A landmark structure - Frank Llyod Wright's Fallingwater.
Data from deflection gauges was sent to a central computer for analysis and storage.
Monostrand tendons were stressed using center stressing splice anchors.
Multistrand stressing operation.
Multistrand tendons were carefully stressed in stages and measured by technicians.
Temporary scaffolding below the main terrace and extending to the stream below.
Working carefully inside a well protected historic structure.

Frank Lloyd Wright's Fallingwater

Project Description 

Completed in 1939, Fallingwater is one of America’s most treasured landmarks. It is comprised of a series of concrete cantilever “trays” 30-feet above a waterfall. Excessive deflections of the cantilever had caused cracking and early efforts at repair had failed to permanently address and repair them. The Western Pennsylvania Conservancy required a solution to preserve this landmark structure. After a thorough design review, the owner and engineer selected an external post-tensioning solution for its durability, aesthetics and structural unobtrusiveness.

For the first time since original construction, the stone floor was removed to expose the inner workings of Wright’s design. To preserve existing building elements and minimize incidental damage, the team “gently” chipped and drilled openings, while keeping construction debris from falling into the stream.

Construction plans called for structural strengthening of three support girders spanning in the north-south direction with multistrand post-tensioning tendons consisting while monostrand post-tensioning tendons were used for the east-west direction.

Additional work items included welding steel cover plates, attaching structural steel channels, injecting epoxy grout, doweling reinforced cast-in-place concrete blocks and the installation of near surface mounted carbon fiber rods. Challenged with preserving Fallingwater’s original setting, furnishings and artwork, the project was successfully completed in six months.