McLaren Engineering Group provided structural and marine engineering services for the construction of two five-story residential buildings above a one-story concrete parking garage structure at Boston’s East Pier. This 288,000-square-foot project was originally designed as a steel-framed structure, but was redesigned by McLaren using wood frame construction, saving the client millions of dollars.
Some of Portside’s unique design features include a steel-framed glass-clad structure for the new Amenity Building with a fully occupied roof terrace, and 10-foot tall parapets to create an aesthetic effect in the corners of the building. The high parapets were framed using vertical wood trusses that were detailed by McLaren to be pre-fabricated and modularized to allow for ease of field installation.
McLaren served as the structural engineer of record on this project, converting the building to include wood-framed structures, reducing the thickness of the perimeter foundation walls, and eliminating almost all grade beams. The McLaren team value engineered the original design which resulted in a $2 million savings in foundation costs alone. The design included an economical 14-inch thick reinforced concrete slab across the plaza area to support weight of the wood buildings, steel amenity building, and courtyard soil surcharge loading over the parking garage.
McLaren also brought in its marine engineering expertise for the condition assessment of the existing bulkhead and the construction of a new seawall extension for the pier. McLaren proactively conducted an inspection of the bulkhead piles ensuring the project wasn’t held up while loading and pile repair was being determined. To further help with drainage, McLaren designed a “self-draining” geofoam subgrade along the waterfront roadway to reduce loading impacts and avoid reinforcement of the existing timber-framed wharf and marine bulkhead.
McLaren also designed a resilient underground concrete parking structure with over nine feet of hydrostatic pressure on slab and walls, as it was situated well below the FEMA 100-year flood plain. Graduated variable-depth roof trusses were designed, creating efficient passage for ductwork vertically through the structure and allowing for roof pitching and drainage, flat ceiling construction, and floor truss alignment.