Arup recently installed its revolutionary ‘damping’ system for The St. Francis Shangri-La Place in the Philippines. The new system, which minimises the standard wobble in high-rise buildings, employs the same technology used to strengthen the Millennium Bridge in London. With this system installed, The St. Francis Shangri-La Place isn’t just the country’s tallest residential building; it is also one of the safest.
“The swaying of tall buildings is a perennial issue caused by high winds and even earthquakes,” says Rob Smith, Associate, Arup. “We’ve worked to find an economical and effective solution to the problem and are delighted that the new technology developed by Arup is being put into practice in a high rise building for the first time today.”
The usual methods employed to strengthen buildings are to reinforce it with significant extra structure or to install tuned mass dampers. Both methods are not only expensive, but also make the building stiffer and heavier while consuming valuable space. The Arup solution works by inserting Viscous Dampers into the St. Francis Shangri-La Place to act as energy absorbers and damp out vibrations. Not only is this a lower-cost solution, it is also more sustainable as it uses less material, and leaves more valuable space inside the building.
Smith explains, “If you imagine designing a fast car, you would not necessarily make it stiff and rigid but you would give is a smart suspension system. Arup’s damping system works in a similar way – it is an agile and intelligent solution to controlling the issue of motion in a building.” Such a solution will give greater safety and peace of mind to residents of the St. Francis Shangri-La Place.
The St Francis Shangri-La Place was commissioned by The Shang Grand Tower Corporation. It is located in the Shangri-La Place integrated community in Mandaluyong City, Philippines. Completion is set for early 2009.
Further information on dampers
All tall buildings will sway sideways due to wind and other exterior forces. While this movement is safe and expected, it needs to be controlled to maintain comfort inside the building. To do this, engineers make bigger columns and walls or install "supplementary damping". Supplementary damping reduces the motion felt by residents in the same way as a car's suspension makes the trip more comfortable on rough roads.
There are many ways to add damping to a building. An established technique is to use a "tuned mass damper" which is a large pendulum at the top of the building. Taipei 101 (currently the world’s tallest complete building) uses this system. The system used in the St Francis Shangri-La Place is the "Damped Outrigger System". Developed by Arup it has several advantages over the tuned mass damper - it is smaller, more effective and more-suited to seismic regions.
Viscous dampers are very similar to shock absorbers found in cars. But instead of damping motion caused by bumps in the road, they damp the motion caused by buffeting winds and other forces. Dampers have been used successfully in some of the world’s most famous buildings. The most famous of which was the World Trade Center in New York, which had thousands of dampers installed. Many buildings in California and Japan use dampers to control movement during earthquakes.
The 32 dampers used in the St Francis Shangri-La Place have been manufactured by FIP Industriale of Italy. They are highly engineered and durable products designed to last.