net monitor perfectly even in the harshest of ... -...
Post on 19-Apr-2020
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00612 singapore 1/2
AT WORKBenjamin Sheares Bridge
NET monitor perfectly even in the harshest of conditions
water of Singapore River; plus, power consumption of all
equipment used must be kept to a bare minimum due to
the lack of constant power supply.
This project was the first use of NET for bridge movement
monitoring in severe environmental conditions. They have
few worries about the lifespan of the instrument and how
often it will break down, to troubleshoot the instruments.
To reach the instruments, workers had to hire a boat to
reach the pile cap where the instruments are installed. It
was also important to make sure the instruments would
not rust and stay durable an entire year.
Opened in 1981, the Benjamin Sheares Bridge is the
longest bridge in Singapore, spanning 1.8km. It is also
the tallest, at 20m. The bridge was named to honor Dr.
Benjamin Henry Sheares, the second president of the
Republic. Built over reclaimed land, the bridge is made of
pre-stressed concrete and links East Coast Parkway on
to Marina Bay on the west coast.
The Marina Bay Bridge across Marina Bay was officially
opened on April 24, 2010. There are two components to
the new bridge – a six-lane roadway for vehicle sand a
six-meter-wide curved pedestrian connection that
overlooks Marina Bay. The spiral-shaped pedestrian
bridge, called the Helix Bridge, is 280m long, while the
Bayfront Bridge, spanning 303m, was picked for the
parallel bridge for vehicles.
The Bayfront Bridge provides a direct connection
between Marina Centre and Marina South. The opening
of this new road network will provide vehicular access to
the upcoming developments in the Marina Bay area,
such as the Marina Bay Sands Integrated Resort Gardens
by the Bay and the Marina Bay Financial Centre.
Monitoring Solution Providers Pte Ltd, (MSP), was
involved in monitoring the movement of the Benjamin
Sheares Bridge and later, the Bayfront Bridge under Land
Transport Authority Contract 905.*
*Contract 905 is for the design, construction and completion of tunnels between Promenade Station and Marina Bay.
To carry on the project, MSP was requested to overcome
severe conditions: the monitoring instruments must have
high ratings in dust and water protection since the
instruments are placed on the pile cap that sat on the
http://www.topcon.co.jp/en/positioning/sokkia/
NET monitor movement affecting the Benjamin Sheares Bridge caused by boring works below the sea level
Helix Bridge
00612 singapore 2/2
AT WORKBenjamin Sheares Bridge
http://www.topcon.co.jp/en/positioning/sokkia/
monitoring perfectly. After year of monitoring, we can
attest that NET is a good and reliable product,” Lim said.
“MSP owns more than 80 NET instruments now. On our
customer concerns were whether MSP are able to deliver
and complete in time, with the NET 1m red laser guide
and Auto lock center, it gave us a lot faster without
looking into the instrument during teaching the prisms.”
Lim said: “With the combination of instruments and
customized software, we have a decided edge over our
competitors.”
NET is installed in the harsh conditions
Bay Front Bridge
Another major challenge for the NET system was the fact
there were no continue power supply on the pile cap; this
was the first time for the NET system to constantly
monitor a job site without continuous power. MSP
Engineer came up with a solution to take the public
lighting power which operates only form 7p.m. to 7a.m.
The engineer visited the monitor site every two weeks
with a control box that included PDA, battery charger,
power converter, timer, four car batteries with which the
PDA can last for two weeks.
There, software linked the PDA and server together for
downloading data and updating the software from the
instruments.
Kenny Lim, Managing Director of MSP, said, “For the
design of the instrument stand, we need to consider the
vibration created by the vehicles that travel on the bridge,
the heat, the sunlight sunlight and the rain. To reduce the
vibration, they place a 5mm rubber mat underneath the
instruments. To avoid the direct sunlight heat, they install
additional sleeves outside the stand with 20mm gaps to
allow the heat to escape. To be honest, we feel easy on
rain damage because the instruments are environmentally
rated to IP64. ”
After the installations, he said, “Our confidence in the
durability of the instruments increased because the data
processing team examined the data closely for the next six
months to ensure the accuracy was constant.
“A year later, we continue to observe the raw data to
make sure it still maintains the highest accuracy. Even
during periods of heavy rain the instrument were still
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