Synergy Construction
Jefferson Park
Community Center, phase 2
Architect: ARC Architects
Owner: Seattle Parks & Recreation
ABC members: Bratrud Middleton Insurance, Northwest Asphalt
The project included construction of a gymnasium and outdoor basketball courts with associated landscaping.
The project was built on pin piles 50 feet from the Beacon Hill Reservoir, requiring constant water quality monitoring and an erosion control plan.
Another challenge was three water pipelines under Beacon Avenue. One of those lines connects to a 32-inch line near the community center that runs to the reservoir. The pipes are 90 years old and the 32-inch pipe section could not be shut off because of a broken valve.
The 32-inch pipe turns into a 20-inch line with unrestrained joints and valves that runs just 12 feet south of where the new gym floor was built. Synergy had to cross the 20-inch line several times with new power, phone and site lighting conduits. It also had to backfill the trenches with controlled density fill (CDF), because the ground could not be compacted for 10 feet on either side of the old line.
Locating the pipes was difficult because as-built drawings were old and inaccurate, requiring crews to hand-dig pot holes and use water flow vibration to find them.
Another challenge was a number of smaller lines running in all directions that were hooked into the 20-inch line.
Damaging any of those lines would have flooded an adjacent neighborhood.
The gym was completed on-time and on-budget.
There were no OSHA-300 recordable incidents or time-loss injuries.