KPFF Consulting Engineers
Oregon State University
StructureCraft
Walsh Construction Co
Framework’s design employs a first of its kind rocking wall core made from nine-ply Cross-Laminated Timber (CLT). Designed to resist the seismic forces generated during a 2500 year seismic event, the building core is capable of rocking, and then recentering itself with no damage to the primary structural system. Post-tensioned steel rods extending the entire length of each building core wall, as well as replaceable U-Shaped Flexural Plates (UFPs) at each floor level absorb the force of a seismic event. This technology, which originated during the 1960s, was further developed following the 2011 Christchurch earthquake in New Zealand.
The team’s all-wood solution, has been designed to integrate “low-damage design” concepts, which reduce repair/replacement costs and downtime following a significant earthquake. The concept exceeds basic life-safety performance requirements by creating a resilient and easily repairable solution; avoiding the need to tear down the building following an earthquake. Once complete, Framework will have the tallest post-tensioned rocking wall in the world.
Framework has a 130' post-tensioned rocking wall core made from CLT.
The design showcases the innovative mass timber structure by expressing the core on the exterior.
CLT Core, Static State (Left) and Rocking State (Right)
Several tests were completed at Oregon State University to validate the structural resiliency of Framework's self-centering post-tensioned CLT rocking wall. These included a series of bare panel tests on full scale nine-ply CLT panels, crushing tests on five-ply CLT panels, and testing of three different splice methods for joining the rocking wall’s nine-ply CLT panels.
CLT wall panel structural testing at Oregon State University. Structural tests were taken well beyond actual building demands to observe failure mechanisms in the CLT panels.