Denver Millennium Bridge | |
---|---|
Mast of Denver’s Millennium Bridge rises to 200 feet (61m), connecting to the footbridge's deck and foundation anchors with post-tensioned steel cables.
|
|
Coordinates | 39°45′16″N 105°00′15″W / 39.7544°N 105.0041°WCoordinates: 39°45′16″N 105°00′15″W / 39.7544°N 105.0041°W |
Carries | Pedestrians |
Crosses | Railroad, Light Rail system |
Locale | Denver, Colorado, United States |
Characteristics | |
Design | Structural steel, post-tensioned cable-stayed bridge |
Total length | 130 feet (40m) |
Width | 80 feet (24m) |
Height | 25 feet (8m) |
Clearance above | 200 feet (61m) |
History | |
Construction cost | $9 million |
Opened | April 22, 2002 |
The Denver Millennium Bridge is the world’s first cable-stayed bridge using post-tensioned structural construction. Its 200-foot (61m) white tapered steel mast rises above Denver’s northwestern skyline, connected to the bridge deck and foundation anchors by steel cables. This unique footbridge crosses railroad tracks and the regional light rail system, climbing no higher than 25 feet (8m) above street level, thereby minimizing the height pedestrians must climb. Located near LoDo (Denver’s lower downtown),in Riverfront Park, the Millennium Bridge connects the popular 16th Street Mall with the Commons Park in the Central Platte Valley District of the Union Station neighborhood. The bridge is the first of three pedestrian bridges between Downtown Denver and the Highland neighborhood.
The name, Denver Millennium Bridge, honors a milestone in time and in Denver’s architectural development. To meet the structural challenge of spanning 130 feet (40m) without a steep increase in elevation, the deck’s structure must be as thin as possible while remaining stable. This suspension bridge uses a steel frame that derives its stiffness from tension by using a single mast that is tilted toward one end of the bridge. Cables supporting the bridge deck are welded to both sides of the mast, but cable to foundation anchors attach to the mast only from the side of the bridge toward which the mast is tilted.
Supportive tension is created by using the mast as a lever to pull the deck up into a shallow arc, keeping the opposite end of the bridge secured by two steel rods. With the mast raised, concrete was poured onto the metal deck frame, pushing the deck into place and applying tension to the cables. The post-tensioned structural construction allows for a substantially thinner 6-inch-thick reinforced concrete slab-on-metal deck. The deck structure is supported by secondary I-Beams, and has an average width of 80 feet (24m).