May 2006 newsletter I wrote for KPE project for Contract 423 stakeholders

1. Issue 4, May 2006Contract 423 - PIE to Ubi Road 2
the The Kallang/Paya Lebar Expressway (KPE) project is
Singapore’s most complex expressway project to date.
With 9 kilometres of underground tunnels to construct,
engineers have had to face challenges ranging from
deep marine clay valleys, a network of underground
utilities, tunnel construction under the operational
east-west MRT line, tunnel construction under the
Geylang River and under the Pelton Canal.

2. KPE Contract 423 scope of works covers the design,
construction and completion of a 2.96 km vehicular
tunnel from PIE to Ubi Road 2. A major part of the
works is located under the Pelton Canal.
ForContract423,thetunnelworksatthePeltonCanal
has offered the greatest challenge to the project
team. The Pelton Canal’s width is between 19 and 27
metres. The KPE tunnels when completed (including
the north bound and south bound carriageways)
measure 34 metres across. How do you construct
a sub-terrain expressway tunnel under a canal,
constrained on both sides by residential buildings,
the closest of which is only 4 metres away from the
excavation edge?
Figure 1 Figure 2
Figure 5 Figure 6
Bored piling works next to Blk 125 Aljunied Road

3. Figure 3 Figure 4
Figure 7 Figure 8
To solve this problem, a half-box tunnel construction method was adopted for building the
tunnel. To illustrate how we accomplished this task, let us focus on the Aljunied area. As
part of the preparation work for the diversion of Pelton Canal, diaphragm walls (concrete
retaining walls) are installed at the extremity of the future KPE north bound tunnel adjacent
to Blk 125 Aljunied Road (see figure 1). Centre sheet piles were then driven into the ground
to form part of the temporary works that are necessary to support the diverted canal.
A temporary canal with equivalent capacity of the Pelton Canal was constructed infront of
Blk 125 Aljunied Road. The water from the original Pelton Canal was diverted into the new
temporary canal (see figure 2). This frees up space for the installation of the diaphragm
walls in front of Blk 122 Paya Lebar Way (see figure 3). To further minimize soil movement
and ensure the robustness of the temporary works, transverse walls and centre diaphragm
walls were installed deeper than the KPE tunnel formation level (see figure 4).The transverse
walls, installed at 7m intervals, formed a rigid support structure to the diaphragm walls
along the whole excavation length. This was followed by bored pile installation to support
the tunnel box and excavation for the south bound half of the tunnel (see figures 5 & 6).

4. Figure 9 Figure 10
Figure 11 Figure 12
In March 2006, we completed the construction of the
KPE south bound tunnel in front of Blk 122 Paya Lebar
Way (see figure 7). We have now embarked on the
construction of the KPE north bound tunnel. The works
that are currently in progress or coming up include
the temporary diversion of the canal on top of the
completed tunnel in front of Blk 122 Paya Lebar Way
(see figure 8), the installation of bored piles, complete
installationofthenorthbounddiaphragmwallsandthe
removal of the diverted Pelton Canal structure adjacent
to Blk 125 Aljunied Road (see figure 9).
The removal of the canal involves the break out of the
temporary Pelton Canal structure adjacent to Blk 125
Aljunied Road. This will be carried out in May 2006.
We are mindful that during the works, there will be
an increase in construction noise, dust and vibration.
We shall carry out noise and dust mitigating measures
such as erection of noise barriers, installation of noise
monitoring equipment to measure noise level and
frequent wetting of the area so as to reduce dust. Noisy
breaking out works will be stopped by 7pm daily from
Mondays to Saturdays, and will not be carried out on
Sundays. Once the diverted canal has been removed,
the north bound tunnel will be excavated and
constructed (see figures 10 & 11). Once all the tunnels
are completed, the Pelton Canal will be reconstructed
back to its original position (see figure 12).

5. For the area between the Pan-Island
Expressway to Aljunied Road, excavation
and strut installation works are in full swing.
Tunnel construction works are expected to
be completed by early 2007, after which,
the re-instatement of the Pelton Canal and
Ajunied Road Bridge will be carried out.
The construction of the KPE tunnels
between Aljunied Road and Merpati Road
area are making good progress. The KPE
The basic structure of KPE Ventilation Building ‘D’ located at the junction of
Upper Paya Lebar Road and Airport Road has been completed
south bound tunnel structures, in front of
Blk 122 Paya Lebar Way were completed in
March 2006. Works are now in progress for
the construction of the north bound tunnel.
The tunnels in the Mattar Road area (from
Block 79/79A to just after the MacPherson
Community Club) have been completed
and construction of the new Pelton Canal is
now in progress.This canal will be reinstated
over the completed tunnels in this area in
May 2006.
ProgressUpdate

6. If you have feedback or
suggestions, please contact:
Mr Michael Yap,
Deputy Manager,
Community Relations,
Land Transport Authority
mobile: 9831 4546
tel: 6396 1600
email: michael_yap@lta.gov.sg
or
Mr Mohd. Zulkafli,
Public Relations Manager of
Samsung Corporation
mobile: 9635 5674
FEEDBACK
Land Transport Authority
No. 1 Hampshire Road, Singapore 219428
Customer Service Line: 1800 225 5582
Fax: 6396 1148
Website: www.lta.gov.sg
For the tunnel between Merpati Road and Paya Lebar Road area,
the KPE south bound half-box tunnels on the Balam Estate side has
been completed. Excavation and tunnel construction works for the
KPE north bound half-box on the Jalan Chengkek side is currently in
progress. The tunnel works in this area are expected to be complete
by early 2007 and the Pelton Canal will be reinstated to its original
alignment by the end of 2007.
Between Paya Lebar Road and Ubi Road 2, tunnel construction
works are substantially complete. Reinstatement of Airport Road to
its original alignment will begin from June 2006 onwards. The basic
structure ofVentilation Building‘D’at the corner of Paya Lebar Road/
Airport Road junction has been completed. Architectural as well as
Electrical and Mechanical (E&M) fit out works are now in progress.
ProgressUpdate
We would like to
thank all the residents
for their patience
and understanding
throughout the
construction of KPE.