Electronic Structural Building Monitoring of Fallingwater

When you need to monitor historic structures, you need the experience and expertise of GeoSonics/Vibra-Tech.

Fallingwater is a historic residential structure designed by Frank Lloyd Wright in 1935 in Mill Run, Pennsylvania and is listed on the U.S. National Register of Historical Places. Fallingwater is a reinforced concrete structure with three formal floors raised over a waterfall on Bear Run. The iconic cantilevered floors and terraces are constructed of upturned beams integrated into a monolithic concrete slab. Since the building’s erection the cantilevered elements have exhibited active deflection and displacements. In 2002, the cantilevers were repaired using post-tensioning and carbon fiber reinforcement. The building is currently exhibiting localized areas of movement and cracking at discrete locations. GeoSonics/Vibra-Tech was retained by the Western Pennsylvania Conservancy in conjunction with Robert Silman Associates to provide long term electronic crack and tilt monitoring of the building in various locations and provide data to Robert Silman Associates for cantilever repair performance.


The setup included the use of optical three-dimensional building survey monitoring, electronic tilt monitors and vibrating wire crack gauges to monitor the potential movement of the unique cantilevered balconies overhanging the waterfall. Crack monitors were also used as repair work was being done to the national historic landmark foundation walls. Over a one year period, monthly reports were generated on field measurements which were compared to baseline data to ensure no movement would endanger the sensitive structure.