1331
Technical Committee 202 /
Comité technique 202
Table 2. Design parameter of secant pile walls (plate model)
Element
Type
EA
(kN/m)
EI
(kN.m
2
/m)
W
(kN/m
2
)
n
Secant pile
Elastic 1.2x10
7
3.6x10
5
14.4
0.15
Predicted magnitude of settlement was 0.39 m at the center
of the road, 0.40 m at the middle and of the road towards to
Tanjung Priok, and 0.38 m at the edge of the road towards
Tanjung Priok. The time required to reach the amount of
settlement is 6500 days.
Summary of settlement and time rate of 3 observation points
as mentioned above can be seen in Table 3.
Table 3. Comparation of settlement value at Sta. 3+750.
Settlement
Existing
Road
Corrugated
concrete
Secant Piles
At center line
0.36 m
0.29 m
0.39 m
At middle
0.41 m
0.33 m
0.40 m
At edge
0.47 m
0.36 m
0.38 m
Time (days)
6800
6900
6500
3.2 Zone 2: Sta 2+376 – Sta. 3+401
In this Zone, there is a section of the road that had been
strengthened by using sheet piles and stone works, while the
other have not exist handling. Construction sheet pile
implemented in 2011. This Zone is very vulnerable to both
submerged from overflow of Japat River and from the
surrounding environment (see Fig. 3), so raising works should
be considered to be implemented.
Analysis of proposed design in this zone is based on the road
cross-section at approximately Sta. 3+275. Design parameters
such as the friction angle, modulus of elasticity obtained by
correlating the CPT #5 on shore and CPT #17 off shore and
evaluation of laboratory tests on undisturbed soil samples in
BH6 at Sta. 3+150 and BH7 at Sta. 3+350.
The results of stability analysis of the existing road condition
indicating the road is relatively in critical condition due to FS =
1.09. Predicted magnitude of settlement were 0.40 m at the
center of the road, 0.51 m at the middle and of the road towards
to Tanjung Priok, and 0.64 m at the edge of the road towards
Tanjung Priok. The time required to reach the amount of
settlement is 580 days.
Therefore, some proposed trial designs were analyzed to
fulfill minimum FS as follow:
3.2.1 Corrugated prestressed concrete sheet piles
The first trial design to strengthen the road is by using
corrugated prestressed concrete sheet piles (see Table 1) to a
depth of 14 m (to sandy silt clay soil, firm to very firm).
To simulate the corresponding field condition i.e. water level
fluctuation, two modeling analysis were conducted, which are to
evaluate the influance of the highest water levels and the lowest
water level measured on the tides. The results of stability
analysis indicated FS = 1.15 at the highest water level, while FS
at the lowest water level is 1.08 with large moments working on
sheet piles 230 kN.m/m.
3.2.2 Corrugated prestressed concrete sheet piles +
horizontal bars
Alternative proposed design is by using concrete sheet piles (see
Table 1) and horizontal steel bars reinforcement (see Table 4)
placed across the road which binds sheet piles with continuous
slab constructed on the left side of the road. Stability analysis
indicates FS = 1.4.
Table 4. Design parameter of horizontal steel bars
Steel grade
Nominal
diameter
(mm)
Ultimate
stress
(MPa)
Cross
section
area (mm)
Ultimate
strength
(kN)
150
45
1035
1716
1779
Raising 0.7m should be performed at this Zone to prevent
the road submerged from overflow of Japat River and from the
surrounding environment. Stability analysis indicates FS after
raising is 1.3 with tensile force on a horizontal rebar is 176.7
kN/m. Predicted magnitude of settlement were 0.40 m at the
center of the road, 0.35 m at the middle and of the road towards
to Tanjung Priok, and 0.25 m at the edge of the road towards
Tanjung Priok. The time required to reach the amount of
settlement is 677 days.
3.2.3 Concrete sheet pile and ground anchor
Strengthening of the road with a combination of concrete sheet
piles (see Table 1) and ground anchor. The results of the
analysis by considering the road reinforced with sheetpile (type
5) combined with additional ground anchors with an inclination
from the horizontal of 40
o
. Giving prestressed ground anchor on
presstress modeled with extreme force drawn from the total
normal stress / FK, i.e. 211kPa / 3 = 70.33 kN/m/m. Extreme
total normal stress obtained based on the forces acting on the
parts that have the greatest displacement. The results of the
analysis showed that the stability of the road which is reinforced
with sheetpile and supplementary reinforcement combined with
ground anchors provide FS = 1.55.
Predicted magnitude of settlement was 0.40 m at the center
of the road, 0.35 m at the middle and of the road towards to
Tanjung Priok, and 0.25 m at the edge of the road towards
Tanjung Priok. The time required to reach the amount of
settlement is 702 days.
3.3 Zone 3: Sta. 3+400 – Sta. 3+860
Analysis of proposed design in this zone is based on the road
cross-section at approximately Sta. 3+750. There is a temporary
construction using bamboo and stone masonry. This location is
expected to potentially experience stability problems and
settlement.
Design parameters such as the friction angle, modulus of
elasticity obtained by correlating the CPT #9 on shore and
evaluation of laboratory tests on undisturbed soil samples in
BH9 at Sta. 3+750.
The results of stability analysis of the existing road condition
indicating the road is relatively in critical condition due to FS =
1.02. Predicted value of settlement during 4600 days was 0.60
m at the centerline, 0.68 m in the middle of the road directions
to Tanjung Priok, and 0.75 m at the edge of the road way to
Tanjung Priok. The time required to reach settlement is 4600
days.
As mentioned above, the existing road condition at Sta.
3+750 is in relatively unstable condition due to FS value = 1.02.
Therefore, some proposed alternative designs were analyzed to
fulfill minimum FS as follow:
3.3.1 Concrete sheet piles and ground anchor
Strengthening of the road with a combination of concrete sheet
piles (see Table 1) and ground anchor. The results of the
analysis by considering the road reinforced with sheetpile (type
5) combined with additional ground anchors with an inclination
from the horizontal of 40
o
. Giving prestressed ground anchor on
presstress modeled with extreme force drawn from the total
normal stress / FK, ie 91.15kPa / 3 = 30.38 kN/m/m. Extreme
total normal stress obtained based on the forces acting on the
parts that have the greatest displacement. The results of the
analysis showed that the stability of the road which is reinforced
