Seismic Upgrade of Boeing Commercial
Airplane Factory
Everrett, USA
Cost of Retrofit: US$65 million.
Savings: US$30 million.
The mammoth Boeing plant, which could contain Disneyland under one roof, is the world’s largest building in volume. It was built in phases from 1968-1991, for the assembly of wide-bodied 747 jetliners world’s largest commercial airplane. The steel frame building is 120 feet high with clear spans of 350 feet and covers more than 98 acres.
In 1996, the Boeing engineers considered several seismic upgrade schemes for this structure. They chose Pall Friction Dampers because they are foolproof in construction and, offer reliable performance at low cost. The performance of friction dampers is independent of velocity therefore the forces on the connections remain constant for any future earthquake. Economy in the design of connections and easy installation of dampers provided significant savings in construction cost and time.
Several types of Pall Friction Dampers, suitably modified to
adapt to site conditions, were incorporated in different types of existing
bracing. Friction dampers of capacity up to 200,000 lbs. and stroke up to
15 inch have been used. Pall Friction Dampers met or exceeded Boeing’s
stringent specifications. Work on seismic upgrade was undertaken in 1998 and
completed in 2001.
