Hoover Dam Bypass
Encyclopedia
The Mike O'Callaghan – Pat Tillman Memorial Bridge, the key component to the Hoover Dam Bypass project, was the first concrete-steel composite arch bridge built in the United States
, and it incorporates the longest concrete arch bridge
in the Western Hemisphere
. Opened on October 19, 2010, this four-lane highway
bridge provides a crossing of the Colorado River
for U.S. Route 93
, linking Nevada
with Arizona
about 1,600 feet (about 500 meters) downstream from the Hoover Dam
. This bridge is located about 30 miles (48 kilometers) southeast of Las Vegas, Nevada
. At 840 feet (260 meters) above the Colorado River, this bridge is the second-highest one in the United States
, following the Royal Gorge Bridge
. Built as part of the Hoover Dam Bypass Project, which was successfully completed within budget at a cost of $240 million, the bridge portion cost $114 million (2010 prices).
to improve safety, security, and traffic capacity. Through extensive studies, this bridge route was determined to be the best route for the bypass.
U.S. Highway 93, in conjunction with U.S. Highway 60 via Wickenburg, Arizona
, is the primary highway between Phoenix, Arizona
, and Las Vegas, Nevada
, two cities that have seen great increases in population since the completion of the Hoover Dam. The section of U.S. 93 that approached and crossed Hoover Dam was not adequate for modern traffic needs. It was too narrow, with just one lane in each direction, it had many dangerous curves, including several hairpin turn
s, and it had poor lines-of-sight, especially at night.
Through highway traffic combined with sightseeing and pedestrian traffic at the dam, the traffic often came to a standstill. As a consequence of the heightened security measures following the September 11, 2001, attacks, truck traffic over the Hoover Dam was diverted south to a bridge crossing the river at Laughlin, Nevada
, in an effort to safeguard the dam from hazardous spills or explosions. This disruption, however, did not eliminate the threat of a possible attack on the dam, since regular traffic still passed over it. Hence, the new bypass and the bridge are intended to improve travel times, replace the dangerous roadway, and reduce the possibility of an attack or an accident at the site of the dam
.
More than 17,000 cars and trucks are using the new bridge daily, a number expected to grow by 50 percent over the next 20 years. This bridge is a key component of the proposed Interstate 11
project.
issued in July 1988. The design of the preferred alternative started in July 2001. Project design was by the Hoover Support team, led by HDR, Inc.
and including T.Y. Lin International, Sverdrup Civil, Inc., and other specialist contributors.
The bridge has a length of 1900 feet (579 m) and a 1060 ft (323.1 m) span. The roadway is 900 ft (274.3 m) above the Colorado River and four lanes wide. This is the first concrete-and-steel composite arch bridge built in the United States. It includes the longest concrete arch in the Western Hemisphere and is also the second highest bridge in the nation, with the arch 840 ft (256 m) above the river. The twin arch ribs are connected by steel struts.
The composite design, using concrete for the arch and columns with steel construction
for the roadway deck, was selected for schedule and cost control while being aesthetically compatible with the Hoover Dam. Sean Holstege in The Arizona Republic has called the bridge "an American triumph". USA Today called it "America's Newest Wonder" on October 18, 2010.
Pedestrian access is provided over the bridge to tourists who wish to take in a different view of the nearby dam and river below, but the dam is not visible for those driving across it. A parking area is provided near the bridge on the Nevada side at what was a staging area during construction. A set of stairs and disabled access
ramps lead to the sidewalk across the bridge.
Work began in 2003 on the approaches in both states and the construction contract for the arch bridge was awarded in October 2004. The largest obstacle to the project was the river crossing. The bridge and the bypass were constructed by a consortium of different government agencies and contractors, among them the Federal Highway Administration
, the Arizona Department of Transportation
, and Nevada Department of Transportation
, with RE Monks Construction and Vastco, Inc, constructing the Arizona Approach, Edward Kraemer & Sons, Inc, the Nevada Approach and Las Vegas Paving Corporation undertaking the roadway surfacing on both approaches. The bridge itself was built by Obayashi Corporation and PSM Construction USA, Inc., while Frehner Construction Company, Inc. was responsible for completing the final roadway installations. A permit problem between Clark County and the subcontractor Casino Ready Mix arose in May 2006 over the operation of a concrete-batch plant for the project, and this caused a four-month delay.
