The original Gilmerton Bascule Bridge was built in 1938 to extend the highway across the Elizabeth River in Chesapeake, Virginia. As the bridge neared its life expectancy, PCL was contracted in 2009 to replace the bridge with a new 1,908-foot-long, vertical lift bridge. The project features 12-foot, diameter-drilled shaft foundations, 225-foot structural steel lift towers, and a 2,400-ton lift span that provides clearance up to 135 feet when fully opened. The bridge was built in partnership with the Virginia Department of Transportation (VDOT) as part of the Full Stakeholder/Joint Project Risk Management Program. This program, a first in the industry, provides a collaborative, project-focused process for successful project delivery. The innovative process fosters a risk-aware culture among all stakeholders, creating the foundation for proactive management and saving VDOT money, time, and resources.
The Gilmerton Bridge Replacement project provides
a new lift span bridge over Elizabeth River, replacing
the existing double-leaf bascule bridge that was
constructed in 1938.
TRANSITIONING FROM OLD TO NEW
Making sure disruptions to 35,000 daily motorists were minimized was of utmost concern to the project’s owner, and PCL worked tirelessly to meet the expectations of both the client and the residents of Chesapeake. Traffic flow was maintained by employing a unique approach to bridge construction: keep the old bridge open while simultaneously building the components of the new structure below and above the old span. The new bridge was constructed in parallel alignment underneath and over the existing bridge and essentially “swallowed up” the old one as construction progressed. Tower construction was performed in the middle of the night to ensure the bridge was open for traffic the next morning. The 2,400-ton lift span was constructed off-site and floated in by barge seven miles through the Port of Hampton Roads; the roadway reopened in half the allotted time, and motorists can now look forward to even fewer bridge disruptions, thanks to the increase in vertical clearance above the river below. Through close collaboration between all stakeholders, the bridge’s improved design means more vessels will be able to pass below with fewer bridge openings.
USING ZERO-VIBRATION TECHNOLOGY
Knowing that an active railway bridge adjacent to the site could be affected by construction, PCL took innovative steps like importing zero-vibration technology to install the 12-foot-in-diameter drilled shafts by pushing temporary casings into the ground and then excavating the soil from within the casing. These were the largest shafts built in the United States using this method. The project team further leveraged technology to create a cost savings of $420,000 for the client, demonstrating that solutions to construction challenges need not make the project costlier. This proactive approach to managing disputes by anticipating challenges ahead of time sets the standard for PCL’s relationship with its building partners.
“Everyone involved in this project should be proud of successfully delivering such a complex project,” said Marc Papini, project manager, Parsons Brinkerhoff, VDOT. “The Gilmerton Bridge serves as a model for how this can be done. For three years, we worked two shifts, mostly seven days a week. The team never once missed a rush hour opening. That is commitment of this team to what’s important to the owner. I want to thank and credit PCL’s leadership for the float-in and for this project. Your dedication to this project has been outstanding and you as well as your team should be proud, because we are proud of you.”