Originally built in 1889, the West Gordon Street bridge in Allentown, Pennsylvania, was in desperate need of a facelift. The National Bridge Index listed it as structurally deficient, the design was no longer compliant with modern standards, it was only load-rated for seven tons and its foundations were destabilizing. Left as-is, the bridge could potentially collapse. Given these conditions, PennDOT opted to replace it with a 112-foot-long, integral abutment, single-span bridge on a pre-drilled steel H-pile foundation, and they awarded the work to our Highway and Bridge division.
To maintain pedestrian traffic across the bridge throughout construction, the project was completed in two phases. During phase one, we installed the new stormwater management system, demolished three quarters of the bridge to leave a portion for pedestrian use and constructed a portion of the new bridge. In phase two, we completed demolition of the existing bridge, moved pedestrian traffic and finished construction of the new bridge.
A START AND STOP SCHEDULE
After only working for a few weeks, our work was suspended for 76 days due to the COVID shut down, sending it into the following construction season. Further complicating things, we could only close the road for nine months, again pushing back our schedule to work around PennDOT’s paving restrictions.
These changes to the schedule meant our crew also had to work around wild and stocked trout seasons, October through December and March through mid-April, as the bridge runs over Jordan Creek. For us, resequencing the schedule was key to keeping the project moving forward. For instance, part of our scope in the first phase included installing a 25-foot bridge approach slab on either side of the bridge. To accommodate the environmental restrictions, we moved this activity to phase two with PennDOT’s approval, allowing us to shorten our schedule by about two weeks.
Mother Nature proved to be another challenge impeding our schedule. During any rainstorm, waters rose and our work was stalled as crews had to wait for the storm to pass, clean up the area and figure out a way to make up for lost time. When remnants of a hurricane resulted in heavier rainfall, the creek rose roughly 12 feet and reached the bottom of the bridge beams. Again, reconfiguring the schedule along with the crew putting in extra time helped us get back on schedule.
“It took a lot of coordination and hard work to successfully deliver this project. I’m extremely proud of the crew’s efforts and ability to pull this off against all odds.”Ron Brown, Highway and Bridge Project Manager
A NEW WAY TO SET BRIDGE BEAMS
This project’s challenges surpassed a complicated schedule. For instance, the team had to find a new way to set the beams. Because of the weight of the beams and width of Jordan Creek, we couldn’t use a single crane. The beams weighed 117,940 pounds each and were 112-feet-long. After much discussion and coordination, we utilized two cranes with a Tri-Link attachment. The Tri- Link pivots in a manner that allows two cranes, positioned on either side of the creek, to attach to it while the beam end is in mid-air. Once the second crane attaches to the beam, the first crane detaches from the Tri-Link and attaches to the opposite end of the beam, thereby “handing it off.” This process was new for our Highway and Bridge crew, and required incredible finesse and coordination by the crane operators to safely hand-off and place the beams.
Despite numerous obstacles, the new bridge, with its decorative railings sitting atop a formed concrete barrier that was architecturally treated and painted to resemble stone, was completed in fall 2021.Categories: Completed Projects, Projects in Construction