Comparison of Force-Based and Displacement-Based seismic design of dissipative post-tensioned rocking timber wall systems
Based on numerical studies performed by the authors, the paper presents to Force-Based (FBD) and Displacement-Based (DBD) seismic Design provisions for dissipative post-tensioned rocking timber wall (Pres-Lam) systems. At first, a discussion on the seismic design requirements of post-tensioned rocking timber wall systems is provided, including suggested material limit states to be considered in the design phase (Ultimate Limit State) also aimed to prevent collapse in case of more severe events. The required amendments to a Force-Based Design provision in accordance to NZS1170.5 are then discussed focussing on the development and significance of the inelastic spectrum scaling factor (kμ). Similarly, the key modifications to design equations required within a Displacement Based Design Provisions are proposed, based on extensive numerical analyses and focusing on the as the design inelastic displacement shape and the equivalent viscous damping. In the final part of the paper a multi-storey building is designed using both FBD and DBD and the two different approaches are discussed.