Part of Military Highway, the Henry G. Gilmerton Bridge carries approximately one million travelers every month while also being the most frequently opened. The Virginia Department of Transportation (VDOT) recognized the need to replace the aging bridge to accommodate future growth in an area becoming increasingly congested, and to facilitate better flow of marine traffic. VDOT embarked on a $134 million replacement project requiring the new bridge to be built on the exact same alignment.
Modjeski and Masters completed preliminary and final design of the new 250-ft long and 89-ft wide lift span – one of the widest lift spans ever. Due to the exceptional width, four 15-ft diameter sheaves were needed on each tower. Eight 12-foot diameter drilled shafts were designed to reach 120 feet below ground and are some of the largest ever constructed using the oscillating method. With only 25 feet between the Gilmerton Bridge and an adjacent railroad bridge, seismic instruments were used to monitor potential settlement of the railroad bridge foundations during installation of the new drilled shafts. This bridge project won the ACEC/VA Pinnacle Award, and was recognized nationally by the NSBA for the Prize Bridge Merit Award (Movable Span Category) and by ACEC as a Project of Merit.
For more information, see our project documentary film on YouTube: https://youtu.be/QfRH2_aoK_w
|Length of Main Span||250 feet|
|Vertical Clearance||135 feet (35 feet when closed)|
|Lanes on Structure||Six lanes|