Serviceability evaluation model for beam bridge with hollow slabs based on multi-source data

ObjectiveTo quantitatively evaluate the service performance of beam bridge with hollow slabs, a polymorphic T-S fault tree model based on multi-source data was established. The membership function and T-S fuzzy control rules were introduced as well to deal with the uncertain relations among events.MethodFirst, through a comparative analysis on influencing factors and monitoring requirements for bridge service performance, a finite element numerical simulation was employed to establish a critical monitoring index system for beam bridge with hollow slabs. The concept of maximum usage degree was proposed, along with its calculation formulas. Second, the key defect indicator database was developed considering the common defect types and inspection data characteristics of such bridges. By integrating these two datasets, a multi-source fused dataset was constructed to reflect the actual performance state of bridge. Third, a polymorphic T-S fault tree model was established based on the analysis on bridge performance degradation mechanisms. Abnormal monitoring indicators and detected distresses were treated as basic events of the model. The performance degradation probability was obtained through statistical occurrence probability, fuzzification processing and gradual iteration; and the service performance health was derived as well. Finally, a five-level health index classification mechanism was established based on the references to current bridge technical condition assessment standards and degradation stage characteristics.ResultA case study of two actual beam bridges with hollow slabs was conducted. The calculated health indices of two bridges were 59.75 and 58.40 respectively, which were classified as Grade Ⅲ according to the evaluation criteria.ConclusionThe calculated probability of strength reduction and durability reduction is highly consistent with the defect distribution characteristics in the inspection report. The model can be extended to evaluate the service performance of similar bridges, and its evaluation results provide practical guidance for routine maintenance and management.