Column pours mark start of Pentagon rebirth
Reconstruction of the damaged portion of the Pentagon got under way in mid-November as crews began pouring concrete for the replacement of damaged and destroyed columns. Column construction began as demolition of the damaged area was being completed (see "Pentagon wedges will be rebuilt," November 2001, page 6).
"The demolition phase is wrapping up and we're already moving into reconstruction," says Ronald Fidler, vice president and project director for Baltimore-based RTKL Associates Inc., executive architect for the reconstruction of the building's damaged wedges 1 and 2.
The A/E firm was awarded a $20.8 million contract in September by the Pentagon Renovation Program for emergency structural assessment, repair and restoration of the area of the building damaged during the Sept. 11 terrorist attack. "Our contract is for the architectural portion of the reconstruction, which includes the core and shell," says Fidler.
Consultants to RTKL are the Washington, D.C., office of A/E firm Helmuth, Obata + Kassabaum Inc., for the façade; Oehrlein & Associates Architects, Washington, D.C., historic consultant; and the Raleigh, N.C., office of Law Engineering, for the roof design.
Though unable to provide specific details about the project because of Pentagon security requirements, Fidler says the reconstructed frame will be composed of concrete. According to Rachel Decker, a Pentagon Renovation Program public affairs specialist, the columns will be steel reinforced. "I don't think the column grid will change tremendously, except for perhaps a few modifications," says Fidler. Design basics
"The design of the project is being based on the previous renovation of Wedge 1, with some enhancements based on recommendations from the Corps of Engineers force-protection study," says Decker. The structural upgrades, such as the steel-reinforced blast-proof windows, that were made to Wedge 1 as part of its renovation, which was nearly complete at the time of the attack, will be included in the reconstruction. Wedge 2, which was being prepared for renovation at the time of the attack, will be reconstructed to bring it up to code as was originally planned.
According to Decker, the reconstruction will include the upgrade of facilities and communications infrastructure, the addition of elevators — the unrenovated areas of the building contain only freight elevators — and removal of hazardous materials such as lead, asbestos, mercury and PCBs.
Renovation officials are reviewing possible security upgrades for the reconstruction. "We are carefully studying all recommendations from the Corps of Engineers as well as those from a building performance task force, which the Pentagon coordinated following Sept. 11," says Decker.
"It's important to remember that the façade, roof and damaged rings of the building will be reconstructed as they were before because it's an historic structure," Fidler says. "We are essentially rebuilding the Pentagon to its original form. In some cases, modifications will be made to some of the materials." Where historic building requirements allow, the reconstruction will adhere to current standards of the Americans with Disabilities Act. Essentially design/build
In its analysis of the structurally acceptable remaining portions of the damaged area, RTKL found nothing salvageable other than the slab on grade. "The slab on grade was repairable. The building will be constructed from there on up," says Fidler.
The project requires heavy collaboration between members of the building team, which also includes New York City-based AMEC as the general contractor. The reconstruction of the Pentagon's outer-most E ring is supposed to be completed by Sept. 11, 2002, the one-year anniversary of the attack.
Though the contract does not specify design/build as the project delivery method, it might as well have, says Fidler. "We are designing and detailing the building as it's being built," he says. "For all intents and purposes, it is design/build."