Multi-Dimensional Seismic Vulnerability Assessment of CLT Coupled Wall System

In this paper, multi-dimensional seismic vulnerability assessment is performed for a cross-laminated timber (CLT) coupled wall (CLT-CW) system. The CLT-CW structural system uses multiple balloon type CLT shear walls connected, at every story, with replaceable coupling beams. For the seismicity of Vancouver, British Columbia–Canada, five 10-story CLT-CW buildings with coupling ratio (CR) values 10–50%, are examined. Two-dimensional numerical model of the system is developed in OpenSees, and incremental dynamic analysis (IDA) is performed using 30 (bi-directional) ground motion records. Bi-dimensional damage demands, maximum inter-storey drift ratio, and residual drift ratio are used to compute the corresponding fragility curves at three different limit state capacities, namely immediate occupancy (IO), life safety (LS), and collapse prevention (CP). From the analyses, it is shown that CLT-CW systems with higher CR values are less vulnerable when compared with those of lower CR values. Moreover, this study has investigated the effect of different combinations of the limit state functions on the resulting fragility curves and seismic vulnerability of the systems.