465 New York Avenue, N.W., Washington, D.C.

Holbert Apple Associates provided structural engineering services for this new 13-story cast-in-place concrete hotel structure, with 2½ levels of below-grade parking, located three blocks from the Walter E. Washington Conventions Center.  The Main Roof and typical hotel floors consist of post-tensioned concrete two-way slabs.  The lower levels and below grade levels consist of mild-reinforced concrete two-way slabs and beams.  Six cast-in-place concrete transfer girders were designed at the 2nd Floor to accommodate the Ground Floor architectural program and below grade parking.  The building foundation consists of a stepped 36” thick cast-in-place concrete mat with 12” drops, which covers the entire footprint of the building.  The structure was designed to support an intensive green roof at the 2nd Floor Low Roof and an extensive green roof at the Main Roof.  The facade consists of a mixture of brick masonry and curtain wall systems.

In addition, Holbert Apple Associates perform structural engineering services required for the relocation of an existing historic, 112-year-old, three (3) story brick bearing wall and wood-framed building from the southeast corner of the site to the southwest corner of the site.  The historic building was braced internally and externally and then raised on steel framing with a custom unified hydraulic jacking system.   The historic building was then moved approximately 100 feet on a series of pneumatic tire dollies and then supported on a temporary steel pile foundation/framing system, design by a specialty foundations engineer.  This allowed for excavation to occur beneath the historic building and allowed for the new below-grade parking garage and apartment building to be constructed below, around, and above the newly relocated historic building.  The building relocation was primarily performed to help maintain the historic setting of the low-rise neighborhood on the west side of the site.