HOOVER DAM BYPASS BRIDGE

UNDER THE GUIDANCE OF

MRS APARNA ROYPRESENTED BYBUDDHADEV NANDI

(2012-5029)

Table of contents introduction Project need & objective Objective of the project Environmental impact assessment Project Design Financial information Technical Information Construction Technical Parts of the bridge Operation & maintenance Achievement Project Schedule Transfer of the project

Introduction

In the beginning called Hoover Dam Bypass Bridge now the official name is MIKE O’CALLAGHAN TILLMAN KILLEY ME-MORIAL Bridge.The work on the bridge started in 2005 and should finish next year.At the moment the structure looks like a traditional suspension bridge. but once the arches are complete the suspending cable on each side will be removed. Extra vertical column will then be installed on arches to carry the road.An estimated 17000 cars and trucks will cross it everyday.

Project Need and objective Potential problems identified

Accidents Sharp turns Limited sight distances

No adequate room for disabled cars

Speed was as low as 15MPH against initial speed of 50MPH

inadequate road capacity

Less travel times

Objective of the project

• To minimise the potential for traffic accidents • To remove the bottlenecks to interstate and international commerce to reduce traffic congested • To reduce travel time • To protect Hoover dam employees, visitors, equipment, power generations capabilities• To provide safe and improved conditions for the maintenance and operation of Hoover dam

Environmental impact assessment studies

• Air quality analysis • Noise analysis • Visual resources analysis • Biological assessments • Archaeological resources survey

The requirement for the design of the bridge was both technical and aesthetics of the bridge, the most important requirement in the design would be design load which in this case was 180 metric tons. Various designs were studied some of them were as follows.

After considering the design criteria for the bridge the team selected composite steel and concrete type of bridge that met all the design criteria.

Project Design

The requirement for the design of the bridge was both technical and aesthetics of the bridge, the most important requirement in the design would be design load which in this case was 180 metric tons. Various designs were studied some of them were as follows.

After considering the design criteria for the bridge the team selected composite steel and concrete type of bridge that met all the design criteria.

Financial informationContract contractor valueArizona Approach

Mont/VASTCO $22M

Navida ApproachEdward Kraemer & sons $30M

River bridgeObayashi/Mitsubishi $114M

Paving Freshener & Las Vegas paving

$15M

Total $181M

Construction❖ Phase 1. Building connection between Colorado Bridge and U.S 93 this included 4 lanes of roadway

❖ Phase2. This was from Navida side, The Roadway from the project start to the Colorado Bridge, started in 2003 and finished in 2005 ahead of time by 2 months. ❖ Phase3. The contractor constructed 2.11 miles of new four-lane highway alignment including six new bridges, a new traffic interchange at US 93 near the Hacienda Casino, retaining walls, wildlife crossing.

❖ Phase4. Asphalt paving of the entire 4 miles from Arizona to Nevada side to the project. This was complete in 2010.

The suspension cables for temporary support

Operation & maintenance The operation and maintenance is either side of the bypass bridge done by Arizona state DOT and Nevada State DOT. The aim of the maintenance is to insure safety, carryout visual and technical inspection of the bridge, to maintain smooth traffic flow, repairs to the bridges, road pavements. The funding for the same comes from the Nevada and Arizona state departments of transportations.

Achievement The project completion on budget was a great success story

although it went slightly away from the schedule. The project primary purpose and objective of reduction in traffic congestion was achieved and this facilitated smooth traffic.

The travel time of the existing road was 16.5minutes while this newly construction facility reduced it to 6 minutes, a total of 10 minutes were saved. This also increased speed. The environmental impact assessment helped reduce and mitigate the problems of environment and also wild life crossing between different points.

Project Schedule

Project TransferThe twin-rib arch of the Colorado River Bridge was completed in August 2009 and the bridge columns were constructed in November 2009. Construction of the entire bypass was completed in September 2010. It was celebrated by making grand ceremony. The bypass opened to traffic a month later in October 2010.

Learning This project helped me a lot in understanding the complexity of the infrastructural project development, in this exercise I learned various surveys required in each stage of the project, the project coordination, construction and impact analysis on the environment. Every project before comes into existence must go through a logical process, I learned practically what process were involved in this project.

The Hoover Dam, Bypass Colorado River Bridge was an extreme challenge, due to the structure itself, advanced construction schemes, and the surrounding environment. The effort of all personnel involved made the incredible graceful bridge into reality. The Hoover dam bypass Colorado River Bridge was completed in 2010, The Bridge was opened to traffic on October 2010. The Project resulted iconic landmark structure set in the Colorado River’s black canyon with a view to historic Hoover Dam. Ten minutes reduction time was another achievement followed by reduction in traffic congestion and accidents.

CONCLUSION

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