Calhoun Greenway

BKBM provided civil and structural engineering for a 185 unit, six-story apartment building in Minneapolis.

Location: Minneapolis, MN
Client: UrbanWorks
Services: Civil, Structural
Square Feet: 257,000
Construction Materials: Masonry, Cast-in-Place Concrete, Wood, Post-Tensioned Concrete
Civil Services: Conceptual, Grading and Drainage, Sidewalk and Trail Design, Land Development, Utility Design, SWPPP, Stormwater Management, Erosion/Sediment Control, Site Demolition
 
The project sits on an approximately 4.69 acre parcel of which 3.44 acres was disturbed. The six-story building, which has a footprint of 0.73 acres, has underground and surface parking, a pool and patios. Stormwater management was constructed to meet the requirements of the City of Minneapolis and Minnehaha Creek Watershed District.  Due to high ground water and contaminated soils, a series of underground filtration systems and rooftop ponding was used.  

Additionally, the new project cut off existing drainage patterns from a property to the south.  A new underground pipe system was constructed to accommodate the 100-year flow from the property. 

The site contained poor soils that required the building structure and pool to be supported on driven piles. The structural system consists of slab on grade at the lowest level and two levels of post-tensioned slabs including the second floor podium that supports five levels of wood framing for the upper floors. Post-tensioned slabs were the preferred structural system in order to minimize floor-to-floor heights and keep the lower level above the water table.

The building features one level of below grade parking with 199 parking stalls that extends beyond the building footprint under a large portion of the site surface parking. The first level includes fitness and lounge amenity spaces and an outdoor pool/amenity space that also extends over a portion of the below-grade parking structure.