Fuzzy-random reliability analysis of building performance

The seismic design practice is developing towards designing building structures to meet multiple performance targets. The performance of a building as a system is affected by structural and non-structural components, as well as the state of contents. Thus, quantification of the building performance involves numerous uncertainties and vagueness. This paper introduces a fuzzy-random model for the performance reliability analysis of RC framed structures considering both structural and nonstructural damages. The limit state for each performance level is defined as an interval of inter-storey drift ratios concerning respectively the non-structural and structural damage with a membership function, while the relative importance of the two aspects is treated through the use of a cost function. At the present stage, the non-structural damage is represented by infill masonry walls, and an extensive survey of experimental data is conducted to establish the probabilistic description of their performance limits. Comparing with the classical reliability model based on single-threshold performance definition, the proposed fuzzy-random model is more robust in the sense that different aspects can be incorporated in the performance assessment of a building system.