Serviceability Reliability Analysis of Reinforced Concrete Structures

A probabilistic model is developed to estimate immediate, creep, and shrinkage deflections. Monte Carlo simulation is used to estimate deflections and probabilities of serviceability failure (lifetime and for each 8 yr tenancy) for reinforced concrete beams sized according to the span-to-depth ratio serviceability requirements of Australian, British, and American Concrete Structures Codes. Serviceability failure is defined to occur when a deflection exceeds an allowable deflection limit as a result of flexure. It was found that the span-to-depth ratio serviceability requirements of these codes produce significantly different serviceability reliabilities. This is probably a consequence of the fact that the serviceability specifications of these codes have not been subjected to code calibration. A code-calibration exercise considering load factors, loading combinations, and/or allowable deflection limits may minimize these variations in serviceability reliabilities.