Bridging the Gaps
Figure 1. Tsurimi Tsubasa Bridge in Japan.Copyright 2004 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved.
Students are presented with a brief history of bridges as they learn about the three main bridge types: beam, arch and suspension. They are introduced to two natural forces — tension and compression — common to all bridges and structures. Throughout history, and today, bridges are important for connecting people to resources, places and other people. Using the associated activities to prototype their own structures, students become more aware of the variety and value of bridges around us in our everyday lives.
Bridges are fascinating feats of engineering. Throughout history, humans have creatively designed everything from rope and plank bridges to the Golden Gate Bridge. Today, primarily civil and structural engineers are responsible for the design of bridges of which we have more than 500,000 in the U.S. that are longer than 100 feet (30 meters). Since bridges must be safe under all anticipated load and weather conditions, in designing today's modern bridges, engineers take into consideration tension and compression forces. They also creatively strive to meet people's needs within budget and material constraints.
After this lesson, students should be able to:
- Discuss several different bridge designs.
- Describe some of the social, economic and cultural impacts of bridges.
- List various considerations of engineers when designing bridges.