In September of 2019 Cascade Bridge was called into action by the City of Portland to assist in the emergency repair of the N Going St. bridge on Swan Island after a train derailment caused critical damage to one of the columns supporting the bridge. After working with the City and KPFF in the design of a temporary repair, Cascade Bridge constructed the repairs in November by installing steel beams adjacent to the damaged column and hydraulically jacking them against the underside of the bridge deck to remove loading from the damaged column. The temporary repairs allowed the City to open up 2 more lanes of traffic on the 6-lane street which serves as the only access on and off Swan Island, home to many businesses, including logistic hubs for UPS and FedEx.
After the temporary repairs were in place, Cascade Bridge then worked again with the City and KPFF in the design of the permanent repairs. It was determined that the best fix would be to install 8 micro piles along the length of the bridge columns in the same transverse alignment as the damaged column, construct a pile cap along this same transverse alignment, install a weathering steel column jacket that encapsulated the damaged column and place grout in the annular space between the damaged column and the steel column jacket, and then install a 12’ tall crash wall on top of the pile cap, in between the existing columns.
The work area was in the direct vicinity of the main switching track for the Albina railyard, requiring all of the permanent repair work to be performed in tight work windows where all train traffic was halted. This in turn required detailed coordination with the Union Pacific Railroad since the repair work would impede their operations. After being delayed twice due to weather conditions, the repair work commenced in Fall of 2021 with the installation of the micropiles during a 7-day closure where 2 crews worked 12-hour shifts around the clock to complete the work. Our team returned to the site in February of 2022 to install the pile cap, steel column jacket, and install the crash wall in 2 separate shutdowns of 7 days and 14 days over a month period, in which we employed 2 crews working 12-hour shifts around the clock. After the repairs to the damaged column was complete and the temporary supports were removed, the City was able to open up the remaining 2 closed lanes of traffic on N Going Street and restore it to normal operating conditions.