Effect of nonstationary extreme wind speeds and ground snow loads on the structural reliability in a future Canadian changing climate

Abstract

Extreme wind speeds and ground snow loads for many regions across North America exhibit non-stationarity in projected future climates. The adequacy of conventional return period design values estimated in the past for the future design life needs to be investigated. Nonstationary extreme value analysis methods were used in several previous studies to evaluate the nonstationarity of extreme wind and snow loads based on the latest future projections for Canada in the RCP8.5 (where RCP denotes the representative concentration pathway) emission scenario. These methods have not been considered in nonstationary reliability analyses. This study will examine the effect of including these nonstationary extreme value analysis methods in the reliability analysis. Investigations were conducted by applying the design value estimated in past stationary climate to the reliability analysis considering nonstationary climatic load effects in the future design life. Two non-stationary extreme value analysis methods were then used to determine the design level value in the nonstationary future climates for mitigating the climate change impact. These two approaches target different risk levels. Both nonstationary methods provide design level values greater than the conventional return period values and can maintain the probability of failure close to the target value at the end of the design life. Analyses were also conducted to examine the climate change impact on the structural reliability for considering principal wind load effects or snow load effects with the companion live load effects.