Construction required hoisting workers and up to 50 short tons (44.6 LT) of materials 890 feet (271.3 m) above the Colorado River using 2300 ft (701 m)-long steel cables held aloft by a "high-line" crane system. High winds caused a cableway failure in September 2006, resulting in a further two year delay. The approach spans, consisting of seven pairs of concrete columns—five on the Nevada side and two on the Arizona side—were completed in March 2008. In November 2008, the construction worker Sherman Jones died in an accident.
The arches are made of 106 pieces—53 per arch—mostly cast in place 24 ft (7.3 m). The arch was constructed from both sides of the bridge concurrently, supported by diagonal cable stays strung from temporary towers. The concrete arch was 50 percent completed in May 2009. and the twin arch spans were completed with the casting of the center segments in the following August. When the two halves of the arch were completed in August 2009, they were only 3/8 in apart, and the gap was filled with a block of reinforced concrete. The temporary cable stays were removed, leaving the arch self-supporting. By December, all eight of the vertical piers on the arch had been set and capped, and at the end of the month the first two of thirty-six 50 short tons (44.6 LT) steel girders had been set into place.
By mid-April 2010, all of the girders were set in place, and for the first time construction crews could walk across the structure from Arizona to Nevada. Shortly thereafter, the pouring of the bridge deck began. The bridge deck was fully paved in July, and the high-line cranes were removed from the site as the overall project neared completion. The bridge was completed with a dedication ceremony on October 14, 2010. and a grand opening party on October 16. It was opened to bicycle and pedestrian traffic on October 18 and to vehicular traffic on October 19, a few weeks earlier than estimated. The building of the bridge was featured in episode 5x02 of the TV series Extreme Engineering
. The filming of this episode took place before the start of work on the arch.
and Pat Tillman
was announced at a ceremony by the Governor of Nevada, Kenny Guinn
, and the Governor of Arizona, Janet Napolitano
. O’Callaghan, a decorated Korean War
veteran, was the Governor of Nevada from 1971 through 1979, and he was the executive editor at the Las Vegas Sun
newspaper for many years until his death on March 5, 2004. Tillman had been a football player for the Arizona State University team
and for the Arizona Cardinals
team. He gave up his multimillion dollar career in the National Football League
to enlist as an infantryman in the U.S. Army, but he was killed by friendly fire in Afghanistan
on April 22, 2004.
The bridge-construction companies Obayashi Corp. and PSM Construction, USA, Inc. absorbed the cost of the debris removal and the rebuilding of the cranes. The reconstruction contract for the cranes was awarded to Cincinnati's F&M Mafco Inc.
, a regular practice that they had adopted following workers' deaths in California
, Washington State, and elsewhere.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and it incorporates the longest concrete arch bridge
Arch bridge
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...
in the Western Hemisphere
Western Hemisphere
The Western Hemisphere or western hemisphere is mainly used as a geographical term for the half of the Earth that lies west of the Prime Meridian and east of the Antimeridian , the other half being called the Eastern Hemisphere.In this sense, the western hemisphere consists of the western portions...
. Opened on October 19, 2010, this four-lane highway
Highway
A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...
bridge provides a crossing of the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
for U.S. Route 93
U.S. Route 93
U.S. Route 93 is a major north–south United States highway in the western United States. The southern terminus is at U.S. Route 60 in Wickenburg, Arizona. The northern terminus is at the Canadian border north of Eureka in Lincoln County, Montana, where the roadway continues into Roosville,...
, linking Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
with Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
about 1,600 feet (about 500 meters) downstream from the Hoover Dam
Hoover Dam
Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President...
. This bridge is located about 30 miles (48 kilometers) southeast of Las Vegas, Nevada
Las Vegas, Nevada
Las Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...
. At 840 feet (260 meters) above the Colorado River, this bridge is the second-highest one in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, following the Royal Gorge Bridge
Royal Gorge Bridge
The Royal Gorge Bridge is a tourist attraction near Cañon City, Colorado, within a theme park. The bridge deck hangs above the Arkansas River, and held the record of highest bridge in the world from 1929 until 2003, when it was surpassed by the Beipanjiang River 2003 Bridge in China. It is a...
. Built as part of the Hoover Dam Bypass Project, which was successfully completed within budget at a cost of $240 million, the bridge portion cost $114 million (2010 prices).
