SEISMIC DETAILING OF POST-TENSIONED TIMBER FRAMES

Pres-Lam technology has been the subject ofcomprehensive research at the University ofCanterbury. Structures are currently being designedand built using Pres-Lam frames. Designers requireinformation on joint performance to accurately detailand specify these systems.A full scale beam column joint has been tested in anumber of configurations to assess the performanceof joint reinforcing and discreet external energydissipating elements.All dissipation options were based on similar principles;mild steel elements with specially detailed yieldingzones subjected to cyclic inelastic displacementdemand. Each of the options tested behaved similarly,and all of the designs tested produced stable, welldefined moment–rotation relationships. Theseincorporated both energy dissipation and recentering.Any damage observed during testing was generallylocalised around the connection of dissipativeelements. While this did not materially affect theperformance of these joints it reinforces the need forwell thought-out and properly designed connectiondetails.Simplified numerical modelling techniques produced12accurate predictions of specimen behaviour in mostcases. Comprehensive design guidelines for Pres-Lamstructures are available.