Development and application of wood shear wall reliability model

This study combines a new hysteretic model for dynamic analysis of wood shear walls, ground motion suites, and an extreme value distribution in order to estimate the seismic reliability of a wood shear wall for varying levels of displacement at various sites around the U.S. Existing suites of ground motions for Los Angeles, Boston, and Seattle, believed to have the same probability of exceedance over a 50 year period, were used to introduce some level of uncertainty in the loading. Multiple wood shear wall experiments were performed at the Peter Grant Timber Engineering Laboratory at Michigan Technological University, Houghton, Michigan, to calibrate the new hysteretic model and introduce some level of uncertainty into the resistance, or hysteresis. Time domain analysis was used to simulate the seismic response of the shear wall. The peak drift of each time domain analysis was recorded and the data points fit to an extreme value distribution (Weibull). The probabilities of failure, and subsequently the reliability indices, were then easily determined from this distribution of the extremes, based on various limit states of excessive drift. The uncertainty in the hysteresis was found to have a negligible affect on the reliability estimates for the Boston site, but had a significant effect for the Los Angeles and Seattle sites. The reliability indices ranged from less than zero to over seven, depending on the site and limit state