Provided structural engineering for renovation of a historically significant hotel and construction of an adjacent 26-story, mixed-use building, including housing, hotel, and commercial spaces, plus five-levels of underground parking. Construction also included a skyway.
Location: Minneapolis, MN
Client: Walsh Bishop Associates
Services: Structural
Construction Materials: Cast-in-Place Concrete, Post-Tensioned Concrete
Provided structural engineering services for the design of a 26-story mixed-use building that wraps two sides of an adjacent historically significant 10-story office building. The complex includes condominiums, a hotel, commercial spaces, five levels of below grade parking, and a skyway extending across 2nd Avenue South. The existing 10-story building was renovated into a restaurant space, offices, and hotel suites that required several new openings in the existing concrete walls to connect to the new structure. The excavation for the five below grade parking levels required soil stabilization below the existing building foundation.
The structural system for the new construction consists of a concrete frame with mild reinforced slabs at the below grade parking levels and post-tensioned slabs at Level 1 and above. Concrete elevator and stair cores provide the primary lateral load resisting system. The primary foundation system is a five foot thick mat foundation. The base of the mat foundation is located just above the water table, which prevented a planned sixth level below grade level. A portion of the below grade structure to the east of the existing Ivy Tower building extends only two levels below grade and is supported on drilled caisson foundations. The building façade consists of architectural precast panels that are supported from the building columns.