Using the past to shape the future
Something’s afoot in downtown Providence. In the heart of the city’s Innovation District, BuroHappold Engineering is nearing completion of work on the Providence River Pedestrian Bridge. Ten years in the making, the design for this bridge has evolved from being a simple crossing to get people from A to B, into an iconic structure that is set to be a real destination for the city’s inhabitants.
This project posed a number of challenges for our team. Initially, our engineers had to realize the new footbridge on top of the existing foundations, piers and abutments of the old I195 interstate that once ran through the site.
In addition, the FEMA recommendations changed just as we completed our first design for the bridge. This caused the State Coastal Management Agency to question whether the bridge would be compromised should sea level rise by 3ft – something that had not previously been a concern. When we discovered that it would, our structural engineers had to rethink their initial design… fast.
As these issues were unfolding, interest in the bridge was continuing to build. As more and more stakeholders and community groups became invested in the project, ambitions likewise began to grow. Meanwhile, the practicalities and budget we were working with remained the same, so we came under increasing pressure to deliver something spectacular within very tight constraints.
It took exceptionally precise design to transform the crumbling relics of an old highway into a fitting new gateway for Providence. Drilling down into the fine details from the outset of the project meant we were able to incorporate these existing elements into our new structure. For example, identifying secondary components like bearing sizes early enabled us to engineer fixed connections that would allow us to secure new steel piers for the bridge atop the existing stone-clad piers of the I195.
We undertook impact assessments to understand how the bridge would be affected by rising sea levels. We found that the design would be able to withstand the rise in terms of water flow, but not in the case of an ice load. By building up the existing piers with concrete, we were able to raise the bridge by the 1.5ft required to ensure its safety without altering our structural design too drastically.
When it came to delivering inspired design on a budget, we drew on our experience to incorporate elements and materials never before used in a Department of Transport project. Although the curved geometry, steel frame and wood decking of the new bridge are features that our engineers deal with on a daily basis, we understood that they were unusual for our client. Because of this, we spent a significant amount of time liaising with them and the general contractor to develop a shared vision.
The care and investment we put in with our client was worth it, as it has enabled us to realize a design that is beautiful and unique – and the public reaction has been outstanding. Because of the efforts of our team, and the fantastic workmanship of all sub-contractors, the final bridge has exceeded any early expectations for the project with minimal amount of field issues.
As well as creating a visual symbol of renewal, the Providence River Pedestrian Bridge provides access to the 40 acres of prime waterfront real estate that was freed up when the old interstate was moved. So while the history of the area will remain embedded in the bridge’s foundations, this new gateway will connect the site to the rest of the city and give it a new lease of life for future generations.
Services and approach
When we integrate our specialist teams around an approach, the benefits to the client multiply