Reliability analysis of existing reinforced concrete bridges for serviceability limit state of maximum crack width

The reliability of reinforced concrete members and systems has been the focus of a considerable amount of research. However, most studies have focused on ultimate strength, rather than serviceability limit state. The calculation for reliability of existing reinforced concrete bridge based on fuzzy random method is illustrated herein by taking maximum crack width of structural member as the analysis object of serviceability limit state. The effects of improvement of live load level and difference of fuzzy failure bound on serviceability reliability are investigated. The failure probability influenced by three different live load level and two different fuzzy failure bounds are discussed. The case analysis suggests that the failure probability under improved live load level increases by 4.24% similar to 9.56%. Even with same mean value, a strict range of general resistance can decrease failure probability by 4.86% similar to 6.70%. The study results are helpful for the evaluation of bridges in use exactly.