Random House Headquarters/Park Imperial

Development Team

Owner/Developer: The Related Companies, NYC
Construction Manager: Plaza Construction Corp., NYC
Architect (Core and Shell): Skidmore, Owings & Merrill, NYC
Architect (Office Interior): HLW International LLP, NYC
Architect (Residential): Ismael Leyva Architects, NYC
Architect (Residential Lobby): Adam D. Tihany International LTD, NYC
Structural Engineer: Thornton-Tomasetti Engineers, NYC
Mechanical, Electrical & Plumbing Engineer: Cosentini Associates NYC
Geotechnical Engineer: Langan Engineering and Environmental Services, NYC
Site and Subway Engineer: Vollmer Associates, NYC
Steel Erector and Fabricator: ADF Steel Corp., NYC
Foundation Contractor: Urban Foundation/Engineering LLP, East Elmhurst, N.Y.
Concrete Contractor (Superstructure): North Side Concrete Corp., Brooklyn, N.Y.

It was like creating two different buildings at the same time.
The first 25 stories of 1745 Broadway between 55th and 56th streets is a steel structure that serves as the world headquarters of Random House Inc. The second 25 stories are a concrete residential tower of luxury condominiums called The Park Imperial.

Four different architectural firms were used to design the 840,000-sq.-ft. two-in-one structure that was completed last year. Skidmore, Owings & Merril designed the core and shell, while HLW International LLP did the office interior and Ismael Leyva Architects and Adam D. Tihany International LTD worked up the residential portions.
Not surprisingly, the chief engineering challenge lay in the marriage of concrete and steel. Because the layout of the residential tower is completely different from the office portion of the building, there is no correlation between its concrete columns and shear walls and the steel columns below.

The 26th and 27th floors were designated as transfer floors. Steel girders were used to pick up the loads from the concrete columns and carry them to a complex of trusses below. The girders, ranging in depth from 55 in. to 87 in., span to transfer trusses that also serve as outrigger trusses for the lateral load-resisting system. The trusses traverse the entire floor and connect to perimeter belt trusses that encircle the structure and help to accommodate the load transfer.

"Loads had to be calculated at each step of the construction process to determine how the weight of the concrete above would settle on the steel structure below, said Matthew DiGiorgi, project manager for Plaza Construction Corp., which served as construction manager for the building. "It took much longer than 'normal' floors would take in a steel frame building."

Construction complexities started long before reaching the 26th floor. Building the foundation, which began in December 1999 under the leadership of Urban Foundation/Engineering LLP of East Elmhurst, N.Y., involved sophisticated underpinning techniques to support adjacent buildings on minipiles at the west side of the site.

On the east side, it was necessary to brace the subway tunnel under Broadway, which was accomplished with caissons and traditional sheeting and shoring methods. At the center of the site, the ground suddenly dropped off. The rock expected close to subgrade was not found, making it necessary to dig another 30 ft. in order to find sound bedrock.

The building also features a Tuned Liquid Column Damper, the first one ever used in the United States, designed to regulate the movement of the building. It consists of two u-shaped concrete tanks, each 20 ft. wide, 70 ft. long and 12 ft. tall, filled with water. It converts wind-induced energy into heat energy and dissipates it into the water from which it is then exhausted from the building.
The use of the TLCD, instead of increasing member sizes or using the standard pendulum tunes mass damper, resulted in considerable savings. The weight of the damper, which holds approximately 100,000 gallons of water, was accommodated by a return to a steel frame above the 49th floor.
The finished building also contains two levels of underground parking and ground-floor retail.