The 2002 and 3003 towers are sister "class a" speculative office buildings located in the central perimeter area of Atlanta. Each building includes an 18-story office structure with 9-levels of parking below. These urban, high-performance office buildings include a light reflective green glass skin with precast eyebrows providing spectacular views of Atlanta's skyline. The intricately detailed lobbies include a striking mix of stone and millwork. A European-style plaza connects the two buildings mixing the landscape with the neighboring restaurant and residential development.
A major challenge on both buildings was the planning and construction of a cantilevered concrete beam, a feature the Architect referred to as the "flying beam," which occurs at the two west corners of the typical elevated floor slab from levels 3 through the roof (17 elevated slabs total) and are simply an extension of the formed slab. They are formed with a block-out in the center with the tips of the cantilevered beams (i.e. at the slab corners) extending out for a total cantilever of over 30 feet thus creating a "flying beam" appearance. Excessive deflection of these flying beams can make it difficult and, in some cases, impossible to install glass and vertical mullions that are part of the strip window system directly beneath flying beams. As a result of our experience with deflection of flying beams on previous projects, Holder understood that an effective approach was necessary to understand and prevent deflection and therefore prevent further problems.
In order to ensure success on these projects, Holder formulated a Constructability and Sequencing Plan early in the Preconstruction phase of the 2002 Summit Project. Holder requested all available design load and allowable live load information from the Design Team in order to better assess constructability. Studies considered factors such as camber and wrecking sequence. All findings were reviewed in detail with the architect, formwork engineer, and formwork subcontractor, and the formwork subcontract was purchased to include special shoring and re-shoring provisions. Even after establishing the plan, Holder remained involved to monitor and log the results of the plan to ensure that it was implemented precisely.
As a result of our proactive approach, we applied lessons learned on previous projects to avoid potential costly and time consuming issues.