Performance-Based Wind Engineering: risk assessment of a long span suspension bridge

It is widely recognized that the most rational way of tackling the risks of engineered facilities and infrastructures, subject to natural and man-made phenomena, and of reducing them, both in designing new facilities and in rehabilitating or retrofitting the existing ones, is Performance-Based Design, usually indicated by the acronym PBD (but a better term would be “Performance-Based Engineering”). The basic concepts of PBD have been applied for almost 30 years in the nuclear power plant industry; later, PBD has been formalized and developed primarily in seismic engineering and has been extended to other engineering fields, like Blast Engineering and Fire Engineering. Wind engineering appears of great potential interest for further developments of PBD. The first steps in this direction go back to an Italian research project, in which the expression "Performance-Based Wind Engineering" (PBWE) was coined. In this paper, the approach proposed for the Performance-Based Seismic Engineering by the Pacific Earthquake Engineering Research Center is extended to the case of PBWE. The general framework of the approach is illustrated and applied to an example case: the assessment of the collapse and out-of-service risks of a long span suspension bridge.