Annapolis Junction Business Park Building 06 is a speculative office building with specific requirements for an anticipated future Government type end-user. The project is the first constructed that uses the load-bearing capacity of tilt-up concrete to achieve the Department of Defense’s stringent requirements for force protection without adding columns or excessive amounts of steel. Several major challenges had to be faced in order to incorporate the design criteria. For progressive collapse requirements in typical framed construction, the building loads are redistributed to the adjacent exterior columns when a structural member is removed. Capturing the load redistribution in tilt wall was more challenging. A 3-D model of the building constructed to properly analyze the loads and determine the distribution. To solve the problem, a series of connection plates were added at each floor to transfer the load from the wall panels above the removed section to the adjacent panels’ vertical elements. We then analyzed the adjacent piers to ensure their moment capacity could withstand the transferred loads. Thickened panel legs, kickers at the panel joints, and embed connections were enhancements to already existing elements uses in tilt-up construction. Panel reinforcing was upsized by about 50% over base conditions. We also found that it is indeed a cost-effective method of construction and can compete with non-blast conventional construction. The building is a Z-shaped floorplate with a centralized core area that divides the leasable area into two pods allowing for independent or inter-linkable workspace. Defensible entries and metal cladding is used to characterize the building exterior as a Class A office space. The building interior uses an abundance of natural light admitted through a continuous clerestory feature at the entire perimeter of the lobby.
The project is LEED Gold Certified.