Arch Bridges Arch Bridges One of the oldest
Arch Bridges
Arch Bridges • One of the oldest types of bridges • Great natural strength • Modern arch bridges span between 200800 feet.
How it works • Instead of pushing straight down, the weight of an arch bridge is carried outward along the curve of the arch to the supports at each end. • These supports, called the abutments, carry the load and keep the ends of the bridge from spreading out. • When supporting its own weight and the weight of crossing traffic, every part of the arch is under compression.
Queenston-Lewiston Bridge • 1, 600 ft
Grand Island Bridges • • 1935 Passenger cars 25 cents over two bridges Cost of bridges $3, 500, 000 Length of bridges: – North bridge 4000 ft – South bridge: 3400 feet.
Dubai to Build the World's Largest Arch Bridge in 2012 • • Here's some info on the bridge as envisioned by New York architecture firm Fxfowle: - It's one mile long and 670 feet tall. - It will have 12 lanes for traffic. - It will cost 817 million dollars. - The bridge will carry more than 2, 000 vehicles per hour in each direction. - A metro line will run across the middle. - Construction begins in March, with a slated completion date of 2012
Cold Spring Arch bridge • Santa Barbara, California
Lupu Bridge – China 12, 795 ft
Try It! Arch Bridges • Position the cardboard on the table so it resembles an arch. • Press down on the center of the arch. • What happens to the ends of the cardboard?
Try It! Arch Bridges • Next, place a stack of books at each end of the arch. • Press again. • Now what happens?
- Slides: 10