January 25, 2018

Status of the Pedestrian Bridges

Our two pedestrian bridges are closed due to deterioration of the supports. While the bridges appear to be safe, they are not structurally sound. Thank you for your patience, and thank you for staying off the bridges.

Our two pedestrian bridges are closed due to deterioration of the supports. While the bridges appear to be safe, they are not structurally sound. Thank you for your patience, and thank you for staying off the bridges.
 
Last summer, as part of routine maintenance, core samples were taken of the main bridge supports. The results of those samples indicated that the timbers had been undermined by a fungal infection. Cores revealed that most of the fleshy parts of wood between the growth rings had been attacked. Structural engineers were consulted, and they recommended the bridges be closed immediately, as no one could predict when they would fail.
 
While investigating the replacement of the bridges, it was determined that the footings don’t meet current seismic code. Additionally, some of the footings have been undermined and are no longer fully supported. The bridges were originally constructed in 1954, and the decking was replaced in 2006. They look sturdier than they actually are.

After a review, it was determined that rather than replace the Templeton bridge, ADA modifications would be made to the existing walkway under Council Chamber, and the bridge would be demolished and not replaced. The bridge from Howard to the cobblestone circle was determined to be critical to replace, as it is a major thoroughfare for residents to the academic side of campus, and the bridge carries major utilities (sewer, water, and electrical) that could not be relocated.
 
The new bridge will meet both seismic and ADA requirements, will include a roof and lighting, is being sourced and manufactured locally, and is being designed and installed to ensure sustainability.
 
Unfortunately the process for replacing the bridges is lengthy and complicated. First we needed to evaluate the various options for bridges, then selection of contractors and preliminary feasibility design was completed. As the bridge spans an environmental zone, the City of Portland requires us to complete a series of reviews on top of the traditional building permitting. A pre-application permit was submitted to the City at the end of the summer and returned with comments by the City in October. In December we submitted our final environmental permits to the City, which will take six to eight weeks or longer to review them. Once that process is completed, we will apply for building permits prior to being allowed to start construction. If all goes well, we will start construction in the late spring, although a wet winter may delay that as excavation and site work may not be possible till the ground dries up. The new bridge is projected to be ready to open early August 2018.
 
Again, thank you for your patience, and thank you for staying off the bridges.

 

For more information, please contact Facilities Services.