Effects of Probability Distribution Characteristics of Snow Load on Relationships between Load Factors and Reliability Indexes of Cylindrical Lattice Shell Roofs with Various Substructure Stiffnesses

There have been no studies on the reliability indexes of cylindrical lattice shell roofs that focus on the effects of substructure stiffness or on the probabilistic characteristics of snow load. This paper investigates the relationships between the reliability index and the snow load factor for cylindrical lattice shell roofs with various substructure stiffnesses under snow loading. The bending stiffness of the substructure is determined on the basis of a model designed in the elastic range for dead loads and seismic force with the base shear coefficient. For a parametric study, the bending stiffness of the substructure is proportioned. The snow loads have the characteristics of a probability distribution of snow depth from the average value and standard deviation results of the 100-year return period snow depth in Japan. All random variables are assumed to follow a log-normal distribution and to be independent of each other. The reliability indexes are calculated using AFOSM method considering different snow depth for a parametric study.