Comparison of seismic performance on plasterboard bracing walls and plywood shear walls in the context of New Zealand light timber-framed structures

Abstract

Most residential buildings in New Zealand are low-rise light timber-framed (LTF) buildings, in which plasterboard bracing walls form the main lateral load resisting system to resist wind and seismic forces. Occasionally plywood shear walls are also used in order to provide higher bracing capacity due to limited wall length. Past studies have suggested that seismic performance of plasterboard bracing walls differs significantly from that of plywood or OSB shear walls which are commonly used in North America. In the 2011 Canterbury earthquakes, LTF houses performed generally well in terms of life safety. However, the total cost incurred to fix all house-related damage was about NZ$12 billion. Although plasterboard bracing walls are the key to the seismic performance of majority of the New Zealand LTF structures, research to quantify their seismic performance is still limited. In this study, seismic performances of plasterboard bracing walls and plywood sheathed walls are compared. Several factors affecting the wall performance are analyzed. A series of numerical models are developed for plasterboard bracing walls and plywood shear walls based on experimental results from walls of different lengths. Then, a case study of time-history analysis is conducted to compare the seismic performance of LTF structures with plasterboard bracing walls and plywood sheathed walls.