Justification for a new bridge
The bypass was constructedConstruction
In the fields of architecture and civil engineering, construction is a process that consists of the building or assembling of infrastructure. Far from being a single activity, large scale construction is a feat of human multitasking...
to improve safety, security, and traffic capacity. Through extensive studies, this bridge route was determined to be the best route for the bypass.
U.S. Highway 93, in conjunction with U.S. Highway 60 via Wickenburg, Arizona
Wickenburg, Arizona
Wickenburg is a town in Maricopa County, Arizona, United States. According to 2006 Census Bureau estimates, the population of the town is 6,423.-Geography:Wickenburg is located at ....
, is the primary highway between Phoenix, Arizona
Phoenix, Arizona
Phoenix is the capital, and largest city, of the U.S. state of Arizona, as well as the sixth most populated city in the United States. Phoenix is home to 1,445,632 people according to the official 2010 U.S. Census Bureau data...
, and Las Vegas, Nevada
Las Vegas, Nevada
Las Vegas is the most populous city in the U.S. state of Nevada and is also the county seat of Clark County, Nevada. Las Vegas is an internationally renowned major resort city for gambling, shopping, and fine dining. The city bills itself as The Entertainment Capital of the World, and is famous...
, two cities that have seen great increases in population since the completion of the Hoover Dam. The section of U.S. 93 that approached and crossed Hoover Dam was not adequate for modern traffic needs. It was too narrow, with just one lane in each direction, it had many dangerous curves, including several hairpin turn
Hairpin turn
A hairpin turn , named for its resemblance to a hairpin/bobby pin, is a bend in a road with a very acute inner angle, making it necessary for an oncoming vehicle to turn almost 180° to continue on the road. Such turns in ramps and trails may be called switchbacks in American English, by analogy...
s, and it had poor lines-of-sight, especially at night.
Through highway traffic combined with sightseeing and pedestrian traffic at the dam, the traffic often came to a standstill. As a consequence of the heightened security measures following the September 11, 2001, attacks, truck traffic over the Hoover Dam was diverted south to a bridge crossing the river at Laughlin, Nevada
Laughlin, Nevada
Laughlin is a census-designated place in Clark County, Nevada, United States, and a port located on the Colorado River. Laughlin is south of Las Vegas, located in the far southern tip of Nevada. It is best known for its gaming, entertainment, and water recreation. As of the 2010 census, the...
, in an effort to safeguard the dam from hazardous spills or explosions. This disruption, however, did not eliminate the threat of a possible attack on the dam, since regular traffic still passed over it. Hence, the new bypass and the bridge are intended to improve travel times, replace the dangerous roadway, and reduce the possibility of an attack or an accident at the site of the dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
.
More than 17,000 cars and trucks are using the new bridge daily, a number expected to grow by 50 percent over the next 20 years. This bridge is a key component of the proposed Interstate 11
Interstate 11
Interstate 11 is a possible designation for a locally-proposed Interstate Highway in the United States to run from Tonopah, Arizona, northwest to Las Vegas, Nevada, by way of Kingman, Arizona. The designation is a local proposal that has not been accepted by AASHTO or FHWA, the agencies normally...
project.
Design
Planning and environmental work was completed and the environmental impact statementEnvironmental impact statement
An environmental impact statement , under United States environmental law, is a document required by the National Environmental Policy Act for certain actions "significantly affecting the quality of the human environment". An EIS is a tool for decision making...
issued in July 1988. The design of the preferred alternative started in July 2001. Project design was by the Hoover Support team, led by HDR, Inc.
HDR, Inc.
HDR Inc. is an employee-owned architectural, engineering and consulting firm based in Omaha, Nebraska, USA. HDR has worked on projects in all 50 U.S. states and in 60 countries, including notable projects such as the Hoover Dam Bypass, TD Ameritrade Park Omaha, and the The Roslin Institute building...
and including T.Y. Lin International, Sverdrup Civil, Inc., and other specialist contributors.
The bridge has a length of 1900 feet (579 m) and a 1060 ft (323.1 m) span. The roadway is 900 ft (274.3 m) above the Colorado River and four lanes wide. This is the first concrete-and-steel composite arch bridge built in the United States. It includes the longest concrete arch in the Western Hemisphere and is also the second highest bridge in the nation, with the arch 840 ft (256 m) above the river. The twin arch ribs are connected by steel struts.
