Fragility Functions for Plasterboard‐Sheathed Walls in Light Timber‐Framed Residential Houses

In New Zealand, plasterboard‐sheathed walls (PSWs) are commonly used as partition walls and seismic bracing walls in low‐rise light timber‐framed (LTF) residential houses. A significant barrier to assessing seismic losses of the LTF residential houses in New Zealand is the lack of fragility functions of these PSWs. This paper reports damage data collected from experimental studies of PSWs, defines a set of damage states, and develops corresponding fragility functions using statistical fitting methods. Fragility functions are proposed for three PSW variants: PSWs with hold‐downs, PSWs without hold‐downs, and PSWs with openings. The proposed fragility functions are compared with the fragility functions specified in FEMA P‐58 for LTF bracing walls and partition walls with plasterboards. The results indicate that PSWs with hold‐downs exhibit more severe damage at minor drifts compared to those without hold‐downs. Additionally, the proposed fragility functions for PSWs are significantly different from the existing functions in FEMA P58. The median storey‐drift values of the fragility functions corresponding to different damage states of PSWs are found to be less than those given in FEMA P‐58 for walls sheathed with wood‐based panels, by about 62.2% for PSWs with hold‐downs and about 34.6% for PSWs without hold‐downs. Moreover, from the proposed fragility functions, the median storey‐drift values for different damage states of PSWs without hold‐downs are much higher (about 137.8%) than those specified in FEMA P‐58 for plasterboard partition walls.