Reliability of wind-resistant design of tubular reinforced concrete towers

There exist considerable disparities among the prevailing international codai provisions for the wind-resistant design of reinforced concrete (RC) tubular towers - with regard to (1) estimation of peak wind moments, (2) estimation of ultimate moments of resistance, and (3) specification of safety factors. This paper highlights these disparities in terms of structural reliability. It is shown that there exists a very wide range of 'global safety factors' underlying the prevailing codai methods for the range of practical design situations. These global safety factors are translated in terms of 'lifetime probabilities of failure' by reliability analysis, using a 'generalized reliability model', and applying Monte Carlo Simulation and Numerical Integration. The results indicate a considerable lack of uniformity among international standards and the presence of widely ranging reliability levels under different design situations. There is an evident need to resolve the codai disparities and to adopt optimal safety factors which consistently achieve a 'target reliability'. In this paper, it is shown how this can be achieved.