Mike O'Callaghan–Pat Tillman Memorial Bridge
36.01214 - 114.742Koordinaten: 36 ° 0 ' 43.7 "N, 114 ° 44' 31.2 " W
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The Mike O'Callaghan - Pat Tillman Memorial Bridge, also known as the Hoover Dam Bypass Bridge and the Colorado River Bridge, opened in 2010, is an arch bridge over the Colorado River in the Black Canyon. It is 580 m long, which makes the U.S. Highway 93 near the Hoover Dam at an altitude of 580 m from Arizona to Nevada. The bridge was one of the longest and highest concrete arch bridges in the Western Hemisphere, as well as the second highest bridge in America on its completion.
History
The bridge is part of the 5.6 km long Hoover Dam Bypass - A bypass road, which relieves the dam Hoover Dam from through traffic and it also bypasses several hairpin bends on the side of Arizona. The idea of a bypass was applied in late 1960s, but only in the years 1998 to 2001 the planning of the road was taken, which crosses 460 m below the Hoover Dam of the Colorado River. The construction of the bridge approach roads began in 2003. During a festive ceremony, the bridge in 2004 after the former football star and a few months earlier fallen in Afghanistan U.S. soldiers Pat Tillman and the former governor of Nevada, Mike O'Callaghan was named. Construction of the bridge began in February 2005. Construction received a setback when on 15 September due to strong winds collapsed the cable crane system. In the accident, no one was injured, but he had a two-year delay in work on the sequence, so that the completion date of 2008 has been postponed to 2010. The traffic was released on 19 October 2010 at 22.00 local time clock.
Already during construction the bridge was an attraction. It is particularly designed a visitors' car park, from which can be achieved through a serpentine path from the base web of the bridge. From this footbridge several suicides were committed by now.
Building
The arch of the bridge consists of two parallel sheets of prestressed concrete, which are connected to eight Vierendeel concrete lined with each other. While the cantilever of the sheet halves, each side was braced by cables to a tied-back tower. Each sheet consists of 52 cast in-place concrete segments. For the two arcs total 6880 m² of high-strength concrete was used. A particular challenge is the over 100 km / h high winds and during the day up to 50 -degrees temperatures, which allowed a setting allowing the concrete only on the night.
On the arches are up to 88 m high three meter long precast reinforced concrete pillars produced, which are connected at the top pairs with a cap. Total 440 prefabricated elements were installed, the piers were in the completion of the bridge, the highest built of prefabricated elements pillar of the world. You wear a steel composite superstructure which consists of a steel box girder with it cast in-situ concrete slab. The box girder was delivered in 35 m long 50 -ton parts.
Pictures of the construction of the bridge
Helicopter view of the under construction bridge arch in May 2009.
Ready bridge arch in September 2009.