BETA
Chapter 1
The physics of resonance
Chapter 2
Tragedies of synchronized steps
Chapter 3
The wobbly Millennium Bridge
Chapter 4
Engineering safer bridges
YOUR GOAL
Master of How marching crowds collapse bridges
Ch 4 · Engineering safer bridges
artiteacher Play this physics game to see how marching crowds can accidentally collapse a bridge. Learn how resonance affects structural engineering.
artiteacher Bridge Resonance
Break your step on the bridge! (Break your step!) The rhythm's gonna shake it down! (Shake it down!)
artiteacher Hydraulic fluid devices act like giant shock absorbers to calm bridge motion.
artiteacher Massive heavy blocks are suspended inside structures to counteract unwanted movement.
Fun Fact
Taipei 101 damper: The Taipei 101 skyscraper uses a giant 660-metric-ton steel ball suspended inside to resist typhoons.
Glossary
resonance (noun)
The amplification of a vibration that occurs when a periodic force is applied at a natural frequency. Engineers retrofitted London's Millennium Bridge with dampers to prevent this effect after its wobbly 2000 opening.
The amplification of a vibration that occurs when a periodic force is applied at a natural frequency. Engineers retrofitted London's Millennium Bridge with dampers to prevent this effect after its wobbly 2000 opening.
Quiz
What type of dampers, resembling giant shock absorbers, were installed on London's Millennium Bridge?
Quiz
What does a 'tuned mass damper' use to counteract the swaying motion of a bridge or building?
Quiz
How many fluid viscous dampers were added to the London Millennium Bridge to cure its wobble?
Quiz
Why are completely rigid bridges not always the best solution to prevent resonance?
Quiz
What advanced computer simulation method do modern engineers use to model bridge behavior under crowd loads?
Quiz
Into what form of energy do viscous dampers convert the kinetic energy of a swaying bridge?
Quiz
In what year did the London Millennium Bridge finally reopen to the public after being retrofitted with dampers?