Pacific Avenue Overpass*
Pacific Avenue Overcrossing
TranTech staff, Kash Nikzad, Jim King, and Theo Trochalakis served as Senior Project Engineers on this award winning project. The Pacific Avenue overcrossing is a 750-foot long, eight-span bridge combined with a two-span, 207-foot ramp to form an elevated int
The project is located in the city of Everett, a growing northwest boomtown north of Seattle. The bridge connects the City Center and Interstate Highway 5 (I-5). Between the City Center and the freeway corridor runs a mainline of the Burlington Northern Santa Fe railroad. The track links the western terminus of the mainline and the principle West Coast North-South route. These tracks carry as many as 30 trains daily, causing traffic delays up to 20 minutes. Pacific Avenue carries 25,000 cars per day, and the traffic backups were impacting the growth and redevelopment of the region.
• The design features an overcrossing with eight pre-cast concrete spans and two spans to create an access ramp.
• The bridge deck is supported on pre-cast Tub-girders, which were used due to depth limitations.
• Pre-stressed girders are economical and low maintenance. A continuity post-tensioning is provided for live load considerations.
• Bridge girders were set on temporary shoring towers and jacked at the center to reduce dead load moments and stresses due to bridge deck. A reverse load was placed on the girders until the cast-in-place deck became composite with the girders and the continuity post-tensioning was installed. This format produced minimum girder depths and 50 percent less post-tensioning.
• Using pre-cast girders held construction time to less than 14 months. A cast-in-place alternative would have required two to four months longer construction time.
• A study showed that the pre-cast alternative cost 15 to 25 percent less than a cast-in-place concrete or a steel bridge.
This bridge was the recipient of the 2002 PCI 1st place national award for bridges with spans of 65 - 135 feet.