4600 Apartments LLC
61 units | 87,888 SF
Green roof with patio
Burke + Union brought 61 attractive apartment units and retail space to a complex site adjacent to the Burke-Gilman Trail. Groundwater, environmentally critical areas, contaminated soils, a peat zone, and generally poor soil conditions made development opportunities along Union Bay difficult and expensive.
Groundwater and well tests on the property found groundwater as close as 1’ below grade and an aquifer that could not be disturbed. Additionally, the peat zone surrounding the property is prone to settlement. The original plans for below-grade parking were abandoned, and the design team redesigned a partial slab-on-grade structure. Working with our geotechnical engineer and shoring subcontractor, we developed a temporary dewatering system that allowed excavation of the below-grade portions of the parking garage along the east property line without impacting the peat zone. Tons of crushed rock were imported as structural subgrade, acting as a porous layer to allow uphill groundwater to flow past the site.
Through outstanding collaboration and document coordination with the design team during preconstruction, many potential issues were caught and addressed before construction began. To facilitate construction in an extremely busy labor market, we organized the finish trades for a smooth, continuous flow of work in the units, improving both quality and schedule performance. In fact, the project was completed nearly two and a half months ahead of schedule.