The composite design, using concrete for the arch and columns with steel construction
Construction
In the fields of architecture and civil engineering, construction is a process that consists of the building or assembling of infrastructure. Far from being a single activity, large scale construction is a feat of human multitasking...
for the roadway deck, was selected for schedule and cost control while being aesthetically compatible with the Hoover Dam. Sean Holstege in The Arizona Republic has called the bridge "an American triumph". USA Today called it "America's Newest Wonder" on October 18, 2010.
Pedestrian access is provided over the bridge to tourists who wish to take in a different view of the nearby dam and river below, but the dam is not visible for those driving across it. A parking area is provided near the bridge on the Nevada side at what was a staging area during construction. A set of stairs and disabled access
Americans with Disabilities Act of 1990
The Americans with Disabilities Act of 1990 is a law that was enacted by the U.S. Congress in 1990. It was signed into law on July 26, 1990, by President George H. W. Bush, and later amended with changes effective January 1, 2009....
ramps lead to the sidewalk across the bridge.
Building the bridge and bypass roads
Federal Highway Administration
The Federal Highway Administration is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two "programs," the Federal-aid Highway Program and the Federal Lands Highway Program...
, the Arizona Department of Transportation
Arizona Department of Transportation
The Arizona Department of Transportation is an Arizona state government agency charged with facilitating mobility within the state. In addition to managing the state's highway system, the agency is also involved with public transportation and municipal airports...
, and Nevada Department of Transportation
Nevada Department of Transportation
The Nevada Department of Transportation is a government agency in the U.S. state of Nevada. NDOT is responsible for maintaining and improving Nevada's highway system, which includes U.S. highways and Interstate highways within the state's boundaries. The department is notable for its...
, with RE Monks Construction and Vastco, Inc, constructing the Arizona Approach, Edward Kraemer & Sons, Inc, the Nevada Approach and Las Vegas Paving Corporation undertaking the roadway surfacing on both approaches. The bridge itself was built by Obayashi Corporation and PSM Construction USA, Inc., while Frehner Construction Company, Inc. was responsible for completing the final roadway installations. A permit problem between Clark County and the subcontractor Casino Ready Mix arose in May 2006 over the operation of a concrete-batch plant for the project, and this caused a four-month delay.
Construction required hoisting workers and up to 50 short tons (44.6 LT) of materials 890 feet (271.3 m) above the Colorado River using 2300 ft (701 m)-long steel cables held aloft by a "high-line" crane system. High winds caused a cableway failure in September 2006, resulting in a further two year delay. The approach spans, consisting of seven pairs of concrete columns—five on the Nevada side and two on the Arizona side—were completed in March 2008. In November 2008, the construction worker Sherman Jones died in an accident.
The arches are made of 106 pieces—53 per arch—mostly cast in place 24 ft (7.3 m). The arch was constructed from both sides of the bridge concurrently, supported by diagonal cable stays strung from temporary towers. The concrete arch was 50 percent completed in May 2009. and the twin arch spans were completed with the casting of the center segments in the following August. When the two halves of the arch were completed in August 2009, they were only 3/8 in apart, and the gap was filled with a block of reinforced concrete. The temporary cable stays were removed, leaving the arch self-supporting. By December, all eight of the vertical piers on the arch had been set and capped, and at the end of the month the first two of thirty-six 50 short tons (44.6 LT) steel girders had been set into place.
By mid-April 2010, all of the girders were set in place, and for the first time construction crews could walk across the structure from Arizona to Nevada. Shortly thereafter, the pouring of the bridge deck began. The bridge deck was fully paved in July, and the high-line cranes were removed from the site as the overall project neared completion. The bridge was completed with a dedication ceremony on October 14, 2010. and a grand opening party on October 16. It was opened to bicycle and pedestrian traffic on October 18 and to vehicular traffic on October 19, a few weeks earlier than estimated. The building of the bridge was featured in episode 5x02 of the TV series Extreme Engineering
Extreme Engineering
Extreme Engineering is a documentary television series that airs on the Discovery Channel and the Science Channel. The program features futuristic and ongoing engineering projects. As of April 2011, the show is airing its ninth season. Danny Forster first hosted the series in season 4 and has been...
. The filming of this episode took place before the start of work on the arch.
