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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

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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