- Pennsylvania Department of Transportation, District 5
- Tamaqua, Pennsylvania
- Our Role
- Design, Traffic Study.
- 60 ft. by 19 ft.
- Construction Cost
- $2.1 million
- New Construction
- Safe mobility and access to businesses in downtown area
- Restored heavy truck access to key regional travel route
- Minimal disruption for travelers during construction.
Each day, 6,000 motorists use SR 209 through downtown Tamaqua. Until recently, the route took them over an underground stone arch culvert built more than a century ago. When the structure was deemed structurally deficient, requiring heavy truck traffic to make a 38-mile detour, the Pennsylvania Department of Transportation initiated its replacement. To avoid disrupting traffic as much as possible, the project was planned for the summer, when school was out, under an aggressive three-month schedule.
Gannett Fleming designed the culvert replacement, including the excavation and demolition of the existing structure and installation of a precast concrete arch to support a new roadway over subterranean Wabash Creek. Excavation support systems and arch centering were carefully designed to ensure public safety on a constrained site surrounded by existing buildings. Our firm also developed a complex maintenance and protection of traffic (MPT) plan that limited disruption during construction. The project was completed before the first day of school as planned, restoring safe mobility throughout the community.
MPT plan development was facilitated by a traffic study that evaluated 12 signalized intersections and counted turning movements to ensure that condition simulation models were properly calibrated for the rerouted traffic during constructon. Under the plan, the local road network was reworked throughout downtown to maintain access to homes and businesses for cars and smaller trucks. One-way streets were converted to two-way streets or reversed, and traffic signals were modified to implement the plan within hours of high-school graduation, maximizing the time available for construction. Parts of the MPT operated so well during construction that local residents asked the borough if they could be made permanent.
Safely replacing a 60-foot underground culvert in the middle of a downtown thoroughfare with minimal disruption was no easy task. The team used flume pipes during demolition to keep Wabash Creek moving, preventing site flooding; a pumped water bypass was used during heavy excavation to maintain creek flow. Round-the-clock vibration monitoring using wireless inclinometers ensured that no damage was sustained by nearby structures during construction.
- Installation of precast concrete arch to replace deficient structure enables safe passage of traffic along the downtown thoroughfare.
- MPT plan, featuring roadway and signal modifications and emergency truck turnarounds, maintained regional mobility as much as possible during construction
- The installation of 50 Americans with Disabilities Act-complaint ramps at the intersections of upgraded roadways improve accessibility.