Implementation of Assure-IT™ for Tacoma Narrow Bridge Project
Client: Washington State Department of Transportation
Project Value: $849M Design-Build Tacoma Narrows Bridge
Products: Assure-IT™
Key Facts
- New 3.4 Mile Suspension Bridge
- Parallel and South of Existing Bridge
- 30 Users
The Tacoma Narrows Bridge, originally designed in the 1950s to handle 60,000 cars per day, was handling over 90,000 cars per day by 2002 when the project to build a new bridge adjacent to it was begun. (The older Tacoma Narrows Bridge replaced a bridge that was destroyed in a 1940 windstorm. The collapse of the first bridge was captured on film and ultimately changed the way suspension bridges were designed.) Major construction work on the new bridge included building a pair of 165-meter-tall towers, spinning cables, and assembling the 46 deck sections that comprise the bridge decking. The entire deck stretches 1,646 meters with the main span stretching 854 meters from tower to tower.
The new suspension bridge was built parallel to and south of the existing bridge, providing two general-purpose lanes and a high occupancy vehicle lane for eastbound traffic. The new bridge included a separated path for bicycles and pedestrians. It was also designed to accommodate a second deck in the future. As part of the overall project the existing bridge was reconfigured to provide two general-purpose lanes and a high occupancy vehicle lane for westbound traffic only. The existing bridgework also included seismic improvements. In addition to the bridge works, the project also constructed 3.4 miles of SR 16 from the Jackson Avenue interchange in Tacoma to a new interchange at 24th and 36th Streets.
The construction contractor needed a cost effective way to manage the numerous Quality Assurance tests associated with this initiative throughout the program lifecycle. Complicating the challenge is the increased speed expected in this design-build project. This “need for speed” is particularly important in the Quality Assurance process as field samples must be collected, analyzed, and statistically verified and reported as quickly as possible so as not to impede the orderly progress of work at the field construction site.