In March 2017, the I-85 Bridge in the heart of Atlanta, Georgia, collapsed following a massive fire. Since then, crews have worked around the clock to safely remove the damaged portions of the bridge and rebuild the 350-foot stretch of damage. Washington state commuters experienced similar headaches in 2013 when a truck struck a portion of the Skagit River Bridge on I-5, causing structural failure.
Bridges require careful engineering to accommodate the weight, vibrations and elements they bear. Oregon demolition services exercise just as must caution when deconstructing the large structures. The United States has over 610,000 bridges, including the 65 steel truss bridges in Portland, Oregon alone. With about 40 percent of the structures in the country being 50 years old or older, Oregon demolition contractors and their counterparts across the nation are continuously called upon for their safe removal.
Famous U.S. Bridges
- Tacoma Narrows Bridge (Tacoma, Washington): A staple in engineering books about how not to build a bridge, the original Tacoma Narrows Bridge was built in 1940. Four months after it opened, the bridge collapsed because designers failed to consider the area’s high wind speeds. Area residents sometimes refer to the Narrows as “Galloping Gertie.” The mile-long suspension bridge was rebuilt in 1950, and spans part of the Puget Sound to connect Tacoma and Gig Harbor.
- Brooklyn Bridge (Brooklyn, New York): Completed in 1883, the Brooklyn Bridge spans the East River, connecting Brooklyn and Manhattan. The iconic landmark is 1.3 miles long and sits 119 feet above the water, tall enough to allow clipper and steam ships to pass beneath. Its construction took 14 years. To prove the bridge’s stability, P.T. Barnum had 21 elephants walk across the promenade.
- Sunshine Skyway Bridge (St. Petersburg, Florida): Completed in 1987, the renovated Sunshine Skyway Bridge spans the Tampa Bay and is the world’s longest cable-stayed concrete bridge at 29,040 feet (5.5 miles). With its taxi-cab-yellow cables, the bridge is hard to miss when visiting the St. Petersburg or Bradenton waterfronts.
- Golden Gate Bridge (San Francisco, California): A West Coast icon, the Golden Gate Bridge, which spans the mile-wide Golden Gate strait between San Francisco and Sausalito, is best known for the International Orange color that painters touch up throughout the year. The 4,200-foot bridge opened in 1937, and the American Society of Civil Engineers deemed it one of the Wonders of the Modern World. Engineers designed the bridge to withstand an 8.0 earthquake, 90-mile-per-hour winds and tidal waves simultaneously.
- George Washington Bridge (New York City, New York): Another New York icon, the George Washington Bridge on the Hudson River connects New York and New Jersey. When the 4,757-foot-long bridge opened in 1931, it only had one level; engineers added a second in 1962. The world’s largest free-flying flag, which measures 90-by-60 feet, hangs beneath the arch of the New Jersey tower.
Oregon Demolition Best Practices for Bridges
As with other types of structures, an industrial Oregon demolition company must methodically deconstruct and dismantle a bridge to ensure the safety of workers and preserve the assets removed. Best practices that the specialists use for selective bridge demolition include:
- Make a plan: Because of their size, bridge demolition requires thorough planning. After identifying the materials used to build the bridge, specialists determine the techniques they’ll use to tear it down. A contractor may employ hydrodemolition or bursting, for example, to remove the pavement.
- Remove steel with specialized equipment: It’s not always safe to demolish a bridge with explosives or wrecking balls. Instead, Oregon demolition contractors use saws, water jets or thermal lances to cut through and dismantle the steel.
- Asset sorting salvaging: As specialists dismantle a bridge, they separate the components into piles for recycling, reuse or resale with the goal of minimizing the amount of waste sent to landfills. A good contractor also helps a client sell the scrap metal from a site to help offset project costs.
The Health of Bridges Across the Nation
In a February 2017 press release, the American Road & Transportation Builders Association reported that about 56,000 bridges in the United States were structurally deficient in 2016. Of these bridges, 1,900 are on the Interstate Highway System. The report also highlights:
- The average age of non-deficient bridges is 39 years, while the average age of deficient bridges is 67 years
- 250,406 bridges in the U.S. (41 percent) are more than four decades old and have never had major reconstruction work; the same is true for 28 percent of the bridges in the country that are more than half-a-century old
- Nearly 40 percent of bridges in the U.S. are 50 years old or older
- If placed end-to-end, the bridges would span 1,276 miles, about the distance from Portland to southwestern Arizona
- Vehicles cross deficient bridges 185 million times per day
- 13,000 interstate bridges require widening, replacement or major reconstruction
- The number of deficient bridges in the U.S. declined by 0.5 percent between 2015 and 2016
Like other types of infrastructure that individuals rely upon daily to maintain their quality of life, bridges require maintenance to keep Americans moving. New technologies and materials make it possible for engineers to build bridges faster and better, while Oregon demolition contractors work hard to ensure the safety of dismantling projects while salvaging materials for future use. As bridges approach the end of their design lives, owners can count on Elder’s Oregon demolition services to bring the greatest returns on their project investments.