Denver Millennium Bridge
Encyclopedia
For other structures of the same name see Millennium Bridge
Millennium Bridge
Several bridges are known as the Millennium Bridge:* in the United Kingdom:** Gateshead Millennium Bridge** Lune Millennium Bridge, in Lancaster, England** Millennium Bridge in Glasgow** Millennium Bridge in London...



The Denver Millennium Bridge is the world’s first cable-stayed bridge
Cable-stayed bridge
A cable-stayed bridge is a bridge that consists of one or more columns , with cables supporting the bridge deck....

 using its 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
Footbridge
A footbridge or pedestrian bridge is a bridge designed for pedestrians and in some cases cyclists, animal traffic and horse riders, rather than vehicular traffic. Footbridges complement the landscape and can be used decoratively to visually link two distinct areas or to signal a transaction...

 crosses railroad tracks and the regional light rail
Light rail
Light rail or light rail transit is a form of urban rail public transportation that generally has a lower capacity and lower speed than heavy rail and metro systems, but higher capacity and higher speed than traditional street-running tram systems...

 system, climbing no higher than 25 feet (8m) above street level, thereby minimizing the height pedestrians must climb. Located near LoDo
LoDo
LoDo, Denver is the lower downtown area of Denver, Colorado, the oldest and original settlement of the city of Denver. It is a mixed-use historic district, known for its nightlife, and serves as an example of success in urban reinvestment and revitalization...

 (Denver’s lower downtown), the Millennium Bridge connects the popular 16th Street Mall
16th Street Mall
The 16th Street Mall is a pedestrian and transit mall in Denver, Colorado. The mall, 1.25 miles long, runs along 16th Street in downtown Denver, from Wewatta Street to the intersection of 16th Avenue and Broadway...

 with the Commons Park in the Central Platte Valley District of the Union Station neighborhood
Union Station, Denver
Union Station is a downtown neighborhood of Denver, Colorado. According to the Piton Foundation, in 2007, the population of the neighborhood was 3,475, and there were 2,530 housing units. Piton Foundation data from 2000 indicates the neighborhood’s average household income was $97,080.The...

. The bridge is the first of three pedestrian bridges between Downtown Denver
Downtown Denver
Downtown Denver is the main financial, commercial, and entertainment district in Denver, Colorado. There is over of office space in downtown Denver, with 130,000 workers....

 and the Highland neighborhood.

Design

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
Suspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century...

 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
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

 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).

History

Preliminary work on the $9-million footbridge
Footbridge
A footbridge or pedestrian bridge is a bridge designed for pedestrians and in some cases cyclists, animal traffic and horse riders, rather than vehicular traffic. Footbridges complement the landscape and can be used decoratively to visually link two distinct areas or to signal a transaction...

 began in 1999. The structural and civil engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

 firm Ove Arup
Arup
Arup is a global professional services firm headquartered in London, United Kingdom which provides engineering, design, planning, project management and consulting services for all aspects of the built environment. The firm is present in Africa, the Americas, Australasia, East Asia, Europe and the...

 & Partners, in conjunction with the architectural design company ArchitectureDenver, developed the design.

Contractor Edward Kraemer & Sons, Inc. implemented the design, subcontracting Colorado Bridge and Iron to fabricate the steel components. The mast was constructed of cone-shaped steel plate sections welded together to form a 3-foot (1m) base, 7-foot (2m) mid-section and 1.5-foot (.5m) tip diameter.

Glass-enclosed elevator
Elevator
An elevator is a type of vertical transport equipment that efficiently moves people or goods between floors of a building, vessel or other structures...

 towers on both ends of the footbridge accommodate pedestrians who have difficulty climbing the stairs leading up to either end of the bridge from street level. The Millennium Bridge was completed and officially opened by Denver Mayor Wellington Webb
Wellington Webb
Wellington E. Webb is a former mayor of Denver, Colorado. He is a graduate of the city's Manual High School. He was Denver's first African-American Mayor.Webb served as mayor of Denver for 12 years, from 1991 to 2003...

on April 22, 2002.

Awards

  • 2002 Urban Design Merit Award, Denver Chapter American Institute of Architects
  • Gold Award, New York Association of Consulting Engineers “Engineering Excellence Awards 2003”

Photo gallery















External links

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