At just over 555 feet, the Washington Monument is the tallest un-reinforced masonry edifice in the world. The project consisted of structural design and construction administration for a full-height exterior scaffold system to facilitate a two-year top-to-bottom restoration of the monument’s masonry walls, including the patching and re-pointing of stones, sealing of cracks, and cleansing of the exterior.
The scaffolding tapered at a 1 ° angle to mirror the slope of the Monument and consisted of 37 linear miles of aluminum tubing with a total surface area of 3.2 acres. No mechanical fasteners were attached to the monument. Instead, pre-stressed corner braces with plastic bearing pads provided lateral stability for the system. The elevator and stairs concealed within the design required elimination of cross-supports in this section and necessitated the use of special horizontal trusses. This careful design not only protected Monument from further damage but also created a striking appearance.
Additional work included structural design of interior renovations, including modifications to floor framing for reconfiguration of the observation platforms, relocation of the existing stair to enhance visitor circulation, and testing of historic wrought iron to determine material properties and yield strength.
Location: Washington, D.C.
Owner: National Park Service
Architect: Michael Graves & Associates
Completion Date: 2001