Seismic design and analysis of self-centering steel plate shear walls

An innovative Self-Centering Steel Plate Shear Wall (SC-SPSW) system is proposed. It relies on post-tensioned (PT) beam-to-column connections that allow beams to rock about their flanges and provide system re-centering capabilities. A design procedure for the SC-SPSW system, developed based on a performance based design (PBD) approach, is presented, followed by analytical results for a prototype SC-SPSW building designed using this PBD approach, and subjected to a suite of ground motions simulating three different seismic hazard levels. The results of the nonlinear response history analyses show the proposed SC-SPSW design procedure to adequately achieve the desired enhanced performance objectives. Concepts of capacity design principle are integrated in the above approach, to prevent in-span plastic hinges of the beam considering reduced moment capacity due to the presence of axial and shear forces and to ensure that PT reinforcement remain elastic, among other things. To facilitate understanding of the behavior and design of an SC-SPSW system, the moment, shear and axial force distribution along the length of a boundary beam are established based on first principles. Closed form formulations describing the moment, shear and axial force beam diagrams are developed based on component capacity design approach and are used in the performance-based system design approach.