When Good Bridges Go Bad

Bee When it comes to bridges, it is critical that they stay up in times of stress. Stress is any force exerted on a bridge…whether from weight, raging storms, or even everyday occurrences such as heat from the sun. A bridge must be constructed so it can handle stress and it should be elastic. The property of elasticity means that if a force is exerted on the bridge, the bridge will be able to return to its original shape.

The best architects sometimes design bridges that are unable to handle stress. Bridge collapses are incredibly dangerous. State guidelines require that bridges be inspected every two years to ensure that bridges remain safe, but potential stressors are always a threat.

Common Bridge Stressors:
  • Weight
  • Storms
  • Corrosion
  • Direct Sunlight
Can you think of any other stressors that can cause a bridge to collapse? There are many more! What are some ways to reduce the effect of these stressors?

Ways to Reduce Effects of Stress:
  • Research area where bridge is to be built (example: if area is prone to inclement weather, there may be a better place to build it)
  • Use a strong material that has elastic properties
  • Calculate how much weight the bridge can hold and make this its capacity (do not allow more weight on the bridge than what you have calculated it can hold)
  • Use strong supports
  • Have regular inspections of your bridge to check for negative effects from stressors
When a bridge collapses, engineers are called out to the site to determine what went wrong. Even so, engineers are not always able to determine a cause.

The following links will connect you to articles that describe bridge collapses. See if you can identify what went wrong with these bridges.