Case Study: Pattullo Bridge Rehabilitation Project

About This Project

The 81-year-old Pattullo Bridge is one of Greater Vancouver’s major arterial crossings. Every day, this through-arch bridge carries tens of thousands of vehicles over the Fraser River between the cities of Surrey and New Westminster. While a replacement bridge is in the works, the current bridge received a series of major upgrades starting in the winter of 2015 to ensure it remains safe and operational until the new bridge is complete.

Scope of services

For Phases 3a and b of the rehabilitation project, which included structural seismic upgrades and deck rehabilitation, TransLink hired BKL to conduct a noise assessment. BKL’s contributions included baseline noise monitoring, 3-D modelling of construction noise, presentations to stakeholders, construction noise monitoring, and associated reporting.

For the assessment, BKL developed noise limits using best practice international standards, and determined how specific rehabilitation-related noise sources—for instance, jackhammering, milling, and grinding—would affect the nearest communities in Surrey and New Westminster.

BKL took an innovative approach to communicating its findings with TransLink and municipal staff from both Surrey and New Westminster. For example, to show how noise levels would change over time, the acoustics team created a series of noise-map videos and presented them to municipal staff. These videos helped stakeholders see how various rehabilitation activities would affect noise levels in different neighbourhoods as they occurred at various points along the span.

Finally, BKL monitored construction noise to confirm that mitigation efforts were effective at keeping noise levels below the adopted hourly noise level criteria.

Example Calculated Noise Contours

Project benefits

By conducting an effective and accurate noise assessment, sharing findings through detailed reports, presenting noise-map videos, and monitoring construction noise, BKL helped TransLink and the cites of Surrey and New Westminster understand the potential effects of project-related noise sources. With that valuable information, they could work with rehabilitation crews to limit noise as much as possible, while also keeping community stakeholders aware of changing noise levels.