Research is getting under way to develop prescriptive code language and performance-based design guidelines for a “rocking frame” structural system that relies on vertically post-tensioned shear walls for seismic resistance. The system promises to improve seismic performance, reduce rebar congestion and enhance constructibility, says the engineer developing it.
“We believe these advantages could significantly impact seismic design and construction of mid-rise and high-rise concrete buildings,” says Steven Tipping, president of structural engineer Tipping Mar (TM), Berkeley, Calif. The engineer thinks the research will show the system’s potential to reduce design loads by 25% and the amount of vertical reinforcement by 50% over a conventional shear wall.