Project Description
DRPILLA provided geotechnical and structural engineering design services of an existing six-story, 4,500-square-foot brick building to be converted into a mixed use commercial and residential property featuring one of New York City’s iconic eateries. The scope of work involved the complete interior and exterior renovation, as well as an addition at the front of the building and the rear of the building.
CLIENT
Serafina Restaurant Group
LOCATION
New York, NY
SERVICES
Geotechnical Engineering
Support of Excavation
Structural Engineering
Special Inspections
COMPLETION
2012
“Sliver Building” Design
The term “Sliver Building,” according to the New York City zoning code, is specifically reserved for a tall building or enlargement that is 45 feet wide or less, such buildings are generally restricted to a height equal to the width of the abutting street or 100 feet, whichever is less. These unique and challenging sites often present issues pertaining to structural stability due to its narrow width when resisting lateral loads. The width of the building is only 19 feet, and the depth extends 90 feet – almost the entire length of the property. The height-to-width aspect ratio, with respect to grade, is 3.45.
Structural Design for Vertical and Horizontal Enlargement
To alter the existing building’s structural system, several issues existed: (1) determining which of the permitted building codes, old or new, should govern the modifications; (2) choosing the appropriate structural design criteria; and (3) deciding how to engineer and construct the building’s new lateral load. A new lateral-force-resisting system was installed after the front wall was removed to maintain two such systems in each direction. In order to leave the space the entire space open, a moment frame system was designed to connect to the metal floor deck by puddle welds for diaphragm shear force transfer at each floor. To resist possible bow actions, steel straps welded to the moment frames were bolted into the brick walls to create sufficient bond to the sidewalls. The moment frame was discontinued at the second floor due to the beam interfering with the front stair opening. To transfer the shear forces securely, horizontal braces were designed at the second floor in between the moment frames. The steel moment frame ended at the basement on a concrete shear wall, which safely dissipates the lateral forces into the ground.
Structural Design for Vertical and Horizontal Enlargement
To alter the existing building’s structural system, several issues existed: (1) determining which of the permitted building codes, old or new, should govern the modifications; (2) choosing the appropriate structural design criteria; and (3) deciding how to engineer and construct the building’s new lateral load. A new lateral-force-resisting system was installed after the front wall was removed to maintain two such systems in each direction. In order to leave the space the entire space open, a moment frame system was designed to connect to the metal floor deck by puddle welds for diaphragm shear force transfer at each floor. To resist possible bow actions, steel straps welded to the moment frames were bolted into the brick walls to create sufficient bond to the sidewalls. The moment frame was discontinued at the second floor due to the beam interfering with the front stair opening. To transfer the shear forces securely, horizontal braces were designed at the second floor in between the moment frames. The steel moment frame ended at the basement on a concrete shear wall, which safely dissipates the lateral forces into the ground.
Structural Design for Vertical and Horizontal Enlargement
To alter the existing building’s structural system, several issues existed: (1) determining which of the permitted building codes, old or new, should govern the modifications; (2) choosing the appropriate structural design criteria; and (3) deciding how to engineer and construct the building’s new lateral load. A new lateral-force-resisting system was installed after the front wall was removed to maintain two such systems in each direction. In order to leave the space the entire space open, a moment frame system was designed to connect to the metal floor deck by puddle welds for diaphragm shear force transfer at each floor. To resist possible bow actions, steel straps welded to the moment frames were bolted into the brick walls to create sufficient bond to the sidewalls. The moment frame was discontinued at the second floor due to the beam interfering with the front stair opening. To transfer the shear forces securely, horizontal braces were designed at the second floor in between the moment frames. The steel moment frame ended at the basement on a concrete shear wall, which safely dissipates the lateral forces into the ground.
