Performance of Log Shear Walls Subjected to Monotonic and Reverse-Cyclic Loading

Abstract

Low-rise buildings are typically designed with shear walls and horizontal diaphragms to resist lateral load during windstorms and earthquakes. Although seismic performance and lateral load resistance behavior are generally well-understood for light-frame wood construction, this is not true for log construction. Research is needed to characterize log shear wall behavior subject to racking loads, and to develop recommendations for designing log walls to resist lateral loads from seismic or wind events. Monotonic and reverse-cyclic tests were conducted on log shear walls with 1:1, 2:1, and 4:1 aspect ratios. These walls showed higher resistance than conventional light-frame shear walls and similar hysteretic behavior to concrete and masonry shear walls. Log walls withstood large in-plane displacements without significant load reduction using lateral bracing typical of that used for light-frame wall testing; however, the test procedure would be improved by providing full-wall support to resist out-of-plane displacements of log shear walls. Design recommendations were developed based on the experiments reported herein.