Seismic performance evaluation of innovative balloon type CLT rocking shear walls

Balloon type cross laminated timber (CLT) rocking shear walls are a novel seismic force resisting system. In this paper, the seismic performance of four 12-story balloon type CLT rocking shear walls, designed by a structural engineering firm located in Vancouver (Canada) using the performance-based design procedure outlined in the technical guideline published by the Canadian Construction Materials center (CCMC)/National Research Council Canada (NRC), is assessed. The seismic performance of the prototype CLT rocking shear walls was investigated using nonlinear time history analyses. Robust nonlinear finite element models were developed using OpenSees and the nonlinear behavior of the displacement-controlled components was calibrated using available experimental data. A detailed site-specific hazard analysis was conducted and sets of ground motions suitable for the prototype buildings were selected. The ground motions were used in a series of incremental dynamic analyses (IDAs) to quantify the adjustable collapse margin ratio (ACMR) of the prototype balloon type CLT rocking shear walls. The results show that the prototype balloon type CLT rocking shear walls designed using the performance-based design procedure outlined in the CCMC/NRC technical guideline have sufficient ACMR when compared to the acceptable limits recommended by FEMA P695.