Contribution of Partition Walls in Lateral Load–Resisting Systems of Low-Rise Light Wood Frame Buildings

Abstract

Prescriptive design is a common practice in North America for low-rise light wood frame buildings. The prescriptive wood-based shear wall details provided in building codes to resist lateral loads were largely derived based on a combination of historical performance and engineering analysis. Inherent within the historical performance assumption is the presence of certain elements such as internal partitions that contribute to direct load resistance and structural redundancy. This inherent assumption is sometimes challenged by design engineers and proponents of alternative lateral load–resisting systems. In an attempt to showcase the contributions of the partition walls, a number of archetypes with various quantities of partitions were analyzed using a finite-element program. In the finite-element models, the wood-based structural shear walls and partition walls with gypsum wallboard were modeled as macroelements, with mechanical properties obtained from previous tests. Assumptions were made for the diaphragm and connection stiffness values. The results show a significant contribution of the partition walls to the lateral load resistance of light wood frame buildings. Partition walls accounted for 55%–71% of the overall lateral resistance of the evaluated buildings. Furthermore, diaphragms and wall-to-diaphragm connections contribute significantly to the overall behavior of the structures.