RELIABILITY-BASED OPTIMUM DESIGN FOR UBC AND NONDETERMINISTIC SEISMICSPECTRA

Reliability-based optimization techniques are developed for steel stru ctures subjected to seismic loadings of the Uniform Building Code and Newmark's nondeterministic seismic response spectra. Reliability is ba sed on two different distributions of response and resistance with two variance approaches. Two objective functions of weight and cost, and various constraints, such as displacements, yielding, and buckling of constituent members, are considered in the optimization formulations. Numerical examples are provided to study sensitivities of parameters, such as variation of earthquake load, different probability distributi ons, different variance approaches, and interacting ground motion on o ptimum solutions.