a more
comprehensive stability and settlement analysis of the road embankment using a more detailed site investigation was conducted. This
paper presents geotechnical data collection, geotechnical characterisation, geotechnical analyses at 4 zones which probable prone to
stability and settlement problems, and some proposed design to strengthen the road embankment.
RÉSUMÉ : La route R.E. Martadinata, située au nord de Djakarta est une artère longue de 7,3 km reliant le port de Tanjung Priok et
la partie occidentale de Djakarta. Elle a été construite il y a 30 ans dans la zone Ancol gagnée sur la mer. Sa structure se composait de
remblai surmonté de chaussées souples, sur les dépôts alluviaux mous du nord de Djakarta, classés comme sols de type CH-MH selon
la classification USCS. Pour compenser le tassement, le niveau de la chaussée a été rehaussé à plusieurs reprises. La rupture d’un
premier remblai de 100 m de longueur s'est produite au PK 2+250 le 16 septembre 2010 à 3h16. Ce tronçon effondré a déjà été réparé.
Cependant, d’autres signes de rupture de remblai sont apparus au PK 4+100 en mars 2011. Pour éviter une nouvelle rupture
potentielle, une étude plus approfondie de stabilité et de tassement a été entreprise, basée sur une reconnaissance géotechnique plus
détaillée. Cet article présente la synthèse des données géotechniques, la caractérisation géotechnique, les analyses géotechniques de 4
zones sujettes à des risque de rupture et de tassements, et quelques unes des mesures préconisées pour renforcer le remblai.
KEYWORDS: slope stability, settlement, raising, lightweigth material, ground anchore
1 INTRODUCTION
R.E. Martadinata road which was originally constructed over 30
years ago is an arterial road linking the Tanjung Priok port in
northen part of Jakarta and the western part of Jakarta. Along
7.5 km of this road, from Simpang Lodan to Gate 3 of the port,
consists of embankment which lies over soft deposit aluvium
soil classified as CH soil based on USCS classification system
and flexible pavement.
The first collapse of a road embankment of R.E. Martadinata
Road occurred at Km 2+250 on September 16, 2010.
Investigation indicates that the road embankment failure was
significantly triggered by the riverbed and slope embankment
scour coupled with the decline in sea water level which was
suspected to be at the lowest level at the failure (Rahadian et al,
2011). The raise of pavement thickness also contributes to
reduce the factor of safety (FS) value. The rehabilitation of this
collapsed road was successfully done by Ministry of Public
Works.
On March 2011, another potential collapse of a road
embankment occurred at KM 4+100. In order to investigate
potential problems that will lead to failure, an extensive site
investigation was carried out.
This paper presents stability and settlement analysis, and
geotechnical data collection for detailed engineering design to
prevent potential loss due to the collapse of Martadinata Road.
Numerical analyses of four zones were performed by using
Plaxis software.
2 SITE CONDITIONS AND SOIL PROPERTIES
Soil parameter determined from both field and laboratory
testing. The field investigation consists of traffic volume survey,
topography and bathymetry survey, tidal measurements, 14
bored holes and 17 Cone Penetration Tests (CPT on shore) on
road embankment, 35 CPT tests in Japat River (CPT off shore)
parallel to the road (Institute of Road Engineering, Ministry of
Public Works. 2011). Soil borings were carried out on the
shoulder of the road towards Tanjung Priok while tests on the
road lanes towards West Jakarta were not done due to
insufficient space. CPT tests were done both on the road and the
Japat River.
Based on the drilled bore logs and CPT, the soil beneath the
road up to 30m deep is classified into 4 layers (see Fig. 1). On
top is a quite thick layer of alluvium clay deposit to a deep of
about 11 m-16 m with the cone tip resistance qc values are
around 784 kPa. Beneath this layer, a layer of sandy silty clay
with average 4 m thick. The third layer is a layer of dense sand
with the average thickness about 8 m with the cone tip
resistance qc values are around 4923 kPa. The last layer is a
layer of sandy silty clay founded between 25 m and 30 m deep.
A 1m- lens of dense sand also founded between 28 m – 29 m
deep at BH 10.
