Pier 62 has always been vital part of the Seattle waterfront. It brings the city and visitors on to Elliott Bay and to the doorstep of the Olympic Mountains beyond. Throughout the 1990 and early 2000s, it was also home to popular events such as the Summer Nights at the Pier concert series. But over time, Pier 62 started to show its age. The wood foundations--affected by tidal influences, waves, and marine foes like gribbles taking millions of tiny bites out of the wood--deteriorated to a point where the pier could no longer support the weight of a large crowd, or even heavy equipment. The City’s plan to bring the public back to Pier 62 starts with new foundations.
Due to schedule constraints in this busy urban waterfront – home to daily influx from tourists, international cruise lines, and ongoing Seattle ferry terminal and viaduct construction -- work needed to be completed on an accelerated timeline with significate coordination between City staff, neighborhood stakeholders, and the structural engineering team.
How We Helped
Aspect provided geotechnical services as part of the City’s team to design these foundations and ultimately replace the pier. We completed a geotechnical engineering study to create geotechnical design criteria and parameters for pile foundations as well as modeling to forecast seismic events. Over the course of 5 months, Aspect staff were onsite and monitoring the installation of 175 steel pipe piles.
A unique feature of this project was the length the project team went to take care of Elliot Bay’s marine life, during pipe foundation installation, through the use of bubble curtains. Bubble curtains are created through a set of aerated rings, like big hula hoops, that have compressed air pumped through them to create a watery ‘curtain’ of air/bubbles to dampen the sound/vibration blasting outward from the loud underwater ringing made by pile driving, thereby protecting marine habitat.
Milestones for the City
The City met its accelerated timeline to finish the geotechnical design and pile installation. Through the bubble curtain approach, the health of marine life near the pier was carefully considered. Now that the foundations of the project have been completed, construction can continue on schedule. With the Pier being rebuilt, the recent SR-99 tunnel opening, and the ongoing viaduct removal, Seattle residents will soon once again be celebrating summer and music on a revitalized Seattle waterfront in the near future.