SW Bridge- Nalley Valley I/C
Tacoma, WA
Project Description
Aiming to reduce congestion on I-5 through Tacoma, Washington, the Westbound Nalley Valley I/C was the first of three phases of bridge construction in the historic Nalley Valley. The project distributes traffic between I-5 and the Tacoma Narrows Bridge toward the Olympic Peninsula. An array of new structures replaced seismically obsolete bridges and provide a much needed increase in traffic capacity.
Owner
Washington State Department of Transportation (WSDOT)
Contractor
Atkinson Construction
Designer
CH2M Hill & WSDOT
Our Role
McNary Bergeron & Associates assisted the contractor in procuring the contract by redesigning two expensive steel bridges to more economical concrete structures.
McNary Bergeron redesigned the SW Line Bridge from a steel tub-girder bridge to a precast segmental box girder bridge, a change that also suits the owner because of the extended design life and reduced maintenance.
McNary Bergeron & Associates is currently providing construction engineering services for the redesigned structure through the casting and erection processes.
Total Contract Value
$120 million
Timeline
January 2009 - February 2011
Construction Method and Specifications
SW Line
- Precast segmental bridge built using the balanced cantilever method with ground-based cranes.
- Segments constructed using the longline precasting method.
- Pier table shells were precast using match-cast methods, erected, and filled with a CIP diaphragm to fulfill stringent seismic requirements and eliminate closure pours near the piers
- Span lengths up to 295 ft
Owner
Washington State Department of Transportation (WSDOT)Contractor
Atkinson ConstructionDesigner
CH2M Hill & WSDOTOur Role
McNary Bergeron & Associates assisted the contractor in procuring the contract by redesigning two expensive steel bridges to more economical concrete structures. McNary Bergeron redesigned the SW Line Bridge from a steel tub-girder bridge to a precast segmental box girder bridge, a change that also suits the owner because of the extended design life and reduced maintenance. McNary Bergeron & Associates is currently providing construction engineering services for the redesigned structure through the casting and erection processes.Total Contract Value
$120 millionTimeline
January 2009 - February 2011Construction Method and Specifications
SW Line- Precast segmental bridge built using the balanced cantilever method with ground-based cranes.
- Segments constructed using the longline precasting method.
- Pier table shells were precast using match-cast methods, erected, and filled with a CIP diaphragm to fulfill stringent seismic requirements and eliminate closure pours near the piers
- Span lengths up to 295 ft
