Renovation of 2 Penn Plaza, New York
Siefert Associates [SA] recently submitted the engineered steel erection sequence, and related temporary support designs, for the unique East Bustle addition to 2 Penn Plaza in New York, NY. This elevated multi-floor assembly was designed to be structurally independent from the existing building to the west, and in its permanent state, it will be supported by an asymmetric layout of HSS columns that are inclined at various angles. The geometry of the framing produces both vertical and rotational deflections as the steel erection progresses upward. SA built 3D models using AutoCAD and RISA to determine the engineering requirements at all intermediate stages of steel erection. SA designed a variety of temporary supports at key locations to handle the vertical and horizontal reaction requirements. Custom dunnage beams were required beneath each vertical support to ensure correct load transfer to the existing plaza level steel below. In addition, SA took advantage of partial floor diaphragm action to minimize the need for added wind bracing. The construction of this complex structure is underway!
Figure 1: Isometric view of 4th floor framing and vertical load temporary supports.
