Structural Depth Study
This thesis study examined the implications related to redesigning the transfer system of 40 Bond Street. The current design includes deep, narrow beams and wide, shallow beams that are congested with reinforcement and require rebar couplers. The redesign completed in the structural depth study employed Vierendeel trusses, rather than beams, in attempts to reduce congestion and provide variety to the grid-like facade. There were three transfer locations including the second floor along the north facade, the third floor at the south facade, and the seventh floor at a 20’-0” setback. There is a transition from 10”x10” concrete columns at 6’-3” on center to fewer columns below at each of these locations. Special care was given to maintain the openness provided by the facade and in plan, so many iterations were completed until arriving at the final designs for each location. The trusses are separated into 50’ and 75’spans and each of the three locations exhibits a different truss arrangement.
These trusses resulted in a slight increase to the overall building weight, but this increase was not enough to suggest seismic forces as the controlling load case. Rather the wind loads, in both directions, were used for the lateral optimization study. This study was included as a part of the structural depth study to see if an alternate shear wall layout would provide greater resistance to the loads. The current layout proved to be the optimal design and the existing 30” mat foundation is also adequately designed to resist any additional weight or forces due to the introduction of the transfer trusses.
Breadth Studies
These trusses undoubtedly affected the architecture of 40 Bond. Vertical members were placed as to not require any change in plan, but both the north and south facades were altered. The first breadth study was done in conjunction with the structural depth study to ensure that logical arrangements were arrived at to highlight the facade architecture and preserve the floor plans. Additional research was done on cast iron buildings in New York and used to determine inspiration for the current design. Similarly, these historic buildings were also used to create a statement with the redesigned facade.
The second breadth topic examined the facade materials and completed the detailing of these materials to enclose the modified structure. Green glass and copper mullions had to be designed to function properly with this new layout. Increased sizes and spans required necessary alterations to ensure these components, which highlight 40 Bond, could still be used. Thermal and moisture protection provided by the building envelop was also researched.
A pdf version of version of the full report may be viewed here. (April 6, 2009)
A pdf version of the executive summary may be viewed here. (April 6, 2009)
A pdf version of the report only (without appendices) may be viewed here. (April 6, 2009)
A pdf version of the appendices may be viewed here. (April 6, 2009)
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