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HEAD HEAD
1. DANGEROUS
BUILDING FAILS
2. MORE DANGEROUS
Leaning Tower of Pisa
Palau de les Arts Reina Sofia
Soft ground and poor foundations caused the Italian bell tower to lean during construction. Work was halted for nearly 100 years.
3. MOST DANGEROUS
Valencia’s opera house looks visually stunning but has fallen into ruin with ceramic tiles falling on the heads of passers-by.
20 Fenchurch Street Nicknamed the WalkieTalkie, this London building’s concave design focuses the Sun’s rays with such intensity it can melt cars.
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DID YOU KNOW? St Anthony Falls Bridge was completed two months ahead of its scheduled Christmas Eve 2008 deadline
Khan Shatyr Entertainment Center The weather conditions in the Kazakhstan capital Astana aren’t particularly stable, ranging from minus-35 degrees Celsius (-31 degrees Fahrenheit) in the winter to plus-35 degrees Celsius (95 degrees Fahrenheit) in the summer. British architect Norman Foster was tasked with creating an entertainment centre that people would flock to even in the most extreme conditions. He created the Khan Shatyr Entertainment Center, the biggest tent in the world at 150 metres (492 feet) high. The triple-layered, translucent ETFE (ethylene tetrafluoroethylene) envelope protects shoppers from the cold, while letting in natural daylight. This helps to maintain temperatures of 14 degrees Celsius (57 degrees Fahrenheit) in the winter and 29 degrees Celsius (84 degrees Fahrenheit) in the summer.
Support
Size
Translucence
Three tubular-steel struts hold the tent up. The 60m (197ft) leg weighs 351 tons and the 70m (230ft) legs weigh 211.5 tons each.
The tent is 150m (492ft) high with a 200 x 195m (656 x 640ft) base.
The translucent material allows natural light and warmth in, while blocking the extremes of cold or heat.
Material The lightweight ETFE material lets in natural light and is supported by steel cables.
Monorail You can zip around the centre by a monorail that circles the complex.
Temperature Cool air jets regulate the temperature inside while warm air currents travel up the walls to prevent ice forming.
Entertainment The centre comprises a park, jogging track, shops, cinemas and restaurants.
Movement sensors
Vibrations
Ice sensors
Corrosion sensor
Placed in the spaces near expansion joints, these sensors check the gaps as they expand and contract with temperature changes.
As vehicles travel over the bridge, accelerometers detect what damage may be caused to it.
To protect pedestrians from icy conditions, sprinklers detect when ice may form and spray an anti-icing solution on the pavement.
Metallic sensors measure the amount of salt on the road’s surface so engineers can prevent steel corrosion.
Size
Temperature gauges
Strain sensors
The curvature of the bridge is constantly monitored as temperature alters its shape.
Sensors in the concrete supports measure the amount of stretching or shortening of the material.
The bridge’s longest span is 154m (504ft) and the road sits 35m (115ft) above the Mississippi River.
Minnesota smart bridge When the Mississippi River Bridge in Minneapolis, Minnesota collapsed in 2007 one of the key features of its replacement – the Saint Anthony Falls Bridge – was the ability to monitor the condition of the bridge so it could WWW.HOWITWORKSDAILY.COM
never happen again. The $234 (£150)-million bridge took under a year to complete and is now known as ‘America’s smartest bridge’. The 371-metre (1,216-foot)-long bridge contains a number of sensors that measure the amount of
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movement caused by weather, air temperature and traffic. It then transmits this data to Minnesota University. Accelerometers are also placed at the mid-point of each girder to check for excessive vibrations.
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