The naming of the bridge
In late 2004, the proposed bridge name honoring Mike O'CallaghanMike O'Callaghan
-External links:* * * *...
and Pat Tillman
Pat Tillman
Corporal Patrick Daniel "Pat" Tillman Jr. was an American football player who left his professional career and enlisted in the United States Army in June 2002 in the aftermath of the September 11, 2001, attacks. He joined the Army Rangers and served several tours in combat before he died in the...
was announced at a ceremony by the Governor of Nevada, Kenny Guinn
Kenny Guinn
Kenneth Carroll "Kenny" Guinn was an American businessman, educator and politician. He was the 27th Governor of Nevada from 1999 to 2007. He was a member of the Republican Party and a former member of the Democratic Party....
, and the Governor of Arizona, Janet Napolitano
Janet Napolitano
Janet Napolitano is the third and current United States Secretary of Homeland Security, serving in the administration of President Barack Obama. She is the fourth person to hold the position, which was created after the 9/11 terrorist attacks. A member of the Democratic Party, she was the 21st...
. O’Callaghan, a decorated Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
veteran, was the Governor of Nevada from 1971 through 1979, and he was the executive editor at the Las Vegas Sun
Las Vegas Sun
The Las Vegas Sun is a Pulitzer Prize-winning newspaper. It is one of Las Vegas, Nevada's two daily newspapers. It is owned by the Greenspun family and is affiliated with Greenspun Media Group....
newspaper for many years until his death on March 5, 2004. Tillman had been a football player for the Arizona State University team
Arizona State Sun Devils football
The Arizona State Sun Devils' football program represents Arizona State University in college football, and competes in NCAA Division I FBS as a member of the Pacific-12 Conference....
and for the Arizona Cardinals
Arizona Cardinals
The Arizona Cardinals are a professional American football team based in Glendale, Arizona, a suburb of Phoenix. They are currently members of the Western Division of the National Football Conference in the National Football League...
team. He gave up his multimillion dollar career in the National Football League
National Football League
The National Football League is the highest level of professional American football in the United States, and is considered the top professional American football league in the world. It was formed by eleven teams in 1920 as the American Professional Football Association, with the league changing...
to enlist as an infantryman in the U.S. Army, but he was killed by friendly fire in Afghanistan
War in Afghanistan (2001–present)
The War in Afghanistan began on October 7, 2001, as the armed forces of the United States of America, the United Kingdom, Australia, and the Afghan United Front launched Operation Enduring Freedom...
on April 22, 2004.
Crane collapse
Strong winds gusting across the Black Canyon on September 15, 2006, appear to have been the cause for the collapse of the "high-line" crane system that was used to carry workmen and materials at the bridge site. No injuries or fatalities occurred because of this accident. Limited construction work resumed in October 2006, but this accident caused a two-year delay in construction.The bridge-construction companies Obayashi Corp. and PSM Construction, USA, Inc. absorbed the cost of the debris removal and the rebuilding of the cranes. The reconstruction contract for the cranes was awarded to Cincinnati's F&M Mafco Inc.
Construction worker's death
Work was also halted when a Las Vegas construction worker, 48-year-old Sherman Jones, was killed during construction while adjusting a cable used to align temporary concrete towers, when a jack punctured his chest. The Obayashi Corporation then resisted efforts for an investigation by the Occupational Safety and Health AdministrationOccupational Safety and Health Administration
The United States Occupational Safety and Health Administration is an agency of the United States Department of Labor. It was created by Congress of the United States under the Occupational Safety and Health Act, signed by President Richard M. Nixon, on December 29, 1970...
, a regular practice that they had adopted following workers' deaths in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Washington State, and elsewhere.
See also
- Robert MaillartRobert MaillartRobert Maillart was a Swiss civil engineer who revolutionized the use of structural reinforced concrete with such designs as the three-hinged arch and the deck-stiffened arch for bridges, and the beamless floor slab and mushroom ceiling for industrial buildings...
, Swiss civil engineerCivil engineerA civil engineer is a person who practices civil engineering; the application of planning, designing, constructing, maintaining, and operating infrastructures while protecting the public and environmental health, as well as improving existing infrastructures that have been neglected.Originally, a...
and designer of the similar Salginatobel BridgeSalginatobel BridgeSalginatobel Bridge is a reinforced concrete arch bridge designed by renowned Swiss civil engineer Robert Maillart. It was constructed across an alpine valley in Schiers, Switzerland between 1929 and 1930...
(1929–1930).
External links
- The Bridge at Hoover Dam Photo Essay by Photographer Jamey Stillings
- Article: "New Cableway System Set For Hoover Dam Bypass"
- Hoover Dam Bridge on HighestBridges.com